Corrupted decoding

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Guest 2
Posts: 903
Joined: Mon Sep 20, 2010 2:18 pm

Corrupted decoding

Post 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
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Rocky
Posts: 3623
Joined: Fri Sep 06, 2019 12:57 pm

Corrupted decoding

Post 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. ;)
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Guest 2
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Corrupted decoding

Post 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.
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Rocky
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Corrupted decoding

Post 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 :salute: . The HEVC parsing is now done by our code and not NVDec. That is needed for linux log file support.
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Guest 2
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Joined: Mon Sep 20, 2010 2:18 pm

Corrupted decoding

Post 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?
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Rocky
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Corrupted decoding

Post 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.
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