[FFmpeg-trac] #10095(ffmpeg:new): contradictory documentation
FFmpeg
trac at avcodec.org
Wed Dec 7 06:00:18 EET 2022
#10095: contradictory documentation
-------------------------------------+-------------------------------------
Reporter: Alin | Type: defect
Status: new | Priority: normal
Component: ffmpeg | Version: 4.4.3
Keywords: | Blocked By:
documentation abiguous misleading |
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
Summary of the bug:
on the page: https://trac.ffmpeg.org/wiki/Hardware/VAAPI
" The -compression_level option controls the local speed/quality tradeoff
in the encoder (that is, the amount of effort expended on trying to get
the best results from local choices like motion estimation and mode
decision), using a nebulous per-device scale. The argument is a small
integer, from 1 up to some limit dependent on the device (not more than 7)
- '''higher values are faster / lower stream quality'''."
--> higher value is faster.
http://www.ffmpeg.org/ffmpeg-codecs.html#VAAPI-encoders
"-compression_level integer
For lossy, this is a quality/speed tradeoff. Higher values give better
quality for a given size at the cost of increased encoding time. For
lossless, this is a size/speed tradeoff. '''Higher values give smaller
size at the cost of increased encoding time'''. More specifically, it
controls the number of extra algorithms and compression tools used, and
varies the combination of these tools. This maps to the method option in
libwebp. The valid range is 0 to 6. Default is 4.
"
--> higher value is increasing the encoding time (this is higher quality
in my understanding).
1. So what is the right statement:
- Higher value is higher quality or lower quality?
- Higher value is more processing or less processing?
2. Valid range is 0 to 6 or 1 to 7?
I am interested in connection to VAAPI with Intel iGPU (video encoding).
--
Ticket URL: <https://trac.ffmpeg.org/ticket/10095>
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