[FFmpeg-devel] H.264: passing 2 fields at once to avcodec_decode_video() gives errors

Reinhard Nissl rnissl
Wed Apr 8 22:19:28 CEST 2009


Hi,

Michael Niedermayer schrieb:

>> AFAIK, H.264 still decoder doesn't support handling more than one picture 
>> (field or frame) in one call, 
> 
> yes, and a patch fixing this is welcome

[...]

> move the few lines of code that are executed after the loop&field into it
> under appropriate if()

Please have a look at the attached patch (based on H.264 spec,
7.4.1.2.3). Is this the right way to go?

The patch isn't complete yet (it misses detection of the first
VCL NAL unit of a primary coded picture as a further condition to
 reset same_access_unit, H.264 spec, 7.4.1.2.4), but it works for
the sample I play with (contains AUDs).

In case it is the right way, what's an appropriate location for
implementing 7.4.1.2.4?

I think, decode_slice_header() would be such a location. On the
other hand, an implementation of 7.4.1.2.4 must exist already
anywhere -- where should I look for it?

Bye.
-- 
Dipl.-Inform. (FH) Reinhard Nissl
mailto:rnissl at gmx.de
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