Add copy of opus library in deps/third_party.

opus/src/opus_decoder.c

+/* Copyright (c) 2010 Xiph.Org Foundation, Skype Limited
+   Written by Jean-Marc Valin and Koen Vos */
+/*
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions
+   are met:
+
+   - Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+
+   - Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+   OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifndef OPUS_BUILD
+#error "OPUS_BUILD _MUST_ be defined to build Opus and you probably want a decent config.h, see README for more details."
+#endif
+
+#include <stdarg.h>
+#include "celt.h"
+#include "opus.h"
+#include "entdec.h"
+#include "modes.h"
+#include "API.h"
+#include "stack_alloc.h"
+#include "float_cast.h"
+#include "opus_private.h"
+#include "os_support.h"
+#include "structs.h"
+#include "define.h"
+#include "mathops.h"
+
+struct OpusDecoder {
+   int          celt_dec_offset;
+   int          silk_dec_offset;
+   int          channels;
+   opus_int32   Fs;          /** Sampling rate (at the API level) */
+   silk_DecControlStruct DecControl;
+   int          decode_gain;
+
+   /* Everything beyond this point gets cleared on a reset */
+#define OPUS_DECODER_RESET_START stream_channels
+   int          stream_channels;
+
+   int          bandwidth;
+   int          mode;
+   int          prev_mode;
+   int          frame_size;
+   int          prev_redundancy;
+
+   opus_uint32  rangeFinal;
+};
+
+#ifdef FIXED_POINT
+static inline opus_int16 SAT16(opus_int32 x) {
+   return x > 32767 ? 32767 : x < -32768 ? -32768 : (opus_int16)x;
+}
+#endif
+
+
+int opus_decoder_get_size(int channels)
+{
+   int silkDecSizeBytes, celtDecSizeBytes;
+   int ret;
+   if (channels<1 || channels > 2)
+      return 0;
+   ret = silk_Get_Decoder_Size( &silkDecSizeBytes );
+   if(ret)
+      return 0;
+   silkDecSizeBytes = align(silkDecSizeBytes);
+   celtDecSizeBytes = celt_decoder_get_size(channels);
+   return align(sizeof(OpusDecoder))+silkDecSizeBytes+celtDecSizeBytes;
+}
+
+int opus_decoder_init(OpusDecoder *st, opus_int32 Fs, int channels)
+{
+   void *silk_dec;
+   CELTDecoder *celt_dec;
+   int ret, silkDecSizeBytes;
+
+   if ((Fs!=48000&&Fs!=24000&&Fs!=16000&&Fs!=12000&&Fs!=8000)
+    || (channels!=1&&channels!=2))
+      return OPUS_BAD_ARG;
+
+   OPUS_CLEAR((char*)st, opus_decoder_get_size(channels));
+   /* Initialize SILK encoder */
+   ret = silk_Get_Decoder_Size(&silkDecSizeBytes);
+   if (ret)
+      return OPUS_INTERNAL_ERROR;
+
+   silkDecSizeBytes = align(silkDecSizeBytes);
+   st->silk_dec_offset = align(sizeof(OpusDecoder));
+   st->celt_dec_offset = st->silk_dec_offset+silkDecSizeBytes;
+   silk_dec = (char*)st+st->silk_dec_offset;
+   celt_dec = (CELTDecoder*)((char*)st+st->celt_dec_offset);
+   st->stream_channels = st->channels = channels;
+
+   st->Fs = Fs;
+   st->DecControl.API_sampleRate = st->Fs;
+   st->DecControl.nChannelsAPI      = st->channels;
+
+   /* Reset decoder */
+   ret = silk_InitDecoder( silk_dec );
+   if(ret)return OPUS_INTERNAL_ERROR;
+
+   /* Initialize CELT decoder */
+   ret = celt_decoder_init(celt_dec, Fs, channels);
+   if(ret!=OPUS_OK)return OPUS_INTERNAL_ERROR;
+
+   celt_decoder_ctl(celt_dec, CELT_SET_SIGNALLING(0));
+
+   st->prev_mode = 0;
+   st->frame_size = Fs/400;
+   return OPUS_OK;
+}
+
+OpusDecoder *opus_decoder_create(opus_int32 Fs, int channels, int *error)
+{
+   int ret;
+   OpusDecoder *st;
+   if ((Fs!=48000&&Fs!=24000&&Fs!=16000&&Fs!=12000&&Fs!=8000)
+    || (channels!=1&&channels!=2))
+   {
+      if (error)
+         *error = OPUS_BAD_ARG;
+      return NULL;
+   }
+   st = (OpusDecoder *)opus_alloc(opus_decoder_get_size(channels));
+   if (st == NULL)
+   {
+      if (error)
+         *error = OPUS_ALLOC_FAIL;
+      return NULL;
+   }
+   ret = opus_decoder_init(st, Fs, channels);
+   if (error)
+      *error = ret;
+   if (ret != OPUS_OK)
+   {
+      opus_free(st);
+      st = NULL;
+   }
+   return st;
+}
+
+static void smooth_fade(const opus_val16 *in1, const opus_val16 *in2,
+      opus_val16 *out, int overlap, int channels,
+      const opus_val16 *window, opus_int32 Fs)
+{
+   int i, c;
+   int inc = 48000/Fs;
+   for (c=0;c<channels;c++)
+   {
+      for (i=0;i<overlap;i++)
+      {
+         opus_val16 w = MULT16_16_Q15(window[i*inc], window[i*inc]);
+         out[i*channels+c] = SHR32(MAC16_16(MULT16_16(w,in2[i*channels+c]),
+                                   Q15ONE-w, in1[i*channels+c]), 15);
+      }
+   }
+}
+
+static int opus_packet_get_mode(const unsigned char *data)
+{
+   int mode;
+   if (data[0]&0x80)
+   {
+      mode = MODE_CELT_ONLY;
+   } else if ((data[0]&0x60) == 0x60)
+   {
+      mode = MODE_HYBRID;
+   } else {
+      mode = MODE_SILK_ONLY;
+   }
+   return mode;
+}
+
+static int opus_decode_frame(OpusDecoder *st, const unsigned char *data,
+      opus_int32 len, opus_val16 *pcm, int frame_size, int decode_fec)
+{
+   void *silk_dec;
+   CELTDecoder *celt_dec;
+   int i, silk_ret=0, celt_ret=0;
+   ec_dec dec;
+   opus_int32 silk_frame_size;
+   VARDECL(opus_int16, pcm_silk);
+   VARDECL(opus_val16, pcm_transition);
+   VARDECL(opus_val16, redundant_audio);
+
+   int audiosize;
+   int mode;
+   int transition=0;
+   int start_band;
+   int redundancy=0;
+   int redundancy_bytes = 0;
+   int celt_to_silk=0;
+   int c;
+   int F2_5, F5, F10, F20;
+   const opus_val16 *window;
+   opus_uint32 redundant_rng = 0;
+   ALLOC_STACK;
+
+   silk_dec = (char*)st+st->silk_dec_offset;
+   celt_dec = (CELTDecoder*)((char*)st+st->celt_dec_offset);
+   F20 = st->Fs/50;
+   F10 = F20>>1;
+   F5 = F10>>1;
+   F2_5 = F5>>1;
+   if (frame_size < F2_5)
+   {
+      RESTORE_STACK;
+      return OPUS_BUFFER_TOO_SMALL;
+   }
+   /* Payloads of 1 (2 including ToC) or 0 trigger the PLC/DTX */
+   if (len<=1)
+   {
+      data = NULL;
+      /* In that case, don't conceal more than what the ToC says */
+      frame_size = IMIN(frame_size, st->frame_size);
+   }
+   if (data != NULL)
+   {
+      audiosize = st->frame_size;
+      mode = st->mode;
+      ec_dec_init(&dec,(unsigned char*)data,len);
+   } else {
+      audiosize = frame_size;
+
+      if (st->prev_mode == 0)
+      {
+         /* If we haven't got any packet yet, all we can do is return zeros */
+         for (i=0;i<audiosize*st->channels;i++)
+            pcm[i] = 0;
+         RESTORE_STACK;
+         return audiosize;
+      } else {
+         mode = st->prev_mode;
+      }
+   }
+
+   /* For CELT/hybrid PLC of more than 20 ms, do multiple calls */
+   if (data==NULL && frame_size > F20 && mode != MODE_SILK_ONLY)
+   {
+      int nb_samples = 0;
+      do {
+         int ret = opus_decode_frame(st, NULL, 0, pcm, F20, 0);
+         if (ret != F20)
+         {
+            RESTORE_STACK;
+            return OPUS_INTERNAL_ERROR;
+         }
+         pcm += F20*st->channels;
+         nb_samples += F20;
+      } while (nb_samples < frame_size);
+      RESTORE_STACK;
+      return frame_size;
+   }
+   ALLOC(pcm_transition, F5*st->channels, opus_val16);
+
+   if (data!=NULL && st->prev_mode > 0 && (
+       (mode == MODE_CELT_ONLY && st->prev_mode != MODE_CELT_ONLY && !st->prev_redundancy)
+    || (mode != MODE_CELT_ONLY && st->prev_mode == MODE_CELT_ONLY) )
+      )
+   {
+      transition = 1;
+      if (mode == MODE_CELT_ONLY)
+         opus_decode_frame(st, NULL, 0, pcm_transition, IMIN(F5, audiosize), 0);
+   }
+   if (audiosize > frame_size)
+   {
+      /*fprintf(stderr, "PCM buffer too small: %d vs %d (mode = %d)\n", audiosize, frame_size, mode);*/
+      RESTORE_STACK;
+      return OPUS_BAD_ARG;
+   } else {
+      frame_size = audiosize;
+   }
+
+   ALLOC(pcm_silk, IMAX(F10, frame_size)*st->channels, opus_int16);
+   ALLOC(redundant_audio, F5*st->channels, opus_val16);
+
+   /* SILK processing */
+   if (mode != MODE_CELT_ONLY)
+   {
+      int lost_flag, decoded_samples;
+      opus_int16 *pcm_ptr = pcm_silk;
+
+      if (st->prev_mode==MODE_CELT_ONLY)
+         silk_InitDecoder( silk_dec );
+
+      /* The SILK PLC cannot produce frames of less than 10 ms */
+      st->DecControl.payloadSize_ms = IMAX(10, 1000 * audiosize / st->Fs);
+
+      if (data != NULL)
+      {
+        st->DecControl.nChannelsInternal = st->stream_channels;
+        if( mode == MODE_SILK_ONLY ) {
+           if( st->bandwidth == OPUS_BANDWIDTH_NARROWBAND ) {
+              st->DecControl.internalSampleRate = 8000;
+           } else if( st->bandwidth == OPUS_BANDWIDTH_MEDIUMBAND ) {
+              st->DecControl.internalSampleRate = 12000;
+           } else if( st->bandwidth == OPUS_BANDWIDTH_WIDEBAND ) {
+              st->DecControl.internalSampleRate = 16000;
+           } else {
+              st->DecControl.internalSampleRate = 16000;
+              silk_assert( 0 );
+           }
+        } else {
+           /* Hybrid mode */
+           st->DecControl.internalSampleRate = 16000;
+        }
+     }
+
+     lost_flag = data == NULL ? 1 : 2 * decode_fec;
+     decoded_samples = 0;
+     do {
+        /* Call SILK decoder */
+        int first_frame = decoded_samples == 0;
+        silk_ret = silk_Decode( silk_dec, &st->DecControl,
+                                lost_flag, first_frame, &dec, pcm_ptr, &silk_frame_size );
+        if( silk_ret ) {
+           if (lost_flag) {
+              /* PLC failure should not be fatal */
+              silk_frame_size = frame_size;
+              for (i=0;i<frame_size*st->channels;i++)
+                 pcm_ptr[i] = 0;
+           } else {
+             RESTORE_STACK;
+             return OPUS_INVALID_PACKET;
+           }
+        }
+        pcm_ptr += silk_frame_size * st->channels;
+        decoded_samples += silk_frame_size;
+      } while( decoded_samples < frame_size );
+   }
+
+   start_band = 0;
+   if (!decode_fec && mode != MODE_CELT_ONLY && data != NULL
+    && ec_tell(&dec)+17+20*(st->mode == MODE_HYBRID) <= 8*len)
+   {
+      /* Check if we have a redundant 0-8 kHz band */
+      if (mode == MODE_HYBRID)
+         redundancy = ec_dec_bit_logp(&dec, 12);
+      else
+         redundancy = 1;
+      if (redundancy)
+      {
+         celt_to_silk = ec_dec_bit_logp(&dec, 1);
+         /* redundancy_bytes will be at least two, in the non-hybrid
+            case due to the ec_tell() check above */
+         redundancy_bytes = mode==MODE_HYBRID ?
+               (opus_int32)ec_dec_uint(&dec, 256)+2 :
+               len-((ec_tell(&dec)+7)>>3);
+         len -= redundancy_bytes;
+         /* This is a sanity check. It should never happen for a valid
+            packet, so the exact behaviour is not normative. */
+         if (len*8 < ec_tell(&dec))
+         {
+            len = 0;
+            redundancy_bytes = 0;
+            redundancy = 0;
+         }
+         /* Shrink decoder because of raw bits */
+         dec.storage -= redundancy_bytes;
+      }
+   }
+   if (mode != MODE_CELT_ONLY)
+      start_band = 17;
+
+   {
+      int endband=21;
+
+      switch(st->bandwidth)
+      {
+      case OPUS_BANDWIDTH_NARROWBAND:
+         endband = 13;
+         break;
+      case OPUS_BANDWIDTH_MEDIUMBAND:
+      case OPUS_BANDWIDTH_WIDEBAND:
+         endband = 17;
+         break;
+      case OPUS_BANDWIDTH_SUPERWIDEBAND:
+         endband = 19;
+         break;
+      case OPUS_BANDWIDTH_FULLBAND:
+         endband = 21;
+         break;
+      }
+      celt_decoder_ctl(celt_dec, CELT_SET_END_BAND(endband));
+      celt_decoder_ctl(celt_dec, CELT_SET_CHANNELS(st->stream_channels));
+   }
+
+   if (redundancy)
+      transition = 0;
+
+   if (transition && mode != MODE_CELT_ONLY)
+      opus_decode_frame(st, NULL, 0, pcm_transition, IMIN(F5, audiosize), 0);
+
+   /* 5 ms redundant frame for CELT->SILK*/
+   if (redundancy && celt_to_silk)
+   {
+      celt_decoder_ctl(celt_dec, CELT_SET_START_BAND(0));
+      celt_decode_with_ec(celt_dec, data+len, redundancy_bytes,
+                          redundant_audio, F5, NULL);
+      celt_decoder_ctl(celt_dec, OPUS_GET_FINAL_RANGE(&redundant_rng));
+   }
+
+   /* MUST be after PLC */
+   celt_decoder_ctl(celt_dec, CELT_SET_START_BAND(start_band));
+
+   if (mode != MODE_SILK_ONLY)
+   {
+      int celt_frame_size = IMIN(F20, frame_size);
+      /* Make sure to discard any previous CELT state */
+      if (mode != st->prev_mode && st->prev_mode > 0 && !st->prev_redundancy)
+         celt_decoder_ctl(celt_dec, OPUS_RESET_STATE);
+      /* Decode CELT */
+      celt_ret = celt_decode_with_ec(celt_dec, decode_fec ? NULL : data,
+                                     len, pcm, celt_frame_size, &dec);
+   } else {
+      unsigned char silence[2] = {0xFF, 0xFF};
+      for (i=0;i<frame_size*st->channels;i++)
+         pcm[i] = 0;
+      /* For hybrid -> SILK transitions, we let the CELT MDCT
+         do a fade-out by decoding a silence frame */
+      if (st->prev_mode == MODE_HYBRID && !(redundancy && celt_to_silk && st->prev_redundancy) )
+      {
+         celt_decoder_ctl(celt_dec, CELT_SET_START_BAND(0));
+         celt_decode_with_ec(celt_dec, silence, 2, pcm, F2_5, NULL);
+      }
+   }
+
+   if (mode != MODE_CELT_ONLY)
+   {
+#ifdef FIXED_POINT
+      for (i=0;i<frame_size*st->channels;i++)
+         pcm[i] = SAT16(pcm[i] + pcm_silk[i]);
+#else
+      for (i=0;i<frame_size*st->channels;i++)
+         pcm[i] = pcm[i] + (opus_val16)((1.f/32768.f)*pcm_silk[i]);
+#endif
+   }
+
+   {
+      const CELTMode *celt_mode;
+      celt_decoder_ctl(celt_dec, CELT_GET_MODE(&celt_mode));
+      window = celt_mode->window;
+   }
+
+   /* 5 ms redundant frame for SILK->CELT */
+   if (redundancy && !celt_to_silk)
+   {
+      celt_decoder_ctl(celt_dec, OPUS_RESET_STATE);
+      celt_decoder_ctl(celt_dec, CELT_SET_START_BAND(0));
+
+      celt_decode_with_ec(celt_dec, data+len, redundancy_bytes, redundant_audio, F5, NULL);
+      celt_decoder_ctl(celt_dec, OPUS_GET_FINAL_RANGE(&redundant_rng));
+      smooth_fade(pcm+st->channels*(frame_size-F2_5), redundant_audio+st->channels*F2_5,
+                  pcm+st->channels*(frame_size-F2_5), F2_5, st->channels, window, st->Fs);
+   }
+   if (redundancy && celt_to_silk)
+   {
+      for (c=0;c<st->channels;c++)
+      {
+         for (i=0;i<F2_5;i++)
+            pcm[st->channels*i+c] = redundant_audio[st->channels*i+c];
+      }
+      smooth_fade(redundant_audio+st->channels*F2_5, pcm+st->channels*F2_5,
+                  pcm+st->channels*F2_5, F2_5, st->channels, window, st->Fs);
+   }
+   if (transition)
+   {
+      if (audiosize >= F5)
+      {
+         for (i=0;i<st->channels*F2_5;i++)
+            pcm[i] = pcm_transition[i];
+         smooth_fade(pcm_transition+st->channels*F2_5, pcm+st->channels*F2_5,
+                     pcm+st->channels*F2_5, F2_5,
+                     st->channels, window, st->Fs);
+      } else {
+         /* Not enough time to do a clean transition, but we do it anyway
+            This will not preserve amplitude perfectly and may introduce
+            a bit of temporal aliasing, but it shouldn't be too bad and
+            that's pretty much the best we can do. In any case, generating this
+            transition it pretty silly in the first place */
+         smooth_fade(pcm_transition, pcm,
+                     pcm, F2_5,
+                     st->channels, window, st->Fs);
+      }
+   }
+
+   if(st->decode_gain)
+   {
+      opus_val32 gain;
+      gain = celt_exp2(MULT16_16_P15(QCONST16(6.48814081e-4f, 25), st->decode_gain));
+      for (i=0;i<frame_size*st->channels;i++)
+      {
+         opus_val32 x;
+         x = MULT16_32_P16(pcm[i],gain);
+         pcm[i] = SATURATE(x, 32767);
+      }
+   }
+
+   if (len <= 1)
+      st->rangeFinal = 0;
+   else
+      st->rangeFinal = dec.rng ^ redundant_rng;
+
+   st->prev_mode = mode;
+   st->prev_redundancy = redundancy && !celt_to_silk;
+   RESTORE_STACK;
+   return celt_ret < 0 ? celt_ret : audiosize;
+
+}
+
+static int parse_size(const unsigned char *data, opus_int32 len, short *size)
+{
+   if (len<1)
+   {
+      *size = -1;
+      return -1;
+   } else if (data[0]<252)
+   {
+      *size = data[0];
+      return 1;
+   } else if (len<2)
+   {
+      *size = -1;
+      return -1;
+   } else {
+      *size = 4*data[1] + data[0];
+      return 2;
+   }
+}
+
+static int opus_packet_parse_impl(const unsigned char *data, opus_int32 len,
+      int self_delimited, unsigned char *out_toc,
+      const unsigned char *frames[48], short size[48], int *payload_offset)
+{
+   int i, bytes;
+   int count;
+   int cbr;
+   unsigned char ch, toc;
+   int framesize;
+   int last_size;
+   const unsigned char *data0 = data;
+
+   if (size==NULL)
+      return OPUS_BAD_ARG;
+
+   framesize = opus_packet_get_samples_per_frame(data, 48000);
+
+   cbr = 0;
+   toc = *data++;
+   len--;
+   last_size = len;
+   switch (toc&0x3)
+   {
+   /* One frame */
+   case 0:
+      count=1;
+      break;
+   /* Two CBR frames */
+   case 1:
+      count=2;
+      cbr = 1;
+      if (!self_delimited)
+      {
+         if (len&0x1)
+            return OPUS_INVALID_PACKET;
+         size[0] = last_size = len/2;
+      }
+      break;
+   /* Two VBR frames */
+   case 2:
+      count = 2;
+      bytes = parse_size(data, len, size);
+      len -= bytes;
+      if (size[0]<0 || size[0] > len)
+         return OPUS_INVALID_PACKET;
+      data += bytes;
+      last_size = len-size[0];
+      break;
+   /* Multiple CBR/VBR frames (from 0 to 120 ms) */
+   default: /*case 3:*/
+      if (len<1)
+         return OPUS_INVALID_PACKET;
+      /* Number of frames encoded in bits 0 to 5 */
+      ch = *data++;
+      count = ch&0x3F;
+      if (count <= 0 || framesize*count > 5760)
+         return OPUS_INVALID_PACKET;
+      len--;
+      /* Padding flag is bit 6 */
+      if (ch&0x40)
+      {
+         int padding=0;
+         int p;
+         do {
+            if (len<=0)
+               return OPUS_INVALID_PACKET;
+            p = *data++;
+            len--;
+            padding += p==255 ? 254: p;
+         } while (p==255);
+         len -= padding;
+      }
+      if (len<0)
+         return OPUS_INVALID_PACKET;
+      /* VBR flag is bit 7 */
+      cbr = !(ch&0x80);
+      if (!cbr)
+      {
+         /* VBR case */
+         last_size = len;
+         for (i=0;i<count-1;i++)
+         {
+            bytes = parse_size(data, len, size+i);
+            len -= bytes;
+            if (size[i]<0 || size[i] > len)
+               return OPUS_INVALID_PACKET;
+            data += bytes;
+            last_size -= bytes+size[i];
+         }
+         if (last_size<0)
+            return OPUS_INVALID_PACKET;
+      } else if (!self_delimited)
+      {
+         /* CBR case */
+         last_size = len/count;
+         if (last_size*count!=len)
+            return OPUS_INVALID_PACKET;
+         for (i=0;i<count-1;i++)
+            size[i] = last_size;
+      }
+      break;
+   }
+   /* Self-delimited framing has an extra size for the last frame. */
+   if (self_delimited)
+   {
+      bytes = parse_size(data, len, size+count-1);
+      len -= bytes;
+      if (size[count-1]<0 || size[count-1] > len)
+         return OPUS_INVALID_PACKET;
+      data += bytes;
+      /* For CBR packets, apply the size to all the frames. */
+      if (cbr)
+      {
+         if (size[count-1]*count > len)
+            return OPUS_INVALID_PACKET;
+         for (i=0;i<count-1;i++)
+            size[i] = size[count-1];
+      } else if(size[count-1] > last_size)
+         return OPUS_INVALID_PACKET;
+   } else
+   {
+      /* Because it's not encoded explicitly, it's possible the size of the
+         last packet (or all the packets, for the CBR case) is larger than
+         1275. Reject them here.*/
+      if (last_size > 1275)
+         return OPUS_INVALID_PACKET;
+      size[count-1] = last_size;
+   }
+
+   if (frames)
+   {
+      for (i=0;i<count;i++)
+      {
+         frames[i] = data;
+         data += size[i];
+      }
+   }
+
+   if (out_toc)
+      *out_toc = toc;
+
+   if (payload_offset)
+      *payload_offset = data-data0;
+
+   return count;
+}
+
+int opus_packet_parse(const unsigned char *data, opus_int32 len,
+      unsigned char *out_toc, const unsigned char *frames[48],
+      short size[48], int *payload_offset)
+{
+   return opus_packet_parse_impl(data, len, 0, out_toc,
+                                 frames, size, payload_offset);
+}
+
+int opus_decode_native(OpusDecoder *st, const unsigned char *data,
+      opus_int32 len, opus_val16 *pcm, int frame_size, int decode_fec,
+      int self_delimited, int *packet_offset)
+{
+   int i, nb_samples;
+   int count, offset;
+   unsigned char toc;
+   int tot_offset;
+   /* 48 x 2.5 ms = 120 ms */
+   short size[48];
+   if (decode_fec<0 || decode_fec>1)
+      return OPUS_BAD_ARG;
+   if (len==0 || data==NULL)
+      return opus_decode_frame(st, NULL, 0, pcm, frame_size, 0);
+   else if (len<0)
+      return OPUS_BAD_ARG;
+
+   tot_offset = 0;
+   st->mode = opus_packet_get_mode(data);
+   st->bandwidth = opus_packet_get_bandwidth(data);
+   st->frame_size = opus_packet_get_samples_per_frame(data, st->Fs);
+   st->stream_channels = opus_packet_get_nb_channels(data);
+
+   count = opus_packet_parse_impl(data, len, self_delimited, &toc, NULL, size, &offset);
+   if (count < 0)
+      return count;
+
+   data += offset;
+   tot_offset += offset;
+
+   if (count*st->frame_size > frame_size)
+      return OPUS_BUFFER_TOO_SMALL;
+   nb_samples=0;
+   for (i=0;i<count;i++)
+   {
+      int ret;
+      ret = opus_decode_frame(st, data, size[i], pcm, frame_size-nb_samples, decode_fec);
+      if (ret<0)
+         return ret;
+      data += size[i];
+      tot_offset += size[i];
+      pcm += ret*st->channels;
+      nb_samples += ret;
+   }
+   if (packet_offset != NULL)
+      *packet_offset = tot_offset;
+   return nb_samples;
+}
+
+#ifdef FIXED_POINT
+
+int opus_decode(OpusDecoder *st, const unsigned char *data,
+      opus_int32 len, opus_val16 *pcm, int frame_size, int decode_fec)
+{
+   return opus_decode_native(st, data, len, pcm, frame_size, decode_fec, 0, NULL);
+}
+
+#ifndef DISABLE_FLOAT_API
+int opus_decode_float(OpusDecoder *st, const unsigned char *data,
+      opus_int32 len, float *pcm, int frame_size, int decode_fec)
+{
+   VARDECL(opus_int16, out);
+   int ret, i;
+   ALLOC_STACK;
+
+   ALLOC(out, frame_size*st->channels, opus_int16);
+
+   ret = opus_decode_native(st, data, len, out, frame_size, decode_fec, 0, NULL);
+   if (ret > 0)
+   {
+      for (i=0;i<ret*st->channels;i++)
+         pcm[i] = (1.f/32768.f)*(out[i]);
+   }
+   RESTORE_STACK;
+   return ret;
+}
+#endif
+
+
+#else
+int opus_decode(OpusDecoder *st, const unsigned char *data,
+      opus_int32 len, opus_int16 *pcm, int frame_size, int decode_fec)
+{
+   VARDECL(float, out);
+   int ret, i;
+   ALLOC_STACK;
+
+   if(frame_size<0)
+   {
+      RESTORE_STACK;
+      return OPUS_BAD_ARG;
+   }
+
+   ALLOC(out, frame_size*st->channels, float);
+
+   ret = opus_decode_native(st, data, len, out, frame_size, decode_fec, 0, NULL);
+   if (ret > 0)
+   {
+      for (i=0;i<ret*st->channels;i++)
+         pcm[i] = FLOAT2INT16(out[i]);
+   }
+   RESTORE_STACK;
+   return ret;
+}
+
+int opus_decode_float(OpusDecoder *st, const unsigned char *data,
+      opus_int32 len, opus_val16 *pcm, int frame_size, int decode_fec)
+{
+   return opus_decode_native(st, data, len, pcm, frame_size, decode_fec, 0, NULL);
+}
+
+#endif
+
+int opus_decoder_ctl(OpusDecoder *st, int request, ...)
+{
+   int ret = OPUS_OK;
+   va_list ap;
+   void *silk_dec;
+   CELTDecoder *celt_dec;
+
+   silk_dec = (char*)st+st->silk_dec_offset;
+   celt_dec = (CELTDecoder*)((char*)st+st->celt_dec_offset);
+
+
+   va_start(ap, request);
+
+   switch (request)
+   {
+   case OPUS_GET_BANDWIDTH_REQUEST:
+   {
+      opus_int32 *value = va_arg(ap, opus_int32*);
+      *value = st->bandwidth;
+   }
+   break;
+   case OPUS_GET_FINAL_RANGE_REQUEST:
+   {
+      opus_uint32 *value = va_arg(ap, opus_uint32*);
+      *value = st->rangeFinal;
+   }
+   break;
+   case OPUS_RESET_STATE:
+   {
+      OPUS_CLEAR((char*)&st->OPUS_DECODER_RESET_START,
+            sizeof(OpusDecoder)-
+            ((char*)&st->OPUS_DECODER_RESET_START - (char*)st));
+
+      celt_decoder_ctl(celt_dec, OPUS_RESET_STATE);
+      silk_InitDecoder( silk_dec );
+      st->stream_channels = st->channels;
+      st->frame_size = st->Fs/400;
+   }
+   break;
+   case OPUS_GET_PITCH_REQUEST:
+   {
+      opus_int32 *value = va_arg(ap, opus_int32*);
+      if (value==NULL)
+      {
+         ret = OPUS_BAD_ARG;
+         break;
+      }
+      if (st->prev_mode == MODE_CELT_ONLY)
+         celt_decoder_ctl(celt_dec, OPUS_GET_PITCH(value));
+      else
+         *value = st->DecControl.prevPitchLag;
+   }
+   break;
+   case OPUS_GET_GAIN_REQUEST:
+   {
+      opus_int32 *value = va_arg(ap, opus_int32*);
+      if (value==NULL)
+      {
+         ret = OPUS_BAD_ARG;
+         break;
+      }
+      *value = st->decode_gain;
+   }
+   break;
+   case OPUS_SET_GAIN_REQUEST:
+   {
+       opus_int32 value = va_arg(ap, opus_int32);
+       if (value<-32768 || value>32767)
+       {
+          ret = OPUS_BAD_ARG;
+          break;
+       }
+       st->decode_gain = value;
+   }
+   break;
+   default:
+      /*fprintf(stderr, "unknown opus_decoder_ctl() request: %d", request);*/
+      ret = OPUS_UNIMPLEMENTED;
+      break;
+   }
+
+   va_end(ap);
+   return ret;
+}
+
+void opus_decoder_destroy(OpusDecoder *st)
+{
+   opus_free(st);
+}
+
+
+int opus_packet_get_bandwidth(const unsigned char *data)
+{
+   int bandwidth;
+   if (data[0]&0x80)
+   {
+      bandwidth = OPUS_BANDWIDTH_MEDIUMBAND + ((data[0]>>5)&0x3);
+      if (bandwidth == OPUS_BANDWIDTH_MEDIUMBAND)
+         bandwidth = OPUS_BANDWIDTH_NARROWBAND;
+   } else if ((data[0]&0x60) == 0x60)
+   {
+      bandwidth = (data[0]&0x10) ? OPUS_BANDWIDTH_FULLBAND :
+                                   OPUS_BANDWIDTH_SUPERWIDEBAND;
+   } else {
+      bandwidth = OPUS_BANDWIDTH_NARROWBAND + ((data[0]>>5)&0x3);
+   }
+   return bandwidth;
+}
+
+int opus_packet_get_samples_per_frame(const unsigned char *data,
+      opus_int32 Fs)
+{
+   int audiosize;
+   if (data[0]&0x80)
+   {
+      audiosize = ((data[0]>>3)&0x3);
+      audiosize = (Fs<<audiosize)/400;
+   } else if ((data[0]&0x60) == 0x60)
+   {
+      audiosize = (data[0]&0x08) ? Fs/50 : Fs/100;
+   } else {
+      audiosize = ((data[0]>>3)&0x3);
+      if (audiosize == 3)
+         audiosize = Fs*60/1000;
+      else
+         audiosize = (Fs<<audiosize)/100;
+   }
+   return audiosize;
+}
+
+int opus_packet_get_nb_channels(const unsigned char *data)
+{
+   return (data[0]&0x4) ? 2 : 1;
+}
+
+int opus_packet_get_nb_frames(const unsigned char packet[], opus_int32 len)
+{
+   int count;
+   if (len<1)
+      return OPUS_BAD_ARG;
+   count = packet[0]&0x3;
+   if (count==0)
+      return 1;
+   else if (count!=3)
+      return 2;
+   else if (len<2)
+      return OPUS_INVALID_PACKET;
+   else
+      return packet[1]&0x3F;
+}
+
+int opus_decoder_get_nb_samples(const OpusDecoder *dec,
+      const unsigned char packet[], opus_int32 len)
+{
+   int samples;
+   int count = opus_packet_get_nb_frames(packet, len);
+
+   if (count<0)
+      return count;
+
+   samples = count*opus_packet_get_samples_per_frame(packet, dec->Fs);
+   /* Can't have more than 120 ms */
+   if (samples*25 > dec->Fs*3)
+      return OPUS_INVALID_PACKET;
+   else
+      return samples;
+}