|author||wm4 <wm4@nowhere>||2012-11-04 18:16:36 +0100|
|committer||wm4 <wm4@nowhere>||2013-01-13 17:39:31 +0100|
video: remove slice based filtering and video output
Slices allowed filtering or drawing video in horizontal bands or blocks. This allowed working on the video in smaller units. In theory, this could bring a performance win by lowering cache pressure, as you didn't have to keep the whole video frame in cache while filtering, only the slice. In practice, the slice code path was barely used for the following reasons: - Multithreaded decoding with ffmpeg didn't use slices. The ffmpeg slice callback was disabled, because it can be called from another thread, and the mplayer video chain is not thread-safe. - There was nothing that would turn "full" images into appropriate slices, so slices were rarely used. - Most filters didn't actually support slices. On the other hand, supporting slices lead to code duplication and more complex code in general. I made some experiments and didn't find any actual measurable performance improvements when using slices. Even ffmpeg removed slices based filtering from libavfilter in favor of simpler code. The most broken thing about the slices code path is that slices can't be queued, like it is done for images in vo.c.
Diffstat (limited to 'DOCS')
1 files changed, 1 insertions, 7 deletions
diff --git a/DOCS/man/en/options.rst b/DOCS/man/en/options.rst
index 271978786d..5265968269 100644
@@ -937,7 +937,7 @@
:8: macroblock (MB) type
:16: per-block quantization parameter (QP)
:32: motion vector
- :0x0040: motion vector visualization (use ``--no-slices``)
+ :0x0040: motion vector visualization
:0x0080: macroblock (MB) skip
@@ -1759,12 +1759,6 @@
This affects smplayer, smplayer2, mplayerosx, and others.
- Drawing video by 16-pixel height slices/bands, instead draws the
- whole frame in a single run. May be faster or slower, depending on video
- card and available cache. It has effect only with libavcodec codecs.
- Enabled by default if applicable; usually disabled when threading is used.
Time frames by repeatedly checking the current time instead of asking
the kernel to wake up mpv at the correct time. Useful if your kernel