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Adds code for parsing self-delimited packets

--- a/src/opus_decoder.c

+++ b/src/opus_decoder.c

@@ -444,14 +444,16 @@

 	}

 }

-int opus_packet_parse(const unsigned char *data, int len,

-      unsigned char *out_toc, const unsigned char *frames[48],

-      short size[48], int *payload_offset)

+static int opus_packet_parse_impl(const unsigned char *data, int 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)

@@ -459,21 +461,26 @@

    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;

-      size[0] = len;

       break;

       /* Two CBR frames */

    case 1:

       count=2;

-      if (len&0x1)

-         return OPUS_CORRUPTED_DATA;

-      size[0] = size[1] = len/2;

+      cbr = 1;

+      if (!self_delimited)

+      {

+         if (len&0x1)

+            return OPUS_CORRUPTED_DATA;

+         size[0] = last_size = len/2;

+      }

       break;

       /* Two VBR frames */

    case 2:

@@ -483,7 +490,7 @@

       if (size[0]<0 || size[0] > len)

          return OPUS_CORRUPTED_DATA;

       data += bytes;

-      size[1] = len-size[0];

+      last_size = len-size[0];

       break;

       /* Multiple CBR/VBR frames (from 0 to 120 ms) */

    case 3:

@@ -512,10 +519,11 @@

       if (len<0)

          return OPUS_CORRUPTED_DATA;

       /* VBR flag is bit 7 */

-      if (ch&0x80)

+      cbr = !(ch&0x80);

+      if (cbr)

       {

          /* VBR case */

-         int last_size=len;

+         last_size = len;

          for (i=0;i<count-1;i++)

          {

             bytes = parse_size(data, len, size+i);

@@ -527,23 +535,44 @@

          }

          if (last_size<0)

             return OPUS_CORRUPTED_DATA;

-         size[count-1]=last_size;

-      } else {

+      } else if (!self_delimited)

+      {

          /* CBR case */

-         int sz = len/count;

-         if (sz*count!=len)

+         last_size = len/count;

+         if (last_size*count!=len)

             return OPUS_CORRUPTED_DATA;

-         for (i=0;i<count;i++)

-            size[i] = sz;

+         for (i=0;i<count-1;i++)

+            size[i] = last_size;

       }

       break;

    }

-   /* 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 (size[count-1] > 1275)

-      return OPUS_CORRUPTED_DATA;

+   /* 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_CORRUPTED_DATA;

+      data += bytes;

+      /* For CBR packets, apply the size to all the frames. */

+      if (cbr)

+      {

+         if (size[count-1]*count > len)

+            return OPUS_CORRUPTED_DATA;

+         for (i=0;i<count-1;i++)

+            size[i] = size[count-1];

+      } else if(size[count-1] > last_size)

+         return OPUS_CORRUPTED_DATA;

+   } 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_CORRUPTED_DATA;

+      size[count-1] = last_size;

+   }

    if (frames)

    {

@@ -563,6 +592,14 @@

    return count;

 }

+int opus_packet_parse(const unsigned char *data, int 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);

+}

+

 #ifdef FIXED_POINT

 int opus_decode(OpusDecoder *st, const unsigned char *data,

       int len, opus_val16 *pcm, int frame_size, int decode_fec)

@@ -585,7 +622,7 @@

 	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(data, len, &toc, NULL, size, &offset);

+	count = opus_packet_parse_impl(data, len, 0, &toc, NULL, size, &offset);

 	if (count < 0)

 	   return count;