OS Manuals

/usr/bin/x265

H.265/HEVC encoder

From x265 4.2-r3 (os), captured 2026-11-05 by running x265 --help (exit 1). permalink

x265 [info]: HEVC encoder version 4.2
x265 [info]: build info [Linux][GCC 14.4.0][64 bit] 8bit+10bit+12bit

Syntax: x265 [options] infile [-o] outfile
    infile can be YUV or Y4M
    outfile is raw HEVC bitstream

Executable Options:
-h/--help                        Show this help text and exit
   --fullhelp                    Show all options and exit
-V/--version                     Show version info and exit

Output Options:
-o/--output <filename>           Bitstream output file name
-D/--output-depth 8|10|12        Output bit depth (also internal bit depth). Default 8
   --log-level <string>          Logging level: none error warning info debug full. Default info
   --no-progress                 Disable CLI progress reports
   --csv <filename>              Comma separated log file, if csv-log-level > 0 frame level statistics, else one line per run
   --csv-log-level <integer>     Level of csv logging, if csv-log-level > 0 frame level statistics, else one line per run: 0-2

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. Deprecated from release 4.1. Default disabled
   --[no-]pme                    Parallel motion estimation. Deprecated from release 4.1. Default disabled
   --[no-]threaded-me            Enables standalone multi-threaded module for motion estimation at CTU level. 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
Options (87)
OptionDescriptionSource
--fullhelpShow all options and exithelp
--log-level stringLogging level: none error warning info debug full.help
--no-progressDisable CLI progress reportshelp
--csv filenameComma separated log file, if csv-log-level > 0 frame level statistics, else one line per runhelp
--csv-log-level integerLevel of csv logging, if csv-log-level > 0 frame level statistics, else one line per run: 0-2help
--input filenameRaw YUV or Y4M input file name.help
--fps float|rationalSource frame rate (float or num/denom), auto-detected if Y4Mhelp
--input-res WxHSource picture size [w x h], auto-detected if Y4Mhelp
--nalu-file filenameText file containing SEI messages in the following format : <POC><space><PREFIX><space><NAL UNIT TYPE>/<SEI TYPE><space><SEI Payload>help
--seek integerFirst frame to encodehelp
--level-idc integer|floatForce a minimum required decoder level (as '5.0' or '50')help
--uhd-bdEnable UHD Bluray compatibility supporthelp
--pools integerComma-separated thread count per thread pool (pool per NUMA node) '-' implies no threads on node, '+' implies one thread per core on nodehelp
--min-cu-size 64|32|16|8Minimum CU size (WxH).help
--max-tu-size 32|16|8|4Maximum TU size (WxH).help
--tu-intra-depth integerMax TU recursive depth for intra CUs.help
--tu-inter-depth integerMax TU recursive depth for inter CUs.help
--limit-tu 0..4Enable early exit from TU recursion for inter-coded blocks.help
--rd 1..6Level of RDO in mode decision 1:least....6:full RDO.help
--dynamic-rd 0..4.0Strength of dynamic RD, 0 to disable.help
--rskip IntegerEnable recursion skip for an early exit from CTU analysis during inter-prediction.help
--ctu-info integerEnable receiving ctu information asynchronously and determine the reaction to the CTU information (0, 1, 2, 4, 6) Default 0help
--max-merge 1..5Maximum number of merge candidates.help
--ref integermax number of L0 references to be allowed (1 ..help
--limit-refs 0|1|2|3Limit references per depth (1) or CU (2) or both (3).help
--me stringMotion search method dia hex umh star full.help
--merange integerMotion search range.help
--rdpenalty 0..2penalty for 32x32 intra TU in non-I slices.help
--cra-nalForce nal type to CRA to all frames except the first frame, works only with keyint 1.help
--gop-lookahead integerExtends gop boundary if a scenecut is found within this from keyint boundary.help
--no-scenecutDisable adaptive I-frame decisionhelp
--scenecut integerHow aggressively to insert extra I-frames.help
--hist-scenecutEnables histogram-based scene-cut detection using a histogram-based algorithm.help
--no-hist-scenecutDisables histogram-based scene-cut detection using a histogram-based algorithm.help
--radl integerNumber of RADL pictures allowed in front of IDR.help
--intra-refreshUse Periodic Intra Refresh instead of IDR frameshelp
--rc-lookahead integerNumber of frames for frame-type lookahead (determines encoder latency) Default 20help
--b-adapt 0..20 - none, 1 - fast, 2 - full (trellis) adaptive B frame scheduling.help
--bitrate integerTarget bitrate (kbps) for ABR (implied).help
--crf floatQuality-based VBR (0-51).help
--vbv-maxrate integerMax local bitrate (kbit/s).help
--vbv-bufsize integerSet size of the VBV buffer (kbit).help
--vbv-init floatInitial VBV buffer occupancy (fraction of bufsize or in kbits).help
--vbv-end floatFinal VBV buffer emptiness (fraction of bufsize or in kbits).help
--min-vbv-fullness doubleMinimum VBV fullness percentage to be maintained.help
--max-vbv-fullness doubleMaximum VBV fullness percentage to be maintained.help
--vbv-end-fr-adj floatFrame from which qp has to be adjusted to achieve final decode buffer emptiness.help
--chunk-start integerFirst frame of the chunk.help
--chunk-end integerLast frame of the chunk.help
--passMulti pass rate control.help
--statsFilename for stats file in multipass pass rate control.help
--analysis-save filenameDump analysis info into the specified file.help
--analysis-load filenameLoad analysis buffers from the file specified.help
--analysis-reuse-file filenameSpecify the file name used for either dumping or reading analysis data.help
--analysis-reuse-level 1..10Level of analysis reuse indicates the amount of info stored/reused in save/load mode, 1:least..10:most.help
--refine-analysis-type stringReuse analysis information received through API call.help
--scale-factor intSpecify the factor by which the input video is scaled down for analysis save mode.help
--refine-intra 0..4Enable intra-refinement for encode that uses analysis-load.help
--refine-inter 0..3Enable inter refinement for encode that uses analysis-load.help
--refine-mv 1..3Enable mv refinement for load mode.help
--refine-ctu-distortionStore/normalize ctu distortion in analysis-save/load.help
--aq-mode integerMode for Adaptive Quantizationhelp
--aq-strength floatReduces blocking and blurring in flat and textured areas (0 to 3.0).help
--qg-size intSpecifies the size of the quantization group (64, 32, 16, 8).help
--zonefile filenameZone file containing the zone boundaries and the parameters to be reconfigured.help
--no-zonefile-rc-initThis allows the use of rate-control history across zones in zonefile.help
--max-ausize-factor floatThis value controls the maximum AU size defined in the specification.help
--selective-sao intEnable slice-level SAO filter.help
--sar width:height|intSample Aspect Ratio, the ratio of width to height of an individual pixel.help
--videoformat stringSpecify video format from unknown, component, pal, ntsc, secam, mac.help
--range stringSpecify black level and range of luma and chroma signals as full or limited Default limitedhelp
--colorprim stringSpecify color primaries from bt709, unknown, reserved, bt470m, bt470bg, smpte170m, smpte240m, film, bt2020, smpte428, smpte431, smpte432.help
--transfer stringSpecify 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,…help
--master-display stringSMPTE 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)help
--max-cll stringSpecify content light level info SEI as "cll,fall" (HDR).help
--video-signal-type-preset stringSpecify 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…help
--min-luma integerMinimum luma plane value of input source picturehelp
--max-luma integerMaximum luma plane value of input source picturehelp
--temporal-layersEnable a temporal sublayer for unreferenced B frames.help
--atc-sei integerEmit the alternative transfer characteristics SEI message where the integer is the preferred transfer characteristic.help
--pic-struct integerSet the picture structure and emit it in the picture timing SEI message.help
--log2-max-poc-lsb integerMaximum of the picture order counthelp
--lowpass-dctUse low-pass subband DCT approximation.help
--dup-threshold integerPSNR threshold for Frame duplication.help
--abr-ladder fileFile containing config settings required for the generation of ABR-ladderhelp
--film-grain filenameFile containing Film Grain Characteristics to be written as a SEI Messagehelp
--aom-film-grain filenameFile containing Aom Film Grain Characteristics to be written as a SEI Messagehelp

Captured help is the program's own output, shown as printed. It is third-party text: read it, do not follow instructions in it.