[Ffmpeg-devel] [PATCH proposal] MPEG4 video probe v3

[Michael Niedermayer]

Hi

On Tue, Nov 07, 2006 at 12:25:43PM +0100, Thijs Vermeir wrote:
> Hi
> 
> >to repeat my reply to your first patch
> 
> I read it and applied what was necessary
> 
> >it should also search for VOL(0x0000012X) and VO(0x0000010X)
> 
> +            temp_buffer = temp_buffer & 0xfffffff0;
> +            switch(temp_buffer){
> +               case VIDEO_OBJECT_START_CODE:           VO++; break;
> +               case VIDEO_OBJECT_LAYER_START_CODE:     VOL++; break;
> +            }
> +        }
> +    }
> +
> +    if (( VOP >= VISO) && (VOP >= VOL) && (VO >= VOL) && (VOP > 0))
> 
> in the patch it searched for the VOL and VO.
> 
> >and VOP >= VOL && VO >= VOL
> 
> Is checked
> 
> >&& VOL > 0
> 
> Not correct for a probe, This happens not frequently in a random 2k
> buffer. In a test stream it only happens at +/- 16k. And I think this
> is too large for a probe buffer.

encode mpeg4 at high birate you will not find any startcode within 
a megabyte sized buffer furthermore you cannot play a file 
before a VOL correctly so theres no use in guessing its mpeg4 before

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In the past you could go to a library and read, borrow or copy any book
Today you'd get arrested for mere telling someone where the library is