mirror of
https://github.com/mpv-player/mpv
synced 2025-01-20 22:40:52 +00:00
misc corrections and clarifications in x264 options.
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@15148 b3059339-0415-0410-9bf9-f77b7e298cf2
This commit is contained in:
parent
e42007d06b
commit
7c538a1bf8
@ -7683,10 +7683,12 @@ are just as big as I-frames, but don't reset the "keyint counter".
|
||||
.
|
||||
.TP
|
||||
.B frameref=<1\-16>
|
||||
Number of previous frames used as predictors in a P-frame (default: 1).
|
||||
This is effective in Anime, but seems to make little difference in
|
||||
live-action source material.
|
||||
Some decoders are unable to deal with large frameref values.
|
||||
Number of previous frames used as predictors in B- and P-frames (default: 1).
|
||||
This is effective in anime, but in live-action material the improvements
|
||||
usually drop off very rapidly above 6 or so reference frames.
|
||||
This has no effect on decoding speed, but does increase the memory needed for
|
||||
decoding.
|
||||
Some decoders can only handle a maximum of 15 reference frames.
|
||||
.
|
||||
.TP
|
||||
.B bframes=<0\-16>
|
||||
@ -7713,7 +7715,10 @@ are predicted from I0 and P4.
|
||||
With this option, they are coded as I0 P4 B2 B1 B3.
|
||||
B2 is the same as above, but B1 is predicted from I0 and B2, and
|
||||
B3 is predicted from B2 and P4.
|
||||
This results in slightly improved compression, at no speed cost.
|
||||
This usually results in slightly improved compression, at almost no
|
||||
speed cost.
|
||||
However, this is an experimental option: it is not fully tuned and
|
||||
may not always help.
|
||||
Requires bframes >= 2.
|
||||
Disadvantage: increases decoding delay to 2 frames.
|
||||
.
|
||||
@ -7726,29 +7731,30 @@ recommend to disable it.
|
||||
.TP
|
||||
.B deblockalpha=<-6\-6>
|
||||
AlphaC0 parameter of deblocking filter (default: 0).
|
||||
This adjusts thresholds for the H.264 deblocking filter.
|
||||
This adjusts thresholds for the H.264 in-loop deblocking filter.
|
||||
First, this parameter adjusts the maximum amount of change that the filter is
|
||||
allowed to cause on any one pixel.
|
||||
Secondly, this parameter affects the threshold for difference across the
|
||||
edge being filtered.
|
||||
A positive value reduces blocking artifacts more, but will also smear details.
|
||||
.br
|
||||
For encodes that are intended to be reasonably high quality, you might
|
||||
want to turn it down a little bit.
|
||||
However, if your source material already has some blocking or noise
|
||||
which you would like to remove, or if it is animation, it may be a good
|
||||
idea to turn it up a little bit.
|
||||
The default behavior of the filter almost always achieves optimal quality,
|
||||
so it is best to either leave it alone, or make only small adjustments.
|
||||
However, if your source material already has some blocking or noise which
|
||||
you would like to remove, it may be a good idea to turn it up a little bit.
|
||||
.
|
||||
.TP
|
||||
.B deblockbeta=<-6\-6>
|
||||
Beta parameter of deblocking filter (default: 0).
|
||||
Affects the maximum allowed gradient within two adjacent blocks.
|
||||
Affects the detail threshold.
|
||||
Very detailed blocks are not filtered, since the smoothing caused by the
|
||||
filter would be more noticeable than the original blocking.
|
||||
.
|
||||
.TP
|
||||
.B (no)cabac
|
||||
Use CABAC (Context-Adaptive Binary Arithmetic Coding) (default: on).
|
||||
Slightly slows down encoding and decoding, but should save 10-15% bitrate.
|
||||
Unless you are looking for speed, you should not disable it.
|
||||
Unless you are looking for decoding speed, you should not disable it.
|
||||
.
|
||||
.TP
|
||||
.B cabacidc=<value>
|
||||
@ -7769,7 +7775,7 @@ directly affect distortion.
|
||||
.
|
||||
.TP
|
||||
.B qp_min=<1\-51> (CBR or two pass)
|
||||
Minimum quantizer, 10\-35 seems to be a useful range (default: 10).
|
||||
Minimum quantizer, 10\-30 seems to be a useful range (default: 10).
|
||||
.
|
||||
.TP
|
||||
.B qp_max=<1\-51> (CBR or two pass)
|
||||
@ -7839,10 +7845,9 @@ Temporal: motion vectors are interpolated from the following P-frame.
|
||||
(default)
|
||||
.RE
|
||||
.PD 1
|
||||
The best choice depends on the movie.
|
||||
Spatial and temporal are approximately the same speed and PSNR,
|
||||
but temporal often looks better.
|
||||
direct_pred=0 is usually both slower and lower quality.
|
||||
direct_pred=0 is both slower and lower quality.
|
||||
.
|
||||
.TP
|
||||
.B (no)weight_b
|
||||
@ -7944,7 +7949,7 @@ Adjust the amount of logging info printed to the screen.
|
||||
.br
|
||||
1: warnings
|
||||
.br
|
||||
2: PSNR, encoding times, and other analysis stats when the encode finishes
|
||||
2: PSNR and other analysis stats when the encode finishes
|
||||
(default)
|
||||
.br
|
||||
3: PSNR, QP, frametype, size, and other stats for every frame
|
||||
|
Loading…
Reference in New Issue
Block a user