ref: 4154dad41e1fe1cd86812836c73787ed5be962dd
parent: 5e9f7fc31db7336ce8c5946a4e3edaf4392af097
author: Jean-Marc Valin <[email protected]>
date: Mon Aug 8 07:57:13 EDT 2011
Refactoring the decoder to create opus_packet_parse()
--- a/src/opus.h
+++ b/src/opus.h
@@ -217,6 +217,10 @@
OPUS_EXPORT void opus_decoder_destroy(OpusDecoder *st);
+OPUS_EXPORT int opus_packet_parse(const unsigned char *data, int len,
+ unsigned char *out_toc, const unsigned char *frames[48],
+ short size[48], const unsigned char **payload);
+
OPUS_EXPORT int opus_packet_get_bandwidth(const unsigned char *data);
OPUS_EXPORT int opus_packet_get_samples_per_frame(const unsigned char *data, int Fs);
OPUS_EXPORT int opus_packet_get_nb_channels(const unsigned char *data);
--- a/src/opus_decoder.c
+++ b/src/opus_decoder.c
@@ -412,12 +412,131 @@
}
}
+int opus_packet_parse(const unsigned char *data, int len,
+ unsigned char *out_toc, const unsigned char *frames[48],
+ short size[48], const unsigned char **payload)
+{+ int i, bytes;
+ int count;
+ unsigned char ch, toc;
+ int framesize;
+
+ if (size==NULL)
+ return OPUS_BAD_ARG;
+
+ framesize = opus_packet_get_samples_per_frame(data, 48000);
+
+ toc = *data++;
+ 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;
+ 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_CORRUPTED_DATA;
+ data += bytes;
+ size[1] = len-size[0];
+ break;
+ /* Multiple CBR/VBR frames (from 0 to 120 ms) */
+ case 3:
+ if (len<1)
+ return OPUS_CORRUPTED_DATA;
+ /* Number of frames encoded in bits 0 to 5 */
+ ch = *data++;
+ count = ch&0x3F;
+ if (count <= 0 || framesize*count > 5760)
+ return OPUS_CORRUPTED_DATA;
+ len--;
+ /* Padding flag is bit 6 */
+ if (ch&0x40)
+ {+ int padding=0;
+ int p;
+ do {+ if (len<=0)
+ return OPUS_CORRUPTED_DATA;
+ p = *data++;
+ len--;
+ padding += p==255 ? 254: p;
+ } while (p==255);
+ len -= padding;
+ }
+ if (len<0)
+ return OPUS_CORRUPTED_DATA;
+ /* VBR flag is bit 7 */
+ if (ch&0x80)
+ {+ /* VBR case */
+ int 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_CORRUPTED_DATA;
+ data += bytes;
+ last_size -= bytes+size[i];
+ }
+ if (last_size<0)
+ return OPUS_CORRUPTED_DATA;
+ size[count-1]=last_size;
+ } else {+ /* CBR case */
+ int sz = len/count;
+ if (sz*count!=len)
+ return OPUS_CORRUPTED_DATA;
+ for (i=0;i<count;i++)
+ size[i] = sz;
+ }
+ 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;
+
+ if (frames)
+ {+ for (i=0;i<count;i++)
+ {+ frames[i] = data;
+ data += size[i];
+ }
+ }
+
+ if (out_toc)
+ *out_toc = toc;
+
+ if (payload)
+ *payload = data;
+
+ return count;
+}
+
+
int opus_decode(OpusDecoder *st, const unsigned char *data,
int len, opus_int16 *pcm, int frame_size, int decode_fec)
{- int i, bytes, nb_samples;
+ int i, nb_samples;
int count;
- unsigned char ch, toc;
+ unsigned char toc;
/* 48 x 2.5 ms = 120 ms */
short size[48];
if (len==0 || data==NULL)
@@ -428,91 +547,11 @@
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);
- toc = *data++;
- 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;
- 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_CORRUPTED_DATA;
- data += bytes;
- size[1] = len-size[0];
- break;
- /* Multiple CBR/VBR frames (from 0 to 120 ms) */
- case 3:
- if (len<1)
- return OPUS_CORRUPTED_DATA;
- /* Number of frames encoded in bits 0 to 5 */
- ch = *data++;
- count = ch&0x3F;
- if (count <= 0 || st->frame_size*count*25 > 3*st->Fs)
- return OPUS_CORRUPTED_DATA;
- len--;
- /* Padding flag is bit 6 */
- if (ch&0x40)
- {- int padding=0;
- int p;
- do {- if (len<=0)
- return OPUS_CORRUPTED_DATA;
- p = *data++;
- len--;
- padding += p==255 ? 254: p;
- } while (p==255);
- len -= padding;
- }
- if (len<0)
- return OPUS_CORRUPTED_DATA;
- /* VBR flag is bit 7 */
- if (ch&0x80)
- {- /* VBR case */
- int 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_CORRUPTED_DATA;
- data += bytes;
- last_size -= bytes+size[i];
- }
- if (last_size<0)
- return OPUS_CORRUPTED_DATA;
- size[count-1]=last_size;
- } else {- /* CBR case */
- int sz = len/count;
- if (sz*count!=len)
- return OPUS_CORRUPTED_DATA;
- for (i=0;i<count;i++)
- size[i] = sz;
- }
- 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] > MAX_PACKET)
- return OPUS_CORRUPTED_DATA;
+
+ count = opus_packet_parse(data, len, &toc, NULL, size, &data);
+ if (count < 0)
+ return count;
+
if (count*st->frame_size > frame_size)
return OPUS_BAD_ARG;
nb_samples=0;
@@ -528,6 +567,8 @@
}
return nb_samples;
}
+
+
int opus_decoder_ctl(OpusDecoder *st, int request, ...)
{va_list ap;