ffmpeg is along with VLC (cvlc) essential tools in the video-guru’s toolkit.

Introduction to ffmpeg

A command line software package (command line interface (CLI), in comparison to GUI – Graphical User Interface application), that exists on all major platforms (macOS, Linux distros, MS Windows).

Amazingly powerful and capable!

• Handles all sorts of parts of media, like (order as used by mediainfo):
  (see also classifications for more)
  1. General – container
  2. Video stream(s)
  3. Audio stream(s)
  4. Text (subtitles)
  5. Other
  6. Image
  7. Menu
• Add, remove, replace, streams (add subtitles to own video)
• Clip parts – extract parts of long materials, cut out a 1 minute sample material for some longer production
• Concatenate files
• Convert between every possible format
• ‘Take a screenshot’ from a video, extract a specific frame, to jpeg, png
• …

 

Getting It, Installation

• macOS, once have brew installed:
  • brew install ffmpeg
  • installs in /usr/local/bin/
• Linux:
  • sudo apt-get install ffmpeg
• Video DownloadHelper Companion App
  • DownloadHelper, when installed, depend on a specific installation
  • google.com/search?q=net.downloadhelper.coapp.app
  • Is installed as:
    /Applications/net.downloadhelper.coapp.app
  • And in folder:
    /Applications/net.downloadhelper.coapp.app/Contents/MacOS/converter/build/mac/64/
    has the following commands:
    • ffmpeg
    • ffplay
    • ffprobe

 

Some Initial Resources

• Home page: ffmpeg.org
  • Documentation: ffmpeg.org/documentation.html
• linuxquestions.org/questions/linux-general-1/convert-mpg-to-mp4-4175514239/
• 20+ FFmpeg Commands For Beginners (2019-05-21) 
  ostechnix.com/20-ffmpeg-commands-beginners/
• search on ffmpeg/share – looking for where profiles maybe stored
  google.com/search?q=ffmpeg%2Fshare

Convert, Transcode, .MPG to H.264 MP4

google.com/search?q=ffmpeg+convert+mov+to+mp4

opensource.com/article/17/6/ffmpeg-convert-media-file-formats

H.264 Video Encoding Guide – trac.ffmpeg.org/wiki/Encode/H.264

I.e., in the case of materials worked on in these examples,

• from files with extension .mpg,
  • and in this case these are MPEG-2 materials
• to files I chose to use extension .mp4, container format that CAN have a variety of variants of MPEG materials including for instance:
  1. ‘MPEG-4’, ‘MPEG-4 Visual’ (MPEG-4 Part 2, H.263-compatible)
  2. H.264, AVC (MPEG-4 Part 10)
  3. H.265, HEVC (MPEG-H Part 2)
  4. (See also Technical (MPEG) for more on MPEG std.)

https://www.google.com/search?q=convert+mpeg2+to+mp4+ffmpeg

Simplest Transcoding

E.g., from https://www.linuxquestions.org/questions/linux-general-1/convert-mpg-to-mp4-4175514239/

ffmpeg -i input.mpg output.mp4

HandBrakeCLI -Z Universal -i input.mpg -o output.mp4

2-Pass or Not

google.com/search?q=ffmpeg+2-pass+or+crf

“1 pass is faster than 2 passes. 2-pass does not make a better quality or smaller file: it only lets you set the output file size (but not the quality), whereas -crf lets you choose the quality (but not the file size).” [superuser.com/questions/1362800/ffmpeg-2-pass-encoding#:~:text=1%20pass%20is%20faster%20than,but%20not%20the%20file%20size).]

gist.github.com/hsab/7c9219c4d57e13a42e06bf1cab90cd44

superuser.com/questions/1362800/ffmpeg-2-pass-encoding

google.com/search?q=ffmpeg+crf

superuser.com/questions/677576/what-is-crf-used-for-in-ffmpeg

Convert, Transcode, to H.265

• google.com/search?q=ffmpeg+to+h265
• trac.ffmpeg.org/wiki/Encode/H.265

Concatenate

google.com/search?q=ffmpeg+concat+videos

trac.ffmpeg.org/wiki/Concatenate

Cut Clip from Video

google.com/search?q=ffmpeg+extract+clip

• -ss h:m:s.xxxor -ss m.msec: start at
  • importation distinction is WHERE placing on command line, at least older ffmpeg
    • before -i <src>: faster search
    • after -i <src>: slower but more accurate
  • (source superuser.com/questions/138331/using-ffmpeg-to-cut-up-video)
• -t h:m:s.xxx : how much material to use

Example:

ffmpeg -i input.wmv -ss 60 -t 60 -acodec copy -vcodec copy output.wmv

Three different cases:

1. From start to some point: -i <in> -t <d> -c copy
2. Mid-section, from – to…..: -i <in> -ss <x> -t <d> -c copy
3. From some point to end..: -i <in> -ss <x> -c copy

Examples:

1. ffmpeg -i input.mp4 -codec copy -t 0:01:00 1st-min.mp4
2. ffmpeg -i input.mp4 -codec copy -ss 0:01:00 -t 0:01:00 2nd-min.mp4

 

Extract Audio

stackoverflow.com/questions/9913032/how-can-i-extract-audio-from-video-with-ffmpeg

x

audacityteam.org

en.wikipedia.org/wiki/Audacity_(audio_editor)

google.com/search?q=audacity

file:///Applications/Audacity.app/Contents/help/manual/man/faq_installing_the_ffmpeg_import_export_library.html

https://lame.buanzo.org/#lameosx64bitdl

Scaling

• google.com/search?q=ffmpeg+rescale+video
• Scaling – trac.ffmpeg.org/wiki/Scaling
• How can I crop a video with ffmpeg? – video.stackexchange.com/questions/4563/how-can-i-crop-a-video-with-ffmpeg

Snapshot, Frame

google.com/search?q=snapshot+from+video+ffmeg

stackoverflow.com/questions/27568254/how-to-extract-1-screenshot-for-a-video-with-ffmpeg-at-a-given-time

Use the -ss option:

ffmpeg -ss 01:23:45 -i input -vframes 1 -q:v 2 output.jpg

• For JPEG output use -q:v to control output quality. Full range is a linear scale of 1-31 where a lower value results in a higher quality. 2-5 is a good range to try.
• The select filter provides an alternative method for more complex needs such as selecting only certain frame types, or 1 per 100, etc.
• Placing -ss before the input will be faster. See FFmpeg Wiki: Seeking and this excerpt from the ffmpeg cli tool documentation:

 

 

ffmpeg Command – Built-in Help

 

im2720:~ johan$ ffmpeg --help
ffmpeg version 4.1.2 Copyright (c) 2000-2019 the FFmpeg developers
  built with Apple LLVM version 10.0.0 (clang-1000.11.45.5)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/4.1.2 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags='-I/Library/Java/JavaVirtualMachines/openjdk-11.0.2.jdk/Contents/Home/include -I/Library/Java/JavaVirtualMachines/openjdk-11.0.2.jdk/Contents/Home/include/darwin' --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libmp3lame --enable-libopus --enable-librubberband --enable-libsnappy --enable-libtesseract --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libspeex --enable-videotoolbox --disable-libjack --disable-indev=jack --enable-libaom --enable-libsoxr
  libavutil      56. 22.100 / 56. 22.100
  libavcodec     58. 35.100 / 58. 35.100
  libavformat    58. 20.100 / 58. 20.100
  libavdevice    58.  5.100 / 58.  5.100
  libavfilter     7. 40.101 /  7. 40.101
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  3.100 /  5.  3.100
  libswresample   3.  3.100 /  3.  3.100
  libpostproc    55.  3.100 / 55.  3.100
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
    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
im2720:~ johan$