Picture Breaking up

I have had quite a few programs that I recorded on my PVR where the picture have broken an awful lot.

I have opened them in VideoReDo and ran the quick stream fix but the result of this usually ends up saying that thousands of fames have been dropped, which means that the files are still unplayable.

Is there anything else within VideoReDo that I can look at or is it using than getting antenna looked at and getting another antenna amplifier or using other software?

Thanks in advance
 

tobyW

Member
My sympathy to you, Phototaker, as I have the same problem.

Unfortunately I doubt that any software can fix it. You need to find the root cause.

In my case, the PVR seemed OK when tested on a different aerial, so I spent half of yesterday crawling among the cobwebs in my attic to check my attic-mounted aerial and connections.

I found a couple of coaxial connectors that had somehow loosened. After I fixed them the TV reported full signal strength. The PVR seemed happier too, but it must be borderline because today the PVR has teased me again.

Not sure what to blame. Deeper investigation needed, such as check the PVR's hard disk connectors (already replaced once).

( Lighthearted footnote: This first surfaced when I tried to record Armageddon and it broke QSF. I had also recorded Armageddon again yesterday. No connection suggested of course!)
 

Dan203

Senior Developer
Staff member
No software that I'm aware of can fix a data stream errors like that. MPEG-2 and H.264 are temporal codecs, which means most of the frames only hold the data that makes them different from the frames that came before them. So even if just one frame is corrupted it will affect every frame that proceeds it until a new key frame comes along to reset the decoder. In MPEG-2 key frames are typically inserted every 1/2 second or so because it's a less efficient codec, so minor glitches don’t typically last long. But with H.264 they can be much, much, further apart. I've seen some H.264 files that only have a key frame every 10 seconds or so. Which means a minor hiccup can effect a much bigger chunk of the video. Since picture data is sort of random by nature, containing just luminescence and color data, it's not really possible to know what should have been there and fix a corrupt frame. Maybe someone much, much, smarter than I could write a AI that could use the surrounding frames to sort of reconstruct what might have been there and replace the corrupt frame, but AFAIK no such program exists. And if it did it likely would be really, really, slow.
 
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