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