[FFmpeg-devel] DVCPRO HD: request for review

Roman Shaposhnik rvs
Tue Aug 26 01:32:05 CEST 2008


On Fri, 2008-08-22 at 17:15 +0200, Thomas Parmegiani wrote:
> Hi all,
> 
> I tested the patch and it seems to have some errors with 720p files :
> 
> According to smpte370 specifications about frame structure :
> 
> <<In the 1080-line system, video data, audio data, and subcode data in 
> one video frame shall be processed in
> each frame. In the 720-line system, these data in two video frames shall 
> be processed within one frame
> duration of the 1080-line system. >>
> 
> So a 720p "frame" consists of two successive 960x720 "fields" (where 
> each "fields" is at the full 960x720 resolution).
> 
> The given code by Dan Maas seems to only read the first 960x720 picture. 
> the second one is dropped. So if you try to transcode a such file you 
> will have half of the total number of frame missing.
> 
> The old code provided by Roman V.Shaposhnik outputs 960x1440 frame which 
> contains both "fields".

I'm not quite sure I understand what you mean by "old code" and "given
code". The current patch aims at decoding 720p as a stream of normal
frames. Even though each DV frame has two of them. If you have practical
examples of where that fails for you -- please make the sample
available.

Thanks,
Roman.





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