Freezers with HD (720p) ts stream

geohei

New member
Hello.

Recordings on some HD (720p) h264 encoded DVB-S channels produces freezers while playing back on STB.
Not all channels are affected.
The freezers occur after 5-10 seconds, and are 1-2 per second from then on.
All this occurs even without cutting the video (= taking it entirely).
Playing back the exported ts stream on VLC (PC) doesn't generate mentioned freezers.

I import ts h264 format.
I export ts h264 format, hence smart rendering.

I believe it appeared after changing from build 806 to 816.

Any ideas?
 

geohei

New member
Hello ... no answers yet.
I need to know where the issue comes from.

Was the question not clear (shall I rephrase)?
Do you need further info?
 

Dan203

Senior Developer
Staff member
The most likely cause is that the original file is using some encoding parameter that we can't match exactly. The encoder we use in VRD is robust, but it doesn't support 100% of all the parameters available in the H.264 spec. So if your source stream is using a parameter that we can't duplicate we get as close as possible for the few frames we need to recode around each cut point. Some players don't handle this sudden change in encoding parameters gracefully and it results in a pause. Unfortunately there isn't anything we can do about it. It's a limitation of the encoder and your specific player. The only thing that would fix it 100% would be to do a full recode on the entire video since that would recode everything to match.
 

geohei

New member
Thanks a lot for the explanantions. I did a recode and indeed, this did the job, though I would have preferred to avoid recode due native footage quality loss.

A question regarding recode. Basically, I just have to adjust the resolution and the average bitrate to my initial stream, and that should do the job more or less (= the result should be as close as possible to the original stream).

Is that correct?
 
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