.TH "x265" "1" "November 2014" "x265 1.4" "User Commands"
.SH NAME
x256 \- encoder for creating H.265/HEVC video streams
.SH SYNOPSIS
x265 [options] infile [\-o] outfile
.SH DESCRIPTION
x256 is a commandline encoder for creating H.265/High Efficiency Video Coding
(HEVC) video streams. \fBinfile\fR can be a YUV or Y4M video stream.
\fBoutfile\fR will be used to store the raw HEVC bitstream.
.SS "Executable Options:"
.TP
\fB\-h\fR/\-\-help
Show this help text and exit
.SS "Output Options:"
.TP
\fB\-o\fR/\-\-output <filename>
Bitstream output file name
.TP
\fB\-\-log\-level\fR <string>
Logging level: none error warning info debug full. Default info
.TP
\fB\-\-no\-progress\fR
Disable CLI progress reports
.TP
\fB\-\-[no\-]cu\-stats\fR
Enable logging stats about distribution of cu across all modes. Default disabled
.TP
\fB\-\-csv\fR <filename>
Comma separated log file, log level >= 3 frame log, else one line per run
.SS "Input Options:"
.TP
\fB\-\-input\fR <filename>
Raw YUV or Y4M input file name. `\-` for stdin
.TP
\fB\-\-y4m\fR
Force parsing of input stream as YUV4MPEG2 regardless of file extension
.TP
\fB\-\-fps\fR <float|rational>
Source frame rate (float or num/denom), auto\-detected if Y4M
.TP
\fB\-\-input\-res\fR WxH
Source picture size [w x h], auto\-detected if Y4M
.TP
\fB\-\-input\-depth\fR <integer>
Bit\-depth of input file. Default 8
.TP
\fB\-\-input\-csp\fR <string>
Source color space: i420, i444 or i422, auto\-detected if Y4M. Default: i420
.TP
\fB\-f\fR/\-\-frames <integer>
Maximum number of frames to encode. Default all
.TP
\fB\-\-seek\fR <integer>
First frame to encode
.TP
\fB\-\-[no\-]interlace\fR <bff|tff>
Indicate input pictures are interlace fields in temporal order. Default progressive
.TP
\fB\-\-dither\fR
Enable dither if downscaling to 8 bit pixels. Default disabled
.SS "Quality reporting metrics:"
.TP
\fB\-\-[no\-]ssim\fR
Enable reporting SSIM metric scores. Default disabled
.TP
\fB\-\-[no\-]psnr\fR
Enable reporting PSNR metric scores. Default disabled
.SS "Profile, Level, Tier:"
.TP
\fB\-\-profile\fR <string>
Enforce an encode profile: main, main10, mainstillpicture
.TP
\fB\-\-level\-idc\fR <integer|float>
Force a minimum required decoder level (as '5.0' or '50')
.TP
\fB\-\-[no\-]high\-tier\fR
If a decoder level is specified, this modifier selects High tier of that level
.SS "Threading, performance:"
.TP
\fB\-\-threads\fR <integer>
Number of threads for thread pool (0: detect CPU core count, default)
.TP
\fB\-F\fR/\-\-frame\-threads <integer>
Number of concurrently encoded frames. 0: auto\-determined by core count
.TP
\fB\-\-[no\-]wpp\fR
Enable Wavefront Parallel Processing. Default enabled
.TP
\fB\-\-[no\-]pmode\fR
Parallel mode analysis. Default disabled
.TP
\fB\-\-[no\-]pme\fR
Parallel motion estimation. Default disabled
.TP
\fB\-\-[no\-]asm\fR <bool|int|string>
Override CPU detection. Default: auto
.SS "Presets:"
.TP
\fB\-p\fR/\-\-preset <string>
Trade off performance for compression efficiency. Default medium
.IP
ultrafast, superfast, veryfast, faster, fast, medium, slow, slower, veryslow, or placebo
.TP
\fB\-t\fR/\-\-tune <string>
Tune the settings for a particular type of source or situation:
.IP
psnr, ssim, zerolatency, or fastdecode
.SS "Quad\-Tree size and depth:"
.TP
\fB\-s\fR/\-\-ctu <64|32|16>
Maximum CU size (default: 64x64). Default 64
.TP
\fB\-\-tu\-intra\-depth\fR <integer>
Max TU recursive depth for intra CUs. Default 1
.TP
\fB\-\-tu\-inter\-depth\fR <integer>
Max TU recursive depth for inter CUs. Default 1
.TP
\fB\-\-[no\-]rect\fR
Enable rectangular motion partitions Nx2N and 2NxN. Default disabled
.TP
\fB\-\-[no\-]amp\fR
Enable asymmetric motion partitions, requires \fB\-\-rect\fR. Default disabled
.SS "Analysis:"
.TP
\fB\-\-rd\fR <0..6>
Level of RD in mode decision 0:least....6:full RDO. Default 3
.TP
\fB\-\-psy\-rd\fR <0..2.0>
Strength of psycho\-visual rate distortion optimization, 0 to disable. Default 0.000000
.TP
\fB\-\-psy\-rdoq\fR <0..50.0>
Strength of psycho\-visual optimization in quantization, 0 to disable. Default 0.000000
.TP
\fB\-\-nr\fR <integer>
An integer value in range of 100 to 1000, which denotes strength of noise reduction. Default disabled
.TP
\fB\-\-[no\-]tskip\-fast\fR
Enable fast intra transform skipping. Default disabled
.TP
\fB\-\-[no\-]early\-skip\fR
Enable early SKIP detection. Default disabled
.TP
\fB\-\-[no\-]fast\-cbf\fR
Enable early outs based on whether residual is coded. Default disabled
.SS "Coding tools:"
.TP
\fB\-w\fR/\-\-[no\-]weightp
Enable weighted prediction in P slices. Default enabled
.TP
\fB\-\-[no\-]weightb\fR
Enable weighted prediction in B slices. Default disabled
.TP
\fB\-\-[no\-]cu\-lossless\fR
Consider lossless mode in CU RDO decisions. Default disabled
.TP
\fB\-\-[no\-]signhide\fR
Hide sign bit of one coeff per TU (rdo). Default enabled
.TP
\fB\-\-[no\-]tskip\fR
Enable intra 4x4 transform skipping. Default disabled
.SS "Temporal / motion search options:"
.TP
\fB\-\-me\fR <string>
Motion search method dia hex umh star full. Default 1
.TP
\fB\-m\fR/\-\-subme <integer>
Amount of subpel refinement to perform (0:least .. 7:most). Default 2
.TP
\fB\-\-merange\fR <integer>
Motion search range. Default 57
.TP
\fB\-\-max\-merge\fR <1..5>
Maximum number of merge candidates. Default 2
.TP
\fB\-\-[no\-]temporal\-mvp\fR
Enable temporal MV predictors. Default enabled
.SS "Spatial / intra options:"
.HP
\fB\-\-[no\-]strong\-intra\-smoothing\fR Enable strong intra smoothing for 32x32 blocks. Default enabled
.TP
\fB\-\-[no\-]constrained\-intra\fR
Constrained intra prediction (use only intra coded reference pixels) Default disabled
.TP
\fB\-\-[no\-]b\-intra\fR
Enable intra in B frames in veryslow presets. Default disabled
.TP
\fB\-\-[no\-]fast\-intra\fR
Enable faster search method for angular intra predictions. Default disabled
.TP
\fB\-\-rdpenalty\fR <0..2>
penalty for 32x32 intra TU in non\-I slices. 0:disabled 1:RD\-penalty 2:maximum. Default 0
.SS "Slice decision options:"
.TP
\fB\-\-[no\-]open\-gop\fR
Enable open\-GOP, allows I slices to be non\-IDR. Default enabled
.TP
\fB\-I\fR/\-\-keyint <integer>
Max IDR period in frames. \fB\-1\fR for infinite\-gop. Default 250
.TP
\fB\-i\fR/\-\-min\-keyint <integer>
Scenecuts closer together than this are coded as I, not IDR. Default: auto
.TP
\fB\-\-no\-scenecut\fR
Disable adaptive I\-frame decision
.TP
\fB\-\-scenecut\fR <integer>
How aggressively to insert extra I\-frames. Default 40
.TP
\fB\-\-rc\-lookahead\fR <integer>
Number of frames for frame\-type lookahead (determines encoder latency) Default 20
.TP
\fB\-\-bframes\fR <integer>
Maximum number of consecutive b\-frames (now it only enables B GOP structure) Default 4
.TP
\fB\-\-bframe\-bias\fR <integer>
Bias towards B frame decisions. Default 0
.TP
\fB\-\-b\-adapt\fR <0..2>
0 \- none, 1 \- fast, 2 \- full (trellis) adaptive B frame scheduling. Default 2
.TP
\fB\-\-[no\-]b\-pyramid\fR
Use B\-frames as references. Default enabled
.TP
\fB\-\-ref\fR <integer>
max number of L0 references to be allowed (1 .. 16) Default 3
.TP
\fB\-\-qpfile\fR <string>
Force frametypes and QPs for some or all frames
Format of each line: framenumber frametype QP
QP is optional (none lets x265 choose). Frametypes: I,i,P,B,b.
QPs are restricted by qpmin/qpmax.
.SS "Rate control, Quantization:"
.TP
\fB\-\-bitrate\fR <integer>
Target bitrate (kbps) for ABR (implied). Default 0
.TP
\fB\-q\fR/\-\-qp <integer>
QP for P slices in CQP mode (implied). \fB\-\-ipratio\fR and \fB\-\-pbration\fR determine other slice QPs
.TP
\fB\-\-crf\fR <float>
Quality\-based VBR (0\-51). Default 28.000000
.TP
\fB\-\-[no\-]lossless\fR
Enable lossless: bypass transform, quant and loop filters globally. Default disabled
.TP
\fB\-\-crf\-max\fR <float>
With CRF+VBV, limit RF to this value. Default 0.000000
May cause VBV underflows!
.TP
\fB\-\-crf\-min\fR <float>
With CRF+VBV, limit RF to this value. Default 0.000000
this specifies a minimum rate factor value for encode!
.TP
\fB\-\-vbv\-maxrate\fR <integer>
Max local bitrate (kbit/s). Default 0
.TP
\fB\-\-vbv\-bufsize\fR <integer>
Set size of the VBV buffer (kbit). Default 0
.TP
\fB\-\-vbv\-init\fR <float>
Initial VBV buffer occupancy (fraction of bufsize or in kbits). Default 0.900000
.TP
\fB\-\-aq\-mode\fR <integer>
Mode for Adaptive Quantization \- 0:none 1:uniform AQ 2:auto variance. Default 2
.TP
\fB\-\-aq\-strength\fR <float>
Reduces blocking and blurring in flat and textured areas.(0 to 3.0). Default 1.000000
.TP
\fB\-\-[no\-]cutree\fR
Enable cutree for Adaptive Quantization. Default enabled
.TP
\fB\-\-ipratio\fR <float>
QP factor between I and P. Default 1.400000
.TP
\fB\-\-pbratio\fR <float>
QP factor between P and B. Default 1.300000
.TP
\fB\-\-cbqpoffs\fR <integer>
Chroma Cb QP Offset. Default 0
.TP
\fB\-\-crqpoffs\fR <integer>
Chroma Cr QP Offset. Default 0
.TP
\fB\-\-stats\fR
Filename for stats file in multipass pass rate control. Default x265_2pass.log
.TP
\fB\-\-pass\fR
Multi pass rate control.
1: First pass, creates stats file
2: Last pass, does not overwrite stats file
3: Nth pass, overwrites stats file
.TP
\fB\-\-[no\-]slow\-firstpass\fR
Enable a slow first pass in a multipass rate control mode. Default disabled
.TP
\fB\-\-analysis\-mode\fR <string|int>
save \- Dump analysis info into file, load \- Load analysis buffers from the file. Default 0
.TP
\fB\-\-analysis\-file\fR <filename>
Specify file name used for either dumping or reading analysis data.
.TP
\fB\-\-scaling\-list\fR <string>
Specify a file containing HM style quant scaling lists or 'default' or 'off'. Default: off
.TP
\fB\-\-lambda\-file\fR <string>
Specify a file containing replacement values for the lambda tables
MAX_MAX_QP+1 floats for lambda table, then again for lambda2 table
Blank lines and lines starting with hash(#) are ignored
Comma is considered to be white\-space
.SS "Loop filters (deblock and SAO):"
.TP
\fB\-\-[no\-]lft\fR
Enable Deblocking Loop Filter. Default enabled
.TP
\fB\-\-[no\-]sao\fR
Enable Sample Adaptive Offset. Default enabled
.TP
\fB\-\-[no\-]sao\-non\-deblock\fR
Use non\-deblocked pixels, else right/bottom boundary areas skipped. Default disabled
.SS "VUI options:"
.TP
\fB\-\-sar\fR <width:height|int>
Sample Aspect Ratio, the ratio of width to height of an individual pixel.
Choose from 0=undef, 1=1:1("square"), 2=12:11, 3=10:11, 4=16:11,
5=40:33, 6=24:11, 7=20:11, 8=32:11, 9=80:33, 10=18:11, 11=15:11,
12=64:33, 13=160:99, 14=4:3, 15=3:2, 16=2:1 or custom ratio of <int:int>. Default 0
.TP
\fB\-\-crop\-rect\fR <string>
Add 'left,top,right,bottom' to the bitstream\-level cropping rectangle
.TP
\fB\-\-overscan\fR <string>
Specify whether it is appropriate for decoder to show cropped region: undef, show or crop. Default undef
.TP
\fB\-\-videoformat\fR <string>
Specify video format from undef, component, pal, ntsc, secam, mac. Default undef
.TP
\fB\-\-range\fR <string>
Specify black level and range of luma and chroma signals as full or limited Default limited
.TP
\fB\-\-colorprim\fR <string>
Specify color primaries from undef, bt709, bt470m, bt470bg, smpte170m,
smpte240m, film, bt2020. Default undef
.TP
\fB\-\-transfer\fR <string>
Specify transfer characteristics from undef, bt709, bt470m, bt470bg, smpte170m,
smpte240m, linear, log100, log316, iec61966\-2\-4, bt1361e, iec61966\-2\-1,
bt2020\-10, bt2020\-12. Default undef
.TP
\fB\-\-colormatrix\fR <string>
Specify color matrix setting from undef, bt709, fcc, bt470bg, smpte170m,
smpte240m, GBR, YCgCo, bt2020nc, bt2020c. Default undef
.TP
\fB\-\-chromaloc\fR <integer>
Specify chroma sample location (0 to 5). Default of 0
.SS "Bitstream options:"
.TP
\fB\-\-[no\-]info\fR
Emit SEI identifying encoder and parameters. Default enabled
.TP
\fB\-\-[no\-]aud\fR
Emit access unit delimiters at the start of each access unit. Default disabled
.TP
\fB\-\-[no\-]hrd\fR
Enable HRD parameters signalling. Default disabled
.TP
\fB\-\-[no\-]repeat\-headers\fR
Emit SPS and PPS headers at each keyframe. Default disabled
.TP
\fB\-\-hash\fR <integer>
Decoded Picture Hash SEI 0: disabled, 1: MD5, 2: CRC, 3: Checksum. Default 0
.SS "Reconstructed video options (debugging):"
.TP
\fB\-r\fR/\-\-recon <filename>
Reconstructed raw image YUV or Y4M output file name
.TP
\fB\-\-recon\-depth\fR <integer>
Bit\-depth of reconstructed raw image file. Defaults to input bit depth, or 8 if Y4M
.PP
.SH "SEE ALSO"
Full documentation may be found at
http://x265.readthedocs.org/en/default/cli.html.