NVENC HEVC problems

[eumagga0x2a]

I tested extensively the NVENC HEVC with the May 1st nightly version, and it worked well in much higher bitrates too.

Thanks, did you test with different (non-zero) values for the number of reference frames?

The only problem was when I set the "use B-frames as references" from middle to each. It resulted in errors.

Please provide some details. Did encoder setup fail? Or did something happen later during the actual encoding process? In doubt please select a short span of a video, reproduce the error(s), close Avidemux and attach admlog.txt from %localappdata%\avidemux\ to your reply.

I also noticed, when I selected MAIN10 to  activate 10 bit encoder, the result was only a 8bit file (according to mediainfo)

Does your NVIDIA graphics card support 10-bit HEVC encoding? Even if it does, the input passed to encoder in Avidemux is always 8-bit, thus selecting the main10 profile doesn't bring any benefits. At best, it just wastes storage.

As libavcodec passes the bit depth of the input to hw encoder, I can imagine that the latter could override the specified profile if appropriate. In order to know for sure, it would be necessary to be able to pass 10-bit pictures to the encoder, which is currently impossible in Avidemux. Implementing support for passing high bit depth pictures from decoder through editor and the video filter chain would require massive changes when not a rewrite of a big part of the application.

[Videograbber]

"Did encoder setup fail? Or did something happen later during the actual encoding process? "

It encodes only the first beginning second of the video.



Encoding 8bit material in 10bit codec always increases the compression efficiency. Of course the original 8bit colors remain roughly the same quality, but the picture is cleaner at the same bitrate. Most transcoders offer 10bit encoding option in "MAIN 10" option. So if somebody select the MAIN10 option, than let it be really 10bit.

[eumagga0x2a]

It encodes only the first beginning second of the video.

Please reproduce this problem, close Avidemux and provide the resulting admlog.txt.

So if somebody select the MAIN10 option, than let it be really 10bit.

I tried to explain why this may be impossible when feeding 8-bit pictures to the encoder, but please select main10 HEVC profile, encode a short video, close Avidemux and provide the resulting admlog.txt.

[Videograbber]

It encodes only the first beginning second of the video.

Please reproduce this problem, close Avidemux and provide the resulting admlog.txt.

So if somebody select the MAIN10 option, than let it be really 10bit.

I tried to explain why this may be impossible when feeding 8-bit pictures to the encoder, but please select main10 HEVC profile, encode a short video, close Avidemux and provide the resulting admlog.txt.

Hello Eumagga!

How can I create such admlog.txt?

Encoding 8 bit material with 10bit codecs increases the efficiency at the same bitrate, thus the quality. It is well proven by SSIM and PSNR tests and subjective visual examinations too. Thus it is no wonder that utmost all transcoder softwares which uses HW encoding also offer that option.

[eumagga0x2a]

How can I create such admlog.txt?

Avidemux creates this log file always when it runs (and overwrites the log file from the previous Avidemux session). I asked you to attach this log file to your reply once you have reproduced the error.

[Videograbber]

How can I create such admlog.txt?

Avidemux creates this log file always when it runs (and overwrites the log file from the previous Avidemux session). I asked you to attach this log file to your reply once you have reproduced the error.

Where is the so-called admlog.txt exactly located?

[eumagga0x2a]

Where is the so-called admlog.txt exactly located?

Maybe my pretty precise description was confusing, but it is as it is:

In doubt please select a short span of a video, reproduce the error(s), close Avidemux and attach admlog.txt from %localappdata%\avidemux\ to your reply.

This means that you can either press the "Windows key" + R, paste the given location and press Return (or Enter) or paste this address into the location bar of Windows Explorer. "%localappdata% is an environment variable which Windows expands to whatever value this variable has on a particular system. In this sense, I already gave you the exact location.

[Videograbber]

Where is the so-called admlog.txt exactly located?

Maybe my pretty precise description was confusing, but it is as it is:

In doubt please select a short span of a video, reproduce the error(s), close Avidemux and attach admlog.txt from %localappdata%\avidemux\ to your reply.

This means that you can either press the "Windows key" + R, paste the given location and press Return (or Enter) or paste this address into the location bar of Windows Explorer. "%localappdata% is an environment variable which Windows expands to whatever value this variable has on a particular system. In this sense, I already gave you the exact location.

Hello Eumagga!

Here is the admlog TXT file.
https://sendgb.com/JMRNHcIs30h

What is the reason of error, when I select the "use B-frames as references" option?

[eumagga0x2a]

Thank you (providing the log as attachment to your reply would have been simpler for everyone, but it worked also the way you did it), the error was

Code Select Expand

[adm_lavLogCallback] 16:00:32-979 [lavc] Failed locking bitstream buffer: invalid param (8):
That was not what I expected to see, will need some time to understand it.

Was it with B-frame mode: each?

You maxed out lookahead, which was rejected by the driver and silently reduced to 28 — did you try to reduce it further to more moderate values?

For the future, it would help if you provide the project script (just the line specifying the video codec and its config) matching the configuration which resulted in particular admlog.txt.

[Videograbber]

Thank you (providing the log as attachment to your reply would have been simpler for everyone, but it worked also the way you did it), the error was

Code Select Expand

[adm_lavLogCallback] 16:00:32-979 [lavc] Failed locking bitstream buffer: invalid param (8):
That was not what I expected to see, will need some time to understand it.

Was it with B-frame mode: each?

You maxed out lookahead, which was rejected by the driver and silently reduced to 28 — did you try to reduce it further to more moderate values?

For the future, it would help if you provide the project script (just the line specifying the video codec and its config) matching the configuration which resulted in particular admlog.txt.

Yes, the B-rame mode was set to each.  In other NVENC HW -accelerated transcoders (like Staxrip or Hybrid)  I always use that  mode without problems.

In Avidemux you can not Max Lookahead, because the NVIDIA Card's real max number of Lookahead is 32 and not 31. (Staxrip and Hybrid use 32 as the max. lookahead without problems)

My NVENC-HEVC settings in pictures:

[Videograbber]

Could you reconstruct the error on your machine too?

[eumagga0x2a]

Yes, and many more since a few hours. Will need some time to sort issues found after graphics card switch.