[Ffmpeg-devel] MPEG4 ISO Compliance (known problems)

[Rahul Kumar]

Hi,
   My apologies for not keeping a detailed record (specially of the
ASP bitstreams). However here are the SP-streams which were
problematic:
1. hit006.m4v
2. hit012.m4v
3. jvc013.m4v
4. mit005.m4v
5. mit025.m4v
6. san014.m4v

(base path: http://standards.iso.org/ittf/PubliclyAvailableStandards/ISO_IEC_14496-4_2004_Conformance_Testing/video_conformance/version_1/simple/)

Of the above the following streams
1. hit012.m4v	(352x288)
2. mit005.m4v	(352x288)
            had skipped frames.
Skipped frames are not handled by:
ff_h263_decode_frame()
{....
    if(ret==FRAME_SKIPED)
        return get_consumed_bytes(s, buf_size);
}

However in case it is handled by top level wrapper then this code is
OK. (FYI: I used a different wrapper to drive libavcodec). Note that
the above "issue(?)" is not included in my earlier bug-report.

Also as far as I remember mit025.m4v had the problem with stuffing
bits and hit006.m4v had problem with un-initialised dc-pred dir
(another problem which I had reported earlier but forgot to include in
my final compilation of errors).

hope this helps

-regards,
rahul


Author: Michael Niedermayer
Date: 2006-05-04 12:28 +100
To: FFMpeg development discussions and patches
Subject: Re: [Ffmpeg-devel] MPEG4 ISO Compliance (known problems)

Hi

On Thu, May 04, 2006 at 11:46:38AM +0100, Rahul Kumar wrote:
> Hi,
> I had used bitstreams from the following links for testing:
>
> Advanced Simple profile
> 1)
> http://standards.iso.org/ittf/PubliclyAvailableStandards/ISO_IEC_14496-4_2004_Conformance_Testing/video_conformance/advanced_simple/
>
> 2)http://standards.iso.org/ittf/PubliclyAvailableStandards/c041935_ISO_IEC_14496-4_2004_Amd_1_2005_Cor_1_2005_Bitstreams.zip
>
> Simple profile
> http://standards.iso.org/ittf/PubliclyAvailableStandards/ISO_IEC_14496-4_2004_Conformance_Testing/video_conformance/version_1/simple/
>
> The ISO decoder can be downloded from:
> http://standards.iso.org/ittf/PubliclyAvailableStandards/c039417_ISO_IEC_14496-5_2001_Amd_4_2004(E)_Reference_Software.zip
>
> hope this helps

thank you, but could you also tell me which specific bitstreams have
problems (and what problem if you know it), otherwise i would have to
compare all against the reference sw which would be redundant work as
apparently you have already done that

[...]

--
Michael

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