Langue: en

Autres versions - même langue

Version: March 2007 (ubuntu - 07/07/09)

Section: 1 (Commandes utilisateur)


x264 - H.264 encoder


x264 [options] -o outfile infile [widthxheight]  


x264 encodes a video stream using the H.264 codec.

Infile can be raw YUV 4:2:0 (in which case resolution is required) or YUV4MPEG 4:2:0 (*.y4m).

Outfile type is selected by filename: .264 (raw bytestream) or .mkv (Matroska).


-h, --help
List the more commonly used options
List all options

Frame-type options:

-I, --keyint <integer>
Maximum GOP size [250]
-i, --min-keyint <integer>
Minimum GOP size [25]
--scenecut <integer>
How aggressively to insert extra I-frames [40]
Faster, less precise scenecut detection. Required and implied by multi-threading.
-b, --bframes <integer>
Number of B-frames between I and P [0]
Disable adaptive B-frame decision
--b-bias <integer>
Influences how often B-frames are used [0]
Keep some B-frames as references
Disable CABAC
-r, --ref <integer>
Number of reference frames [1]
Disable loop filter
-f, --deblock <alpha:beta>
Loop filter AlphaC0 and Beta parameters [0:0]
Enable pure-interlaced mode


-q, --qp <integer>
Set QP (0=lossless) [26]
-B, --bitrate <integer>
Set bitrate (kbit/s)
--crf <float>
Quality-based VBR (nominal QP)
--vbv-maxrate <integer> Max local bitrate (kbit/s) [0]
--vbv-bufsize <integer> Enable CBR and set size of the VBV buffer (kbit) [0]
--vbv-init <float>
Initial VBV buffer occupancy [0.9]
--qpmin <integer>
Set min QP [10]
--qpmax <integer>
Set max QP [51]
--qpstep <integer>
Set max QP step [4]
--ratetol <float>
Allowed variance of average bitrate [1.0]
--ipratio <float>
QP factor between I and P [1.40]
--pbratio <float>
QP factor between P and B [1.30]
--chroma-qp-offset <integer>
QP difference between chroma and luma [0]
-p, --pass <1|2|3>
Enable multipass ratecontrol - 1: First pass, creates stats file - 2: Last pass, does not overwrite stats file - 3: Nth pass, overwrites stats file
--stats <string>
Filename for 2 pass stats ["x264_2pass.log"]
--rceq <string>
Ratecontrol equation ["blurCplx^(1-qComp)"]
--qcomp <float>
QP curve compression: 0.0 => CBR, 1.0 => CQP [0.60]
--cplxblur <float>
Reduce fluctuations in QP (before curve compression) [20.0]
--qblur <float>
Reduce fluctuations in QP (after curve compression) [0.5]
--zones <zone0>/<zone1>/...
Tweak the bitrate of some regions of the video Each zone is of the form
<start frame>,<end frame>,<option> where <option> is either
q=<integer> (force QP)
b=<float> (bitrate multiplier)
--qpfile <string>
Force frametypes and QPs


-A, --partitions <string>
Partitions to consider ["p8x8,b8x8,i8x8,i4x4"] - p8x8, p4x4, b8x8, i8x8, i4x4 - none, all (p4x4 requires p8x8. i8x8 requires --8x8dct.)
--direct <string>
Direct MV prediction mode ["spatial"] - none, spatial, temporal, auto
--direct-8x8 <-1|0|1>
Direct prediction size [-1] - 0: 4x4 - 1: 8x8 - -1: smallest possible according to level
-w, --weightb
Weighted prediction for B-frames
--me <string>
Integer pixel motion estimation method ["hex"] - dia: diamond search, radius 1 (fast) - hex: hexagonal search, radius 2 - umh: uneven multi-hexagon search - esa: exhaustive search (slow)
--merange <integer>
Maximum motion vector search range [16]
--mvrange <integer>
Maximum motion vector length [-1 (auto)]
--mvrange-thread <int>
Minimum buffer between threads [-1 (auto)]
-m, --subme <integer>
Subpixel motion estimation and partition decision quality: 1=fast, 7=best. [5]
RD based mode decision for B-frames. Requires subme 6.
Decide references on a per partition basis
Ignore chroma in motion estimation
Jointly optimize both MVs in B-frames
-8, --8x8dct
Adaptive spatial transform size
-t, --trellis <integer>
Trellis RD quantization. Requires CABAC. [0] - 0: disabled - 1: enabled only on the final encode of a MB - 2: enabled on all mode decisions
Disables early SKIP detection on P-frames
Disables coefficient thresholding on P-frames
--nr <integer>
Noise reduction [0]
--deadzone-inter <int>
Set the size of the inter luma quantization deadzone [21]
--deadzone-intra <int>
Set the size of the intra luma quantization deadzone [11] Deadzones should be in the range 0 - 32.
--cqm <string>
Preset quant matrices ["flat"] - jvt, flat
--cqmfile <string>
Read custom quant matrices from a JM-compatible file Overrides any other --cqm* options.
--cqm4 <list>
Set all 4x4 quant matrices Takes a comma-separated list of 16 integers.
--cqm8 <list>
Set all 8x8 quant matrices Takes a comma-separated list of 64 integers.
--cqm4i, --cqm4p, --cqm8i, --cqm8p
Set both luma and chroma quant matrices
--cqm4iy, --cqm4ic, --cqm4py, --cqm4pc
Set individual quant matrices

Video Usability Info (Annex E): The VUI settings are not used by the encoder but are merely suggestions to the playback equipment. See doc/vui.txt for details. Use at your own risk.

--overscan <string>
Specify crop overscan setting ["undef"] - undef, show, crop
--videoformat <string>
Specify video format ["undef"] - component, pal, ntsc, secam, mac, undef
--fullrange <string>
Specify full range samples setting ["off"] - off, on
--colorprim <string>
Specify color primaries ["undef"] - undef, bt709, bt470m, bt470bg
smpte170m, smpte240m, film
--transfer <string>
Specify transfer characteristics ["undef"] - undef, bt709, bt470m, bt470bg, linear,
log100, log316, smpte170m, smpte240m
--colormatrix <string>
Specify color matrix setting ["undef"] - undef, bt709, fcc, bt470bg
smpte170m, smpte240m, GBR, YCgCo
--chromaloc <integer>
Specify chroma sample location (0 to 5) [0]


-o, --output
Specify output file
--sar width:height
Specify Sample Aspect Ratio
--fps <float|rational>
Specify framerate
--seek <integer>
First frame to encode
--frames <integer>
Maximum number of frames to encode
--level <string>
Specify level (as defined by Annex A)
-v, --verbose
Print stats for each frame
Show a progress indicator while encoding
Quiet Mode
Disable PSNR computation
Disable SSIM computation
--threads <integer>
Parallel encoding
Run Avisynth in its own thread
Slightly improve quality of SMP, at the cost of repeatability
Disable all CPU optimizations
Show MB types overlayed on the encoded video
--sps-id <integer>
Set SPS and PPS id numbers [0]
Use access unit delimiters




x264 was written by Laurent Aimar <fenrir@via.ecp.fr> et al.

This manual page was written by Sam Hocevar <sam@zoy.org> for the Debian project (but may be used by others).