[FFmpeg-cvslog] r10908 - trunk/libavformat/mpeg.c

Måns Rullgård mans
Sat Nov 3 15:29:45 CET 2007


michael <subversion at mplayerhq.hu> writes:

> Author: michael
> Date: Sat Nov  3 14:48:30 2007
> New Revision: 10908
>
> Log:
> fix misdetection of mp3could_not_find_codec_parameters.mp3
>
> Modified:
>    trunk/libavformat/mpeg.c
>
> Modified: trunk/libavformat/mpeg.c
> ==============================================================================
> --- trunk/libavformat/mpeg.c	(original)
> +++ trunk/libavformat/mpeg.c	Sat Nov  3 14:48:30 2007
> @@ -44,6 +44,26 @@ static int cdxa_probe(AVProbeData *p)
>          return 0;
>  }
>
> +static int check_pes(uint8_t *p, uint8_t *end){
> +    int pes1;
> +    int pes2=      (p[3] & 0xC0) == 0x80
> +                && (p[4] & 0xC0) != 0x40
> +                &&((p[4] & 0xC0) == 0x00 || (p[4]&0xC0)>>2 == (p[6]&0xF0));
> +
> +    for(p+=3; p<end && *p == 0xFF; p++);

What is the purpose of this?  MPEG PS doesn't have unspecified-length
sequences of 0xff bytes.

> +    if((*p&0xC0) == 0x40) p+=2;
> +    if((*p&0xF0) == 0x20){
> +        pes1= p[0]&p[2]&p[4]&1;
> +        p+=5;
> +    }else if((*p&0xF0) == 0x30){
> +        pes1= p[0]&p[2]&p[4]&p[5]&p[7]&p[9]&1;
> +        p+=10;
> +    }else
> +        pes1 = *p == 0x0F;
> +
> +    return pes1||pes2;
> +}
> +
>  static int mpegps_probe(AVProbeData *p)
>  {
>      uint32_t code= -1;
> @@ -58,11 +78,13 @@ static int mpegps_probe(AVProbeData *p)
>      for(i=0; i<p->buf_size; i++){
>          code = (code<<8) + p->buf[i];
>          if ((code & 0xffffff00) == 0x100) {
> +            int pes= check_pes(p->buf+i, p->buf+i+p->buf_size);

Shouldn't that be check_pes(p->buf+i, p->buf+p->buf_size)?

>              if(code == SYSTEM_HEADER_START_CODE) sys++;
>              else if(code == PRIVATE_STREAM_1)    priv1++;
>              else if(code == PACK_START_CODE)     pspack++;
> -            else if((code & 0xf0) == VIDEO_ID)   vid++;
> -            else if((code & 0xe0) == AUDIO_ID)   audio++;
> +            else if((code & 0xf0) == VIDEO_ID && pes) vid++;
> +            else if((code & 0xe0) == AUDIO_ID && pes) audio++;
>          }
>      }
>

-- 
M?ns Rullg?rd
mans at mansr.com




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