Input Options:

--input <filename>

Raw YUV or Y4M input file name. `-` for stdin

--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

--dolby-vision-profile <float|integer> Specifies Dolby Vision profile ID. Currently, only profile 5, profile 8.1 and profile 8.2 are enabled. Specified as '5' or '50'. Default 0 (disabled).

--dolby-vision-rpu <filename> File containing Dolby Vision RPU metadata.

If given, x265's Dolby Vision metadata parser will fill the RPU field of input pictures with the metadata read from the file. Default NULL (disabled).

--nalu-file <filename>

Text file containing SEI messages in the following format : <POC><space><PREFIX><space><NAL UNIT TYPE>/<SEI TYPE><space><SEI Payload>

-f/--frames <integer> Maximum number of frames to encode. Default all

--seek <integer>

First frame to encode

--[no-]field

Enable or disable field coding. Default disabled

--[no-]copy-pic

Copy buffers of input picture in the frame. Default enabled

Quality reporting metrics:

--[no-]ssim

Enable reporting SSIM metric scores. Default disabled

--[no-]psnr

Enable reporting PSNR metric scores. Default disabled

Profile, Level, Tier: -P/--profile <string> Enforce an encode profile: main, main10, mainstillpicture

--level-idc <integer|float>

Force a minimum required decoder level (as '5.0' or '50')

--[no-]high-tier

If a decoder level is specified, this modifier selects the High tier of that level

--uhd-bd

Enable UHD Bluray compatibility support

--[no-]allow-non-conformance

Allow the encoder to generate profile NONE bitstreams. Default disabled

Threading, performance:

--pools <integer,...>

Comma-separated thread count per thread pool (pool per NUMA node) '-' implies no threads on node, '+' implies one thread per core on node

-F/--frame-threads <integer> Number of concurrently encoded frames. 0: auto-determined by core count

--[no-]wpp

Enable Wavefront Parallel Processing. Default enabled

--[no-]slices <integer>

Enable Multiple Slices feature. Default 1

--[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, grain, zerolatency, fastdecode

Quad-Tree size and depth: -s/--ctu <64|32|16> Maximum CU size (WxH). Default 64

--min-cu-size <64|32|16|8>

Minimum CU size (WxH). Default 8

--max-tu-size <32|16|8|4>

Maximum TU size (WxH). Default 32

--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

--limit-tu <0..4>

Enable early exit from TU recursion for inter-coded blocks. Default 0

Analysis:

--rd <1..6>

Level of RDO in mode decision 1:least....6:full RDO. Default 3

--[no-]psy-rd <0..5.0>

Strength of psycho-visual rate-distortion optimization, 0 to disable. Default 2.0

--[no-]rdoq-level <0|1|2>

Level of RDO in quantization - 0:none. - 1:levels. - 2:levels & coding groups.

Default 0

--[no-]psy-rdoq <0..50.0>

Strength of psycho-visual optimization in RDO quantization, 0 to disable. Default 0.0

--dynamic-rd <0..4.0>

Strength of dynamic RD, 0 to disable. Default 0.00

--[no-]ssim-rd

Enable ssim rate-distortion optimization, 0 to disable. Default disabled

--[no-]rd-refine

Enable QP-based RD refinement for rd levels 5 and 6. Default disabled

--[no-]early-skip

Enable early SKIP detection. Default enabled

--rskip <Integer>

Enable recursion skip for an early exit from CTU analysis during inter-prediction. - 0: disabled. - 1: exit using RD cost & CU homogeneity. - 2: exit using CU edge density.

Default 1

--ctu-info <integer>

Enable receiving ctu information asynchronously and determine the reaction to the CTU information (0, 1, 2, 4, 6) Default 0 - 1: force the partitions if CTU information is present - 2: functionality of (1) and reduce qp if CTU information has changed - 4: functionality of (1) and force Inter modes when CTU Information has changed, merge/skip otherwise Enable this option only when planning to invoke the API function x265_encoder_ctu_info to copy ctu-info asynchronously

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

Temporal / motion search options:

--max-merge <1..5>

Maximum number of merge candidates. Default 3

--ref <integer>

max number of L0 references to be allowed (1 .. 16) Default 3

--limit-refs <0|1|2|3>

Limit references per depth (1) or CU (2) or both (3). Default 1

--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

--[no-]rect

Enable rectangular motion partitions Nx2N and 2NxN. Default disabled

--[no-]amp

Enable asymmetric motion partitions, requires --rect. Default disabled

--[no-]limit-modes

Limit rectangular and asymmetric motion predictions. Default 0

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 enabled

--[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

--cra-nal

Force nal type to CRA to all frames except the first frame, works only with keyint 1. Default disabled

-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

--gop-lookahead <integer>

Extends gop boundary if a scenecut is found within this from keyint boundary. Default 0

--no-scenecut

Disable adaptive I-frame decision

--scenecut <integer>

How aggressively to insert extra I-frames. Default 40

--hist-scenecut

Enables histogram-based scene-cut detection using a histogram-based algorithm.

--no-hist-scenecut

Disables histogram-based scene-cut detection using a histogram-based algorithm.

--[no-]fades

Enable detection and handling of fade-in regions. Default disabled

--radl <integer>

Number of RADL pictures allowed in front of IDR. Default 0

--intra-refresh

Use Periodic Intra Refresh instead of IDR frames

--rc-lookahead <integer>

Number of frames for frame-type lookahead (determines encoder latency) Default 20

--lookahead-threads <integer> Number of threads to be dedicated to perform lookahead only. Default 0

-b/--bframes <0..16> Maximum number of consecutive b-frames. Default 4

--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

--[no-]-hrd-concat

Set HRD concatenation flag for the first keyframe in the buffering period SEI. Default disabled

Rate control, Adaptive Quantization:

--bitrate <integer>

Target bitrate (kbps) for ABR (implied). Default 0

--crf <float>

Quality-based VBR (0-51). Default 28.0

--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 0.90

--vbv-end <float>

Final VBV buffer emptiness (fraction of bufsize or in kbits). Default 0 (disabled)

--min-vbv-fullness <double>

Minimum VBV fullness percentage to be maintained. Default 50.00

--max-vbv-fullness <double>

Maximum VBV fullness percentage to be maintained. Default 80.00

--vbv-end-fr-adj <float>

Frame from which qp has to be adjusted to achieve final decode buffer emptiness. Default 0

--chunk-start <integer>

First frame of the chunk. Default 0 (disabled)

--chunk-end <integer>

Last frame of the chunk. Default 0 (disabled)

--pass

Multi pass rate control. - 1 : First pass, creates stats file - 2 : Last pass, does not overwrite the stats file - 3 : Nth pass, overwrites the stats file

--[no-]multi-pass-opt-analysis

Refine analysis in 2 pass based on analysis information from pass 1

--[no-]multi-pass-opt-distortion Use distortion of CTU from pass 1 to refine qp in 2 pass

--[no-]vbv-live-multi-pass

Enable real-time VBV in rate control 2 pass. Default disabled

--stats

Filename for stats file in multipass pass rate control. Default x265_2pass.log

--[no-]analyze-src-pics

Motion estimation uses source frame planes. Default disable

--[no-]slow-firstpass

Enable a slow first pass in a multipass rate control mode. Default enabled

--[no-]strict-cbr

Enable stricter conditions and tolerance for bitrate deviations in CBR mode. Default disabled

--analysis-save <filename>

Dump analysis info into the specified file. Default Disabled

--analysis-load <filename>

Load analysis buffers from the file specified. Default Disabled

--analysis-reuse-file <filename>

Specify the file name used for either dumping or reading analysis data. Default x265_analysis.dat

--analysis-reuse-level <1..10>

Level of analysis reuse indicates the amount of info stored/reused in save/load mode, 1:least..10:most. Now deprecated. Default 0

--analysis-save-reuse-level <1..10> Indicates the amount of analysis info stored in save mode, 1:least..10:most. Default 0

--analysis-load-reuse-level <1..10> Indicates the amount of analysis info reused in load mode, 1:least..10:most. Default 0

--refine-analysis-type <string>

Reuse analysis information received through API call. Supported options are AVC and HEVC. Default disabled - 0

--scale-factor <int>

Specify the factor by which the input video is scaled down for analysis save mode. Default 0

--refine-intra <0..4>

Enable intra-refinement for encode that uses analysis-load. - 0 : Forces both mode and depth from the save encode. - 1 : Functionality of (0) + evaluate all intra modes at min-cu-size's depth when current depth is one smaller than min-cu-size's depth. - 2 : Functionality of (1) + irrespective of size evaluates all angular modes when the save encode decides the best mode as angular. - 3 : Functionality of (1) + irrespective of size evaluates all intra modes. - 4 : Re-evaluate all intra blocks, does not reuse data from save encode.

Default:0

--refine-inter <0..3>

Enable inter refinement for encode that uses analysis-load. - 0 : Forces both mode and depth from the save encode. - 1 : Functionality of (0) + evaluate all inter modes at min-cu-size's depth when current depth is one smaller than

min-cu-size's depth. When save encode decides the current block as skip(for all sizes) evaluate skip/merge.

- 2 : Functionality of (1) + irrespective of size restricts the modes evaluated when specific modes are decided as the best mode by the save encode. - 3 : Functionality of (1) + irrespective of size evaluates all inter modes.

Default:0

--[no-]dynamic-refine

Dynamically changes refine-inter level for each CU. Default disabled

--refine-mv <1..3>

Enable mv refinement for load mode. Default 1

--refine-ctu-distortion

Store/normalize ctu distortion in analysis-save/load. - 0 : Disabled. - 1 : Store/Load ctu distortion to/from the file specified in analysis-save/load.

Default 0 - Disabled

--aq-mode <integer>

Mode for Adaptive Quantization - 0:none - 1:uniform AQ - 2:auto variance - 3:auto variance with bias to dark scenes - 4:auto variance with edge information.

Default 2

--[no-]hevc-aq

Mode for HEVC Adaptive Quantization. Default disabled

--aq-strength <float>

Reduces blocking and blurring in flat and textured areas (0 to 3.0). Default 1.00

--qp-adaptation-range <float> Delta QP range by QP adaptation based on a psycho-visual model (1.0 to 6.0). Default 1.00

--[no-]aq-motion

Block level QP adaptation based on the relative motion between the block and the frame. Default disabled

--qg-size <int>

Specifies the size of the quantization group (64, 32, 16, 8). Default 32

--[no-]cutree

Enable cutree for Adaptive Quantization. Default enabled

--[no-]rc-grain

Enable rate-control mode to handle grains specifically. Turned on with tune grain. Default disabled

--[no-]const-vbv

Enable consistent vbv. Turned on with tune grain. Default disabled

--zonefile <filename>

Zone file containing the zone boundaries and the parameters to be reconfigured.

--no-zonefile-rc-init

This allows the use of rate-control history across zones in zonefile.

--max-ausize-factor <float>

This value controls the maximum AU size defined in the specification. It represents the percentage of maximum AU size used. Default 1.0

Loop filters (deblock and SAO):

--[no-]deblock

Enable Deblocking Loop Filter, optionally specify tC: Beta offsets Default enabled

--[no-]sao

Enable Sample Adaptive Offset. Default enabled

--[no-]limit-sao

Limit Sample Adaptive Offset types. Default disabled

--selective-sao <int>

Enable slice-level SAO filter. Default 0

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

--videoformat <string>

Specify video format from unknown, component, pal, ntsc, secam, mac. Default unknown

--range <string>

Specify black level and range of luma and chroma signals as full or limited Default limited

--colorprim <string>

Specify color primaries from bt709, unknown, reserved, bt470m, bt470bg, smpte170m, smpte240m, film, bt2020, smpte428, smpte431, smpte432. Default unknown

--transfer <string>

Specify transfer characteristics from bt709, unknown, reserved, bt470m, bt470bg, smpte170m, smpte240m, linear, log100, log316, iec61966-2-4, bt1361e, iec61966-2-1, bt2020-10, bt2020-12, smpte2084, smpte428, arib-std-b67. Default unknown

--master-display <string>

SMPTE ST 2086 master display color volume info SEI (HDR) format: G(x,y)B(x,y)R(x,y)WP(x,y)L(max,min)

--max-cll <string>

Specify content light level info SEI as "cll,fall" (HDR).

--video-signal-type-preset <string>

Specify combinations of color primaries, transfer characteristics, color matrix, range of luma and chroma signals, and chroma sample location format: <system-id>[:<color-volume>] This has higher precedence than individual VUI parameters. If any individual VUI option is specified together with this, which changes the values set corresponding to the system-id or color-volume, it will be discarded. The color-volume can be used only with the system-id options BT2100_PQ_YCC, BT2100_PQ_ICTCP, and BT2100_PQ_RGB. system-id options and their corresponding values:

BT601_525:

--colorprim smpte170m --transfer smpte170m --colormatrix smpte170m --range limited --chromaloc 0

BT601_626:

--colorprim bt470bg --transfer smpte170m --colormatrix bt470bg --range limited --chromaloc 0

BT709_YCC:

--colorprim bt709 --transfer bt709 --colormatrix bt709 --range limited --chromaloc 0

BT709_RGB:

--colorprim bt709 --transfer bt709 --colormatrix gbr --range limited

BT2020_YCC_NCL:

--colorprim bt2020 --transfer bt2020-10 --colormatrix bt709 --range limited --chromaloc 2

BT2020_RGB:

--colorprim bt2020 --transfer smpte2084 --colormatrix bt2020nc --range limited

BT2100_PQ_YCC:

--colorprim bt2020 --transfer smpte2084 --colormatrix bt2020nc --range limited --chromaloc 2

BT2100_PQ_ICTCP: --colorprim bt2020 --transfer smpte2084 --colormatrix ictcp --range limited --chromaloc 2

BT2100_PQ_RGB: --colorprim bt2020 --transfer smpte2084 --colormatrix gbr --range limited BT2100_HLG_YCC: --colorprim bt2020 --transfer arib-std-b67 --colormatrix bt2020nc --range limited --chromaloc 2 BT2100_HLG_RGB: --colorprim bt2020 --transfer arib-std-b67 --colormatrix gbr --range limited FR709_RGB: --colorprim bt709 --transfer bt709 --colormatrix gbr --range full FR2020_RGB: --colorprim bt2020 --transfer bt2020-10 --colormatrix gbr --range full FRP3D65_YCC: --colorprim smpte432 --transfer bt709 --colormatrix smpte170m --range full --chromaloc 1

color-volume options and their corresponding values:

P3D65x1000n0005: --master-display G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(10000000,5) P3D65x4000n005: --master-display G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(40000000,50) BT2100x108n0005: --master-display G(8500,39850)B(6550,2300)R(34000,146000)WP(15635,16450)L(10000000,1)

--[no-]cll

Emit content light level info SEI. Default enabled

--[no-]hdr10

Control dumping of HDR10 SEI packet. If max-cll or master-display has non-zero values, this is enabled. Default disabled

--[no-]hdr-opt

Add luma and chroma offsets for HDR/WCG content. Default disabled. Now deprecated.

--[no-]hdr10-opt

Block-level QP optimization for HDR10 content. Default disabled.

--min-luma <integer>

Minimum luma plane value of input source picture

--max-luma <integer>

Maximum luma plane value of input source picture

Bitstream options:

--[no-]repeat-headers

Emit SPS and PPS headers at each keyframe. Default disabled

--[no-]info

Emit SEI identifying encoder and parameters. Default enabled

--[no-]hrd

Enable HRD parameters signaling. Default disabled

--[no-]idr-recovery-sei

Emit recovery point infor SEI at each IDR frame

--temporal-layers

Enable a temporal sublayer for unreferenced B frames. Default disabled

--[no-]aud

Emit access unit delimiters at the start of each access unit. Default disabled

--[no-]eob

Emit end of bitstream nal unit at the end of the bitstream. Default disabled

--[no-]eos

Emit end of sequence nal unit at the end of every coded video sequence. Default disabled

--atc-sei <integer>

Emit the alternative transfer characteristics SEI message where the integer is the preferred transfer characteristic. Default disabled

--pic-struct <integer>

Set the picture structure and emit it in the picture timing SEI message. Values in the range 0..12. See D.3.3 of the HEVC spec. for a detailed explanation.

--log2-max-poc-lsb <integer>

Maximum of the picture order count

--[no-]vui-timing-info

Emit VUI timing information in the bitstream. Default enabled

--[no-]vui-hrd-info

Emit VUI HRD information in the bitstream. Default enabled

--[no-]opt-qp-pps

Dynamically optimize QP in PPS (instead of default 26) based on QPs in previous GOP. Default disabled

--[no-]opt-ref-list-length-pps

Dynamically set L0 and L1 ref list length in PPS (instead of default 0) based on values in the last GOP. Default disabled

--[no-]multi-pass-opt-rps

Enable storing commonly used RPS in SPS in multi-pass mode. Default disabled

--[no-]opt-cu-delta-qp

Optimize to signal consistent CU level delta QPs in the frame. Default disabled

--lowpass-dct

Use low-pass subband DCT approximation. Default disabled

--[no-]frame-dup

Enable Frame duplication. Default disabled

--dup-threshold <integer>

PSNR threshold for Frame duplication. Default 70

--[no-]mcstf

Enable GOP-based temporal filter. Default 0

ABR-ladder settings

--abr-ladder <file>

File containing config settings required for the generation of ABR-ladder

SEI Message Options

--film-grain <filename>

File containing Film Grain Characteristics to be written as a SEI Message

--aom-film-grain <filename>

File containing Aom Film Grain Characteristics to be written as a SEI Message

--[no-]frame-rc

Enable configuring Rate Control parameters(QP, CRF or Bitrate) at frame level.Default 0 Enable this option only when planning to invoke the API function x265_encoder_reconfig to configure Rate Control parameters

Use --fullhelp for a full listing (or --log-level full --help)

Complete documentation may be found at http://x265.readthedocs.org/en/default/cli.html

x265 [info]: build info [Linux][GCC 14.2.0][64 bit] 8bit+10bit+12bit x265 [info]: using cpu capabilities: MMX2 SSE2Fast LZCNT SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2