generic-library/ffmpeg
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

flac: allow reading of full metadata headers from extradata

Browse Source 
Originally committed as revision 7161 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Aurelien Jacobs 2006-11-23 22:22:03 +00:00
parent 3e954443dd
commit 17c90b9d62
1 changed files with 56 additions and 47 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

103
libavcodec/flac.c
View File

@ -95,18 +95,23 @@ static int64_t get_utf8(GetBitContext *gb){
}
static void metadata_streaminfo(FLACContext *s);
static void dump_headers(FLACContext *s);
static void allocate_buffers(FLACContext *s);
static int metadata_parse(FLACContext *s);
static int flac_decode_init(AVCodecContext * avctx)
{
FLACContext *s = avctx->priv_data;
s->avctx = avctx;
/* initialize based on the demuxer-supplied streamdata header */
if (avctx->extradata_size == FLAC_STREAMINFO_SIZE) {
if (avctx->extradata_size > 4) {
/* initialize based on the demuxer-supplied streamdata header */
init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size*8);
metadata_streaminfo(s);
dump_headers(s);
if (avctx->extradata_size == FLAC_STREAMINFO_SIZE) {
metadata_streaminfo(s);
allocate_buffers(s);
} else {
metadata_parse(s);
}
}
return 0;
@ -159,7 +164,51 @@ static void metadata_streaminfo(FLACContext *s)
skip_bits(&s->gb, 64); /* md5 sum */
skip_bits(&s->gb, 64); /* md5 sum */
allocate_buffers(s);
dump_headers(s);
}
/**
* Parse a list of metadata blocks. This list of blocks must begin with
* the fLaC marker.
* @param s the flac decoding context containing the gb bit reader used to
* parse metadata
* @return 1 if some metadata was read, 0 if no fLaC marker was found
*/
static int metadata_parse(FLACContext *s)
{
int i, metadata_last, metadata_type, metadata_size, streaminfo_updated=0;
if (show_bits_long(&s->gb, 32) == MKBETAG('f','L','a','C')) {
skip_bits(&s->gb, 32);
av_log(s->avctx, AV_LOG_DEBUG, "STREAM HEADER\n");
do {
metadata_last = get_bits(&s->gb, 1);
metadata_type = get_bits(&s->gb, 7);
metadata_size = get_bits_long(&s->gb, 24);
av_log(s->avctx, AV_LOG_DEBUG,
" metadata block: flag = %d, type = %d, size = %d\n",
metadata_last, metadata_type, metadata_size);
if (metadata_size) {
switch (metadata_type) {
case METADATA_TYPE_STREAMINFO:
metadata_streaminfo(s);
streaminfo_updated = 1;
break;
default:
for (i=0; i<metadata_size; i++)
skip_bits(&s->gb, 8);
}
}
} while (!metadata_last);
if (streaminfo_updated)
allocate_buffers(s);
return 1;
}
return 0;
}
static int decode_residuals(FLACContext *s, int channel, int pred_order)
@ -528,7 +577,6 @@ static int flac_decode_frame(AVCodecContext *avctx,
uint8_t *buf, int buf_size)
{
FLACContext *s = avctx->priv_data;
int metadata_last, metadata_type, metadata_size;
int tmp = 0, i, j = 0, input_buf_size = 0;
int16_t *samples = data;
@ -559,47 +607,8 @@ static int flac_decode_frame(AVCodecContext *avctx,
init_get_bits(&s->gb, buf, buf_size*8);
/* fLaC signature (be) */
if (show_bits_long(&s->gb, 32) == bswap_32(ff_get_fourcc("fLaC")))
if (!metadata_parse(s))
{
skip_bits(&s->gb, 32);
av_log(s->avctx, AV_LOG_DEBUG, "STREAM HEADER\n");
do {
metadata_last = get_bits(&s->gb, 1);
metadata_type = get_bits(&s->gb, 7);
metadata_size = get_bits_long(&s->gb, 24);
av_log(s->avctx, AV_LOG_DEBUG, " metadata block: flag = %d, type = %d, size = %d\n",
metadata_last, metadata_type,
metadata_size);
if(metadata_size){
switch(metadata_type)
{
case METADATA_TYPE_STREAMINFO:{
metadata_streaminfo(s);
/* Buffer might have been reallocated, reinit bitreader */
if(buf != &s->bitstream[s->bitstream_index])
{
int bits_count = get_bits_count(&s->gb);
buf= &s->bitstream[s->bitstream_index];
init_get_bits(&s->gb, buf, buf_size*8);
skip_bits(&s->gb, bits_count);
}
dump_headers(s);
break;}
default:
for(i=0; i<metadata_size; i++)
skip_bits(&s->gb, 8);
}
}
} while(!metadata_last);
}
else
{
tmp = show_bits(&s->gb, 16);
if(tmp != 0xFFF8){
av_log(s->avctx, AV_LOG_ERROR, "FRAME HEADER not here\n");