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Output file format

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cp2

My video editor of choice, VideoRedo, is currently going through a new release and beta versions.

In order to resolve an issue I sent them a sample file which I had captured from a hdmi source into a Hauppauge Colossus 2 card using DVBViewer. 
They have come back to me saying “ I do see an issue in that the vps, sps, and pps are NOT being repeated throughout the file. 

Up to now I think that I have had a workflow that masked this from me (I output mkv files) and I can probably find a way to continue that in the new version.

However, I don’t know enough to know whether I should worry about what they think is a deficiency! Can you comment?

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Griga
vor 4 Stunden schrieb cp2:

 I do see an issue in that the vps, sps, and pps are NOT being repeated throughout the file.

 

Video Parameter Set, Sequence Parameter Set and Picture Parameter Set are H.264/H.265 (HEVC) video headers. DVBViewer and the DVBViewer Media Server record them as received (= as broadcasted or encoded by the source device). The video data is changed in no way. So the VideoRedo guys are actually talking about the Colossus output.

 

In a transport stream (.ts) container the headers are repeated periodically within the video stream (Annex B format) so that video editing / player software can start reading at random points. This is a mandatory requirement for live streams. Missing headers may affect the ability to skip / jump within a recorded file. So in order to find out if there is really a deficiency I would try jumping forward / backward to different positions with standard players like VLC or DVBViewer (using LAV filters).

 

In a MP4 or MKV container things are different, because the H.264/H.265 headers are stored "out of band" in special sections (e.g. MP4 boxes) as part of the container, not within the video data (AVCC format). This saves repeating the same headers again and again. Software that "understands" the container format knows where to look for the headers. It doesn't have to find them somewhere in the video data.

 

If you want to dive deeper into this matter, continue reading here.

 

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cp2

Thanks for this explanation. I remember that it was a struggle for you to get DVBViewer to communicate with the Colossus due to it not using “standard” pins. I therefore cannot be surprised that there are other difficulties that have emerged.

I have experienced difficulties navigating through files and the automatic “resume” function of my LG tv is not too happy either.

However, remuxing to mkv is a massive help and now I have an inkling why.

in retrospect getting it all to work up to now has been a bit of a miracle.

As for diving deeper I can’t swim and now is a bit late to learn!

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cp2

JUst to say that VideoRedo have come up with a solution involving changing a parameter in their advanced HEVC settings - "IDR Frequency = every I Frame is IDR". This will become the default if you use Intel QS.

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