Documentation:Modules/x264

This page is about the H.264 encoder. Were you looking for h26x, the H.264 decoder?

See also: Documentation:Modules/x265

Module: x264
Type	Muxer
First VLC version	0.7.2
Last VLC version	-
Operating system(s)	all
Description	H.264/MPEG-4 Part 10/AVC encoder (x264)
Shortcut(s)	-

Options

Frame-type

• sout-x264-keyint <integer> : Maximum GOP size default value: 250
• sout-x264-min-keyint <integer> : Minimum GOP size default value: 25
• sout-x264-opengop <boolean> : Use recovery points to close GOPs default value: disabled
• sout-x264-bluray-compat <boolean> : Enable compatibility hacks for Blu-ray support default value: disabled
• sout-x264-scenecut <integer [-1 .. 100]> : Extra I-frames aggressivity default value: 40
• sout-x264-bframes <integer [0 .. 16]> : B-frames between I and P default value: 3
• sout-x264-b-adapt <integer [0 .. 2]> : Adaptive B-frame decision default value: 1
• sout-x264-b-bias <integer [-100 .. 100]> : Influence (bias) B-frames usage default value: 0
• sout-x264-bpyramid <string> {none,strict,normal} : Keep some B-frames as references default value: "normal"
• sout-x264-cabac <boolean> : CABAC default value: enabled
• sout-x264-fullrange <boolean> : Use fullrange instead of TV colorrange default value: disabled
• sout-x264-ref <integer [1 .. 16]> : Number of reference frames default value: 3
• sout-x264-nf <boolean> : Skip loop filter default value: disabled
• sout-x264-deblock <string> : Loop filter AlphaC0 and Beta parameters alpha:beta default value: "0:0"
• sout-x264-psy-rd <string> : Strength of psychovisual optimization default value: "1.0:0.0"
• sout-x264-psy <boolean> : Use Psy-optimizations default value: enabled
• sout-x264-level <string> : H.264 level default value: "0"
• sout-x264-profile <string> : H.264 profile default value: "high"
• sout-x264-interlaced <boolean> : Interlaced mode default value: disabled
• sout-x264-frame-packing <integer> {-1,0,1,2,3,4,5,6} : Frame packing default value: -1
• sout-x264-slices <integer> : Force number of slices per frame default value: 0
• sout-x264-slice-max-size <integer> : Limit the size of each slice in bytes default value: 0
• sout-x264-slice-max-mbs <integer> : Limit the size of each slice in macroblocks default value: 0
• sout-x264-hrd <string> : HRD-timing information default value: "none"

Rate control

• sout-x264-qp <integer [-1 .. 51]> : Set QP default value: -1
• sout-x264-crf <integer [0 .. 51]> : Quality-based VBR default value: 23
• sout-x264-qpmin <integer [0 .. 51]> : Min QP default value: 10
• sout-x264-qpmax <integer [0 .. 51]> : Max QP default value: 51
• sout-x264-qpstep <integer [0 .. 51]> : Max QP step between frames default value: 4
• sout-x264-ratetol <float [0 .. 100]> : Average bitrate tolerance default value: 1.0
• sout-x264-vbv-maxrate <integer> : Max local bitrate default value: 0
• sout-x264-vbv-bufsize <integer> : VBV buffer default value: 0
• sout-x264-vbv-init <float [0 .. 1]> : Initial VBV buffer occupancy default value: 0.9
• sout-x264-ipratio <float [1 .. 2]> : QP factor between I and P default value: 1.40
• sout-x264-pbratio <float [1 .. 2]> : QP factor between P and B default value: 1.30
• sout-x264-chroma-qb-offset <integer> : QP difference between chroma and luma default value: 0
• sout-x264-pass <integer> {0,1,2,3} : Multipass ratecontrol default value: 0
• sout-x264-qcomp <float [0 .. 1]> : QP curve compression default value: 0.60
• sout-x264-cplxblur <float> : Reduce fluctuations in QP default value: 20.0
• sout-x264-qblur <float> : Reduce fluctuations in QP default value: 0.5
• sout-x264-aq-mode <integer> {0,1,2} : Defines bitdistribution mode for AQ, default 1 default value: X264_AQ_VARIANCE
• sout-x264-aq-strength <float> : Strength of AQ default value: 1.0

Analysis

• sout-x264-partitions <string> {none,fast,normal,slow,all} : Partitions to consider default value: "normal"
• sout-x264-direct <string> {none,spatial,temporal,auto} : Direct MV prediction mode default value: "spatial"
• sout-x264-direct-8x8 <integer [-1 .. 1]> : Direct prediction size default value: 1
• sout-x264-weightb <boolean> : Weighted prediction for B-frames default value: enabled
• sout-x264-weightp <integer [0 .. 2]> : Weighted prediction for P-frames default value: 2
• sout-x264-me <string> {dia,hex,umh,esa,tesa} : Integer pixel motion estimation method default value: "hex"
• sout-x264-merange <integer [1 .. 64]> : Maximum motion vector search range default value: 16
• sout-x264-mvrange <integer> : Maximum motion vector length default value: -1
• sout-x264-mvrange-thread <integer> : Minimum buffer space between threads default value: -1
• sout-x264-subme <integer [1 .. 9]> : Subpixel motion estimation and partition decision quality default value: 7
• sout-x264-mixed-refs <boolean> : Decide references on a per partition basis default value: enabled
• sout-x264-chroma-me <boolean> : Chroma in motion estimation default value: enabled
• sout-x264-8x8dct <boolean> : Adaptive spatial transform size default value: enabled
• sout-x264-trellis <integer> {0,1,2} : Trellis RD quantization: This requires CABAC default value: 1
• sout-x264-lookahead <integer [0 .. 60]> : Framecount to use on frametype lookahead default value: 40
• sout-x264-intra-refresh <boolean> : Use Periodic Intra Refresh default value: disabled
• sout-x264-mbtree <boolean> : Use mb-tree ratecontrol default value: enabled
• sout-x264-fast-pskip <boolean> : Early SKIP detection on P-frames default value: enabled
• sout-x264-dct-decimate <boolean> : Coefficient thresholding on P-frames default value: enabled
• sout-x264-nr <integer [0 .. 1000]> : Noise reduction default value: 0
• sout-x264-deadzone-inter <integer [0 .. 32]> : Inter luma quantization deadzone default value: 21
• sout-x264-deadzone-intra <integer [0 .. 32]> : Intra luma quantization deadzone default value: 11

Input/Output

• sout-x264-non-deterministic <boolean> : Non-deterministic optimizations when threaded default value: disabled
• sout-x264-asm <boolean> : CPU optimizations default value: enabled
• sout-x264-psnr <boolean> : PSNR computation default value: disabled
• sout-x264-ssim <boolean> : SSIM computation default value: disabled
• sout-x264-quiet <boolean> : Quiet mode default value: disabled
• sout-x264-sps-id <integer> : SPS and PPS id numbers default value: 0
• sout-x264-aud <boolean> : Access unit delimiters default value: disabled
• sout-x264-verbose <boolean> : Statistics default value: disabled
• sout-x264-stats <string> : Filename for 2 pass stats file default value: "x264_2pass.log"
• sout-x264-preset <string> : Default preset setting used default value: NULL
• sout-x264-tune <string> : Default tune setting used default value: NULL
• sout-x264-options <string> : x264 advanced options, in the form {opt=val,op2=val2} default value: NULL

Appendix

For the option --sout-x264-frame-packing:

-1

disabled

0

checkerboard - pixels are alternatively from L and R

1

column alternation - L and R are interlaced by column

2

row alternation - L and R are interlaced by row

3

side by side - L is on the left, R on the right

4

top bottom - L is on top, R on bottom

5

frame alternation - one view per frame

For the option --sout-x264-pass:

1

First pass, creates stats file

2

Last pass, does not overwrite stats file

3

N^th pass, overwrites stats file

For the option --sout-x264-aq-mode:

0

Disabled

1

Current x264 default mode

2

uses log(var)² instead of log(var) and attempts to adapt strength per frame

For the option --sout-x264-trellis:

0

disabled

1

enabled only on the final encode of a MB

2

enabled on all mode decisions

Source code

• modules/codec/x264.c

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