Opened 5 years ago

Last modified 22 months ago

#7004 open defect

Documentation: please clarify jpeg2000 encoding quality range

Reported by: cri Owned by:
Priority: minor Component: documentation
Version: git-master Keywords: j2k
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no

Description

The ffmpeg-all man page says, about the jpeg2000 encoder:

the "-q:v" option can be used to set the encoding quality

In the JPG standard, the quality parameter has a 1-100 range (100 being the best), while the "-q:v" option works the opposite way: 1 is the best (I don't know the highest value).

Please specify the supported range in the documentation, and clarify that lower value = better quality.

Change History (2)

comment:1 by Carl Eugen Hoyos, 5 years ago

Keywords: j2k added
Priority: normalminor
Status: newopen
Version: unspecifiedgit-master

comment:2 by Balling, 22 months ago

Also, should not .i64 = 1 be here?

https://github.com/FFmpeg/FFmpeg/blob/069d2b4a50a6eb2f925f36884e6b9bd9a1e54670/libavcodec/j2kenc.c#L1822

Why it is printing ffmpeg -h encoder=jpeg2000

  -pred              <int>        E..V....... DWT Type (from 0 to 1) (default dwt97int)
     dwt97int        0            E..V.......
     dwt53           0            E..V.......

Why dwt53 is 0?? it should be 1, no?

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