ffmpeg memo

ffmpeg

## 字幕流格式转化 srt 转webvtt格式
ffmpeg -i output.srt output.vtt

## 字幕流格式转化 转 ASS
ffmpeg -i output.srt output.ass

ffmpeg --help

ffmpeg version 5.1.4-0+deb12u1 Copyright (c) 2000-2023 the FFmpeg developers
  built with gcc 12 (Debian 12.2.0-14)
  configuration: --prefix=/usr --extra-version=0+deb12u1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libglslang --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librabbitmq --enable-librist --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzimg --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --disable-sndio --enable-libjxl --enable-pocketsphinx --enable-librsvg --enable-libmfx --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-libplacebo --enable-librav1e --enable-shared
  libavutil      57. 28.100 / 57. 28.100
  libavcodec     59. 37.100 / 59. 37.100
  libavformat    59. 27.100 / 59. 27.100
  libavdevice    59.  7.100 / 59.  7.100
  libavfilter     8. 44.100 /  8. 44.100
  libswscale      6.  7.100 /  6.  7.100
  libswresample   4.  7.100 /  4.  7.100
  libpostproc    56.  6.100 / 56.  6.100
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/protocol
    See 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 methods

Global 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.
-vol volume         change audio volume (256=normal)

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        disposition

Video 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)
-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
-ab bitrate         audio bitrate (please use -b:a)
-b bitrate          video bitrate (please use -b:v)
-dn                 disable data

Audio 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)
-vol volume         change audio volume (256=normal)
-af filter_graph    set audio filters

Subtitle 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

whisper

./whisper --help

sage: whisper (-h) (--model MODEL) (--model_dir MODEL_DIR) (--device DEVICE)
               (--output_dir OUTPUT_DIR) (--output_format {txt,vtt,srt,tsv,json,all})
               (--verbose VERBOSE) (--task {transcribe,translate})
               (--language {af,am,ar,as,az,ba,be,bg,bn,bo,br,bs,ca,cs,cy,da,de,el,en,es,et,eu,fa,fi,fo,fr,gl,gu,ha,haw,he,hi,hr,ht,hu,hy,id,is,it,ja,jw,ka,kk,km,kn,ko,la,lb,ln,lo,lt,lv,mg,mi,mk,ml,mn,mr,ms,mt,my,ne,nl,nn,no,oc,pa,pl,ps,pt,ro,ru,sa,sd,si,sk,sl,sn,so,sq,sr,su,sv,sw,ta,te,tg,th,tk,tl,tr,tt,uk,ur,uz,vi,yi,yo,yue,zh,Afrikaans,Albanian,Amharic,Arabic,Armenian,Assamese,Azerbaijani,Bashkir,Basque,Belarusian,Bengali,Bosnian,Breton,Bulgarian,Burmese,Cantonese,Castilian,Catalan,Chinese,Croatian,Czech,Danish,Dutch,English,Estonian,Faroese,Finnish,Flemish,French,Galician,Georgian,German,Greek,Gujarati,Haitian,Haitian Creole,Hausa,Hawaiian,Hebrew,Hindi,Hungarian,Icelandic,Indonesian,Italian,Japanese,Javanese,Kannada,Kazakh,Khmer,Korean,Lao,Latin,Latvian,Letzeburgesch,Lingala,Lithuanian,Luxembourgish,Macedonian,Malagasy,Malay,Malayalam,Maltese,Mandarin,Maori,Marathi,Moldavian,Moldovan,Mongolian,Myanmar,Nepali,Norwegian,Nynorsk,Occitan,Panjabi,Pashto,Persian,Polish,Portuguese,Punjabi,Pushto,Romanian,Russian,Sanskrit,Serbian,Shona,Sindhi,Sinhala,Sinhalese,Slovak,Slovenian,Somali,Spanish,Sundanese,Swahili,Swedish,Tagalog,Tajik,Tamil,Tatar,Telugu,Thai,Tibetan,Turkish,Turkmen,Ukrainian,Urdu,Uzbek,Valencian,Vietnamese,Welsh,Yiddish,Yoruba})
               (--temperature TEMPERATURE) (--best_of BEST_OF) (--beam_size BEAM_SIZE)
               (--patience PATIENCE) (--length_penalty LENGTH_PENALTY)
               (--suppress_tokens SUPPRESS_TOKENS) (--initial_prompt INITIAL_PROMPT)
               (--condition_on_previous_text CONDITION_ON_PREVIOUS_TEXT) (--fp16 FP16)
               (--temperature_increment_on_fallback TEMPERATURE_INCREMENT_ON_FALLBACK)
               (--compression_ratio_threshold COMPRESSION_RATIO_THRESHOLD)
               (--logprob_threshold LOGPROB_THRESHOLD)
               (--no_speech_threshold NO_SPEECH_THRESHOLD)
               (--word_timestamps WORD_TIMESTAMPS)
               (--prepend_punctuations PREPEND_PUNCTUATIONS)
               (--append_punctuations APPEND_PUNCTUATIONS)
               (--highlight_words HIGHLIGHT_WORDS) (--max_line_width MAX_LINE_WIDTH)
               (--max_line_count MAX_LINE_COUNT)
               (--max_words_per_line MAX_WORDS_PER_LINE) (--threads THREADS)
               audio 

positional arguments:
  audio                 audio file(s) to transcribe

optional arguments:
  -h, --help            show this help message and exit
  --model MODEL         name of the Whisper model to use (default: small)
  --model_dir MODEL_DIR
                        the path to save model files; uses ~/.cache/whisper by default
                        (default: None)
  --device DEVICE       device to use for PyTorch inference (default: cpu)
  --output_dir OUTPUT_DIR, -o OUTPUT_DIR
                        directory to save the outputs (default: .)
  --output_format {txt,vtt,srt,tsv,json,all}, -f {txt,vtt,srt,tsv,json,all}
                        format of the output file; if not specified, all available
                        formats will be produced (default: all)
  --verbose VERBOSE     whether to print out the progress and debug messages (default:
                        True)
  --task {transcribe,translate}
                        whether to perform X->X speech recognition ('transcribe') or
                        X->English translation ('translate') (default: transcribe)
  --language {af,am,ar,as,az,ba,be,bg,bn,bo,br,bs,ca,cs,cy,da,de,el,en,es,et,eu,fa,fi,fo,fr,gl,gu,ha,haw,he,hi,hr,ht,hu,hy,id,is,it,ja,jw,ka,kk,km,kn,ko,la,lb,ln,lo,lt,lv,mg,mi,mk,ml,mn,mr,ms,mt,my,ne,nl,nn,no,oc,pa,pl,ps,pt,ro,ru,sa,sd,si,sk,sl,sn,so,sq,sr,su,sv,sw,ta,te,tg,th,tk,tl,tr,tt,uk,ur,uz,vi,yi,yo,yue,zh,Afrikaans,Albanian,Amharic,Arabic,Armenian,Assamese,Azerbaijani,Bashkir,Basque,Belarusian,Bengali,Bosnian,Breton,Bulgarian,Burmese,Cantonese,Castilian,Catalan,Chinese,Croatian,Czech,Danish,Dutch,English,Estonian,Faroese,Finnish,Flemish,French,Galician,Georgian,German,Greek,Gujarati,Haitian,Haitian Creole,Hausa,Hawaiian,Hebrew,Hindi,Hungarian,Icelandic,Indonesian,Italian,Japanese,Javanese,Kannada,Kazakh,Khmer,Korean,Lao,Latin,Latvian,Letzeburgesch,Lingala,Lithuanian,Luxembourgish,Macedonian,Malagasy,Malay,Malayalam,Maltese,Mandarin,Maori,Marathi,Moldavian,Moldovan,Mongolian,Myanmar,Nepali,Norwegian,Nynorsk,Occitan,Panjabi,Pashto,Persian,Polish,Portuguese,Punjabi,Pushto,Romanian,Russian,Sanskrit,Serbian,Shona,Sindhi,Sinhala,Sinhalese,Slovak,Slovenian,Somali,Spanish,Sundanese,Swahili,Swedish,Tagalog,Tajik,Tamil,Tatar,Telugu,Thai,Tibetan,Turkish,Turkmen,Ukrainian,Urdu,Uzbek,Valencian,Vietnamese,Welsh,Yiddish,Yoruba}
                        language spoken in the audio, specify None to perform language
                        detection (default: None)
  --temperature TEMPERATURE
                        temperature to use for sampling (default: 0)
  --best_of BEST_OF     number of candidates when sampling with non-zero temperature
                        (default: 5)
  --beam_size BEAM_SIZE
                        number of beams in beam search, only applicable when temperature
                        is zero (default: 5)
  --patience PATIENCE   optional patience value to use in beam decoding, as in
                        https://arxiv.org/abs/2204.05424, the default (1.0) is
                        equivalent to conventional beam search (default: None)
  --length_penalty LENGTH_PENALTY
                        optional token length penalty coefficient (alpha) as in
                        https://arxiv.org/abs/1609.08144, uses simple length
                        normalization by default (default: None)
  --suppress_tokens SUPPRESS_TOKENS
                        comma-separated list of token ids to suppress during sampling;
                        '-1' will suppress most special characters except common
                        punctuations (default: -1)
  --initial_prompt INITIAL_PROMPT
                        optional text to provide as a prompt for the first window.
                        (default: None)
  --condition_on_previous_text CONDITION_ON_PREVIOUS_TEXT
                        if True, provide the previous output of the model as a prompt
                        for the next window; disabling may make the text inconsistent
                        across windows, but the model becomes less prone to getting
                        stuck in a failure loop (default: True)
  --fp16 FP16           whether to perform inference in fp16; True by default (default:
                        True)
  --temperature_increment_on_fallback TEMPERATURE_INCREMENT_ON_FALLBACK
                        temperature to increase when falling back when the decoding
                        fails to meet either of the thresholds below (default: 0.2)
  --compression_ratio_threshold COMPRESSION_RATIO_THRESHOLD
                        if the gzip compression ratio is higher than this value, treat
                        the decoding as failed (default: 2.4)
  --logprob_threshold LOGPROB_THRESHOLD
                        if the average log probability is lower than this value, treat
                        the decoding as failed (default: -1.0)
  --no_speech_threshold NO_SPEECH_THRESHOLD
                        if the probability of the <|nospeech|> token is higher than this
                        value AND the decoding has failed due to `logprob_threshold`,
                        consider the segment as silence (default: 0.6)
  --word_timestamps WORD_TIMESTAMPS
                        (experimental) extract word-level timestamps and refine the
                        results based on them (default: False)
  --prepend_punctuations PREPEND_PUNCTUATIONS
                        if word_timestamps is True, merge these punctuation symbols with
                        the next word (default: "'“¿(({-)
  --append_punctuations APPEND_PUNCTUATIONS
                        if word_timestamps is True, merge these punctuation symbols with
                        the previous word (default: "'.。,，!！?？:：”))}、)
  --highlight_words HIGHLIGHT_WORDS
                        (requires --word_timestamps True) underline each word as it is
                        spoken in srt and vtt (default: False)
  --max_line_width MAX_LINE_WIDTH
                        (requires --word_timestamps True) the maximum number of
                        characters in a line before breaking the line (default: None)
  --max_line_count MAX_LINE_COUNT
                        (requires --word_timestamps True) the maximum number of lines in
                        a segment (default: None)
  --max_words_per_line MAX_WORDS_PER_LINE
                        (requires --word_timestamps True, no effect with
                        --max_line_width) the maximum number of words in a segment
                        (default: None)
  --threads THREADS     number of threads used by torch for CPU inference; supercedes
                        MKL_NUM_THREADS/OMP_NUM_THREADS (default: 0)