Langue: en

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Version: October 2010 (ubuntu - 24/10/10)

Section: 1 (Commandes utilisateur)


x264 - fast h264 encoder


x264 core:98 Ubuntu_2:0.98.1653+git88b90d9-3 Syntax: x264 [options] -o outfile infile [widthxheight]

Infile can be raw YUV 4:2:0 (in which case resolution is required),

or YUV4MPEG 4:2:0 (*.y4m), or Avisynth if compiled with support (no). or libav* formats if compiled with lavf support (yes) or ffms support (no).

Outfile type is selected by filename:

.264 -> Raw bytestream .mkv -> Matroska .flv -> Flash Video .mp4 -> MP4 if compiled with GPAC support (yes)


-h, --help
List basic options
List more options
List all options

Example usage:

Constant quality mode:
x264 --crf 24 -o <output> <input>
Two-pass with a bitrate of 1000kbps:
x264 --pass 1 --bitrate 1000 -o <output> <input> x264 --pass 2 --bitrate 1000 -o <output> <input>
x264 --crf 0 -o <output> <input>
Maximum PSNR at the cost of speed and visual quality:
x264 --preset placebo --tune psnr -o <output> <input>
Constant bitrate at 1000kbps with a 2 second-buffer:
x264 --vbv-bufsize 2000 --bitrate 1000 -o <output> <input>


Force the limits of an H.264 profile [high] Overrides all settings. - baseline:
--no-8x8dct --bframes 0 --no-cabac --cqm flat --weightp 0 No interlaced. No lossless.
- main:
--no-8x8dct --cqm flat No lossless.
- high:
No lossless.
Use a preset to select encoding settings [medium] Overridden by user settings. - ultrafast:
--no-8x8dct --aq-mode 0 --b-adapt 0 --bframes 0 --no-cabac --no-deblock --no-mbtree --me dia --no-mixed-refs --partitions none --ref 1 --scenecut 0 --subme 0 --trellis 0 --no-weightb --weightp 0
- superfast:
--no-mbtree --me dia --no-mixed-refs --partitions i8x8,i4x4 --ref 1 --subme 1 --trellis 0 --weightp 0
- veryfast:
--no-mbtree --no-mixed-refs --ref 1 --subme 2 --trellis 0 --weightp 0
- faster:
--no-mixed-refs --rc-lookahead 20 --ref 2 --subme 4 --weightp 1
- fast:
--rc-lookahead 30 --ref 2 --subme 6
- medium:
Default settings apply.
- slow:
--b-adapt 2 --direct auto --me umh --rc-lookahead 50 --ref 5 --subme 8
- slower:
--b-adapt 2 --direct auto --me umh --partitions all --rc-lookahead 60 --ref 8 --subme 9 --trellis 2
- veryslow:
--b-adapt 2 --bframes 8 --direct auto --me umh --merange 24 --partitions all --ref 16 --subme 10 --trellis 2 --rc-lookahead 60
- placebo:
--bframes 16 --b-adapt 2 --direct auto --slow-firstpass --no-fast-pskip --me tesa --merange 24 --partitions all --rc-lookahead 60 --ref 16 --subme 10 --trellis 2
Tune the settings for a particular type of source or situation
Overridden by user settings. Multiple tunings are separated by commas. Only one psy tuning can be used at a time. - film (psy tuning):
--deblock -1:-1 --psy-rd <unset>:0.15
- animation (psy tuning):
--bframes {+2} --deblock 1:1 --psy-rd 0.4:<unset> --aq-strength 0.6 --ref {Double if >1 else 1}
- grain (psy tuning):
--aq-strength 0.5 --no-dct-decimate --deadzone-inter 6 --deadzone-intra 6 --deblock -2:-2 --ipratio 1.1 --pbratio 1.1 --psy-rd <unset>:0.25 --qcomp 0.8
- stillimage (psy tuning):
--aq-strength 1.2 --deblock -3:-3 --psy-rd 2.0:0.7
- psnr (psy tuning):
--aq-mode 0 --no-psy
- ssim (psy tuning):
--aq-mode 2 --no-psy
- fastdecode:
--no-cabac --no-deblock --no-weightb --weightp 0
- zerolatency:
--bframes 0 --force-cfr --rc-lookahead 0 --sync-lookahead 0 --sliced-threads
Don't force these faster settings with --pass 1: --no-8x8dct --me dia --partitions none --ref 1 --subme {2 if >2 else unchanged} --trellis 0 --fast-pskip

Frame-type options:

-I, --keyint <integer>
Maximum GOP size [250]
-i, --min-keyint <integer>
Minimum GOP size [auto]
Disable adaptive I-frame decision
--scenecut <integer>
How aggressively to insert extra I-frames [40]
Use Periodic Intra Refresh instead of IDR frames
-b, --bframes <integer>
Number of B-frames between I and P [3]
--b-adapt <integer>
Adaptive B-frame decision method [1] Higher values may lower threading efficiency. - 0: Disabled - 1: Fast - 2: Optimal (slow with high --bframes)
--b-bias <integer>
Influences how often B-frames are used [0]
--b-pyramid <string>
Keep some B-frames as references [normal] - none: Disabled - strict: Strictly hierarchical pyramid - normal: Non-strict (not Blu-ray compatible)
Disable CABAC
-r, --ref <integer>
Number of reference frames [3]
Disable loop filter
-f, --deblock <alpha:beta>
Loop filter parameters [0:0]
--slices <integer>
Number of slices per frame; forces rectangular slices and is overridden by other slicing options
--slice-max-size <integer> Limit the size of each slice in bytes
--slice-max-mbs <integer> Limit the size of each slice in macroblocks
Enable interlaced mode (top field first)
Enable interlaced mode (bottom field first)
Enable constrained intra prediction.
--pulldown <string>
Use soft pulldown to change frame rate - none, 22, 32, 64, double, triple, euro (requires cfr input)
Flag stream as interlaced but encode progressive. Makes it possible to encode 25p and 30p Blu-Ray streams. Ignored in interlaced mode.


-q, --qp <integer>
Force constant QP (0-51, 0=lossless)
-B, --bitrate <integer>
Set bitrate (kbit/s)
--crf <float>
Quality-based VBR (0-51, 0=lossless) [23.0]
--rc-lookahead <integer> Number of frames for frametype lookahead [40]
--vbv-maxrate <integer> Max local bitrate (kbit/s) [0]
--vbv-bufsize <integer> Set size of the VBV buffer (kbit) [0]
--vbv-init <float>
Initial VBV buffer occupancy [0.9]
--crf-max <float>
With CRF+VBV, limit RF to this value May cause VBV underflows!
--qpmin <integer>
Set min QP [10]
--qpmax <integer>
Set max QP [51]
--qpstep <integer>
Set max QP step [4]
--ratetol <float>
Tolerance of ABR ratecontrol and VBV [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]
--aq-mode <integer>
AQ method [1] - 0: Disabled - 1: Variance AQ (complexity mask) - 2: Auto-variance AQ (experimental)
--aq-strength <float>
Reduces blocking and blurring in flat and textured areas. [1.0]
-p, --pass <integer>
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"]
Disable mb-tree ratecontrol.
--qcomp <float>
QP curve compression [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 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 for some or all frames Format of each line: framenumber frametype QP QP of -1 lets x264 choose. Frametypes: I,i,P,B,b. QPs are restricted by qpmin/qpmax.


-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
Disable weighted prediction for B-frames
--weightp <integer>
Weighted prediction for P-frames [2] - 0: Disabled - 1: Blind offset - 2: Smart analysis
--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 - tesa: hadamard 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 mode decision [7] - 0: fullpel only (not recommended) - 1: SAD mode decision, one qpel iteration - 2: SATD mode decision - 3-5: Progressively more qpel - 6: RD mode decision for I/P-frames - 7: RD mode decision for all frames - 8: RD refinement for I/P-frames - 9: RD refinement for all frames - 10: QP-RD - requires trellis=2, aq-mode>0
Strength of psychovisual optimization ["1.0:0.0"] #1: RD (requires subme>=6) #2: Trellis (requires trellis, experimental)
Disable all visual optimizations that worsen both PSNR and SSIM.
Don't decide references on a per partition basis
Ignore chroma in motion estimation
Disable adaptive spatial transform size
-t, --trellis <integer>
Trellis RD quantization. Requires CABAC. [1] - 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]
--nal-hrd <string>
Signal HRD information (requires vbv-bufsize) - none, vbr, cbr (cbr not allowed in .mp4)
Force pic_struct in Picture Timing SEI


-o, --output
Specify output file
--muxer <string>
Specify output container format ["auto"] - auto, raw, mkv, flv, mp4
--demuxer <string>
Specify input container format ["auto"] - auto, yuv, y4m, lavf
--index <string>
Filename for input index 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
Don't show the progress indicator while encoding
Quiet Mode
Enable PSNR computation
Enable SSIM computation
--threads <integer>
Force a specific number of threads
Low-latency but lower-efficiency threading
Run Avisynth in its own thread
--sync-lookahead <integer> Number of buffer frames for threaded lookahead
Slightly improve quality of SMP, at the cost of repeatability
--asm <integer>
Override CPU detection
Disable all CPU optimizations
Show MB types overlayed on the encoded video
--dump-yuv <string>
Save reconstructed frames
--sps-id <integer>
Set SPS and PPS id numbers [0]
Use access unit delimiters
Force constant framerate timestamp generation
--tcfile-in <string>
Force timestamp generation with timecode file
--tcfile-out <string>
Output timecode v2 file from input timestamps
--timebase <int/int>
Specify timebase numerator and denominator
Specify timebase numerator for input timecode file or specify timebase denominator for other input

built on Oct 5 2010, gcc: 4.4.5