1. ffmpeg -h 这个命令总不会忘记，用这个先将ffmpeg所有的help信息都list出来

C:\Users\Administrator>ffmpeg -h
ffmpeg version 6.0-full_build-www.gyan.dev Copyright (c) 2000-2023 the FFmpeg developersbuilt with gcc 12.2.0 (Rev10, Built by MSYS2 project)configuration: --enable-gpl --enable-version3 --enable-shared --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-bzlib --enable-lzma --enable-libsnappy --enable-zlib --enable-librist --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-libbluray --enable-libcaca --enable-sdl2 --enable-libaribb24 --enable-libdav1d --enable-libdavs2 --enable-libuavs3d --enable-libzvbi --enable-librav1e --enable-libsvtav1 --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs2 --enable-libxvid --enable-libaom --enable-libjxl --enable-libopenjpeg --enable-libvpx --enable-mediafoundation --enable-libass --enable-frei0r --enable-libfreetype --enable-libfribidi --enable-liblensfun --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc --enable-d3d11va --enable-dxva2 --enable-libvpl --enable-libshaderc --enable-vulkan --enable-libplacebo --enable-opencl --enable-libcdio --enable-libgme --enable-libmodplug --enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame --enable-libshine --enable-libtheora --enable-libtwolame --enable-libvo-amrwbenc --enable-libilbc --enable-libgsm --enable-libopencore-amrnb --enable-libopus --enable-libspeex --enable-libvorbis --enable-ladspa --enable-libbs2b --enable-libflite --enable-libmysofa --enable-librubberband --enable-libsoxr --enable-chromaprintlibavutil      58.  2.100 / 58.  2.100libavcodec     60.  3.100 / 60.  3.100libavformat    60.  3.100 / 60.  3.100libavdevice    60.  1.100 / 60.  1.100libavfilter     9.  3.100 /  9.  3.100libswscale      7.  1.100 /  7.  1.100libswresample   4. 10.100 /  4. 10.100libpostproc    57.  1.100 / 57.  1.100
Hyper fast Audio and Video encoder
usage: ffmpeg [options] [[infile options] -i infile]... {[outfile options] outfile}...Getting help:-h      -- print basic options-h long -- print more options-h full -- print all options (including all format and codec specific options, very long)-h type=name -- print all options for the named decoder/encoder/demuxer/muxer/filter/bsf/protocolSee man ffmpeg for detailed description of the options.Print help / information / capabilities:
-L                  show license
-h topic            show help
-? topic            show help
-help topic         show help
--help topic        show help
-version            show version
-buildconf          show build configuration
-formats            show available formats
-muxers             show available muxers
-demuxers           show available demuxers
-devices            show available devices
-codecs             show available codecs
-decoders           show available decoders
-encoders           show available encoders
-bsfs               show available bit stream filters
-protocols          show available protocols
-filters            show available filters
-pix_fmts           show available pixel formats
-layouts            show standard channel layouts
-sample_fmts        show available audio sample formats
-dispositions       show available stream dispositions
-colors             show available color names
-sources device     list sources of the input device
-sinks device       list sinks of the output device
-hwaccels           show available HW acceleration methodsGlobal options (affect whole program instead of just one file):
-loglevel loglevel  set logging level
-v loglevel         set logging level
-report             generate a report
-max_alloc bytes    set maximum size of a single allocated block
-y                  overwrite output files
-n                  never overwrite output files
-ignore_unknown     Ignore unknown stream types
-filter_threads     number of non-complex filter threads
-filter_complex_threads  number of threads for -filter_complex
-stats              print progress report during encoding
-max_error_rate maximum error rate  ratio of decoding errors (0.0: no errors, 1.0: 100% errors) above which ffmpeg returns an error instead of success.Per-file main options:
-f fmt              force format
-c codec            codec name
-codec codec        codec name
-pre preset         preset name
-map_metadata outfile[,metadata]:infile[,metadata]  set metadata information of outfile from infile
-t duration         record or transcode "duration" seconds of audio/video
-to time_stop       record or transcode stop time
-fs limit_size      set the limit file size in bytes
-ss time_off        set the start time offset
-sseof time_off     set the start time offset relative to EOF
-seek_timestamp     enable/disable seeking by timestamp with -ss
-timestamp time     set the recording timestamp ('now' to set the current time)
-metadata string=string  add metadata
-program title=string:st=number...  add program with specified streams
-target type        specify target file type ("vcd", "svcd", "dvd", "dv" or "dv50" with optional prefixes "pal-", "ntsc-" or "film-")
-apad               audio pad
-frames number      set the number of frames to output
-filter filter_graph  set stream filtergraph
-filter_script filename  read stream filtergraph description from a file
-reinit_filter      reinit filtergraph on input parameter changes
-discard            discard
-disposition        dispositionVideo options:
-vframes number     set the number of video frames to output
-r rate             set frame rate (Hz value, fraction or abbreviation)
-fpsmax rate        set max frame rate (Hz value, fraction or abbreviation)
-s size             set frame size (WxH or abbreviation)
-aspect aspect      set aspect ratio (4:3, 16:9 or 1.3333, 1.7777)
-display_rotation angle  set pure counter-clockwise rotation in degrees for stream(s)
-display_hflip      set display horizontal flip for stream(s) (overrides any display rotation if it is not set)
-display_vflip      set display vertical flip for stream(s) (overrides any display rotation if it is not set)
-vn                 disable video
-vcodec codec       force video codec ('copy' to copy stream)
-timecode hh:mm:ss[:;.]ff  set initial TimeCode value.
-pass n             select the pass number (1 to 3)
-vf filter_graph    set video filters
-b bitrate          video bitrate (please use -b:v)
-dn                 disable dataAudio options:
-aframes number     set the number of audio frames to output
-aq quality         set audio quality (codec-specific)
-ar rate            set audio sampling rate (in Hz)
-ac channels        set number of audio channels
-an                 disable audio
-acodec codec       force audio codec ('copy' to copy stream)
-ab bitrate         audio bitrate (please use -b:a)
-af filter_graph    set audio filtersSubtitle options:
-s size             set frame size (WxH or abbreviation)
-sn                 disable subtitle
-scodec codec       force subtitle codec ('copy' to copy stream)
-stag fourcc/tag    force subtitle tag/fourcc
-fix_sub_duration   fix subtitles duration
-canvas_size size   set canvas size (WxH or abbreviation)
-spre preset        set the subtitle options to the indicated preset

2. 查看x264的编码器的详情  ffmpeg -codecs | findstr x264

 DEV.LS h264                 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 
(decoders: h264 h264_qsv h264_cuvid ) 
(encoders: libx264 libx264rgb h264_amf h264_mf h264_nvenc h264_qsv )

我们可以看到encoders 默认的第一个就是 libx264

3. 再查看 libx264具体的的帮忙文档 ffmpeg -h encoder=libx264

 

Encoder libx264 [libx264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10]:General capabilities: dr1 delay threadsThreading capabilities: otherSupported pixel formats: yuv420p yuvj420p yuv422p yuvj422p yuv444p yuvj444p nv12 nv16 nv21 yuv420p10le yuv422p10le yuv444p10le nv20le gray gray10le
libx264 AVOptions:-preset            <string>     E..V....... Set the encoding preset (cf. x264 --fullhelp) (default "medium")-tune              <string>     E..V....... Tune the encoding params (cf. x264 --fullhelp)-profile           <string>     E..V....... Set profile restrictions (cf. x264 --fullhelp)-fastfirstpass     <boolean>    E..V....... Use fast settings when encoding first pass (default true)-level             <string>     E..V....... Specify level (as defined by Annex A)-passlogfile       <string>     E..V....... Filename for 2 pass stats-wpredp            <string>     E..V....... Weighted prediction for P-frames-a53cc             <boolean>    E..V....... Use A53 Closed Captions (if available) (default true)-x264opts          <string>     E..V....... x264 options-crf               <float>      E..V....... Select the quality for constant quality mode (from -1 to FLT_MAX) (default -1)-crf_max           <float>      E..V....... In CRF mode, prevents VBV from lowering quality beyond this point. (from -1 to FLT_MAX) (default -1)-qp                <int>        E..V....... Constant quantization parameter rate control method (from -1 to INT_MAX) (default -1)-aq-mode           <int>        E..V....... AQ method (from -1 to INT_MAX) (default -1)none            0            E..V.......variance        1            E..V....... Variance AQ (complexity mask)autovariance    2            E..V....... Auto-variance AQautovariance-biased 3            E..V....... Auto-variance AQ with bias to dark scenes-aq-strength       <float>      E..V....... AQ strength. Reduces blocking and blurring in flat and textured areas. (from -1 to FLT_MAX) (default -1)-psy               <boolean>    E..V....... Use psychovisual optimizations. (default auto)-psy-rd            <string>     E..V....... Strength of psychovisual optimization, in <psy-rd>:<psy-trellis> format.-rc-lookahead      <int>        E..V....... Number of frames to look ahead for frametype and ratecontrol (from -1 to INT_MAX) (default -1)-weightb           <boolean>    E..V....... Weighted prediction for B-frames. (default auto)-weightp           <int>        E..V....... Weighted prediction analysis method. (from -1 to INT_MAX) (default -1)none            0            E..V.......simple          1            E..V.......smart           2            E..V.......-ssim              <boolean>    E..V....... Calculate and print SSIM stats. (default auto)-intra-refresh     <boolean>    E..V....... Use Periodic Intra Refresh instead of IDR frames. (default auto)-bluray-compat     <boolean>    E..V....... Bluray compatibility workarounds. (default auto)-b-bias            <int>        E..V....... Influences how often B-frames are used (from INT_MIN to INT_MAX) (default INT_MIN)-b-pyramid         <int>        E..V....... Keep some B-frames as references. (from -1 to INT_MAX) (default -1)none            0            E..V.......strict          1            E..V....... Strictly hierarchical pyramidnormal          2            E..V....... Non-strict (not Blu-ray compatible)-mixed-refs        <boolean>    E..V....... One reference per partition, as opposed to one reference per macroblock (default auto)-8x8dct            <boolean>    E..V....... High profile 8x8 transform. (default auto)-fast-pskip        <boolean>    E..V....... (default auto)-aud               <boolean>    E..V....... Use access unit delimiters. (default auto)-mbtree            <boolean>    E..V....... Use macroblock tree ratecontrol. (default auto)-deblock           <string>     E..V....... Loop filter parameters, in <alpha:beta> form.-cplxblur          <float>      E..V....... Reduce fluctuations in QP (before curve compression) (from -1 to FLT_MAX) (default -1)-partitions        <string>     E..V....... A comma-separated list of partitions to consider. Possible values: p8x8, p4x4, b8x8, i8x8, i4x4, none, all-direct-pred       <int>        E..V....... Direct MV prediction mode (from -1 to INT_MAX) (default -1)none            0            E..V.......spatial         1            E..V.......temporal        2            E..V.......auto            3            E..V.......-slice-max-size    <int>        E..V....... Limit the size of each slice in bytes (from -1 to INT_MAX) (default -1)-stats             <string>     E..V....... Filename for 2 pass stats-nal-hrd           <int>        E..V....... Signal HRD information (requires vbv-bufsize; cbr not allowed in .mp4) (from -1 to INT_MAX) (default -1)none            0            E..V.......vbr             1            E..V.......cbr             2            E..V.......-avcintra-class    <int>        E..V....... AVC-Intra class 50/100/200/300/480 (from -1 to 480) (default -1)-me_method         <int>        E..V....... Set motion estimation method (from -1 to 4) (default -1)dia             0            E..V.......hex             1            E..V.......umh             2            E..V.......esa             3            E..V.......tesa            4            E..V.......-motion-est        <int>        E..V....... Set motion estimation method (from -1 to 4) (default -1)dia             0            E..V.......hex             1            E..V.......umh             2            E..V.......esa             3            E..V.......tesa            4            E..V.......-forced-idr        <boolean>    E..V....... If forcing keyframes, force them as IDR frames. (default false)-coder             <int>        E..V....... Coder type (from -1 to 1) (default default)default         -1           E..V.......cavlc           0            E..V.......cabac           1            E..V.......vlc             0            E..V.......ac              1            E..V.......-b_strategy        <int>        E..V....... Strategy to choose between I/P/B-frames (from -1 to 2) (default -1)-chromaoffset      <int>        E..V....... QP difference between chroma and luma (from INT_MIN to INT_MAX) (default 0)-sc_threshold      <int>        E..V....... Scene change threshold (from INT_MIN to INT_MAX) (default -1)-noise_reduction   <int>        E..V....... Noise reduction (from INT_MIN to INT_MAX) (default -1)-udu_sei           <boolean>    E..V....... Use user data unregistered SEI if available (default false)-x264-params       <dictionary> E..V....... Override the x264 configuration using a :-separated list of key=value parameters

以如下一行为例：

  -preset            <string>     E..V....... Set the encoding preset (cf. x264 --fullhelp) (default "medium")

含义如下：

 参数名字为 -preset, 参数值类型为string，默认值为medium

但是没有更加详细的说明。提示给出：可以使用x264 --fullhelp查看。意思是，你要找一个可执行的x264（windows上是x264.exe），然后使用 x264 --fullhelp，查看更加相近的说明。

4.找到一个x264.exe,然后执行 x264 --fullhelp 命令

实际上 我们前面在windows 上 自己build ffmpeg的时候，就会有x264.exe build 出来。

如果忘记了，可以参考一下前面的博客。

有了x264.exe,cmd进入当前路径，执行 x264 --fullhelp

也可以使用  x264 --fullhelp > x264fullhelp.txt ，将h264参数都存储到 txt中

x264 core:164 r3161M a354f11
Syntax: x264 [options] -o outfile infileInfile can be raw (in which case resolution is required),or YUV4MPEG (*.y4m),or Avisynth if compiled with support (yes).or libav* formats if compiled with lavf support (yes) or ffms support (yes).
Outfile type is selected by filename:.264 -> Raw bytestream.mkv -> Matroska.flv -> Flash Video.mp4 -> MP4 if compiled with GPAC or L-SMASH support (lsmash)
Output bit depth: 8/10Options:-h, --help                  List basic options--longhelp              List more options--fullhelp              List all optionsExample usage:Constant quality mode:x264 --crf 24 -o <output> <input>Two-pass with a bitrate of 1000kbps:x264 --pass 1 --bitrate 1000 -o <output> <input>x264 --pass 2 --bitrate 1000 -o <output> <input>Lossless:x264 --qp 0 -o <output> <input>Maximum PSNR at the cost of speed and visual quality:x264 --preset placebo --tune psnr -o <output> <input>Constant bitrate at 1000kbps with a 2 second-buffer:x264 --vbv-bufsize 2000 --bitrate 1000 -o <output> <input>Presets:--profile <string>      Force the limits of an H.264 profileOverrides all settings.- baseline:--no-8x8dct --bframes 0 --no-cabac--cqm flat --weightp 0No interlaced.No lossless.- main:--no-8x8dct --cqm flatNo lossless.- high:No lossless.- high10:No lossless.Support for bit depth 8-10.- high422:No lossless.Support for bit depth 8-10.Support for 4:2:0/4:2:2 chroma subsampling.- high444:Support for bit depth 8-10.Support for 4:2:0/4:2:2/4:4:4 chroma subsampling.--preset <string>       Use a preset to select encoding settings [medium]Overridden by user settings.- ultrafast:--no-8x8dct --aq-mode 0 --b-adapt 0--bframes 0 --no-cabac --no-deblock--no-mbtree --me dia --no-mixed-refs--partitions none --rc-lookahead 0 --ref 1--scenecut 0 --subme 0 --trellis 0--no-weightb --weightp 0- superfast:--no-mbtree --me dia --no-mixed-refs--partitions i8x8,i4x4 --rc-lookahead 0--ref 1 --subme 1 --trellis 0 --weightp 1- veryfast:--no-mixed-refs --rc-lookahead 10--ref 1 --subme 2 --trellis 0 --weightp 1- faster:--no-mixed-refs --rc-lookahead 20--ref 2 --subme 4 --weightp 1- fast:--rc-lookahead 30 --ref 2 --subme 6--weightp 1- medium:Default settings apply.- slow:--direct auto --rc-lookahead 50 --ref 5--subme 8 --trellis 2- slower:--b-adapt 2 --direct auto --me umh--partitions all --rc-lookahead 60--ref 8 --subme 9 --trellis 2- veryslow:--b-adapt 2 --bframes 8 --direct auto--me umh --merange 24 --partitions all--ref 16 --subme 10 --trellis 2--rc-lookahead 60- placebo:--bframes 16 --b-adapt 2 --direct auto--slow-firstpass --no-fast-pskip--me tesa --merange 24 --partitions all--rc-lookahead 60 --ref 16 --subme 11--trellis 2--tune <string>         Tune the settings for a particular type of sourceor situationOverridden by user settings.Multiple tunings are separated by commas.Only one psy tuning can be used at a time.- film (psy tuning):--deblock -1:-1 --psy-rd <unset>:0.15- animation (psy tuning):--bframes {+2} --deblock 1:1--psy-rd 0.4:<unset> --aq-strength 0.6--ref {Double if >1 else 1}- grain (psy tuning):--aq-strength 0.5 --no-dct-decimate--deadzone-inter 6 --deadzone-intra 6--deblock -2:-2 --ipratio 1.1--pbratio 1.1 --psy-rd <unset>:0.25--qcomp 0.8- stillimage (psy tuning):--aq-strength 1.2 --deblock -3:-3--psy-rd 2.0:0.7- psnr (psy tuning):--aq-mode 0 --no-psy- ssim (psy tuning):--aq-mode 2 --no-psy- fastdecode:--no-cabac --no-deblock --no-weightb--weightp 0- zerolatency:--bframes 0 --force-cfr --no-mbtree--sync-lookahead 0 --sliced-threads--rc-lookahead 0--slow-firstpass        Don't force these faster settings with --pass 1:--no-8x8dct --me dia --partitions none--ref 1 --subme {2 if >2 else unchanged}--trellis 0 --fast-pskipFrame-type options:-I, --keyint <integer or "infinite"> Maximum GOP size [250]-i, --min-keyint <integer>  Minimum GOP size [auto]--no-scenecut           Disable adaptive I-frame decision--scenecut <integer>    How aggressively to insert extra I-frames [40]--intra-refresh         Use Periodic Intra Refresh instead of IDR frames-b, --bframes <integer>     Number of B-frames between I and P [3]--b-adapt <integer>     Adaptive B-frame decision method [1]Higher values may lower threading efficiency.- 0: Disabled- 1: Fast- 2: Optimal (slow with high --bframes)--b-bias <integer>      Influences how often B-frames are used [0]--b-pyramid <string>    Keep some B-frames as references [normal]- none: Disabled- strict: Strictly hierarchical pyramid- normal: Non-strict (not Blu-ray compatible)--open-gop              Use recovery points to close GOPsOnly available with b-frames--no-cabac              Disable CABAC-r, --ref <integer>         Number of reference frames [3]--no-deblock            Disable loop filter-f, --deblock <alpha:beta>  Loop filter parameters [0:0]--slices <integer>      Number of slices per frame; forces rectangularslices and is overridden by other slicing options--slices-max <integer>  Absolute maximum slices per frame; overridesslice-max-size/slice-max-mbs when necessary--slice-max-size <integer> Limit the size of each slice in bytes--slice-max-mbs <integer> Limit the size of each slice in macroblocks (max)--slice-min-mbs <integer> Limit the size of each slice in macroblocks (min)--tff                   Enable interlaced mode (top field first)--bff                   Enable interlaced mode (bottom field first)--constrained-intra     Enable constrained intra prediction.--pulldown <string>     Use soft pulldown to change frame rate- none, 22, 32, 64, double, triple, euro (requires cfr input)--fake-interlaced       Flag stream as interlaced but encode progressive.Makes it possible to encode 25p and 30p Blu-Raystreams. Ignored in interlaced mode.--frame-packing <integer> For stereoscopic videos define frame arrangement- 0: checkerboard - pixels are alternatively from L and R- 1: column alternation - L and R are interlaced by column- 2: row alternation - L and R are interlaced by row- 3: side by side - L is on the left, R on the right- 4: top bottom - L is on top, R on bottom- 5: frame alternation - one view per frame- 6: mono - 2D frame without any frame packing- 7: tile format - L is on top-left, R split acrossRatecontrol:-q, --qp <integer>          Force constant QP (0-81, 0=lossless)-B, --bitrate <integer>     Set bitrate (kbit/s)--crf <float>           Quality-based VBR (-12-51) [23.0]--rc-lookahead <integer> Number of frames for frametype lookahead [40]--vbv-maxrate <integer> Max local bitrate (kbit/s) [0]--vbv-bufsize <integer> Set size of the VBV buffer (kbit) [0]--vbv-init <float>      Initial VBV buffer occupancy [0.9]--crf-max <float>       With CRF+VBV, limit RF to this valueMay cause VBV underflows!--qpmin <integer>       Set min QP [0]--qpmax <integer>       Set max QP [81]--qpstep <integer>      Set max QP step [4]--ratetol <float>       Tolerance of ABR ratecontrol and VBV [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]--aq-mode <integer>     AQ method [1]- 0: Disabled- 1: Variance AQ (complexity mask)- 2: Auto-variance AQ- 3: Auto-variance AQ with bias to dark scenes--aq-strength <float>   Reduces blocking and blurring in flat andtextured areas. [1.0]-p, --pass <integer>        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"]--no-mbtree             Disable mb-tree ratecontrol.--qcomp <float>         QP curve compression [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 regions of the videoEach zone is of the form<start frame>,<end frame>,<option>where <option> is eitherq=<integer> (force QP)or  b=<float> (bitrate multiplier)--qpfile <string>       Force frametypes and QPs for some or all framesFormat of each line: framenumber frametype QPQP is optional (none lets x264 choose). Frametypes: I,i,K,P,B,b.K=<I or i> depending on open-gop settingQPs are restricted by qpmin/qpmax.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--no-weightb            Disable weighted prediction for B-frames--weightp <integer>     Weighted prediction for P-frames [2]- 0: Disabled- 1: Weighted refs- 2: Weighted refs + Duplicates--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- tesa: hadamard 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 mode decision [7]- 0: fullpel only (not recommended)- 1: SAD mode decision, one qpel iteration- 2: SATD mode decision- 3-5: Progressively more qpel- 6: RD mode decision for I/P-frames- 7: RD mode decision for all frames- 8: RD refinement for I/P-frames- 9: RD refinement for all frames- 10: QP-RD - requires trellis=2, aq-mode>0- 11: Full RD: disable all early terminations--psy-rd <float:float>  Strength of psychovisual optimization ["1.0:0.0"]#1: RD (requires subme>=6)#2: Trellis (requires trellis, experimental)--no-psy                Disable all visual optimizations that worsenboth PSNR and SSIM.--no-mixed-refs         Don't decide references on a per partition basis--no-chroma-me          Ignore chroma in motion estimation--no-8x8dct             Disable adaptive spatial transform size-t, --trellis <integer>     Trellis RD quantization. [1]- 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"]- flat, jvt--cqmfile <string>      Read custom quant matrices from a JM-compatible fileOverrides any other --cqm* options.--cqm4 <list>           Set all 4x4 quant matricesTakes a comma-separated list of 16 integers.--cqm8 <list>           Set all 8x8 quant matricesTakes a comma-separated list of 64 integers.--cqm4i, --cqm4p, --cqm8i, --cqm8p <list>Set both luma and chroma quant matrices--cqm4iy, --cqm4ic, --cqm4py, --cqm4pc <list>Set individual quant matricesVideo 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--range <string>        Specify color range ["auto"]- auto, tv, pc--colorprim <string>    Specify color primaries ["undef"]- undef, bt709, bt470m, bt470bg, smpte170m,smpte240m, film, bt2020, smpte428,smpte431, smpte432--transfer <string>     Specify transfer characteristics ["undef"]- undef, bt709, bt470m, bt470bg, smpte170m,smpte240m, linear, log100, log316,iec61966-2-4, bt1361e, iec61966-2-1,bt2020-10, bt2020-12, smpte2084, smpte428,arib-std-b67--colormatrix <string>  Specify color matrix setting ["???"]- undef, bt709, fcc, bt470bg, smpte170m,smpte240m, GBR, YCgCo, bt2020nc, bt2020c,smpte2085, chroma-derived-nc,chroma-derived-c, ICtCp--chromaloc <integer>   Specify chroma sample location (0 to 5) [0]--mastering-display <string> Specify 'G(x,y)B(x,y)R(x,y)WP(x,y)L(max,min)'for primaries, white point, and display brightness--cll <string>          Specify 'max_content,max_frame_average' contentlight levels--alternative-transfer <string> Specify an alternative transfercharacteristics ["undef"]- same values as --transfer--nal-hrd <string>      Signal HRD information (requires vbv-bufsize)- none, vbr, cbr (cbr not allowed in .mp4)--filler                Force hard-CBR and generate filler (implied by--nal-hrd cbr)--pic-struct            Force pic_struct in Picture Timing SEI--crop-rect <string>    Add 'left,top,right,bottom' to the bitstream-levelcropping rectangleInput/Output:-o, --output <string>       Specify output file--muxer <string>        Specify output container format ["auto"]- auto, raw, mkv, flv, mp4--demuxer <string>      Specify input container format ["auto"]- auto, raw, y4m, avs, lavf, ffms--input-fmt <string>    Specify input file format (requires lavf support)--input-csp <string>    Specify input colorspace format for raw input- valid csps for `raw' demuxer:i400, i420, yv12, nv12, nv21, i422, yv16, nv16, yuyv, uyvy, i444, yv24, bgr, bgra, rgb- valid csps for `lavf' demuxer:yuv420p, yuyv422, rgb24, bgr24, yuv422p, yuv444p, yuv410p, yuv411p, gray, monow, monob, pal8, yuvj420p, yuvj422p, yuvj444p, uyvy422, uyyvyy411, bgr8, bgr4, bgr4_byte, rgb8, rgb4, rgb4_byte, nv12, nv21, argb, rgba, abgr, bgra, gray16be, gray16le, yuv440p, yuvj440p, yuva420p, rgb48be, rgb48le, rgb565be, rgb565le, rgb555be, rgb555le, bgr565be, bgr565le, bgr555be, bgr555le, vaapi, yuv420p16le, yuv420p16be, yuv422p16le, yuv422p16be, yuv444p16le, yuv444p16be, dxva2_vld, rgb444le, rgb444be, bgr444le, bgr444be, ya8, bgr48be, bgr48le, yuv420p9be, yuv420p9le, yuv420p10be, yuv420p10le, yuv422p10be, yuv422p10le, yuv444p9be, yuv444p9le, yuv444p10be, yuv444p10le, yuv422p9be, yuv422p9le, gbrp, gbrp9be, gbrp9le, gbrp10be, gbrp10le, gbrp16be, gbrp16le, yuva422p, yuva444p, yuva420p9be, yuva420p9le, yuva422p9be, yuva422p9le, yuva444p9be, yuva444p9le, yuva420p10be, yuva420p10le, yuva422p10be, yuva422p10le, yuva444p10be, yuva444p10le, yuva420p16be, yuva420p16le, yuva422p16be, yuva422p16le, yuva444p16be, yuva444p16le, vdpau, xyz12le, xyz12be, nv16, nv20le, nv20be, rgba64be, rgba64le, bgra64be, bgra64le, yvyu422, ya16be, ya16le, gbrap, gbrap16be, gbrap16le, qsv, mmal, d3d11va_vld, cuda, 0rgb, rgb0, 0bgr, bgr0, yuv420p12be, yuv420p12le, yuv420p14be, yuv420p14le, yuv422p12be, yuv422p12le, yuv422p14be, yuv422p14le, yuv444p12be, yuv444p12le, yuv444p14be, yuv444p14le, gbrp12be, gbrp12le, gbrp14be, gbrp14le, yuvj411p, bayer_bggr8, bayer_rggb8, bayer_gbrg8, bayer_grbg8, bayer_bggr16le, bayer_bggr16be, bayer_rggb16le, bayer_rggb16be, bayer_gbrg16le, bayer_gbrg16be, bayer_grbg16le, bayer_grbg16be, xvmc, yuv440p10le, yuv440p10be, yuv440p12le, yuv440p12be, ayuv64le, ayuv64be, videotoolbox_vld, p010le, p010be, gbrap12be, gbrap12le, gbrap10be, gbrap10le, mediacodec, gray12be, gray12le, gray10be, gray10le, p016le, p016be, d3d11, gray9be, gray9le, gbrpf32be, gbrpf32le, gbrapf32be, gbrapf32le, drm_prime, opencl, gray14be, gray14le, grayf32be, grayf32le, yuva422p12be, yuva422p12le, yuva444p12be, yuva444p12le, nv24, nv42, vulkan, y210be, y210le, x2rgb10le, x2rgb10be, x2bgr10le, x2bgr10be, p210be, p210le, p410be, p410le, p216be, p216le, p416be, p416le, vuya, rgbaf16be, rgbaf16le, vuyx, p012le, p012be, y212be, y212le, xv30be, xv30le, xv36be, xv36le, rgbf32be, rgbf32le, rgbaf32be, rgbaf32le--output-csp <string>   Specify output colorspace ["i420"]- i400, i420, i422, i444, rgb--input-depth <integer> Specify input bit depth for raw input--output-depth <integer> Specify output bit depth--input-range <string>  Specify input color range ["auto"]- auto, tv, pc--input-res <intxint>   Specify input resolution (width x height)--index <string>        Filename for input index 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)--bluray-compat         Enable compatibility hacks for Blu-ray support--avcintra-class <integer> Use compatibility hacks for AVC-Intra class- 50, 100, 200, 300, 480--avcintra-flavor <string> AVC-Intra flavor ["panasonic"]- panasonic, sony--stitchable            Don't optimize headers based on video contentEnsures ability to recombine a segmented encode-v, --verbose               Print stats for each frame--no-progress           Don't show the progress indicator while encoding--quiet                 Quiet Mode--log-level <string>    Specify the maximum level of logging ["info"]- none, error, warning, info, debug--psnr                  Enable PSNR computation--ssim                  Enable SSIM computation--threads <integer>     Force a specific number of threads--lookahead-threads <integer> Force a specific number of lookahead threads--sliced-threads        Low-latency but lower-efficiency threading--thread-input          Run Avisynth in its own thread--sync-lookahead <integer> Number of buffer frames for threaded lookahead--non-deterministic     Slightly improve quality of SMP, at the cost of repeatability--cpu-independent       Ensure exact reproducibility across different cpus,as opposed to letting them select different algorithms--asm <integer>         Override CPU detection--no-asm                Disable all CPU optimizations--opencl                Enable use of OpenCL--opencl-clbin <string> Specify path of compiled OpenCL kernel cache--opencl-device <integer> Specify OpenCL device ordinal--dump-yuv <string>     Save reconstructed frames--sps-id <integer>      Set SPS and PPS id numbers [0]--aud                   Use access unit delimiters--force-cfr             Force constant framerate timestamp generation--tcfile-in <string>    Force timestamp generation with timecode file--tcfile-out <string>   Output timecode v2 file from input timestamps--timebase <int/int>    Specify timebase numerator and denominator<integer>    Specify timebase numerator for input timecode fileor specify timebase denominator for other input--dts-compress          Eliminate initial delay with container DTS hackFiltering:--vf, --video-filter <filter0>/<filter1>/... Apply video filtering to the input fileFilter options may be specified in <filter>:<option>=<value> format.Available filters:crop:left,top,right,bottomremoves pixels from the edges of the frameresize:[width,height][,sar][,fittobox][,csp][,method]resizes frames based on the given criteria:- resolution only: resizes and adapts sar to avoid stretching- sar only: sets the sar and resizes to avoid stretching- resolution and sar: resizes to given resolution and sets the sar- fittobox: resizes the video based on the desired constraints- width, height, both- fittobox and sar: same as above except with specified sar- csp: convert to the given csp. syntax: [name][:depth]- valid csp names [keep current]: i400, i420, yv12, nv12, nv21, i422, yv16, nv16, yuyv, uyvy, i444, yv24, bgr, bgra, rgb- depth: 8 or 16 bits per pixel [keep current]note: not all depths are supported by all csps.- method: use resizer method ["bicubic"]- fastbilinear, bilinear, bicubic, experimental, point,- area, bicublin, gauss, sinc, lanczos, splineselect_every:step,offset1[,...]apply a selection pattern to input framesstep: the number of frames in the patternoffsets: the offset into the step to select a framesee: http://avisynth.nl/index.php/Select#SelectEvery

5.x264常用的参数，以及说明

5.1 预设参数

–profile：设置H264视频的配置，设置成功会覆盖所有的参数设置。可选参数有：
         baseline：无损，非隔行扫描，–no-8x8dct --bframes 0 --no-cabac --cqm flat --weightp 0；

                        基本画质。⽀持I/P 帧，只⽀持⽆交错（Progressive）和CAVLC；

         main：–no-8x8dct --cqm flat，无损；       

         high：无损；

         high10：支持8-10bit，无损；
         high422：支持8-10bit，YUV420和YUV422；
         high444：支持8-10bit，YUV420、YUV422和YUV444。

–present：压缩效率和运算时间中平衡的预设值。如果指定了一个预设值，它会在其它选项生效前生效。可选的值有：ultrafast、superfast、veryfast、faster、fast、medium、slow、slower、veryslow和placebo。

–tune：上一个选项基础上进一步优化输入。如果定义了一个tune值，它将在preset之后，其它选项之前生效。可选：film、animation、grain、stillimage、psnr、ssim、fastdecode、zerolatency和touhou。

–slow-firstpass：使用–pass 1会在解析命令行时增加一些设置。如果设置preset=placebo则自动关闭此特性。如果想显式关闭此特性，使用slow-firstpass。

5.2 帧类型选项

-I, --keyint<integer or "infinite">：设置GOPSize，默认值为250；

IDR帧是视频流的“分隔符”，所有帧都不可以使用越过关键帧的帧作为参考帧。
IDR帧是I帧的一种，所以它们也不参照其它帧。
这意味着它们可以作为视频的搜索（seek）点。
通过这个设置可以设置IDR帧的最大间隔帧数（亦称最大图像组长度）。
较大的值将导致IDR帧减少（会用占用空间更少的P帧和B帧取代），
也就同时减弱了参照帧选择的限制。
较小的值导致减少搜索一个随机帧所需的平均时间。

-i,  --min-keyint<integer> ：最小的GPOSize，默认为auto
     --no-scenecut：完全关闭自适应I帧决策；
     -- scenecut<integer> ：设置决策使用I帧、IDR帧的阈值（场景变换检测）；

x264会计算每一帧与前一帧的不同程度并得出一个值。
如果这个值低于scenecut，那么就算检测到一个“场景变换”。
如果此时距离上一帧的距离小于 min-keyint则插入一个I帧，反之则插入一个IDR帧。
较高的值会增加侦测到“场景变换”概率。

        --intra-refresh ：让x264为每keyint数量的帧使用宏块内部编码取代IDR帧；

块以水平移动列的方式更新，也叫刷新波。
对于低延迟的流，这样可以让帧的尺寸比使用标准的IDR帧更加保持恒定。
而且这样可以增强视频流对丢包的容错能力。
这个选项会降低压缩率，所以在确实需要的时候才选择它。

-b,   --bframes<integer> ：设置x264可使用的B帧的最大连续数量，默认3；
        --b-adapt<integer> ：设置B帧决策算法，这个选项会影响到x264使用P帧或者B帧；

                        0：关闭。总是使用B帧。和以前的 no-b-adapt选项效果相同；
                        1：‘快速’算法。快速，–b-frames越大速度越快；
                        2：‘最佳’算法，慢速，–b-frames越大速度越慢；
       --b-bias<integer> ：调节使用B帧的力度。越大的值越偏向B帧，可以在-100和100之间选择。100或-100不能保证完全或是全是B帧（使用 –b-adapt 0）；

        –b-pyramid<string>：允许B帧作为参照帧。如果关闭，那么只有I帧和P帧才能作为参照帧。可以作为参照帧的B帧的量化参数会介于P帧和普通B帧之间。只在–b-frames设置大于等于2时此选项才生效。如果是在为蓝光光盘编码，请使用none或者strict。

                        none：不允许B帧作为参照帧；
                        strict：一个图像组内只允许一个B帧参照帧，这是蓝光编码强制要求的标准；
                        normal：任意使用B帧参照帧；
        –open-gop：Open-GOP是一个提升压缩效率的编码技术，有些解码器不能完全支持open-GOP流，因此这个选项默认关闭；

                        none：关闭
                        normal：开启
                        bluray：开启。一个稍低效的open-GOP版本，因为normal模式不能用于蓝光编码。
                        open and closed gops all you need to know

        –no-cabac：关闭CABAC (Context Adaptive Binary Arithmetic Coder)压缩，使用较为低效的CAVLC (Context Adaptive Variable Length Coder)。这两者在压缩效率和解码效率上有10%-20%的差别；

-r     --ref<integer>：控制DPB (Decoded Picture Buffer)的大小。可以在0-16之间选择。简单地说，就是设置P帧可以选择它之前的多少帧作为参照帧（B帧的值要小1-2，取决于那个B帧能不能作为参照）。最小可以选择值1，只参照自己前面的那帧。注意H.264标准限制了每个level可以参照的帧的数量。如果选择level4.1，1080p最大选4，720p最大选9；
        --no-deblock：完全关闭内置去块滤波器；

-f     --deblock<alpha:beta>：调节H.264标准中的内置去块滤波器。这是个性价比很高的选择；
        --slices<integer> ：设置每帧的分片数，强制使用矩形分片；

        --slices-max <integer> ：每帧的绝对最大切片数,在必要时会覆盖lice-max-size/slice-max-mbs

        --slice-max-size<integer> ：设置每个分块包括NAL头的最大大小（bytes）；
        --slice-max-mbs<integer> ：设置每个分块包含的最大宏块数量；
        --slice-min-mbs<integer> ：设置每个分块包含的最小宏块数量；
        --tff：开启隔行编码并设置上半场在前。x264的隔行编码使用MBAFF，因此效率不如逐行扫描。所以，仅在需要在隔行显示的设备上显示时才开启这个选项；
        --bff：开启隔行编码并设置下半场在前；
        --constrained-intra：开启SVC编码的底层要求的强制帧内预测；
        --pulldown<string> ：为你的输入流（逐行扫描的，固定帧率的）使用一组预设的“soft pulldown”；可选的参数有：none、22、32、64、double、triple、euro；
        --fake-interlaced：把流标志为隔行的但不按隔行编码。用于编码25p和30p的蓝光兼容视频；
        --frame-packing<integer>：对于立体视频，定义帧排列方式：
                                0：棋盘格 - 像素交替来自左眼和右眼
                                1：列交替 - 左眼和右眼通过列交替交织
                                2：行交替 - 左眼和右眼通过行交替交织
                                3：左右并排 - 左眼在左侧，右眼在右侧
                                4：上下并排 - 左眼在上方，右眼在下方
                                5：帧交替 - 每帧显示一个视图
                                6：单眼 - 2D帧，没有任何帧包装
                                7：平铺格式 - 左眼在左上方，右眼分割在其余区域

5.3 码率控制

-q,     --qp<integer>  ：强制使用恒定的QP值（0-81，0=无损）；
-B,    --bitrate<integer>  ：设置比特率（kbit/s）；
        --crf<float> ：基于质量的可变比特率（-12-51）[23.0]；
        --rc-lookahead<integer>  ：预测帧类型的帧数 [40]；
        --vbv-maxrate<integer>  ：最大本地比特率（kbit/s）[0]；
        --vbv-bufsize<integer>  ：设置VBV缓冲区大小（kbit）[0]；
        --vbv-init<float> ：初始VBV缓冲区占用率 [0.9]；
        --crf-max<float> ：使用CRF+VBV时，限制RF到此值可能导致VBV下溢！；
        --qpmin<integer>：设置最小QP值 [0]；
        --qpmax<integer>：设置最大QP值 [81]；
        --qpstep<integer>：设置最大QP步长 [4]；
        --ratetol<float>：ABR速率控制和VBV的容差 [1.0]；
        --ipratio<float>：I和P之间的QP因子 [1.40]；
        --pbratio<float>：P和B之间的QP因子 [1.30]；
        --chroma-qp-offset<integer> ：色度与亮度之间的QP差异 [0]；
        --aq-mode<integer> ：AQ方法 [1]；
                                0: 禁用；
                                1: 方差AQ（复杂度掩码）；
                                2: 自动方差AQ；
                                3: 自动方差AQ，并偏向于暗场景；
        –aq-strength<float>：减少平坦和纹理区域中的块和模糊 [1.0]；

-p,     --pass<integer>：启用多通道速率控制；
                                1: 第一遍，创建统计文件；
                                2: 最后一遍，不覆盖统计文件；
                                3: 第N遍，覆盖统计文件；
        --stats<string> ：用于两遍统计的文件名 [“x264_2pass.log”]；
        --no-mbtree：禁用mb-tree速率控制；
        --qcomp<float> ：QP曲线压缩 [0.60]；
        --cplxblur<float> ：减少QP的波动（曲线压缩之前） [20.0]；
        --qblur<float> ：减少QP的波动（曲线压缩之后） [0.5]；
        --zones：调整视频区域的比特率；每个区域的格式为<起始帧数>，<结束帧数>，<选项>，其中<选项>可以是q=<整数>（强制QP）或 b=<浮点数>（比特率倍增器）；
       --qpfile<string>   ：强制一些或所有帧的帧类型和QP值；每行的格式：帧号 帧类型 QPQP是可选的（none表示由x264选择）。帧类型：I，i，K，P，B，b。K=<I或i>取决于open-gop设置QP受qpmin/qpmax的限制。

5.4 分析

-A，–partitions:要考虑的分区。可选值为[“p8x8, b8x8, i8x8, i4x4”]，表示考虑的分区类型，包括p8x8、p4x4、b8x8、i8x8、i4x4、none和all。
–direct:直接运动矢量（MV）预测模式。可选值为[“spatial”]，表示直接MV预测模式，包括none、spatial、temporal和auto。
–no-weightb:禁用B帧的加权预测。
–weightp:P帧的加权预测。可选值为[2]，表示加权预测的类型，包括0（禁用）、1（加权参考帧）和2（加权参考帧+复制帧）。
–me:整数像素运动估计方法。可选值为[“hex”]，表示整数像素运动估计方法，包括dia（钻石搜索，半径1，快速）、hex（六边形搜索，半径2）、umh（不均匀多六边形搜索）、esa（穷举搜索）和tesa（哈达玛穷举搜索，慢）。
–merange:最大运动矢量搜索范围，默认值为16。
–mvrange:最大运动矢量长度，默认值为-1（自动）。
–mvrange-thread:线程之间的最小缓冲区，默认值为-1（自动）。
-m, --subme:亚像素运动估计和模式决策。可选值为[7]，表示亚像素运动估计和模式决策的级别，包括0（仅全像素，不推荐使用）、1（SAD模式决策，一次qpel迭代）、2（SATD模式决策）等。
–psy-rd:心理视觉优化的强度，默认值为"1.0:0.0"。其中，#1表示RD（需要subme>=6），#2表示Trellis（需要trellis，实验性）。
–no-psy:禁用所有恶化PSNR和SSIM的视觉优化。
–no-mixed-refs:不基于每个分区来决定引用帧。
–no-chroma-me:忽略运动估计中的色度。
–no-8x8dct:禁用自适应空间变换大小。
-t, --trellis:Trellis RD量化，默认值为1。可选值为0（禁用）、1（仅在MB的最终编码中启用）、2（在所有模式决策中启用）。
–no-fast-pskip:在P帧上禁用早期SKIP检测。
–no-dct-decimate:在P帧上禁用系数阈值。
–nr:降噪，默认值为0。
–deadzone-inter:设置互帧亮度量化deadzone的大小，默认值为21。
–deadzone-intra:设置帧内亮度量化deadzone的大小，默认值为11。deadzone的大小应在0到32之间。
–cqm:预设量化矩阵。可选值为[“flat”]，表示预设的量化矩阵类型，包括flat和jvt。
–cqmfile:从与JM兼容的文件中读取自定义的量化矩阵。会覆盖其他–cqm*选项。
–cqm4:设置所有的4x4量化矩阵。需要提供一个由16个整数组成的逗号分隔列表。
–cqm8:设置所有的8x8量化矩阵。需要提供一个由64个整数组成的逗号分隔列表。
–cqm4i, --cqm4p, --cqm8i, --cqm8p:同时设置亮度和色度的量化矩阵。
–cqm4iy, --cqm4ic, --cqm4py, --cqm4pc:设置单独的亮度和色度量化矩阵。

5.5 设置视频可用性信息

  VUI设置不被编码器使用，只是对播放设备的建议。

–overscan：指定裁剪超扫描设置。可选值为[“undef”]，表示裁剪超扫描的设置，包括undef、show和crop。
–videoformat：指定视频格式。可选值为[“undef”]，表示视频格式，包括component、pal、ntsc、secam、mac和undef。
–range：指定颜色范围。可选值为[“auto”]，表示颜色范围，包括auto、tv和pc。
–colorprim：指定颜色原色。可选值为[“undef”]，表示颜色原色，包括undef、bt709、bt470m、bt470bg、smpte170m、smpte240m、film、bt2020、smpte428、smpte431和smpte432。
–transfer：指定传输特性。可选值为[“undef”]，表示传输特性，包括undef、bt709、bt470m、bt470bg、smpte170m、smpte240m、linear、log100、log316、iec61966-2-4、bt1361e、iec61966-2-1、bt2020-10、bt2020-12、smpte2084、smpte428和arib-std-b67。
–colormatrix：指定颜色矩阵设置。可选值为[“???”]，表示颜色矩阵设置，包括undef、bt709、fcc、bt470bg、smpte170m、smpte240m、GBR、YCgCo、bt2020nc、bt2020c、smpte2085、chroma-derived-nc、chroma-derived-c和ICtCp。
–chromaloc：指定色度采样位置（0到5）。默认值为0。
**–mastering-display ：指定主显示器的亮度、白点和显示亮度。格式为’G(x,y)B(x,y)R(x,y)WP(x,y)L(max,min)'。
–cll：指定内容光亮度的最大值和最大帧平均值。格式为’max_content,max_frame_average’。
–alternative-transfer：指定备用传输特性。可选值与–transfer相同。
–nal-hrd：信号HRD信息（需要vbv-bufsize）。可选值为none、vbr、cbr（.mp4中不允许使用cbr）。
–filler：强制使用硬CBR并生成填充数据（隐含–nal-hrd cbr）。
–pic-struct：强制在图像定时SEI中使用pic_struct。
–crop-rect：将’left,top,right,bottom’添加到比特流级别的裁剪矩形。