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Corrupted decoding
Posted: Fri Oct 20, 2023 5:00 am
by Guest 2
I have a issue with videos with high number of bframes and dgdecodenv.
SW decoders such as L-SMASH-Works decode it perfectly, while dgdecodenv gives corrupted output without any warning.
If I recall well, some previous version DGIndexNV gave error when trying to open videos with high bframes number.
Here is the sample
https://pixeldrain.com/u/JSsdkdnu
Corrupted decoding
Posted: Fri Oct 20, 2023 12:18 pm
by Rocky
Increasing the number of DPB frames from 16 to 20 solves this. Yes, it's about the number of B frames. There is a lot of discussion on the internet about this. I'll make a slipstream today or tomorrow for that. Can't do it straightaway as there are some other things in the pipeline not quite done.
Formally, I should check if 20 exceeds the limit for the specified AVC level. If so I could bail out with illegal stream. But there's no problem handling a DPB of 20, so need to get school-marmish, especially when the SW players are fine with it. Increasing it increases the GPU memory requirements but we're well out of the GTX 8800 era.
Corrupted decoding
Posted: Fri Oct 20, 2023 2:29 pm
by Guest 2
Rocky wrote: ↑Fri Oct 20, 2023 12:18 pm
Formally, I should check if 20 exceeds the limit for the specified AVC level.
Isn't there a HW limitation to number of B-Frames? I saw there is for encoding, don't know about decoding.
Corrupted decoding
Posted: Fri Oct 20, 2023 8:23 pm
by Rocky
Please test this 64-bit build:
https://rationalqm.us/misc/Guest 2.zip
The NVDec decode sample uses DPB size 20, so there can't be any applicable limitation there.
This does decode correctly but I want you to test it too and let me know if you see any regressions. The HEVC parsing was totally revamped per code from
Sherman . The HEVC parsing is now done by our code and not NVDec. That is needed for linux log file support.
Corrupted decoding
Posted: Sat Oct 21, 2023 6:11 am
by Guest 2
Rocky wrote: ↑Fri Oct 20, 2023 8:23 pm
Please test this 64-bit build
Works fine, thank you!
Rocky wrote: ↑Fri Oct 20, 2023 8:23 pm
let me know if you see any regressions
Nothing that I can notice.
Rocky wrote: ↑Fri Oct 20, 2023 8:23 pm
The HEVC parsing was totally revamped per code from Sherman
Thank you Sherman! The AVC parsing is ok?
Corrupted decoding
Posted: Sat Oct 21, 2023 6:36 am
by Rocky
Thank you for your testing.
Only HEVC parsing was affected because we already used our own code for AVC/MPEG/VC1, rather than NVDec parsing.