smarten up the SVQ3 extradata decoder without changing the external API

Originally committed as revision 2878 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Mike Melanson 2004-03-13 20:07:38 +00:00
parent bda702fc4d
commit 14284f78c5
1 changed files with 12 additions and 4 deletions

View File

@ -766,6 +766,7 @@ static int svq3_decode_frame (AVCodecContext *avctx,
MpegEncContext *const s = avctx->priv_data;
H264Context *const h = avctx->priv_data;
int m, mb_type;
unsigned char *extradata;
*data_size = 0;
@ -790,13 +791,20 @@ static int svq3_decode_frame (AVCodecContext *avctx,
alloc_tables (h);
if (avctx->extradata && avctx->extradata_size >= 0x64
&& !memcmp (avctx->extradata, "SVQ3", 4)) {
/* prowl for the "SEQH" marker in the extradata */
extradata = (unsigned char *)avctx->extradata;
for (m = 0; m < avctx->extradata_size; m++) {
if (!memcmp (extradata, "SEQH", 4))
break;
extradata++;
}
/* if a match was found, parse the extra data */
if (!memcmp (extradata, "SEQH", 4)) {
GetBitContext gb;
init_get_bits (&gb, (uint8_t *) avctx->extradata + 0x62,
8*(avctx->extradata_size - 0x62));
init_get_bits (&gb, extradata + 0x8, 8*8);
/* 'frame size code' and optional 'width, height' */
if (get_bits (&gb, 3) == 7) {