ffmpeg

Convert between different media types

The following command converts file.mp4 to file.mp3.

The -i flag specifies the input file.

ffmpeg -i file.mp4 file.mp3

Cutting/extracting parts from an existing video

The following command extracted the part from 00:48 through 02:39. Is this the canonical way to do that? I don't know.

ffmpeg -i inputfile.mp4 -ss 00:00:48 -to 00:02:39 -async 1 -strict -2 outputfile.mp4

Merging mp3 files

The concat: instruction combined with -acodec copy allows to concatenate multiple mp3 into one.

ffmpeg -i "concat:one.mp3|two.mp3|three.mp3|four.mp3" -acodec copy merged.mp3

Print duration of an mp3

ffmpeg -i Multiverse/Mutliverse.mp3  2>&1 | grep Duration

Compare with mp3info.

Compiling ffmpeg under Cygwin 64

Based on How to compile ffmpeg under Cygwin, I was able to compile ffmpeg (plus libmp3lame) for Cygwin 64 like so:

First, I had to compile libmp3lame

The configure.guess script (apparently dating back to 2003) had to be replaced by http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.guess;hb=HEAD

As per https://github.com/HPCE/hpce-2015-cw2/issues/3, the lines 138 and 139 in frontend/lametime.c had to be commented:

       //#elif defined __CYGWIN__
       //    setmode(fileno(fp), _O_BINARY);

Then, with the usual ./configure, make, make install trilogy, libmp3lame could be built and installed.

After that, ffmpeg could be build:

apt-cyg install binutils, gcc-core, git, make, ming, mingw64-x86_64-runtime, yasm, texi2html, diffutils, dos2unix
git clone git://source.ffmpeg.org/ffmpeg.git ffmpeg
dos2unix configure
LDFLAGS=-L/usr/local/lib ./configure --enable-shared --disable-static --enable-libmp3lame
make
make install

Update 2023-08-27

A tweet by @ursgehrig suggests to add --disable-indev=gdigrab when configuring ffmpeg:

…
LDFLAGS=-L/usr/local/lib ./configure --enable-shared --disable-static --disable-indev=gdigrab --enable-libmp3lame
…

Showing available input devices

ffmpeg -list_devices true -f dshow -i dummy

Record (capture) screen

ffmpeg -y -f dshow -i audio="Mikrofon (High Definition Audio" -f gdigrab -video_size 1440x900 -i desktop -vcodec h264 foo.mkv

Find name of audio with -list_devices (see above).

dshow stands for DirectShow caputure, gdigrap for GDI PI Windows frame grabber (See ffmpeg -formats).

Recoding microphone and pc's audio (mixing both audio sources with -filter_complex amerge)

ffmpeg -framerate 10 -f dshow -i video="screen-capture-recorder":audio="virtual-audio-capturer" -f dshow -i audio="Mikrofon (High Definition Audio" -filter_complex amerge -ac 2 -ar 44100 -acodec aac -ab 192k -pix_fmt yuv420p -r 30 -vcodec h264 -crf 27 -preset ultrafast -f mp4 undo.mp4

Checking version

The version of ffmpeg can by checked with -version (one hyphen only!):

ffmpeg -version

Part of ImageMagick

Apparently, ffmpeg is also part of an ImageMagick distribution.

Command line options

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.

Global options

Global options affect whole programs rather than 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 num`	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

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

TODO

Was or is there not also a -movflags option?