#10095 closed defect (invalid)
contradictory documentation
| Reported by: | Alin | Owned by: | |
|---|---|---|---|
| Priority: | minor | Component: | documentation |
| Version: | git-master | Keywords: | vaapi |
| Cc: | Blocked By: | ||
| Blocking: | Reproduced by developer: | no | |
| Analyzed by developer: | no |
Description
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).
- So what is the right statement:
- Higher value is higher quality or lower quality?
- Higher value is more processing or less processing?
- Valid range is 0 to 6 or 1 to 7?
I am interested in connection to VAAPI with Intel iGPU (video encoding).
Change History (5)
comment:1 by , 17 months ago
| Component: | ffmpeg → documentation |
|---|---|
| Keywords: | vaapi added; documentation abiguous misleading removed |
| Priority: | normal → minor |
| Version: | 4.4.3 → git-master |
follow-up: 3 comment:2 by , 17 months ago
| Resolution: | → invalid |
|---|---|
| Status: | new → closed |
comment:3 by , 17 months ago
| Resolution: | invalid |
|---|---|
| Status: | closed → reopened |
Replying to Carl Eugen Hoyos:
It appears to me that the only issue is that your quote is wrong.
what do you mean the quote is wrong? info is copy and paste from the links provided above.
click on those links and you will see exactly that info.
comment:5 by , 17 months ago
For completeness this is what I found when I clicked on this link:
compression_level
Speed / quality tradeoff: higher values are faster / worse quality.
It appears to me that the only issue is that your quote is wrong.