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x264

NAME

x264 - H.264 encoder

SYNOPSIS

x264 [options] -o outfile infile [widthxheight]  

DESCRIPTION

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).

OPTIONS

-h, --help

List the more commonly used options

--longhelp

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]

--pre-scenecut

Faster, less precise scenecut detection. Required and implied by multi-threading.

-b, --bframes <integer>

Number of B-frames between I and P [0]

--no-b-adapt

Disable adaptive B-frame decision

--b-bias <integer>

Influences how often B-frames are used [0]

--b-pyramid

Keep some B-frames as references

--no-cabac

Disable CABAC

-r, --ref <integer>

Number of reference frames [1]

--no-deblock

Disable loop filter

-f, --deblock <alpha:beta>

Loop filter AlphaC0 and Beta parameters [0:0]

--interlaced

Enable pure-interlaced mode

Ratecontrol:

-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)

or

b=<float> (bitrate multiplier)

--qpfile <string>

Force frametypes and QPs

Analysis:

-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]

--b-rdo

RD based mode decision for B-frames. Requires subme 6.

--mixed-refs

Decide references on a per partition basis

--no-chroma-me

Ignore chroma in motion estimation

--bime

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

--no-fast-pskip

Disables early SKIP detection on P-frames

--no-dct-decimate

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]

Input/Output:

-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

--progress

Show a progress indicator while encoding

--quiet

Quiet Mode

--no-psnr

Disable PSNR computation

--no-ssim

Disable SSIM computation

--threads <integer>

Parallel encoding

--thread-input

Run Avisynth in its own thread

--non-deterministic

Slightly improve quality of SMP, at the cost of repeatability

--no-asm

Disable all CPU optimizations

--visualize

Show MB types overlayed on the encoded video

--sps-id <integer>

Set SPS and PPS id numbers [0]

--aud

Use access unit delimiters

SEE ALSO

ffmpeg(1)

AUTHORS

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).