Convert Video from Different Formats
You need to have ffmpeg installed. It's usually installed on linux.
If you don't have ffmpeg, try avconv. For some years around 2015, avconv is rename of ffmpeg.
Convert mov to MP4
ffmpeg -f mov -i x.mov x.mp4
Note, .mov is Apple's movie format.
Convert webm to MP4
ffmpeg -f webm -i x.webm x.mp4
Note, .webm is Google's movie format.
Clip a Video
ffmpeg -ss 00:10:05 -i input.mp4 -to 00:13:50 -c copy output.mp4
-ss time_off- Set the start time offset
-to time_stop- Record or transcode stop time
Find Out What's Inside a Video Container
“.mp4”, “.mkv” etc are Video/audio container formats. They package together video file, audio files, and other files, of various formats into 1 file.
To find out what's inside, use ffprobe, e.g.
ffprobe file.mkv
Example output:
~/web/xahmusic_org/music/i $ ffprobe xx.mkv
ffprobe version 3.4 Copyright (c) 2007-2017 the FFmpeg developers
built with Apple LLVM version 9.0.0 (clang-900.0.37)
configuration: --prefix=/usr/local/Cellar/ffmpeg/3.4 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-gpl --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --enable-videotoolbox --disable-lzma
libavutil 55. 78.100 / 55. 78.100
libavcodec 57.107.100 / 57.107.100
libavformat 57. 83.100 / 57. 83.100
libavdevice 57. 10.100 / 57. 10.100
libavfilter 6.107.100 / 6.107.100
libavresample 3. 7. 0 / 3. 7. 0
libswscale 4. 8.100 / 4. 8.100
libswresample 2. 9.100 / 2. 9.100
libpostproc 54. 7.100 / 54. 7.100
Input #0, matroska,webm, from 'xx.mkv':
Metadata:
COMPATIBLE_BRANDS: iso6avc1mp41
MAJOR_BRAND : dash
MINOR_VERSION : 0
ENCODER : Lavf57.83.100
Duration: 00:05:04.90, start: 0.000000, bitrate: 1329 kb/s
Stream #0:0: Video: h264 (Main), yuv420p(tv, bt709, progressive), 1280x720 [SAR 1:1 DAR 16:9], 29.97 fps, 29.97 tbr, 1k tbn, 59.94 tbc (default)
Metadata:
HANDLER_NAME : VideoHandler
DURATION : 00:05:04.871000000
Stream #0:1(eng): Audio: vorbis, 44100 Hz, stereo, fltp (default)
Metadata:
DURATION : 00:05:04.903000000
Put a Opus Audio into a .Webm Container
ffmpeg -i x.opus -c:a copy x.webm
Add Opus Audio into Existing Webm
ffmpeg -i y.webm -i x.opus -c:v copy -c:a copy x.webm
Extract Audio from Video
extract audio file inside file x.mp4 and name it x.m4a
ffmpeg -i x.mp4 -vn -acodec copy x.m4a
ffmpeg -f mp4 -i x.mp4 -vn -c:a copy x.m4a
or
ffmpeg -f mp4 -i x.mp4 -map 0:1 -c:a copy x.m4a
-map 0:1 means stream number 1 from file number 0, which would usually be the audio track (edit as necessary). specifying a map at all disables the default map which would be to copy every stream, so you get only the audio, not both. -c:a copy means just copy it, no re-encoding. You may also want to specify a -f for the output to choose a container fomat; I am not sure what it will use by default, probably the same as the input.
2018-11-26 thanks to harvhat https://noagendasocial.com/@harvhat and matthew skala https://mstdn.io/web/accounts/18568
syntax of ffmpeg
The general syntax of ffmpeg is:
ffmpeg options infile_options -i infileName outfile_options outfileName
-f fmt- force format fmt
ffmpeg manual
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
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
-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 errors (0.0: no errors, 1.0: 100% errors) above which ffmpeg returns an error instead of success.
-bits_per_raw_sample number set the number of bits per raw sample
-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)
-s size set frame size (WxH or abbreviation)
-aspect aspect set aspect ratio (4:3, 16:9 or 1.3333, 1.7777)
-bits_per_raw_sample number set the number of bits per raw sample
-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