[FFmpeg-devel] does ffmpeg decoder clipps the num_ref_frames to MaxDpbSize when num_ref_frames exeeds MaxDpbSize

Michael Niedermayer michaelni at gmx.at
Fri Apr 27 05:31:15 CEST 2012


On Thu, Apr 26, 2012 at 08:19:47AM +0100, chemsi mehdi wrote:
> 
>  
>  
> Hi All,
>  
> I have a stream which is properly decoded with VLC but the professional tool (Elecard) has raisen many issues

I think VLC is a professional tool too.


>  
> 
> the stream presents an encoding violation that leads to noticed macrobloks at display stage.
>   
> As it is encoded the stream needs 16 reference frame buffers and such number exceeds the MaxDpbSize
>  
> (maximum number of reference frame buffer) which is encoded as 9.
>  
> H264 standards(subclauseA.3.1 or A.3.2) states that The value of reference frame buffer number
>  
> (num_ref_frames)shall be in the range of 0 to MaxDpbSize.
>  
> I knew that VLC player uses fffmpeg to decode H264.  
>  
> does ffmpeg decoder clipps the num_ref_frames to MaxDpbSize when num_ref_frames exeeds MaxDpbSize?

why should ffmpeg do that ?


[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The misfortune of the wise is better than the prosperity of the fool.
-- Epicurus
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: Digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20120427/34bcf54f/attachment.asc>


More information about the ffmpeg-devel mailing list