Revert "Update opus to 1.3.1 and opusfile to 0.11"

This reverts commit e00426c512a7905f5f925d382c443bab7a0ca693.

The way we handle platform-specific intrinsics is not good, so the
current state will not compile on armv8. This commit also requires
SSE4.1 support, which is likely not a good idea for portable binaries.

We'll have to redo this with more caution after 3.2 is released, or
we might simply drop opus as we're only using it as dependency for
theora right now.

Fixes #33606.

1 files changed, 581 insertions, 828 deletions

diff --git a/thirdparty/opus/opus_encoder.c b/thirdparty/opus/opus_encoder.c
index e98ac5b8d0..9a516a884a 100644
--- a/thirdparty/opus/opus_encoder.c
+++ b/thirdparty/opus/opus_encoder.c
@@ -53,10 +53,6 @@
 
 #define MAX_ENCODER_BUFFER 480
 
-#ifndef DISABLE_FLOAT_API
-#define PSEUDO_SNR_THRESHOLD 316.23f    /* 10^(25/10) */
-#endif
-
 typedef struct {
    opus_val32 XX, XY, YY;
    opus_val16 smoothed_width;
@@ -86,7 +82,6 @@ struct OpusEncoder {
     int          encoder_buffer;
     int          lfe;
     int          arch;
-    int          use_dtx;                 /* general DTX for both SILK and CELT */
 #ifndef DISABLE_FLOAT_API
     TonalityAnalysisState analysis;
 #endif
@@ -102,8 +97,6 @@ struct OpusEncoder {
     int          prev_channels;
     int          prev_framesize;
     int          bandwidth;
-    /* Bandwidth determined automatically from the rate (before any other adjustment) */
-    int          auto_bandwidth;
     int          silk_bw_switch;
     /* Sampling rate (at the API level) */
     int          first;
@@ -112,10 +105,7 @@ struct OpusEncoder {
     opus_val16   delay_buffer[MAX_ENCODER_BUFFER*2];
 #ifndef DISABLE_FLOAT_API
     int          detected_bandwidth;
-    int          nb_no_activity_frames;
-    opus_val32   peak_signal_energy;
 #endif
-    int          nonfinal_frame; /* current frame is not the final in a packet */
     opus_uint32  rangeFinal;
 };
 
@@ -123,46 +113,38 @@ struct OpusEncoder {
    middle (memoriless) threshold. The second column is the hysteresis
    (difference with the middle) */
 static const opus_int32 mono_voice_bandwidth_thresholds[8] = {
-         9000,  700, /* NB<->MB */
-         9000,  700, /* MB<->WB */
-        13500, 1000, /* WB<->SWB */
-        14000, 2000, /* SWB<->FB */
+        11000, 1000, /* NB<->MB */
+        14000, 1000, /* MB<->WB */
+        17000, 1000, /* WB<->SWB */
+        21000, 2000, /* SWB<->FB */
 };
 static const opus_int32 mono_music_bandwidth_thresholds[8] = {
-         9000,  700, /* NB<->MB */
-         9000,  700, /* MB<->WB */
-        11000, 1000, /* WB<->SWB */
-        12000, 2000, /* SWB<->FB */
+        12000, 1000, /* NB<->MB */
+        15000, 1000, /* MB<->WB */
+        18000, 2000, /* WB<->SWB */
+        22000, 2000, /* SWB<->FB */
 };
 static const opus_int32 stereo_voice_bandwidth_thresholds[8] = {
-         9000,  700, /* NB<->MB */
-         9000,  700, /* MB<->WB */
-        13500, 1000, /* WB<->SWB */
-        14000, 2000, /* SWB<->FB */
+        11000, 1000, /* NB<->MB */
+        14000, 1000, /* MB<->WB */
+        21000, 2000, /* WB<->SWB */
+        28000, 2000, /* SWB<->FB */
 };
 static const opus_int32 stereo_music_bandwidth_thresholds[8] = {
-         9000,  700, /* NB<->MB */
-         9000,  700, /* MB<->WB */
-        11000, 1000, /* WB<->SWB */
-        12000, 2000, /* SWB<->FB */
+        12000, 1000, /* NB<->MB */
+        18000, 2000, /* MB<->WB */
+        21000, 2000, /* WB<->SWB */
+        30000, 2000, /* SWB<->FB */
 };
 /* Threshold bit-rates for switching between mono and stereo */
-static const opus_int32 stereo_voice_threshold = 19000;
-static const opus_int32 stereo_music_threshold = 17000;
+static const opus_int32 stereo_voice_threshold = 30000;
+static const opus_int32 stereo_music_threshold = 30000;
 
 /* Threshold bit-rate for switching between SILK/hybrid and CELT-only */
 static const opus_int32 mode_thresholds[2][2] = {
       /* voice */ /* music */
-      {  64000,      10000}, /* mono */
-      {  44000,      10000}, /* stereo */
-};
-
-static const opus_int32 fec_thresholds[] = {
-        12000, 1000, /* NB */
-        14000, 1000, /* MB */
-        16000, 1000, /* WB */
-        20000, 1000, /* SWB */
-        22000, 1000, /* FB */
+      {  64000,      16000}, /* mono */
+      {  36000,      16000}, /* stereo */
 };
 
 int opus_encoder_get_size(int channels)
@@ -263,8 +245,7 @@ int opus_encoder_init(OpusEncoder* st, opus_int32 Fs, int channels, int applicat
     st->bandwidth = OPUS_BANDWIDTH_FULLBAND;
 
 #ifndef DISABLE_FLOAT_API
-    tonality_analysis_init(&st->analysis, st->Fs);
-    st->analysis.application = st->application;
+    tonality_analysis_init(&st->analysis);
 #endif
 
     return OPUS_OK;
@@ -342,11 +323,10 @@ static void silk_biquad_float(
 }
 #endif
 
-static void hp_cutoff(const opus_val16 *in, opus_int32 cutoff_Hz, opus_val16 *out, opus_val32 *hp_mem, int len, int channels, opus_int32 Fs, int arch)
+static void hp_cutoff(const opus_val16 *in, opus_int32 cutoff_Hz, opus_val16 *out, opus_val32 *hp_mem, int len, int channels, opus_int32 Fs)
 {
    opus_int32 B_Q28[ 3 ], A_Q28[ 2 ];
    opus_int32 Fc_Q19, r_Q28, r_Q22;
-   (void)arch;
 
    silk_assert( cutoff_Hz <= silk_int32_MAX / SILK_FIX_CONST( 1.5 * 3.14159 / 1000, 19 ) );
    Fc_Q19 = silk_DIV32_16( silk_SMULBB( SILK_FIX_CONST( 1.5 * 3.14159 / 1000, 19 ), cutoff_Hz ), Fs/1000 );
@@ -366,10 +346,9 @@ static void hp_cutoff(const opus_val16 *in, opus_int32 cutoff_Hz, opus_val16 *ou
    A_Q28[ 1 ] = silk_SMULWW( r_Q22, r_Q22 );
 
 #ifdef FIXED_POINT
-   if( channels == 1 ) {
-      silk_biquad_alt_stride1( in, B_Q28, A_Q28, hp_mem, out, len );
-   } else {
-      silk_biquad_alt_stride2( in, B_Q28, A_Q28, hp_mem, out, len, arch );
+   silk_biquad_alt( in, B_Q28, A_Q28, hp_mem, out, len, channels );
+   if( channels == 2 ) {
+       silk_biquad_alt( in+1, B_Q28, A_Q28, hp_mem+2, out+1, len, channels );
    }
 #else
    silk_biquad_float( in, B_Q28, A_Q28, hp_mem, out, len, channels );
@@ -385,17 +364,21 @@ static void dc_reject(const opus_val16 *in, opus_int32 cutoff_Hz, opus_val16 *ou
    int c, i;
    int shift;
 
-   /* Approximates -round(log2(6.3*cutoff_Hz/Fs)) */
-   shift=celt_ilog2(Fs/(cutoff_Hz*4));
+   /* Approximates -round(log2(4.*cutoff_Hz/Fs)) */
+   shift=celt_ilog2(Fs/(cutoff_Hz*3));
    for (c=0;c<channels;c++)
    {
       for (i=0;i<len;i++)
       {
-         opus_val32 x, y;
-         x = SHL32(EXTEND32(in[channels*i+c]), 14);
-         y = x-hp_mem[2*c];
+         opus_val32 x, tmp, y;
+         x = SHL32(EXTEND32(in[channels*i+c]), 15);
+         /* First stage */
+         tmp = x-hp_mem[2*c];
          hp_mem[2*c] = hp_mem[2*c] + PSHR32(x - hp_mem[2*c], shift);
-         out[channels*i+c] = EXTRACT16(SATURATE(PSHR32(y, 14), 32767));
+         /* Second stage */
+         y = tmp - hp_mem[2*c+1];
+         hp_mem[2*c+1] = hp_mem[2*c+1] + PSHR32(tmp - hp_mem[2*c+1], shift);
+         out[channels*i+c] = EXTRACT16(SATURATE(PSHR32(y, 15), 32767));
       }
    }
 }
@@ -403,41 +386,24 @@ static void dc_reject(const opus_val16 *in, opus_int32 cutoff_Hz, opus_val16 *ou
 #else
 static void dc_reject(const opus_val16 *in, opus_int32 cutoff_Hz, opus_val16 *out, opus_val32 *hp_mem, int len, int channels, opus_int32 Fs)
 {
-   int i;
-   float coef, coef2;
-   coef = 6.3f*cutoff_Hz/Fs;
-   coef2 = 1-coef;
-   if (channels==2)
+   int c, i;
+   float coef;
+
+   coef = 4.0f*cutoff_Hz/Fs;
+   for (c=0;c<channels;c++)
    {
-      float m0, m2;
-      m0 = hp_mem[0];
-      m2 = hp_mem[2];
       for (i=0;i<len;i++)
       {
-         opus_val32 x0, x1, out0, out1;
-         x0 = in[2*i+0];
-         x1 = in[2*i+1];
-         out0 = x0-m0;
-         out1 = x1-m2;
-         m0 = coef*x0 + VERY_SMALL + coef2*m0;
-         m2 = coef*x1 + VERY_SMALL + coef2*m2;
-         out[2*i+0] = out0;
-         out[2*i+1] = out1;
+         opus_val32 x, tmp, y;
+         x = in[channels*i+c];
+         /* First stage */
+         tmp = x-hp_mem[2*c];
+         hp_mem[2*c] = hp_mem[2*c] + coef*(x - hp_mem[2*c]) + VERY_SMALL;
+         /* Second stage */
+         y = tmp - hp_mem[2*c+1];
+         hp_mem[2*c+1] = hp_mem[2*c+1] + coef*(tmp - hp_mem[2*c+1]) + VERY_SMALL;
+         out[channels*i+c] = y;
       }
-      hp_mem[0] = m0;
-      hp_mem[2] = m2;
-   } else {
-      float m0;
-      m0 = hp_mem[0];
-      for (i=0;i<len;i++)
-      {
-         opus_val32 x, y;
-         x = in[i];
-         y = x-m0;
-         m0 = coef*x + VERY_SMALL + coef2*m0;
-         out[i] = y;
-      }
-      hp_mem[0] = m0;
    }
 }
 #endif
@@ -555,57 +521,287 @@ static opus_int32 user_bitrate_to_bitrate(OpusEncoder *st, int frame_size, int m
 }
 
 #ifndef DISABLE_FLOAT_API
+/* Don't use more than 60 ms for the frame size analysis */
+#define MAX_DYNAMIC_FRAMESIZE 24
+/* Estimates how much the bitrate will be boosted based on the sub-frame energy */
+static float transient_boost(const float *E, const float *E_1, int LM, int maxM)
+{
+   int i;
+   int M;
+   float sumE=0, sumE_1=0;
+   float metric;
+
+   M = IMIN(maxM, (1<<LM)+1);
+   for (i=0;i<M;i++)
+   {
+      sumE += E[i];
+      sumE_1 += E_1[i];
+   }
+   metric = sumE*sumE_1/(M*M);
+   /*if (LM==3)
+      printf("%f\n", metric);*/
+   /*return metric>10 ? 1 : 0;*/
+   /*return MAX16(0,1-exp(-.25*(metric-2.)));*/
+   return MIN16(1,(float)sqrt(MAX16(0,.05f*(metric-2))));
+}
+
+/* Viterbi decoding trying to find the best frame size combination using look-ahead
+
+   State numbering:
+    0: unused
+    1:  2.5 ms
+    2:  5 ms (#1)
+    3:  5 ms (#2)
+    4: 10 ms (#1)
+    5: 10 ms (#2)
+    6: 10 ms (#3)
+    7: 10 ms (#4)
+    8: 20 ms (#1)
+    9: 20 ms (#2)
+   10: 20 ms (#3)
+   11: 20 ms (#4)
+   12: 20 ms (#5)
+   13: 20 ms (#6)
+   14: 20 ms (#7)
+   15: 20 ms (#8)
+*/
+static int transient_viterbi(const float *E, const float *E_1, int N, int frame_cost, int rate)
+{
+   int i;
+   float cost[MAX_DYNAMIC_FRAMESIZE][16];
+   int states[MAX_DYNAMIC_FRAMESIZE][16];
+   float best_cost;
+   int best_state;
+   float factor;
+   /* Take into account that we damp VBR in the 32 kb/s to 64 kb/s range. */
+   if (rate<80)
+      factor=0;
+   else if (rate>160)
+      factor=1;
+   else
+      factor = (rate-80.f)/80.f;
+   /* Makes variable framesize less aggressive at lower bitrates, but I can't
+      find any valid theoretical justification for this (other than it seems
+      to help) */
+   for (i=0;i<16;i++)
+   {
+      /* Impossible state */
+      states[0][i] = -1;
+      cost[0][i] = 1e10;
+   }
+   for (i=0;i<4;i++)
+   {
+      cost[0][1<<i] = (frame_cost + rate*(1<<i))*(1+factor*transient_boost(E, E_1, i, N+1));
+      states[0][1<<i] = i;
+   }
+   for (i=1;i<N;i++)
+   {
+      int j;
+
+      /* Follow continuations */
+      for (j=2;j<16;j++)
+      {
+         cost[i][j] = cost[i-1][j-1];
+         states[i][j] = j-1;
+      }
+
+      /* New frames */
+      for(j=0;j<4;j++)
+      {
+         int k;
+         float min_cost;
+         float curr_cost;
+         states[i][1<<j] = 1;
+         min_cost = cost[i-1][1];
+         for(k=1;k<4;k++)
+         {
+            float tmp = cost[i-1][(1<<(k+1))-1];
+            if (tmp < min_cost)
+            {
+               states[i][1<<j] = (1<<(k+1))-1;
+               min_cost = tmp;
+            }
+         }
+         curr_cost = (frame_cost + rate*(1<<j))*(1+factor*transient_boost(E+i, E_1+i, j, N-i+1));
+         cost[i][1<<j] = min_cost;
+         /* If part of the frame is outside the analysis window, only count part of the cost */
+         if (N-i < (1<<j))
+            cost[i][1<<j] += curr_cost*(float)(N-i)/(1<<j);
+         else
+            cost[i][1<<j] += curr_cost;
+      }
+   }
+
+   best_state=1;
+   best_cost = cost[N-1][1];
+   /* Find best end state (doesn't force a frame to end at N-1) */
+   for (i=2;i<16;i++)
+   {
+      if (cost[N-1][i]<best_cost)
+      {
+         best_cost = cost[N-1][i];
+         best_state = i;
+      }
+   }
+
+   /* Follow transitions back */
+   for (i=N-1;i>=0;i--)
+   {
+      /*printf("%d ", best_state);*/
+      best_state = states[i][best_state];
+   }
+   /*printf("%d\n", best_state);*/
+   return best_state;
+}
+
+static int optimize_framesize(const void *x, int len, int C, opus_int32 Fs,
+                int bitrate, opus_val16 tonality, float *mem, int buffering,
+                downmix_func downmix)
+{
+   int N;
+   int i;
+   float e[MAX_DYNAMIC_FRAMESIZE+4];
+   float e_1[MAX_DYNAMIC_FRAMESIZE+3];
+   opus_val32 memx;
+   int bestLM=0;
+   int subframe;
+   int pos;
+   int offset;
+   VARDECL(opus_val32, sub);
+
+   subframe = Fs/400;
+   ALLOC(sub, subframe, opus_val32);
+   e[0]=mem[0];
+   e_1[0]=1.f/(EPSILON+mem[0]);
+   if (buffering)
+   {
+      /* Consider the CELT delay when not in restricted-lowdelay */
+      /* We assume the buffering is between 2.5 and 5 ms */
+      offset = 2*subframe - buffering;
+      celt_assert(offset>=0 && offset <= subframe);
+      len -= offset;
+      e[1]=mem[1];
+      e_1[1]=1.f/(EPSILON+mem[1]);
+      e[2]=mem[2];
+      e_1[2]=1.f/(EPSILON+mem[2]);
+      pos = 3;
+   } else {
+      pos=1;
+      offset=0;
+   }
+   N=IMIN(len/subframe, MAX_DYNAMIC_FRAMESIZE);
+   /* Just silencing a warning, it's really initialized later */
+   memx = 0;
+   for (i=0;i<N;i++)
+   {
+      float tmp;
+      opus_val32 tmpx;
+      int j;
+      tmp=EPSILON;
+
+      downmix(x, sub, subframe, i*subframe+offset, 0, -2, C);
+      if (i==0)
+         memx = sub[0];
+      for (j=0;j<subframe;j++)
+      {
+         tmpx = sub[j];
+         tmp += (tmpx-memx)*(float)(tmpx-memx);
+         memx = tmpx;
+      }
+      e[i+pos] = tmp;
+      e_1[i+pos] = 1.f/tmp;
+   }
+   /* Hack to get 20 ms working with APPLICATION_AUDIO
+      The real problem is that the corresponding memory needs to use 1.5 ms
+      from this frame and 1 ms from the next frame */
+   e[i+pos] = e[i+pos-1];
+   if (buffering)
+      N=IMIN(MAX_DYNAMIC_FRAMESIZE, N+2);
+   bestLM = transient_viterbi(e, e_1, N, (int)((1.f+.5f*tonality)*(60*C+40)), bitrate/400);
+   mem[0] = e[1<<bestLM];
+   if (buffering)
+   {
+      mem[1] = e[(1<<bestLM)+1];
+      mem[2] = e[(1<<bestLM)+2];
+   }
+   return bestLM;
+}
+
+#endif
+
+#ifndef DISABLE_FLOAT_API
 #ifdef FIXED_POINT
 #define PCM2VAL(x) FLOAT2INT16(x)
 #else
 #define PCM2VAL(x) SCALEIN(x)
 #endif
-
-void downmix_float(const void *_x, opus_val32 *y, int subframe, int offset, int c1, int c2, int C)
+void downmix_float(const void *_x, opus_val32 *sub, int subframe, int offset, int c1, int c2, int C)
 {
    const float *x;
+   opus_val32 scale;
    int j;
-
    x = (const float *)_x;
    for (j=0;j<subframe;j++)
-      y[j] = PCM2VAL(x[(j+offset)*C+c1]);
+      sub[j] = PCM2VAL(x[(j+offset)*C+c1]);
    if (c2>-1)
    {
       for (j=0;j<subframe;j++)
-         y[j] += PCM2VAL(x[(j+offset)*C+c2]);
+         sub[j] += PCM2VAL(x[(j+offset)*C+c2]);
    } else if (c2==-2)
    {
       int c;
       for (c=1;c<C;c++)
       {
          for (j=0;j<subframe;j++)
-            y[j] += PCM2VAL(x[(j+offset)*C+c]);
+            sub[j] += PCM2VAL(x[(j+offset)*C+c]);
       }
    }
+#ifdef FIXED_POINT
+   scale = (1<<SIG_SHIFT);
+#else
+   scale = 1.f;
+#endif
+   if (C==-2)
+      scale /= C;
+   else
+      scale /= 2;
+   for (j=0;j<subframe;j++)
+      sub[j] *= scale;
 }
 #endif
 
-void downmix_int(const void *_x, opus_val32 *y, int subframe, int offset, int c1, int c2, int C)
+void downmix_int(const void *_x, opus_val32 *sub, int subframe, int offset, int c1, int c2, int C)
 {
    const opus_int16 *x;
+   opus_val32 scale;
    int j;
-
    x = (const opus_int16 *)_x;
    for (j=0;j<subframe;j++)
-      y[j] = x[(j+offset)*C+c1];
+      sub[j] = x[(j+offset)*C+c1];
    if (c2>-1)
    {
       for (j=0;j<subframe;j++)
-         y[j] += x[(j+offset)*C+c2];
+         sub[j] += x[(j+offset)*C+c2];
    } else if (c2==-2)
    {
       int c;
       for (c=1;c<C;c++)
       {
          for (j=0;j<subframe;j++)
-            y[j] += x[(j+offset)*C+c];
+            sub[j] += x[(j+offset)*C+c];
       }
    }
+#ifdef FIXED_POINT
+   scale = (1<<SIG_SHIFT);
+#else
+   scale = 1.f/32768;
+#endif
+   if (C==-2)
+      scale /= C;
+   else
+      scale /= 2;
+   for (j=0;j<subframe;j++)
+      sub[j] *= scale;
 }
 
 opus_int32 frame_size_select(opus_int32 frame_size, int variable_duration, opus_int32 Fs)
@@ -615,24 +811,53 @@ opus_int32 frame_size_select(opus_int32 frame_size, int variable_duration, opus_
       return -1;
    if (variable_duration == OPUS_FRAMESIZE_ARG)
       new_size = frame_size;
-   else if (variable_duration >= OPUS_FRAMESIZE_2_5_MS && variable_duration <= OPUS_FRAMESIZE_120_MS)
-   {
-      if (variable_duration <= OPUS_FRAMESIZE_40_MS)
-         new_size = (Fs/400)<<(variable_duration-OPUS_FRAMESIZE_2_5_MS);
-      else
-         new_size = (variable_duration-OPUS_FRAMESIZE_2_5_MS-2)*Fs/50;
-   }
+   else if (variable_duration == OPUS_FRAMESIZE_VARIABLE)
+      new_size = Fs/50;
+   else if (variable_duration >= OPUS_FRAMESIZE_2_5_MS && variable_duration <= OPUS_FRAMESIZE_60_MS)
+      new_size = IMIN(3*Fs/50, (Fs/400)<<(variable_duration-OPUS_FRAMESIZE_2_5_MS));
    else
       return -1;
    if (new_size>frame_size)
       return -1;
-   if (400*new_size!=Fs   && 200*new_size!=Fs   && 100*new_size!=Fs   &&
-        50*new_size!=Fs   &&  25*new_size!=Fs   &&  50*new_size!=3*Fs &&
-        50*new_size!=4*Fs &&  50*new_size!=5*Fs &&  50*new_size!=6*Fs)
+   if (400*new_size!=Fs && 200*new_size!=Fs && 100*new_size!=Fs &&
+            50*new_size!=Fs && 25*new_size!=Fs && 50*new_size!=3*Fs)
       return -1;
    return new_size;
 }
 
+opus_int32 compute_frame_size(const void *analysis_pcm, int frame_size,
+      int variable_duration, int C, opus_int32 Fs, int bitrate_bps,
+      int delay_compensation, downmix_func downmix
+#ifndef DISABLE_FLOAT_API
+      , float *subframe_mem
+#endif
+      )
+{
+#ifndef DISABLE_FLOAT_API
+   if (variable_duration == OPUS_FRAMESIZE_VARIABLE && frame_size >= Fs/200)
+   {
+      int LM = 3;
+      LM = optimize_framesize(analysis_pcm, frame_size, C, Fs, bitrate_bps,
+            0, subframe_mem, delay_compensation, downmix);
+      while ((Fs/400<<LM)>frame_size)
+         LM--;
+      frame_size = (Fs/400<<LM);
+   } else
+#else
+   (void)analysis_pcm;
+   (void)C;
+   (void)bitrate_bps;
+   (void)delay_compensation;
+   (void)downmix;
+#endif
+   {
+      frame_size = frame_size_select(frame_size, variable_duration, Fs);
+   }
+   if (frame_size<0)
+      return -1;
+   return frame_size;
+}
+
 opus_val16 compute_stereo_width(const opus_val16 *pcm, int frame_size, opus_int32 Fs, StereoWidthState *mem)
 {
    opus_val32 xx, xy, yy;
@@ -679,12 +904,6 @@ opus_val16 compute_stereo_width(const opus_val16 *pcm, int frame_size, opus_int3
       xy += SHR32(pxy, 10);
       yy += SHR32(pyy, 10);
    }
-#ifndef FIXED_POINT
-   if (!(xx < 1e9f) || celt_isnan(xx) || !(yy < 1e9f) || celt_isnan(yy))
-   {
-      xy = xx = yy = 0;
-   }
-#endif
    mem->XX += MULT16_32_Q15(short_alpha, xx-mem->XX);
    mem->XY += MULT16_32_Q15(short_alpha, xy-mem->XY);
    mem->YY += MULT16_32_Q15(short_alpha, yy-mem->YY);
@@ -715,354 +934,6 @@ opus_val16 compute_stereo_width(const opus_val16 *pcm, int frame_size, opus_int3
    return EXTRACT16(MIN32(Q15ONE, MULT16_16(20, mem->max_follower)));
 }
 
-static int decide_fec(int useInBandFEC, int PacketLoss_perc, int last_fec, int mode, int *bandwidth, opus_int32 rate)
-{
-   int orig_bandwidth;
-   if (!useInBandFEC || PacketLoss_perc == 0 || mode == MODE_CELT_ONLY)
-      return 0;
-   orig_bandwidth = *bandwidth;
-   for (;;)
-   {
-      opus_int32 hysteresis;
-      opus_int32 LBRR_rate_thres_bps;
-      /* Compute threshold for using FEC at the current bandwidth setting */
-      LBRR_rate_thres_bps = fec_thresholds[2*(*bandwidth - OPUS_BANDWIDTH_NARROWBAND)];
-      hysteresis = fec_thresholds[2*(*bandwidth - OPUS_BANDWIDTH_NARROWBAND) + 1];
-      if (last_fec == 1) LBRR_rate_thres_bps -= hysteresis;
-      if (last_fec == 0) LBRR_rate_thres_bps += hysteresis;
-      LBRR_rate_thres_bps = silk_SMULWB( silk_MUL( LBRR_rate_thres_bps,
-            125 - silk_min( PacketLoss_perc, 25 ) ), SILK_FIX_CONST( 0.01, 16 ) );
-      /* If loss <= 5%, we look at whether we have enough rate to enable FEC.
-         If loss > 5%, we decrease the bandwidth until we can enable FEC. */
-      if (rate > LBRR_rate_thres_bps)
-         return 1;
-      else if (PacketLoss_perc <= 5)
-         return 0;
-      else if (*bandwidth > OPUS_BANDWIDTH_NARROWBAND)
-         (*bandwidth)--;
-      else
-         break;
-   }
-   /* Couldn't find any bandwidth to enable FEC, keep original bandwidth. */
-   *bandwidth = orig_bandwidth;
-   return 0;
-}
-
-static int compute_silk_rate_for_hybrid(int rate, int bandwidth, int frame20ms, int vbr, int fec, int channels) {
-   int entry;
-   int i;
-   int N;
-   int silk_rate;
-   static int rate_table[][5] = {
-  /*  |total| |-------- SILK------------|
-              |-- No FEC -| |--- FEC ---|
-               10ms   20ms   10ms   20ms */
-      {    0,     0,     0,     0,     0},
-      {12000, 10000, 10000, 11000, 11000},
-      {16000, 13500, 13500, 15000, 15000},
-      {20000, 16000, 16000, 18000, 18000},
-      {24000, 18000, 18000, 21000, 21000},
-      {32000, 22000, 22000, 28000, 28000},
-      {64000, 38000, 38000, 50000, 50000}
-   };
-   /* Do the allocation per-channel. */
-   rate /= channels;
-   entry = 1 + frame20ms + 2*fec;
-   N = sizeof(rate_table)/sizeof(rate_table[0]);
-   for (i=1;i<N;i++)
-   {
-      if (rate_table[i][0] > rate) break;
-   }
-   if (i == N)
-   {
-      silk_rate = rate_table[i-1][entry];
-      /* For now, just give 50% of the extra bits to SILK. */
-      silk_rate += (rate-rate_table[i-1][0])/2;
-   } else {
-      opus_int32 lo, hi, x0, x1;
-      lo = rate_table[i-1][entry];
-      hi = rate_table[i][entry];
-      x0 = rate_table[i-1][0];
-      x1 = rate_table[i][0];
-      silk_rate = (lo*(x1-rate) + hi*(rate-x0))/(x1-x0);
-   }
-   if (!vbr)
-   {
-      /* Tiny boost to SILK for CBR. We should probably tune this better. */
-      silk_rate += 100;
-   }
-   if (bandwidth==OPUS_BANDWIDTH_SUPERWIDEBAND)
-      silk_rate += 300;
-   silk_rate *= channels;
-   /* Small adjustment for stereo (calibrated for 32 kb/s, haven't tried other bitrates). */
-   if (channels == 2 && rate >= 12000)
-      silk_rate -= 1000;
-   return silk_rate;
-}
-
-/* Returns the equivalent bitrate corresponding to 20 ms frames,
-   complexity 10 VBR operation. */
-static opus_int32 compute_equiv_rate(opus_int32 bitrate, int channels,
-      int frame_rate, int vbr, int mode, int complexity, int loss)
-{
-   opus_int32 equiv;
-   equiv = bitrate;
-   /* Take into account overhead from smaller frames. */
-   if (frame_rate > 50)
-      equiv -= (40*channels+20)*(frame_rate - 50);
-   /* CBR is about a 8% penalty for both SILK and CELT. */
-   if (!vbr)
-      equiv -= equiv/12;
-   /* Complexity makes about 10% difference (from 0 to 10) in general. */
-   equiv = equiv * (90+complexity)/100;
-   if (mode == MODE_SILK_ONLY || mode == MODE_HYBRID)
-   {
-      /* SILK complexity 0-1 uses the non-delayed-decision NSQ, which
-         costs about 20%. */
-      if (complexity<2)
-         equiv = equiv*4/5;
-      equiv -= equiv*loss/(6*loss + 10);
-   } else if (mode == MODE_CELT_ONLY) {
-      /* CELT complexity 0-4 doesn't have the pitch filter, which costs
-         about 10%. */
-      if (complexity<5)
-         equiv = equiv*9/10;
-   } else {
-      /* Mode not known yet */
-      /* Half the SILK loss*/
-      equiv -= equiv*loss/(12*loss + 20);
-   }
-   return equiv;
-}
-
-#ifndef DISABLE_FLOAT_API
-
-int is_digital_silence(const opus_val16* pcm, int frame_size, int channels, int lsb_depth)
-{
-   int silence = 0;
-   opus_val32 sample_max = 0;
-#ifdef MLP_TRAINING
-   return 0;
-#endif
-   sample_max = celt_maxabs16(pcm, frame_size*channels);
-
-#ifdef FIXED_POINT
-   silence = (sample_max == 0);
-   (void)lsb_depth;
-#else
-   silence = (sample_max <= (opus_val16) 1 / (1 << lsb_depth));
-#endif
-
-   return silence;
-}
-
-#ifdef FIXED_POINT
-static opus_val32 compute_frame_energy(const opus_val16 *pcm, int frame_size, int channels, int arch)
-{
-   int i;
-   opus_val32 sample_max;
-   int max_shift;
-   int shift;
-   opus_val32 energy = 0;
-   int len = frame_size*channels;
-   (void)arch;
-   /* Max amplitude in the signal */
-   sample_max = celt_maxabs16(pcm, len);
-
-   /* Compute the right shift required in the MAC to avoid an overflow */
-   max_shift = celt_ilog2(len);
-   shift = IMAX(0, (celt_ilog2(sample_max) << 1) + max_shift - 28);
-
-   /* Compute the energy */
-   for (i=0; i<len; i++)
-      energy += SHR32(MULT16_16(pcm[i], pcm[i]), shift);
-
-   /* Normalize energy by the frame size and left-shift back to the original position */
-   energy /= len;
-   energy = SHL32(energy, shift);
-
-   return energy;
-}
-#else
-static opus_val32 compute_frame_energy(const opus_val16 *pcm, int frame_size, int channels, int arch)
-{
-   int len = frame_size*channels;
-   return celt_inner_prod(pcm, pcm, len, arch)/len;
-}
-#endif
-
-/* Decides if DTX should be turned on (=1) or off (=0) */
-static int decide_dtx_mode(float activity_probability,    /* probability that current frame contains speech/music */
-                           int *nb_no_activity_frames,    /* number of consecutive frames with no activity */
-                           opus_val32 peak_signal_energy, /* peak energy of desired signal detected so far */
-                           const opus_val16 *pcm,         /* input pcm signal */
-                           int frame_size,                /* frame size */
-                           int channels,
-                           int is_silence,                 /* only digital silence detected in this frame */
-                           int arch
-                          )
-{
-   opus_val32 noise_energy;
-
-   if (!is_silence)
-   {
-      if (activity_probability < DTX_ACTIVITY_THRESHOLD)  /* is noise */
-      {
-         noise_energy = compute_frame_energy(pcm, frame_size, channels, arch);
-
-         /* but is sufficiently quiet */
-         is_silence = peak_signal_energy >= (PSEUDO_SNR_THRESHOLD * noise_energy);
-      }
-   }
-
-   if (is_silence)
-   {
-      /* The number of consecutive DTX frames should be within the allowed bounds */
-      (*nb_no_activity_frames)++;
-
-      if (*nb_no_activity_frames > NB_SPEECH_FRAMES_BEFORE_DTX)
-      {
-         if (*nb_no_activity_frames <= (NB_SPEECH_FRAMES_BEFORE_DTX + MAX_CONSECUTIVE_DTX))
-            /* Valid frame for DTX! */
-            return 1;
-         else
-            (*nb_no_activity_frames) = NB_SPEECH_FRAMES_BEFORE_DTX;
-      }
-   } else
-      (*nb_no_activity_frames) = 0;
-
-   return 0;
-}
-
-#endif
-
-static opus_int32 encode_multiframe_packet(OpusEncoder *st,
-                                           const opus_val16 *pcm,
-                                           int nb_frames,
-                                           int frame_size,
-                                           unsigned char *data,
-                                           opus_int32 out_data_bytes,
-                                           int to_celt,
-                                           int lsb_depth,
-                                           int float_api)
-{
-   int i;
-   int ret = 0;
-   VARDECL(unsigned char, tmp_data);
-   int bak_mode, bak_bandwidth, bak_channels, bak_to_mono;
-   VARDECL(OpusRepacketizer, rp);
-   int max_header_bytes;
-   opus_int32 bytes_per_frame;
-   opus_int32 cbr_bytes;
-   opus_int32 repacketize_len;
-   int tmp_len;
-   ALLOC_STACK;
-
-   /* Worst cases:
-    * 2 frames: Code 2 with different compressed sizes
-    * >2 frames: Code 3 VBR */
-   max_header_bytes = nb_frames == 2 ? 3 : (2+(nb_frames-1)*2);
-
-   if (st->use_vbr || st->user_bitrate_bps==OPUS_BITRATE_MAX)
-      repacketize_len = out_data_bytes;
-   else {
-      cbr_bytes = 3*st->bitrate_bps/(3*8*st->Fs/(frame_size*nb_frames));
-      repacketize_len = IMIN(cbr_bytes, out_data_bytes);
-   }
-   bytes_per_frame = IMIN(1276, 1+(repacketize_len-max_header_bytes)/nb_frames);
-
-   ALLOC(tmp_data, nb_frames*bytes_per_frame, unsigned char);
-   ALLOC(rp, 1, OpusRepacketizer);
-   opus_repacketizer_init(rp);
-
-   bak_mode = st->user_forced_mode;
-   bak_bandwidth = st->user_bandwidth;
-   bak_channels = st->force_channels;
-
-   st->user_forced_mode = st->mode;
-   st->user_bandwidth = st->bandwidth;
-   st->force_channels = st->stream_channels;
-
-   bak_to_mono = st->silk_mode.toMono;
-   if (bak_to_mono)
-      st->force_channels = 1;
-   else
-      st->prev_channels = st->stream_channels;
-
-   for (i=0;i<nb_frames;i++)
-   {
-      st->silk_mode.toMono = 0;
-      st->nonfinal_frame = i<(nb_frames-1);
-
-      /* When switching from SILK/Hybrid to CELT, only ask for a switch at the last frame */
-      if (to_celt && i==nb_frames-1)
-         st->user_forced_mode = MODE_CELT_ONLY;
-
-      tmp_len = opus_encode_native(st, pcm+i*(st->channels*frame_size), frame_size,
-         tmp_data+i*bytes_per_frame, bytes_per_frame, lsb_depth, NULL, 0, 0, 0, 0,
-         NULL, float_api);
-
-      if (tmp_len<0)
-      {
-         RESTORE_STACK;
-         return OPUS_INTERNAL_ERROR;
-      }
-
-      ret = opus_repacketizer_cat(rp, tmp_data+i*bytes_per_frame, tmp_len);
-
-      if (ret<0)
-      {
-         RESTORE_STACK;
-         return OPUS_INTERNAL_ERROR;
-      }
-   }
-
-   ret = opus_repacketizer_out_range_impl(rp, 0, nb_frames, data, repacketize_len, 0, !st->use_vbr);
-
-   if (ret<0)
-   {
-      RESTORE_STACK;
-      return OPUS_INTERNAL_ERROR;
-   }
-
-   /* Discard configs that were forced locally for the purpose of repacketization */
-   st->user_forced_mode = bak_mode;
-   st->user_bandwidth = bak_bandwidth;
-   st->force_channels = bak_channels;
-   st->silk_mode.toMono = bak_to_mono;
-
-   RESTORE_STACK;
-   return ret;
-}
-
-static int compute_redundancy_bytes(opus_int32 max_data_bytes, opus_int32 bitrate_bps, int frame_rate, int channels)
-{
-   int redundancy_bytes_cap;
-   int redundancy_bytes;
-   opus_int32 redundancy_rate;
-   int base_bits;
-   opus_int32 available_bits;
-   base_bits = (40*channels+20);
-
-   /* Equivalent rate for 5 ms frames. */
-   redundancy_rate = bitrate_bps + base_bits*(200 - frame_rate);
-   /* For VBR, further increase the bitrate if we can afford it. It's pretty short
-      and we'll avoid artefacts. */
-   redundancy_rate = 3*redundancy_rate/2;
-   redundancy_bytes = redundancy_rate/1600;
-
-   /* Compute the max rate we can use given CBR or VBR with cap. */
-   available_bits = max_data_bytes*8 - 2*base_bits;
-   redundancy_bytes_cap = (available_bits*240/(240+48000/frame_rate) + base_bits)/8;
-   redundancy_bytes = IMIN(redundancy_bytes, redundancy_bytes_cap);
-   /* It we can't get enough bits for redundancy to be worth it, rely on the decoder PLC. */
-   if (redundancy_bytes > 4 + 8*channels)
-      redundancy_bytes = IMIN(257, redundancy_bytes);
-   else
-      redundancy_bytes = 0;
-   return redundancy_bytes;
-}
-
 opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_size,
                 unsigned char *data, opus_int32 out_data_bytes, int lsb_depth,
                 const void *analysis_pcm, opus_int32 analysis_size, int c1, int c2,
@@ -1100,7 +971,6 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
     AnalysisInfo analysis_info;
     int analysis_read_pos_bak=-1;
     int analysis_read_subframe_bak=-1;
-    int is_silence = 0;
 #endif
     VARDECL(opus_val16, tmp_prefill);
 
@@ -1109,19 +979,15 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
     max_data_bytes = IMIN(1276, out_data_bytes);
 
     st->rangeFinal = 0;
-    if (frame_size <= 0 || max_data_bytes <= 0)
+    if ((!st->variable_duration && 400*frame_size != st->Fs && 200*frame_size != st->Fs && 100*frame_size != st->Fs &&
+         50*frame_size != st->Fs &&  25*frame_size != st->Fs &&  50*frame_size != 3*st->Fs)
+         || (400*frame_size < st->Fs)
+         || max_data_bytes<=0
+         )
     {
        RESTORE_STACK;
        return OPUS_BAD_ARG;
     }
-
-    /* Cannot encode 100 ms in 1 byte */
-    if (max_data_bytes==1 && st->Fs==(frame_size*10))
-    {
-      RESTORE_STACK;
-      return OPUS_BUFFER_TOO_SMALL;
-    }
-
     silk_enc = (char*)st+st->silk_enc_offset;
     celt_enc = (CELTEncoder*)((char*)st+st->celt_enc_offset);
     if (st->application == OPUS_APPLICATION_RESTRICTED_LOWDELAY)
@@ -1135,55 +1001,31 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
 #ifndef DISABLE_FLOAT_API
     analysis_info.valid = 0;
 #ifdef FIXED_POINT
-    if (st->silk_mode.complexity >= 10 && st->Fs>=16000)
+    if (st->silk_mode.complexity >= 10 && st->Fs==48000)
 #else
-    if (st->silk_mode.complexity >= 7 && st->Fs>=16000)
+    if (st->silk_mode.complexity >= 7 && st->Fs==48000)
 #endif
     {
-       is_silence = is_digital_silence(pcm, frame_size, st->channels, lsb_depth);
        analysis_read_pos_bak = st->analysis.read_pos;
        analysis_read_subframe_bak = st->analysis.read_subframe;
        run_analysis(&st->analysis, celt_mode, analysis_pcm, analysis_size, frame_size,
              c1, c2, analysis_channels, st->Fs,
              lsb_depth, downmix, &analysis_info);
-
-       /* Track the peak signal energy */
-       if (!is_silence && analysis_info.activity_probability > DTX_ACTIVITY_THRESHOLD)
-          st->peak_signal_energy = MAX32(MULT16_32_Q15(QCONST16(0.999f, 15), st->peak_signal_energy),
-                compute_frame_energy(pcm, frame_size, st->channels, st->arch));
-    } else if (st->analysis.initialized) {
-       tonality_analysis_reset(&st->analysis);
     }
 #else
     (void)analysis_pcm;
     (void)analysis_size;
-    (void)c1;
-    (void)c2;
-    (void)analysis_channels;
-    (void)downmix;
 #endif
 
-#ifndef DISABLE_FLOAT_API
-    /* Reset voice_ratio if this frame is not silent or if analysis is disabled.
-     * Otherwise, preserve voice_ratio from the last non-silent frame */
-    if (!is_silence)
-      st->voice_ratio = -1;
+    st->voice_ratio = -1;
 
+#ifndef DISABLE_FLOAT_API
     st->detected_bandwidth = 0;
     if (analysis_info.valid)
     {
        int analysis_bandwidth;
        if (st->signal_type == OPUS_AUTO)
-       {
-          float prob;
-          if (st->prev_mode == 0)
-             prob = analysis_info.music_prob;
-          else if (st->prev_mode == MODE_CELT_ONLY)
-             prob = analysis_info.music_prob_max;
-          else
-             prob = analysis_info.music_prob_min;
-          st->voice_ratio = (int)floor(.5+100*(1-prob));
-       }
+          st->voice_ratio = (int)floor(.5+100*(1-analysis_info.music_prob));
 
        analysis_bandwidth = analysis_info.bandwidth;
        if (analysis_bandwidth<=12)
@@ -1197,8 +1039,6 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
        else
           st->detected_bandwidth = OPUS_BANDWIDTH_FULLBAND;
     }
-#else
-    st->voice_ratio = -1;
 #endif
 
     if (st->channels==2 && st->force_channels!=1)
@@ -1212,13 +1052,12 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
     if (!st->use_vbr)
     {
        int cbrBytes;
-       /* Multiply by 12 to make sure the division is exact. */
-       int frame_rate12 = 12*st->Fs/frame_size;
+       /* Multiply by 3 to make sure the division is exact. */
+       int frame_rate3 = 3*st->Fs/frame_size;
        /* We need to make sure that "int" values always fit in 16 bits. */
-       cbrBytes = IMIN( (12*st->bitrate_bps/8 + frame_rate12/2)/frame_rate12, max_data_bytes);
-       st->bitrate_bps = cbrBytes*(opus_int32)frame_rate12*8/12;
-       /* Make sure we provide at least one byte to avoid failing. */
-       max_data_bytes = IMAX(1, cbrBytes);
+       cbrBytes = IMIN( (3*st->bitrate_bps/8 + frame_rate3/2)/frame_rate3, max_data_bytes);
+       st->bitrate_bps = cbrBytes*(opus_int32)frame_rate3*8/3;
+       max_data_bytes = cbrBytes;
     }
     if (max_data_bytes<3 || st->bitrate_bps < 3*frame_rate*8
        || (frame_rate<50 && (max_data_bytes*frame_rate<300 || st->bitrate_bps < 2400)))
@@ -1226,63 +1065,25 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
        /*If the space is too low to do something useful, emit 'PLC' frames.*/
        int tocmode = st->mode;
        int bw = st->bandwidth == 0 ? OPUS_BANDWIDTH_NARROWBAND : st->bandwidth;
-       int packet_code = 0;
-       int num_multiframes = 0;
-
        if (tocmode==0)
           tocmode = MODE_SILK_ONLY;
        if (frame_rate>100)
           tocmode = MODE_CELT_ONLY;
-       /* 40 ms -> 2 x 20 ms if in CELT_ONLY or HYBRID mode */
-       if (frame_rate==25 && tocmode!=MODE_SILK_ONLY)
-       {
-          frame_rate = 50;
-          packet_code = 1;
-       }
-
-       /* >= 60 ms frames */
-       if (frame_rate<=16)
-       {
-          /* 1 x 60 ms, 2 x 40 ms, 2 x 60 ms */
-          if (out_data_bytes==1 || (tocmode==MODE_SILK_ONLY && frame_rate!=10))
-          {
-             tocmode = MODE_SILK_ONLY;
-
-             packet_code = frame_rate <= 12;
-             frame_rate = frame_rate == 12 ? 25 : 16;
-          }
-          else
-          {
-             num_multiframes = 50/frame_rate;
-             frame_rate = 50;
-             packet_code = 3;
-          }
-       }
-
+       if (frame_rate < 50)
+          tocmode = MODE_SILK_ONLY;
        if(tocmode==MODE_SILK_ONLY&&bw>OPUS_BANDWIDTH_WIDEBAND)
           bw=OPUS_BANDWIDTH_WIDEBAND;
        else if (tocmode==MODE_CELT_ONLY&&bw==OPUS_BANDWIDTH_MEDIUMBAND)
           bw=OPUS_BANDWIDTH_NARROWBAND;
        else if (tocmode==MODE_HYBRID&&bw<=OPUS_BANDWIDTH_SUPERWIDEBAND)
           bw=OPUS_BANDWIDTH_SUPERWIDEBAND;
-
        data[0] = gen_toc(tocmode, frame_rate, bw, st->stream_channels);
-       data[0] |= packet_code;
-
-       ret = packet_code <= 1 ? 1 : 2;
-
-       max_data_bytes = IMAX(max_data_bytes, ret);
-
-       if (packet_code==3)
-          data[1] = num_multiframes;
-
+       ret = 1;
        if (!st->use_vbr)
        {
           ret = opus_packet_pad(data, ret, max_data_bytes);
           if (ret == OPUS_OK)
              ret = max_data_bytes;
-          else
-             ret = OPUS_INTERNAL_ERROR;
        }
        RESTORE_STACK;
        return ret;
@@ -1290,8 +1091,7 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
     max_rate = frame_rate*max_data_bytes*8;
 
     /* Equivalent 20-ms rate for mode/channel/bandwidth decisions */
-    equiv_rate = compute_equiv_rate(st->bitrate_bps, st->channels, st->Fs/frame_size,
-          st->use_vbr, 0, st->silk_mode.complexity, st->silk_mode.packetLossPercentage);
+    equiv_rate = st->bitrate_bps - (40*st->channels+20)*(st->Fs/frame_size - 50);
 
     if (st->signal_type == OPUS_SIGNAL_VOICE)
        voice_est = 127;
@@ -1332,17 +1132,7 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
        }
 #endif
     }
-    /* Update equivalent rate for channels decision. */
-    equiv_rate = compute_equiv_rate(st->bitrate_bps, st->stream_channels, st->Fs/frame_size,
-          st->use_vbr, 0, st->silk_mode.complexity, st->silk_mode.packetLossPercentage);
-
-    /* Allow SILK DTX if DTX is enabled but the generalized DTX cannot be used,
-       e.g. because of the complexity setting or sample rate. */
-#ifndef DISABLE_FLOAT_API
-    st->silk_mode.useDTX = st->use_dtx && !(analysis_info.valid || is_silence);
-#else
-    st->silk_mode.useDTX = st->use_dtx;
-#endif
+    equiv_rate = st->bitrate_bps - (40*st->stream_channels+20)*(st->Fs/frame_size - 50);
 
     /* Mode selection depending on application and signal type */
     if (st->application == OPUS_APPLICATION_RESTRICTED_LOWDELAY)
@@ -1391,15 +1181,10 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
        /* When FEC is enabled and there's enough packet loss, use SILK */
        if (st->silk_mode.useInBandFEC && st->silk_mode.packetLossPercentage > (128-voice_est)>>4)
           st->mode = MODE_SILK_ONLY;
-       /* When encoding voice and DTX is enabled but the generalized DTX cannot be used,
-          use SILK in order to make use of its DTX. */
+       /* When encoding voice and DTX is enabled, set the encoder to SILK mode (at least for now) */
        if (st->silk_mode.useDTX && voice_est > 100)
           st->mode = MODE_SILK_ONLY;
 #endif
-
-       /* If max_data_bytes represents less than 6 kb/s, switch to CELT-only mode */
-       if (max_data_bytes < (frame_rate > 50 ? 9000 : 6000)*frame_size / (st->Fs * 8))
-          st->mode = MODE_CELT_ONLY;
     } else {
        st->mode = st->user_forced_mode;
     }
@@ -1409,6 +1194,19 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
        st->mode = MODE_CELT_ONLY;
     if (st->lfe)
        st->mode = MODE_CELT_ONLY;
+    /* If max_data_bytes represents less than 8 kb/s, switch to CELT-only mode */
+    if (max_data_bytes < (frame_rate > 50 ? 12000 : 8000)*frame_size / (st->Fs * 8))
+       st->mode = MODE_CELT_ONLY;
+
+    if (st->stream_channels == 1 && st->prev_channels ==2 && st->silk_mode.toMono==0
+          && st->mode != MODE_CELT_ONLY && st->prev_mode != MODE_CELT_ONLY)
+    {
+       /* Delay stereo->mono transition by two frames so that SILK can do a smooth downmix */
+       st->silk_mode.toMono = 1;
+       st->stream_channels = 2;
+    } else {
+       st->silk_mode.toMono = 0;
+    }
 
     if (st->prev_mode > 0 &&
         ((st->mode != MODE_CELT_ONLY && st->prev_mode == MODE_CELT_ONLY) ||
@@ -1428,22 +1226,23 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
             }
         }
     }
-
-    /* When encoding multiframes, we can ask for a switch to CELT only in the last frame. This switch
-     * is processed above as the requested mode shouldn't interrupt stereo->mono transition. */
-    if (st->stream_channels == 1 && st->prev_channels ==2 && st->silk_mode.toMono==0
-          && st->mode != MODE_CELT_ONLY && st->prev_mode != MODE_CELT_ONLY)
+    /* For the first frame at a new SILK bandwidth */
+    if (st->silk_bw_switch)
     {
-       /* Delay stereo->mono transition by two frames so that SILK can do a smooth downmix */
-       st->silk_mode.toMono = 1;
-       st->stream_channels = 2;
-    } else {
-       st->silk_mode.toMono = 0;
+       redundancy = 1;
+       celt_to_silk = 1;
+       st->silk_bw_switch = 0;
+       prefill=1;
     }
 
-    /* Update equivalent rate with mode decision. */
-    equiv_rate = compute_equiv_rate(st->bitrate_bps, st->stream_channels, st->Fs/frame_size,
-          st->use_vbr, st->mode, st->silk_mode.complexity, st->silk_mode.packetLossPercentage);
+    if (redundancy)
+    {
+       /* Fair share of the max size allowed */
+       redundancy_bytes = IMIN(257, max_data_bytes*(opus_int32)(st->Fs/200)/(frame_size+st->Fs/200));
+       /* For VBR, target the actual bitrate (subject to the limit above) */
+       if (st->use_vbr)
+          redundancy_bytes = IMIN(redundancy_bytes, st->bitrate_bps/1600);
+    }
 
     if (st->mode != MODE_CELT_ONLY && st->prev_mode == MODE_CELT_ONLY)
     {
@@ -1458,7 +1257,17 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
         const opus_int32 *voice_bandwidth_thresholds, *music_bandwidth_thresholds;
         opus_int32 bandwidth_thresholds[8];
         int bandwidth = OPUS_BANDWIDTH_FULLBAND;
+        opus_int32 equiv_rate2;
 
+        equiv_rate2 = equiv_rate;
+        if (st->mode != MODE_CELT_ONLY)
+        {
+           /* Adjust the threshold +/- 10% depending on complexity */
+           equiv_rate2 = equiv_rate2 * (45+st->silk_mode.complexity)/50;
+           /* CBR is less efficient by ~1 kb/s */
+           if (!st->use_vbr)
+              equiv_rate2 -= 1000;
+        }
         if (st->channels==2 && st->force_channels!=1)
         {
            voice_bandwidth_thresholds = stereo_voice_bandwidth_thresholds;
@@ -1479,19 +1288,15 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
             hysteresis = bandwidth_thresholds[2*(bandwidth-OPUS_BANDWIDTH_MEDIUMBAND)+1];
             if (!st->first)
             {
-                if (st->auto_bandwidth >= bandwidth)
+                if (st->bandwidth >= bandwidth)
                     threshold -= hysteresis;
                 else
                     threshold += hysteresis;
             }
-            if (equiv_rate >= threshold)
+            if (equiv_rate2 >= threshold)
                 break;
         } while (--bandwidth>OPUS_BANDWIDTH_NARROWBAND);
-        /* We don't use mediumband anymore, except when explicitly requested or during
-           mode transitions. */
-        if (bandwidth == OPUS_BANDWIDTH_MEDIUMBAND)
-           bandwidth = OPUS_BANDWIDTH_WIDEBAND;
-        st->bandwidth = st->auto_bandwidth = bandwidth;
+        st->bandwidth = bandwidth;
         /* Prevents any transition to SWB/FB until the SILK layer has fully
            switched to WB mode and turned the variable LP filter off */
         if (!st->first && st->mode != MODE_CELT_ONLY && !st->silk_mode.inWBmodeWithoutVariableLP && st->bandwidth > OPUS_BANDWIDTH_WIDEBAND)
@@ -1544,8 +1349,6 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
        st->bandwidth = IMIN(st->bandwidth, st->detected_bandwidth);
     }
 #endif
-    st->silk_mode.LBRR_coded = decide_fec(st->silk_mode.useInBandFEC, st->silk_mode.packetLossPercentage,
-          st->silk_mode.LBRR_coded, st->mode, &st->bandwidth, equiv_rate);
     celt_encoder_ctl(celt_enc, OPUS_SET_LSB_DEPTH(lsb_depth));
 
     /* CELT mode doesn't support mediumband, use wideband instead */
@@ -1554,34 +1357,15 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
     if (st->lfe)
        st->bandwidth = OPUS_BANDWIDTH_NARROWBAND;
 
-    curr_bandwidth = st->bandwidth;
-
-    /* Chooses the appropriate mode for speech
-       *NEVER* switch to/from CELT-only mode here as this will invalidate some assumptions */
-    if (st->mode == MODE_SILK_ONLY && curr_bandwidth > OPUS_BANDWIDTH_WIDEBAND)
-        st->mode = MODE_HYBRID;
-    if (st->mode == MODE_HYBRID && curr_bandwidth <= OPUS_BANDWIDTH_WIDEBAND)
-        st->mode = MODE_SILK_ONLY;
-
-    /* Can't support higher than >60 ms frames, and >20 ms when in Hybrid or CELT-only modes */
-    if ((frame_size > st->Fs/50 && (st->mode != MODE_SILK_ONLY)) || frame_size > 3*st->Fs/50)
+    /* Can't support higher than wideband for >20 ms frames */
+    if (frame_size > st->Fs/50 && (st->mode == MODE_CELT_ONLY || st->bandwidth > OPUS_BANDWIDTH_WIDEBAND))
     {
-       int enc_frame_size;
+       VARDECL(unsigned char, tmp_data);
        int nb_frames;
-
-       if (st->mode == MODE_SILK_ONLY)
-       {
-         if (frame_size == 2*st->Fs/25)  /* 80 ms -> 2x 40 ms */
-           enc_frame_size = st->Fs/25;
-         else if (frame_size == 3*st->Fs/25)  /* 120 ms -> 2x 60 ms */
-           enc_frame_size = 3*st->Fs/50;
-         else                            /* 100 ms -> 5x 20 ms */
-           enc_frame_size = st->Fs/50;
-       }
-       else
-         enc_frame_size = st->Fs/50;
-
-       nb_frames = frame_size/enc_frame_size;
+       int bak_mode, bak_bandwidth, bak_channels, bak_to_mono;
+       VARDECL(OpusRepacketizer, rp);
+       opus_int32 bytes_per_frame;
+       opus_int32 repacketize_len;
 
 #ifndef DISABLE_FLOAT_API
        if (analysis_read_pos_bak!= -1)
@@ -1591,34 +1375,74 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
        }
 #endif
 
-       ret = encode_multiframe_packet(st, pcm, nb_frames, enc_frame_size, data,
-                                      out_data_bytes, to_celt, lsb_depth, float_api);
+       nb_frames = frame_size > st->Fs/25 ? 3 : 2;
+       bytes_per_frame = IMIN(1276,(out_data_bytes-3)/nb_frames);
 
-       RESTORE_STACK;
-       return ret;
-    }
+       ALLOC(tmp_data, nb_frames*bytes_per_frame, unsigned char);
 
-    /* For the first frame at a new SILK bandwidth */
-    if (st->silk_bw_switch)
-    {
-       redundancy = 1;
-       celt_to_silk = 1;
-       st->silk_bw_switch = 0;
-       /* Do a prefill without reseting the sampling rate control. */
-       prefill=2;
-    }
+       ALLOC(rp, 1, OpusRepacketizer);
+       opus_repacketizer_init(rp);
 
-    /* If we decided to go with CELT, make sure redundancy is off, no matter what
-       we decided earlier. */
-    if (st->mode == MODE_CELT_ONLY)
-        redundancy = 0;
+       bak_mode = st->user_forced_mode;
+       bak_bandwidth = st->user_bandwidth;
+       bak_channels = st->force_channels;
 
-    if (redundancy)
-    {
-       redundancy_bytes = compute_redundancy_bytes(max_data_bytes, st->bitrate_bps, frame_rate, st->stream_channels);
-       if (redundancy_bytes == 0)
-          redundancy = 0;
+       st->user_forced_mode = st->mode;
+       st->user_bandwidth = st->bandwidth;
+       st->force_channels = st->stream_channels;
+       bak_to_mono = st->silk_mode.toMono;
+
+       if (bak_to_mono)
+          st->force_channels = 1;
+       else
+          st->prev_channels = st->stream_channels;
+       for (i=0;i<nb_frames;i++)
+       {
+          int tmp_len;
+          st->silk_mode.toMono = 0;
+          /* When switching from SILK/Hybrid to CELT, only ask for a switch at the last frame */
+          if (to_celt && i==nb_frames-1)
+             st->user_forced_mode = MODE_CELT_ONLY;
+          tmp_len = opus_encode_native(st, pcm+i*(st->channels*st->Fs/50), st->Fs/50,
+                tmp_data+i*bytes_per_frame, bytes_per_frame, lsb_depth,
+                NULL, 0, c1, c2, analysis_channels, downmix, float_api);
+          if (tmp_len<0)
+          {
+             RESTORE_STACK;
+             return OPUS_INTERNAL_ERROR;
+          }
+          ret = opus_repacketizer_cat(rp, tmp_data+i*bytes_per_frame, tmp_len);
+          if (ret<0)
+          {
+             RESTORE_STACK;
+             return OPUS_INTERNAL_ERROR;
+          }
+       }
+       if (st->use_vbr)
+          repacketize_len = out_data_bytes;
+       else
+          repacketize_len = IMIN(3*st->bitrate_bps/(3*8*50/nb_frames), out_data_bytes);
+       ret = opus_repacketizer_out_range_impl(rp, 0, nb_frames, data, repacketize_len, 0, !st->use_vbr);
+       if (ret<0)
+       {
+          RESTORE_STACK;
+          return OPUS_INTERNAL_ERROR;
+       }
+       st->user_forced_mode = bak_mode;
+       st->user_bandwidth = bak_bandwidth;
+       st->force_channels = bak_channels;
+       st->silk_mode.toMono = bak_to_mono;
+       RESTORE_STACK;
+       return ret;
     }
+    curr_bandwidth = st->bandwidth;
+
+    /* Chooses the appropriate mode for speech
+       *NEVER* switch to/from CELT-only mode here as this will invalidate some assumptions */
+    if (st->mode == MODE_SILK_ONLY && curr_bandwidth > OPUS_BANDWIDTH_WIDEBAND)
+        st->mode = MODE_HYBRID;
+    if (st->mode == MODE_HYBRID && curr_bandwidth <= OPUS_BANDWIDTH_WIDEBAND)
+        st->mode = MODE_SILK_ONLY;
 
     /* printf("%d %d %d %d\n", st->bitrate_bps, st->stream_channels, st->mode, curr_bandwidth); */
     bytes_target = IMIN(max_data_bytes-redundancy_bytes, st->bitrate_bps * frame_size / (st->Fs * 8)) - 1;
@@ -1643,7 +1467,7 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
 
     if (st->application == OPUS_APPLICATION_VOIP)
     {
-       hp_cutoff(pcm, cutoff_Hz, &pcm_buf[total_buffer*st->channels], st->hp_mem, frame_size, st->channels, st->Fs, st->arch);
+       hp_cutoff(pcm, cutoff_Hz, &pcm_buf[total_buffer*st->channels], st->hp_mem, frame_size, st->channels, st->Fs);
     } else {
        dc_reject(pcm, 3, &pcm_buf[total_buffer*st->channels], st->hp_mem, frame_size, st->channels, st->Fs);
     }
@@ -1668,7 +1492,6 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
     if (st->mode != MODE_CELT_ONLY)
     {
         opus_int32 total_bitRate, celt_rate;
-        opus_int activity;
 #ifdef FIXED_POINT
        const opus_int16 *pcm_silk;
 #else
@@ -1676,26 +1499,30 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
        ALLOC(pcm_silk, st->channels*frame_size, opus_int16);
 #endif
 
-        activity = VAD_NO_DECISION;
-#ifndef DISABLE_FLOAT_API
-        if( analysis_info.valid ) {
-            /* Inform SILK about the Opus VAD decision */
-            activity = ( analysis_info.activity_probability >= DTX_ACTIVITY_THRESHOLD );
-        }
-#endif
-
         /* Distribute bits between SILK and CELT */
         total_bitRate = 8 * bytes_target * frame_rate;
         if( st->mode == MODE_HYBRID ) {
+            int HB_gain_ref;
             /* Base rate for SILK */
-            st->silk_mode.bitRate = compute_silk_rate_for_hybrid(total_bitRate,
-                  curr_bandwidth, st->Fs == 50 * frame_size, st->use_vbr, st->silk_mode.LBRR_coded,
-                  st->stream_channels);
+            st->silk_mode.bitRate = st->stream_channels * ( 5000 + 1000 * ( st->Fs == 100 * frame_size ) );
+            if( curr_bandwidth == OPUS_BANDWIDTH_SUPERWIDEBAND ) {
+                /* SILK gets 2/3 of the remaining bits */
+                st->silk_mode.bitRate += ( total_bitRate - st->silk_mode.bitRate ) * 2 / 3;
+            } else { /* FULLBAND */
+                /* SILK gets 3/5 of the remaining bits */
+                st->silk_mode.bitRate += ( total_bitRate - st->silk_mode.bitRate ) * 3 / 5;
+            }
+            /* Don't let SILK use more than 80% */
+            if( st->silk_mode.bitRate > total_bitRate * 4/5 ) {
+                st->silk_mode.bitRate = total_bitRate * 4/5;
+            }
             if (!st->energy_masking)
             {
                /* Increasingly attenuate high band when it gets allocated fewer bits */
                celt_rate = total_bitRate - st->silk_mode.bitRate;
-               HB_gain = Q15ONE - SHR32(celt_exp2(-celt_rate * QCONST16(1.f/1024, 10)), 1);
+               HB_gain_ref = (curr_bandwidth == OPUS_BANDWIDTH_SUPERWIDEBAND) ? 3000 : 3600;
+               HB_gain = SHL32((opus_val32)celt_rate, 9) / SHR32((opus_val32)celt_rate + st->stream_channels * HB_gain_ref, 6);
+               HB_gain = HB_gain < (opus_val32)Q15ONE*6/7 ? HB_gain + Q15ONE/7 : Q15ONE;
             }
         } else {
             /* SILK gets all bits */
@@ -1742,6 +1569,7 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
               st->silk_mode.bitRate += 3*rate_offset/5;
            else
               st->silk_mode.bitRate += rate_offset;
+           bytes_target += rate_offset * frame_size / (8 * st->Fs);
         }
 
         st->silk_mode.payloadSize_ms = 1000 * frame_size / st->Fs;
@@ -1752,7 +1580,7 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
         } else if (curr_bandwidth == OPUS_BANDWIDTH_MEDIUMBAND) {
             st->silk_mode.desiredInternalSampleRate = 12000;
         } else {
-            celt_assert( st->mode == MODE_HYBRID || curr_bandwidth == OPUS_BANDWIDTH_WIDEBAND );
+            silk_assert( st->mode == MODE_HYBRID || curr_bandwidth == OPUS_BANDWIDTH_WIDEBAND );
             st->silk_mode.desiredInternalSampleRate = 16000;
         }
         if( st->mode == MODE_HYBRID ) {
@@ -1762,53 +1590,40 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
             st->silk_mode.minInternalSampleRate = 8000;
         }
 
-        st->silk_mode.maxInternalSampleRate = 16000;
         if (st->mode == MODE_SILK_ONLY)
         {
            opus_int32 effective_max_rate = max_rate;
+           st->silk_mode.maxInternalSampleRate = 16000;
            if (frame_rate > 50)
               effective_max_rate = effective_max_rate*2/3;
-           if (effective_max_rate < 8000)
+           if (effective_max_rate < 13000)
            {
               st->silk_mode.maxInternalSampleRate = 12000;
               st->silk_mode.desiredInternalSampleRate = IMIN(12000, st->silk_mode.desiredInternalSampleRate);
            }
-           if (effective_max_rate < 7000)
+           if (effective_max_rate < 9600)
            {
               st->silk_mode.maxInternalSampleRate = 8000;
               st->silk_mode.desiredInternalSampleRate = IMIN(8000, st->silk_mode.desiredInternalSampleRate);
            }
+        } else {
+           st->silk_mode.maxInternalSampleRate = 16000;
         }
 
         st->silk_mode.useCBR = !st->use_vbr;
 
         /* Call SILK encoder for the low band */
+        nBytes = IMIN(1275, max_data_bytes-1-redundancy_bytes);
 
-        /* Max bits for SILK, counting ToC, redundancy bytes, and optionally redundancy. */
-        st->silk_mode.maxBits = (max_data_bytes-1)*8;
-        if (redundancy && redundancy_bytes >= 2)
-        {
-           /* Counting 1 bit for redundancy position and 20 bits for flag+size (only for hybrid). */
-           st->silk_mode.maxBits -= redundancy_bytes*8 + 1;
-           if (st->mode == MODE_HYBRID)
-              st->silk_mode.maxBits -= 20;
-        }
+        st->silk_mode.maxBits = nBytes*8;
+        /* Only allow up to 90% of the bits for hybrid mode*/
+        if (st->mode == MODE_HYBRID)
+           st->silk_mode.maxBits = (opus_int32)st->silk_mode.maxBits*9/10;
         if (st->silk_mode.useCBR)
         {
-           if (st->mode == MODE_HYBRID)
-           {
-              st->silk_mode.maxBits = IMIN(st->silk_mode.maxBits, st->silk_mode.bitRate * frame_size / st->Fs);
-           }
-        } else {
-           /* Constrained VBR. */
-           if (st->mode == MODE_HYBRID)
-           {
-              /* Compute SILK bitrate corresponding to the max total bits available */
-              opus_int32 maxBitRate = compute_silk_rate_for_hybrid(st->silk_mode.maxBits*st->Fs / frame_size,
-                    curr_bandwidth, st->Fs == 50 * frame_size, st->use_vbr, st->silk_mode.LBRR_coded,
-                    st->stream_channels);
-              st->silk_mode.maxBits = maxBitRate * frame_size / st->Fs;
-           }
+           st->silk_mode.maxBits = (st->silk_mode.bitRate * frame_size / (st->Fs * 8))*8;
+           /* Reduce the initial target to make it easier to reach the CBR rate */
+           st->silk_mode.bitRate = IMAX(1, st->silk_mode.bitRate-2000);
         }
 
         if (prefill)
@@ -1831,9 +1646,7 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
             for (i=0;i<st->encoder_buffer*st->channels;i++)
                 pcm_silk[i] = FLOAT2INT16(st->delay_buffer[i]);
 #endif
-            silk_Encode( silk_enc, &st->silk_mode, pcm_silk, st->encoder_buffer, NULL, &zero, prefill, activity );
-            /* Prevent a second switch in the real encode call. */
-            st->silk_mode.opusCanSwitch = 0;
+            silk_Encode( silk_enc, &st->silk_mode, pcm_silk, st->encoder_buffer, NULL, &zero, 1 );
         }
 
 #ifdef FIXED_POINT
@@ -1842,14 +1655,20 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
         for (i=0;i<frame_size*st->channels;i++)
             pcm_silk[i] = FLOAT2INT16(pcm_buf[total_buffer*st->channels + i]);
 #endif
-        ret = silk_Encode( silk_enc, &st->silk_mode, pcm_silk, frame_size, &enc, &nBytes, 0, activity );
+        ret = silk_Encode( silk_enc, &st->silk_mode, pcm_silk, frame_size, &enc, &nBytes, 0 );
         if( ret ) {
             /*fprintf (stderr, "SILK encode error: %d\n", ret);*/
             /* Handle error */
            RESTORE_STACK;
            return OPUS_INTERNAL_ERROR;
         }
-
+        if (nBytes==0)
+        {
+           st->rangeFinal = 0;
+           data[-1] = gen_toc(st->mode, st->Fs/frame_size, curr_bandwidth, st->stream_channels);
+           RESTORE_STACK;
+           return 1;
+        }
         /* Extract SILK internal bandwidth for signaling in first byte */
         if( st->mode == MODE_SILK_ONLY ) {
             if( st->silk_mode.internalSampleRate == 8000 ) {
@@ -1860,24 +1679,14 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
                curr_bandwidth = OPUS_BANDWIDTH_WIDEBAND;
             }
         } else {
-            celt_assert( st->silk_mode.internalSampleRate == 16000 );
-        }
-
-        st->silk_mode.opusCanSwitch = st->silk_mode.switchReady && !st->nonfinal_frame;
-
-        if (nBytes==0)
-        {
-           st->rangeFinal = 0;
-           data[-1] = gen_toc(st->mode, st->Fs/frame_size, curr_bandwidth, st->stream_channels);
-           RESTORE_STACK;
-           return 1;
+            silk_assert( st->silk_mode.internalSampleRate == 16000 );
         }
 
+        st->silk_mode.opusCanSwitch = st->silk_mode.switchReady;
         /* FIXME: How do we allocate the redundancy for CBR? */
         if (st->silk_mode.opusCanSwitch)
         {
-           redundancy_bytes = compute_redundancy_bytes(max_data_bytes, st->bitrate_bps, frame_rate, st->stream_channels);
-           redundancy = (redundancy_bytes != 0);
+           redundancy = 1;
            celt_to_silk = 0;
            st->silk_bw_switch = 1;
         }
@@ -1918,18 +1727,40 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
 
         if (st->mode == MODE_HYBRID)
         {
+            int len;
+
+            len = (ec_tell(&enc)+7)>>3;
+            if (redundancy)
+               len += st->mode == MODE_HYBRID ? 3 : 1;
             if( st->use_vbr ) {
-                celt_encoder_ctl(celt_enc, OPUS_SET_BITRATE(st->bitrate_bps-st->silk_mode.bitRate));
-                celt_encoder_ctl(celt_enc, OPUS_SET_VBR_CONSTRAINT(0));
+                nb_compr_bytes = len + bytes_target - (st->silk_mode.bitRate * frame_size) / (8 * st->Fs);
+            } else {
+                /* check if SILK used up too much */
+                nb_compr_bytes = len > bytes_target ? len : bytes_target;
             }
         } else {
             if (st->use_vbr)
             {
+                opus_int32 bonus=0;
+#ifndef DISABLE_FLOAT_API
+                if (st->variable_duration==OPUS_FRAMESIZE_VARIABLE && frame_size != st->Fs/50)
+                {
+                   bonus = (60*st->stream_channels+40)*(st->Fs/frame_size-50);
+                   if (analysis_info.valid)
+                      bonus = (opus_int32)(bonus*(1.f+.5f*analysis_info.tonality));
+                }
+#endif
                 celt_encoder_ctl(celt_enc, OPUS_SET_VBR(1));
                 celt_encoder_ctl(celt_enc, OPUS_SET_VBR_CONSTRAINT(st->vbr_constraint));
-                celt_encoder_ctl(celt_enc, OPUS_SET_BITRATE(st->bitrate_bps));
+                celt_encoder_ctl(celt_enc, OPUS_SET_BITRATE(st->bitrate_bps+bonus));
+                nb_compr_bytes = max_data_bytes-1-redundancy_bytes;
+            } else {
+                nb_compr_bytes = bytes_target;
             }
         }
+
+    } else {
+        nb_compr_bytes = 0;
     }
 
     ALLOC(tmp_prefill, st->channels*st->Fs/400, opus_val16);
@@ -1955,14 +1786,7 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
     }
     st->prev_HB_gain = HB_gain;
     if (st->mode != MODE_HYBRID || st->stream_channels==1)
-    {
-       if (equiv_rate > 32000)
-          st->silk_mode.stereoWidth_Q14 = 16384;
-       else if (equiv_rate < 16000)
-          st->silk_mode.stereoWidth_Q14 = 0;
-       else
-          st->silk_mode.stereoWidth_Q14 = 16384 - 2048*(opus_int32)(32000-equiv_rate)/(equiv_rate-14000);
-    }
+       st->silk_mode.stereoWidth_Q14 = IMIN((1<<14),2*IMAX(0,equiv_rate-30000));
     if( !st->energy_masking && st->channels == 2 ) {
         /* Apply stereo width reduction (at low bitrates) */
         if( st->hybrid_stereo_width_Q14 < (1 << 14) || st->silk_mode.stereoWidth_Q14 < (1 << 14) ) {
@@ -1985,23 +1809,19 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
     if ( st->mode != MODE_CELT_ONLY && ec_tell(&enc)+17+20*(st->mode == MODE_HYBRID) <= 8*(max_data_bytes-1))
     {
         /* For SILK mode, the redundancy is inferred from the length */
-        if (st->mode == MODE_HYBRID)
+        if (st->mode == MODE_HYBRID && (redundancy || ec_tell(&enc)+37 <= 8*nb_compr_bytes))
            ec_enc_bit_logp(&enc, redundancy, 12);
         if (redundancy)
         {
             int max_redundancy;
             ec_enc_bit_logp(&enc, celt_to_silk, 1);
             if (st->mode == MODE_HYBRID)
-            {
-               /* Reserve the 8 bits needed for the redundancy length,
-                  and at least a few bits for CELT if possible */
-               max_redundancy = (max_data_bytes-1)-((ec_tell(&enc)+8+3+7)>>3);
-            }
+               max_redundancy = (max_data_bytes-1)-nb_compr_bytes;
             else
                max_redundancy = (max_data_bytes-1)-((ec_tell(&enc)+7)>>3);
             /* Target the same bit-rate for redundancy as for the rest,
                up to a max of 257 bytes */
-            redundancy_bytes = IMIN(max_redundancy, redundancy_bytes);
+            redundancy_bytes = IMIN(max_redundancy, st->bitrate_bps/1600);
             redundancy_bytes = IMIN(257, IMAX(2, redundancy_bytes));
             if (st->mode == MODE_HYBRID)
                 ec_enc_uint(&enc, redundancy_bytes-2, 256);
@@ -2023,7 +1843,7 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
         ec_enc_done(&enc);
         nb_compr_bytes = ret;
     } else {
-       nb_compr_bytes = (max_data_bytes-1)-redundancy_bytes;
+       nb_compr_bytes = IMIN((max_data_bytes-1)-redundancy_bytes, nb_compr_bytes);
        ec_enc_shrink(&enc, nb_compr_bytes);
     }
 
@@ -2031,12 +1851,6 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
     if (redundancy || st->mode != MODE_SILK_ONLY)
        celt_encoder_ctl(celt_enc, CELT_SET_ANALYSIS(&analysis_info));
 #endif
-    if (st->mode == MODE_HYBRID) {
-       SILKInfo info;
-       info.signalType = st->silk_mode.signalType;
-       info.offset = st->silk_mode.offset;
-       celt_encoder_ctl(celt_enc, CELT_SET_SILK_INFO(&info));
-    }
 
     /* 5 ms redundant frame for CELT->SILK */
     if (redundancy && celt_to_silk)
@@ -2044,7 +1858,6 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
         int err;
         celt_encoder_ctl(celt_enc, CELT_SET_START_BAND(0));
         celt_encoder_ctl(celt_enc, OPUS_SET_VBR(0));
-        celt_encoder_ctl(celt_enc, OPUS_SET_BITRATE(OPUS_BITRATE_MAX));
         err = celt_encode_with_ec(celt_enc, pcm_buf, st->Fs/200, data+nb_compr_bytes, redundancy_bytes, NULL);
         if (err < 0)
         {
@@ -2068,25 +1881,15 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
            celt_encode_with_ec(celt_enc, tmp_prefill, st->Fs/400, dummy, 2, NULL);
            celt_encoder_ctl(celt_enc, CELT_SET_PREDICTION(0));
         }
-        /* If false, we already busted the budget and we'll end up with a "PLC frame" */
+        /* If false, we already busted the budget and we'll end up with a "PLC packet" */
         if (ec_tell(&enc) <= 8*nb_compr_bytes)
         {
-           /* Set the bitrate again if it was overridden in the redundancy code above*/
-           if (redundancy && celt_to_silk && st->mode==MODE_HYBRID && st->use_vbr)
-              celt_encoder_ctl(celt_enc, OPUS_SET_BITRATE(st->bitrate_bps-st->silk_mode.bitRate));
-           celt_encoder_ctl(celt_enc, OPUS_SET_VBR(st->use_vbr));
            ret = celt_encode_with_ec(celt_enc, pcm_buf, frame_size, NULL, nb_compr_bytes, &enc);
            if (ret < 0)
            {
               RESTORE_STACK;
               return OPUS_INTERNAL_ERROR;
            }
-           /* Put CELT->SILK redundancy data in the right place. */
-           if (redundancy && celt_to_silk && st->mode==MODE_HYBRID && st->use_vbr)
-           {
-              OPUS_MOVE(data+ret, data+nb_compr_bytes, redundancy_bytes);
-              nb_compr_bytes = nb_compr_bytes+redundancy_bytes;
-           }
         }
     }
 
@@ -2102,15 +1905,7 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
         celt_encoder_ctl(celt_enc, OPUS_RESET_STATE);
         celt_encoder_ctl(celt_enc, CELT_SET_START_BAND(0));
         celt_encoder_ctl(celt_enc, CELT_SET_PREDICTION(0));
-        celt_encoder_ctl(celt_enc, OPUS_SET_VBR(0));
-        celt_encoder_ctl(celt_enc, OPUS_SET_BITRATE(OPUS_BITRATE_MAX));
 
-        if (st->mode == MODE_HYBRID)
-        {
-           /* Shrink packet to what the encoder actually used. */
-           nb_compr_bytes = ret;
-           ec_enc_shrink(&enc, nb_compr_bytes);
-        }
         /* NOTE: We could speed this up slightly (at the expense of code size) by just adding a function that prefills the buffer */
         celt_encode_with_ec(celt_enc, pcm_buf+st->channels*(frame_size-N2-N4), N4, dummy, 2, NULL);
 
@@ -2140,23 +1935,6 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
 
     st->first = 0;
 
-    /* DTX decision */
-#ifndef DISABLE_FLOAT_API
-    if (st->use_dtx && (analysis_info.valid || is_silence))
-    {
-       if (decide_dtx_mode(analysis_info.activity_probability, &st->nb_no_activity_frames,
-             st->peak_signal_energy, pcm, frame_size, st->channels, is_silence, st->arch))
-       {
-          st->rangeFinal = 0;
-          data[0] = gen_toc(st->mode, st->Fs/frame_size, curr_bandwidth, st->stream_channels);
-          RESTORE_STACK;
-          return 1;
-       }
-    } else {
-       st->nb_no_activity_frames = 0;
-    }
-#endif
-
     /* In the unlikely case that the SILK encoder busted its target, tell
        the decoder to call the PLC */
     if (ec_tell(&enc) > (max_data_bytes-1)*8)
@@ -2184,6 +1962,7 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
     if (!st->use_vbr)
     {
        if (opus_packet_pad(data, ret, max_data_bytes) != OPUS_OK)
+
        {
           RESTORE_STACK;
           return OPUS_INTERNAL_ERROR;
@@ -2202,15 +1981,18 @@ opus_int32 opus_encode_float(OpusEncoder *st, const float *pcm, int analysis_fra
 {
    int i, ret;
    int frame_size;
+   int delay_compensation;
    VARDECL(opus_int16, in);
    ALLOC_STACK;
 
-   frame_size = frame_size_select(analysis_frame_size, st->variable_duration, st->Fs);
-   if (frame_size <= 0)
-   {
-      RESTORE_STACK;
-      return OPUS_BAD_ARG;
-   }
+   if (st->application == OPUS_APPLICATION_RESTRICTED_LOWDELAY)
+      delay_compensation = 0;
+   else
+      delay_compensation = st->delay_compensation;
+   frame_size = compute_frame_size(pcm, analysis_frame_size,
+         st->variable_duration, st->channels, st->Fs, st->bitrate_bps,
+         delay_compensation, downmix_float, st->analysis.subframe_mem);
+
    ALLOC(in, frame_size*st->channels, opus_int16);
 
    for (i=0;i<frame_size*st->channels;i++)
@@ -2226,7 +2008,18 @@ opus_int32 opus_encode(OpusEncoder *st, const opus_int16 *pcm, int analysis_fram
                 unsigned char *data, opus_int32 out_data_bytes)
 {
    int frame_size;
-   frame_size = frame_size_select(analysis_frame_size, st->variable_duration, st->Fs);
+   int delay_compensation;
+   if (st->application == OPUS_APPLICATION_RESTRICTED_LOWDELAY)
+      delay_compensation = 0;
+   else
+      delay_compensation = st->delay_compensation;
+   frame_size = compute_frame_size(pcm, analysis_frame_size,
+         st->variable_duration, st->channels, st->Fs, st->bitrate_bps,
+         delay_compensation, downmix_int
+#ifndef DISABLE_FLOAT_API
+         , st->analysis.subframe_mem
+#endif
+         );
    return opus_encode_native(st, pcm, frame_size, data, out_data_bytes, 16,
                              pcm, analysis_frame_size, 0, -2, st->channels, downmix_int, 0);
 }
@@ -2237,15 +2030,18 @@ opus_int32 opus_encode(OpusEncoder *st, const opus_int16 *pcm, int analysis_fram
 {
    int i, ret;
    int frame_size;
+   int delay_compensation;
    VARDECL(float, in);
    ALLOC_STACK;
 
-   frame_size = frame_size_select(analysis_frame_size, st->variable_duration, st->Fs);
-   if (frame_size <= 0)
-   {
-      RESTORE_STACK;
-      return OPUS_BAD_ARG;
-   }
+   if (st->application == OPUS_APPLICATION_RESTRICTED_LOWDELAY)
+      delay_compensation = 0;
+   else
+      delay_compensation = st->delay_compensation;
+   frame_size = compute_frame_size(pcm, analysis_frame_size,
+         st->variable_duration, st->channels, st->Fs, st->bitrate_bps,
+         delay_compensation, downmix_int, st->analysis.subframe_mem);
+
    ALLOC(in, frame_size*st->channels, float);
 
    for (i=0;i<frame_size*st->channels;i++)
@@ -2259,7 +2055,14 @@ opus_int32 opus_encode_float(OpusEncoder *st, const float *pcm, int analysis_fra
                       unsigned char *data, opus_int32 out_data_bytes)
 {
    int frame_size;
-   frame_size = frame_size_select(analysis_frame_size, st->variable_duration, st->Fs);
+   int delay_compensation;
+   if (st->application == OPUS_APPLICATION_RESTRICTED_LOWDELAY)
+      delay_compensation = 0;
+   else
+      delay_compensation = st->delay_compensation;
+   frame_size = compute_frame_size(pcm, analysis_frame_size,
+         st->variable_duration, st->channels, st->Fs, st->bitrate_bps,
+         delay_compensation, downmix_float, st->analysis.subframe_mem);
    return opus_encode_native(st, pcm, frame_size, data, out_data_bytes, 24,
                              pcm, analysis_frame_size, 0, -2, st->channels, downmix_float, 1);
 }
@@ -2290,9 +2093,6 @@ int opus_encoder_ctl(OpusEncoder *st, int request, ...)
                break;
             }
             st->application = value;
-#ifndef DISABLE_FLOAT_API
-            st->analysis.application = value;
-#endif
         }
         break;
         case OPUS_GET_APPLICATION_REQUEST:
@@ -2411,7 +2211,7 @@ int opus_encoder_ctl(OpusEncoder *st, int request, ...)
             {
                goto bad_arg;
             }
-            st->use_dtx = value;
+            st->silk_mode.useDTX = value;
         }
         break;
         case OPUS_GET_DTX_REQUEST:
@@ -2421,7 +2221,7 @@ int opus_encoder_ctl(OpusEncoder *st, int request, ...)
             {
                goto bad_arg;
             }
-            *value = st->use_dtx;
+            *value = st->silk_mode.useDTX;
         }
         break;
         case OPUS_SET_COMPLEXITY_REQUEST:
@@ -2622,15 +2422,15 @@ int opus_encoder_ctl(OpusEncoder *st, int request, ...)
         case OPUS_SET_EXPERT_FRAME_DURATION_REQUEST:
         {
             opus_int32 value = va_arg(ap, opus_int32);
-            if (value != OPUS_FRAMESIZE_ARG    && value != OPUS_FRAMESIZE_2_5_MS &&
-                value != OPUS_FRAMESIZE_5_MS   && value != OPUS_FRAMESIZE_10_MS  &&
-                value != OPUS_FRAMESIZE_20_MS  && value != OPUS_FRAMESIZE_40_MS  &&
-                value != OPUS_FRAMESIZE_60_MS  && value != OPUS_FRAMESIZE_80_MS  &&
-                value != OPUS_FRAMESIZE_100_MS && value != OPUS_FRAMESIZE_120_MS)
+            if (value != OPUS_FRAMESIZE_ARG   && value != OPUS_FRAMESIZE_2_5_MS &&
+                value != OPUS_FRAMESIZE_5_MS  && value != OPUS_FRAMESIZE_10_MS  &&
+                value != OPUS_FRAMESIZE_20_MS && value != OPUS_FRAMESIZE_40_MS  &&
+                value != OPUS_FRAMESIZE_60_MS && value != OPUS_FRAMESIZE_VARIABLE)
             {
                goto bad_arg;
             }
             st->variable_duration = value;
+            celt_encoder_ctl(celt_enc, OPUS_SET_EXPERT_FRAME_DURATION(value));
         }
         break;
         case OPUS_GET_EXPERT_FRAME_DURATION_REQUEST:
@@ -2659,26 +2459,6 @@ int opus_encoder_ctl(OpusEncoder *st, int request, ...)
            *value = st->silk_mode.reducedDependency;
         }
         break;
-        case OPUS_SET_PHASE_INVERSION_DISABLED_REQUEST:
-        {
-            opus_int32 value = va_arg(ap, opus_int32);
-            if(value<0 || value>1)
-            {
-               goto bad_arg;
-            }
-            celt_encoder_ctl(celt_enc, OPUS_SET_PHASE_INVERSION_DISABLED(value));
-        }
-        break;
-        case OPUS_GET_PHASE_INVERSION_DISABLED_REQUEST:
-        {
-            opus_int32 *value = va_arg(ap, opus_int32*);
-            if (!value)
-            {
-               goto bad_arg;
-            }
-            celt_encoder_ctl(celt_enc, OPUS_GET_PHASE_INVERSION_DISABLED(value));
-        }
-        break;
         case OPUS_RESET_STATE:
         {
            void *silk_enc;
@@ -2727,33 +2507,6 @@ int opus_encoder_ctl(OpusEncoder *st, int request, ...)
             ret = celt_encoder_ctl(celt_enc, OPUS_SET_ENERGY_MASK(value));
         }
         break;
-        case OPUS_GET_IN_DTX_REQUEST:
-        {
-            opus_int32 *value = va_arg(ap, opus_int32*);
-            if (!value)
-            {
-                goto bad_arg;
-            }
-            if (st->silk_mode.useDTX && (st->prev_mode == MODE_SILK_ONLY || st->prev_mode == MODE_HYBRID)) {
-                /* DTX determined by Silk. */
-                int n;
-                void *silk_enc = (char*)st+st->silk_enc_offset;
-                *value = 1;
-                for (n=0;n<st->silk_mode.nChannelsInternal;n++) {
-                    *value = *value && ((silk_encoder*)silk_enc)->state_Fxx[n].sCmn.noSpeechCounter >= NB_SPEECH_FRAMES_BEFORE_DTX;
-                }
-            }
-#ifndef DISABLE_FLOAT_API
-            else if (st->use_dtx) {
-                /* DTX determined by Opus. */
-                *value = st->nb_no_activity_frames >= NB_SPEECH_FRAMES_BEFORE_DTX;
-            }
-#endif
-            else {
-                *value = 0;
-            }
-        }
-        break;
 
         case CELT_GET_MODE_REQUEST:
         {