diff options
| author | Michael Niedermayer <michaelni@gmx.at> | 2009-09-14 21:29:19 +0000 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2009-09-14 21:29:19 +0000 |
| commit | 89c4e176f6b22ddfadaea2ff698a7c479ede474e (patch) | |
| tree | b8817cc37b85f922f85cae91320ac1e4defcbd60 /libavformat/raw.c | |
| parent | 05bdd33a128dea4cea31d8b77072901f29e9ffff (diff) | |
Rewrite h261_probe().
New code can detect h261 startcodes even when the first is damaged or not at the
begin. It also passes probetest v2 & v3.
Originally committed as revision 19845 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavformat/raw.c')
| -rw-r--r-- | libavformat/raw.c | 36 |
1 files changed, 29 insertions, 7 deletions
diff --git a/libavformat/raw.c b/libavformat/raw.c index a935ce56cd..a3227cd453 100644 --- a/libavformat/raw.c +++ b/libavformat/raw.c @@ -489,14 +489,36 @@ static int h263_probe(AVProbeData *p) #if CONFIG_H261_DEMUXER static int h261_probe(AVProbeData *p) { - int code; - const uint8_t *d; - - d = p->buf; - code = (d[0] << 12) | (d[1] << 4) | (d[2] >> 4); - if (code == 0x10) { - return 50; + uint32_t code= -1; + int i; + int valid_psc=0; + int invalid_psc=0; + int next_gn=0; + int src_fmt=0; + GetBitContext gb; + + init_get_bits(&gb, p->buf, p->buf_size*8); + + for(i=0; i<p->buf_size*8; i++){ + code = (code<<1) + get_bits1(&gb); + if ((code & 0xffff0000) == 0x10000) { + int gn= (code>>12)&0xf; + if(!gn) + src_fmt= code&8; + if(gn != next_gn) invalid_psc++; + else valid_psc++; + + if(src_fmt){ // CIF + next_gn= (gn+1 )%13; + }else{ //QCIF + next_gn= (gn+1+!!gn)% 7; + } + } } + if(valid_psc > 2*invalid_psc + 4){ + return 50; + }else if(valid_psc > 2*invalid_psc + 2) + return 25; return 0; } #endif |