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Adds code for parsing self-delimited packets

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This commit is contained in:
Timothy B. Terriberry 2011-08-18 23:29:52 -04:00 • committed by Jean-Marc Valin
parent 69549ac05b
commit 7954065c77
1 changed files with 60 additions and 23 deletions
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69
src/opus_decoder.c
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@ -444,14 +444,16 @@ static int parse_size(const unsigned char *data, int len, short *size)
}
}
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 @@ int opus_packet_parse(const unsigned char *data, int len,
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;
cbr = 1;
if (!self_delimited)
{
if (len&0x1)
return OPUS_CORRUPTED_DATA;
size[0] = size[1] = len/2;
size[0] = last_size = len/2;
}
break;
/* Two VBR frames */
case 2:
@ -483,7 +490,7 @@ int opus_packet_parse(const unsigned char *data, int len,
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 @@ int opus_packet_parse(const unsigned char *data, int len,
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 @@ int opus_packet_parse(const unsigned char *data, int len,
}
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;
}
/* 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 (size[count-1] > 1275)
if (last_size > 1275)
return OPUS_CORRUPTED_DATA;
size[count-1] = last_size;
}
if (frames)
{
@ -563,6 +592,14 @@ int opus_packet_parse(const unsigned char *data, int len,
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 @@ int opus_decode_float(OpusDecoder *st, const unsigned char *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(data, len, &toc, NULL, size, &offset);
count = opus_packet_parse_impl(data, len, 0, &toc, NULL, size, &offset);
if (count < 0)
return count;