Opened 8 weeks ago

Closed 2 weeks ago

#11365 closed defect (fixed)

wrong qmin range for av1_nvenc

Reported by: y1dj1sqd Owned by: Timo Rothenpieler <timo@rothenpieler.org>
Priority: normal Component: ffmpeg
Version: git-master Keywords: NVENC av1_nvenc qmin
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no

Description

Summary of the bug:
How to reproduce:

% ffmpeg -i input.mkv -an -c:v av1_nvenc -b:v 4M -qmin 80 output.mkv

ffmpeg version N-118106-g350ebef112-20241222 Copyright (c) 2000-2024 the FFmpeg developers

built on 2024-12-22

It does print the following error:

Value 80.000000 for parameter 'qmin' out of range [-1 - 69]
Error setting option qmin to value 80.

It thinks that the QP range would end at 69 but av1_nvenc qp range max is 255.

Change History (4)

comment:1 by Timo R., 8 weeks ago

qmin is a global option, nvenc has no influence on the range there.
Not sure if the range of the global option can just be extended without further consequences.

comment:2 by y1dj1sqd, 8 weeks ago

In case this is not possible with the global option is there another way to set higher minQP values for nvenc?

comment:3 by Timo R., 8 weeks ago

No, an entire new option will need to be added, which in a sense is a breaking change.
Alternative, for AV1, the value could be multiplied by some factor, to at least somewhat match its range.

comment:4 by Timo Rothenpieler <timo@rothenpieler.org>, 2 weeks ago

Owner: set to Timo Rothenpieler <timo@rothenpieler.org>
Resolution: fixed
Status: newclosed

In 89b37b4d/ffmpeg:

avcodec/nvenc: use encoder level options for qmin/qmax

AV1 uses a vastly different range than what the global options permit,
and also for the other codecs the range of the global options is at
least misaligned.

Fixes #11365

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