Difference between revisions of "FFmpeg"

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[[Category:Audio/Video]]
 
[[Category:Audio/Video]]
{{i18n|FFmpeg}}
 
 
 
{{Article summary start}}
 
{{Article summary start}}
 
{{Article summary text|This article attempts to walk users through the installation, usage and configuration of FFmpeg.}}
 
{{Article summary text|This article attempts to walk users through the installation, usage and configuration of FFmpeg.}}
 
{{Article summary end}}
 
{{Article summary end}}
  
[http://www.ffmpeg.org/ FFmpeg] is command-line driven collection of tools which enables the decoding, encoding, conversion and playback of [http://ffmpeg.org/general.html#Supported-File-Formats-and-Codecs most audio and video streams].
+
From the [http://www.ffmpeg.org/ FFmpeg homepage]:
 +
:''FFmpeg is a complete, cross-platform solution to record, convert and stream audio and video. It includes libavcodec - the leading audio/video codec library.''
  
 
== Package installation ==
 
== Package installation ==
{{Pkg|FFmpeg}} is part of the [[Official_repositories#.5Bextra.5D|official Arch Linux [extra] repository]].
 
  
{{bc|# pacman -S ffmpeg}}
+
[[pacman|Install]] {{Pkg|ffmpeg}} from the [[official repositories]].
 +
 
 +
{{Note|The version in the official repositories does not include all codecs due to license constraints. Notably, the Fraunhofer AAC codec and the AAC+ codec are not included. {{AUR|ffmpeg-full}} from [[AUR]] supplies all codecs.}}
 +
 
 +
A drop-in replacement fork called {{AUR|libav}} is available in AUR. The binary it provides is called '''avconv''' instead of '''ffmpeg'''.
  
 
== Encoding examples ==
 
== Encoding examples ==
 +
 +
=== Screen cast to .webm ===
 +
 +
Using '''x11grab''' to video grab your display and using '''ALSA''' for sound. First we create lossless raw file {{ic|test.mkv}}.
 +
 +
$ ffmpeg -f x11grab -r 30 -i :0.0 -f alsa -i hw:0,0 -acodec flac -vcodec ffvhuff test.mkv
 +
 +
Then we process this {{ic|test.mkv}} file into a smaller {{ic|test.webm}} end product. Complex switches like {{ic|c:a}} and {{ic|c:v}} convert the stream into what's needed for [http://en.wikipedia.org/wiki/WebM WebM].
 +
 +
$ ffmpeg -y -i test.mkv -c:a libvorbis -q:a 3 -c:v libvpx -b:v 2000k test.webm
 +
 +
See https://github.com/kaihendry/recordmydesktop2.0/blob/master/r2d2.sh for a more fleshed out example.
  
 
=== VOB to any container ===
 
=== VOB to any container ===
 +
 
Concatenate the desired [[Wikipedia:VOB|VOB]] files into a single VOB file:  
 
Concatenate the desired [[Wikipedia:VOB|VOB]] files into a single VOB file:  
  $ cat VTS_01_1.VOB VTS_01_2.VOB VTS_01_3.VOB VTS_01_4.VOB > Transformers.3.Dark.of.the.Moon.VOB
+
  $ cat ''video-1''.VOB ''video-2''.VOB ''video-3''.VOB > ''output''.VOB
Or concatenate and then pipe the output VOB to FFmpeg:  
+
Concatenate and then pipe the output VOB to FFmpeg to use a different format:
  $ cat VTS_01_1.VOB VTS_01_2.VOB VTS_01_3.VOB VTS_01_4.VOB > Transformers.3.Dark.of.the.Moon.VOB | ffmpeg -i ...
+
  $ cat ''video-1''.VOB ''video-2''.VOB ''video-3''.VOB > ''output''.VOB | ffmpeg -i ...
 +
 
 +
=== x264 lossless ===
  
=== x264 Lossless ===
 
 
The ''ultrafast'' preset will provide the fastest encoding and is useful for quick capturing (such as screencasting):
 
The ''ultrafast'' preset will provide the fastest encoding and is useful for quick capturing (such as screencasting):
{{bc|ffmpeg -i input -vcodec libx264 -preset ultrafast -qp 0 -acodec copy output.mkv}}
+
$ ffmpeg -i input -vcodec libx264 -preset ultrafast -qp 0 -acodec copy output.mkv
 
On the opposite end of the preset spectrum is ''veryslow'' and will encode slower than ''ultrafast'' but provide a smaller output file size:
 
On the opposite end of the preset spectrum is ''veryslow'' and will encode slower than ''ultrafast'' but provide a smaller output file size:
{{bc|ffmpeg -i input -vcodec libx264 -preset veryslow -qp 0 -acodec copy output.mkv}}
+
$ ffmpeg -i input -vcodec libx264 -preset veryslow -qp 0 -acodec copy output.mkv
 
Both examples will provide the same quality output.
 
Both examples will provide the same quality output.
  
 
=== Single-pass MPEG-2 (near lossless) ===
 
=== Single-pass MPEG-2 (near lossless) ===
 +
 
Allow FFmpeg to automatically set DVD standardized parameters. Encode to DVD [[Wikipedia:MPEG-2|MPEG-2]] at a frame rate of 30 frames/second:
 
Allow FFmpeg to automatically set DVD standardized parameters. Encode to DVD [[Wikipedia:MPEG-2|MPEG-2]] at a frame rate of 30 frames/second:
  
  ffmpeg -i 13.Assassins.VOB -target ntsc-dvd -sameq 13.Assassins.mpg
+
  $ ffmpeg -i ''video''.VOB -target ntsc-dvd -sameq ''output''.mpg
  
 
Encode to DVD MPEG-2 at a frame rate of 24 frames/second:
 
Encode to DVD MPEG-2 at a frame rate of 24 frames/second:
  
  ffmpeg -i 13.Assassins.VOB -target film-dvd -sameq 13.Assassins.mpg
+
  $ ffmpeg -i ''video''.VOB -target film-dvd -sameq ''output''.mpg
  
=== Single-pass x264 (very high-quality) ===
+
=== x264: constant rate factor ===
{{ic|threads}}={{ic|0}} '''=''' automatically detect and select the appropriate number of threads:  
+
{{bc|1=ffmpeg -i Transformers.3.Dark.of.the.Moon.VOB -acodec libmp3lame -ab 256k -vcodec libx264 -preset veryslow -crf 15 -threads 0 -x264opts frameref=15:fast_pskip=0 Transformers.3.Dark.of.the.Moon.mkv}}
+
{{ic|tune}} option should be set to [http://forum.doom9.org/showthread.php?t=149394 match the type and content of the of media being encoded]:
+
{{bc|1=ffmpeg -i 13.Assassins.VOB -acodec libmp3lame -ab 256k -vcodec libx264 -preset veryslow -tune film -crf 15 -threads 0 -x264opts frameref=15:fast_pskip=0 13.Assassins.mkv}}
+
  
* [http://lame.sourceforge.net/ libmp3lame] is generally recommended over [http://www.audiocoding.com/faac.html libfaac] encoding at all bitrates.
+
Used when you want a specific quality output. General usage is to use the highest {{ic|-crf}} value that still provides an acceptable quality. A sane range is 18-28 and 23 is default. 18 is considered to be visually lossless. Use the slowest {{ic|-preset}} you have patience for. See the [https://ffmpeg.org/trac/ffmpeg/wiki/x264EncodingGuide x264 Encoding Guide] for more information.
 +
$ ffmpeg -i ''video'' -vcodec libx264 -preset slow -crf 22 -acodec libmp3lame -aq 4 ''output''.mkv
 +
{{ic|-tune}} option can be used to [http://forum.doom9.org/showthread.php?t=149394 match the type and content of the of media being encoded].
 +
 
 +
=== YouTube ===
 +
 
 +
FFmpeg is very useful to encode videos and strip their size before you upload them on YouTube. The following single line of code takes an input file and outputs a mkv container.
 +
 
 +
$ ffmpeg -i ''video'' -c:v libx264 -crf 18 -preset slow -pix_fmt yuv420p -c:a copy ''output''.mkv
 +
 
 +
For more information see the [https://bbs.archlinux.org/viewtopic.php?pid=1200667#p1200667 forums]. You can also create a custom alias {{ic|ytconvert}} which takes the name of the input file as first argument and the name of the .mkv container as second argument. To do so add the following to your {{ic|~/.bashrc}}:
 +
 
 +
youtubeConvert(){
 +
ffmpeg -i $1 -c:v libx264 -crf 18 -preset slow -pix_fmt yuv420p -c:a copy $2.mkv
 +
}
 +
alias ytconvert=youtubeConvert
 +
See also [https://bbs.archlinux.org/viewtopic.php?pid=1200542#p1200542 Arch Linux forum thread].
  
 
=== Two-pass x264 (very high-quality) ===
 
=== Two-pass x264 (very high-quality) ===
 +
 
Audio deactivated as only video statistics are recorded during the first of multiple pass runs:  
 
Audio deactivated as only video statistics are recorded during the first of multiple pass runs:  
{{bc|1=ffmpeg -i Transformers.3.Dark.of.the.Moon.VOB -an -vcodec libx264 -pass 1 -preset veryslow -threads 0 -b 3000k -x264opts frameref=15:fast_pskip=0 -f rawvideo -y /dev/null}}
+
$ ffmpeg -i ''video''.VOB -an -vcodec libx264 -pass 1 -preset veryslow \
 +
-threads 0 -b 3000k -x264opts frameref=15:fast_pskip=0 -f rawvideo -y /dev/null
 
Container format is automatically detected and muxed into from the output file extenstion ({{ic|.mkv}}):
 
Container format is automatically detected and muxed into from the output file extenstion ({{ic|.mkv}}):
{{bc|1=ffmpeg -i Transformers.3.Dark.of.the.Moon.VOB -acodec libvo-aacenc -ab 256k -ar 96000 -vcodec libx264 -pass 2 -preset veryslow -threads 0 -b 3000k -x264opts frameref=15:fast_pskip=0 Transformers.3.Dark.of.the.Moon.mkv}}
+
$ ffmpeg -i ''video''.VOB -acodec libvo-aacenc -ab 256k -ar 96000 -vcodec libx264 \
 +
-pass 2 -preset veryslow -threads 0 -b 3000k -x264opts frameref=15:fast_pskip=0 ''video''.mkv
 +
 
 +
{{Tip|If you receive {{ic|Unknown encoder 'libvo-aacenc'}} error (given the fact that your ffmpeg is compiled with libvo-aacenc enabled), you may want to try {{ic|-acodec libvo_aacenc}}, an underscore instead of hyphen.}}
  
 
=== Two-pass MPEG-4 (very high-quality) ===
 
=== Two-pass MPEG-4 (very high-quality) ===
 +
 
Audio deactivated as only video statistics are logged during the first of multiple pass runs:  
 
Audio deactivated as only video statistics are logged during the first of multiple pass runs:  
{{bc|ffmpeg -i Transformers.3.Dark.of.the.Moon.VOB -an -vcodec mpeg4 -pass 1 -mbd 2 -trellis 2 -flags +cbp+mv0 -pre_dia_size 4 -dia_size 4 -precmp 4 -cmp 4 -subcmp 4 -preme 2 -qns 2 -b 3000k -f rawvideo -y /dev/null}}
+
$ ffmpeg -i ''video''.VOB -an -vcodec mpeg4 -pass 1 -mbd 2 -trellis 2 -flags +cbp+mv0 \
 +
-pre_dia_size 4 -dia_size 4 -precmp 4 -cmp 4 -subcmp 4 -preme 2 -qns 2 -b 3000k \
 +
-f rawvideo -y /dev/null
  
 
Container format is automatically detected and muxed into from the output file extenstion ({{ic|.avi}}):
 
Container format is automatically detected and muxed into from the output file extenstion ({{ic|.avi}}):
{{bc|ffmpeg -i Transformers.3.Dark.of.the.Moon.VOB -acodec copy -vcodec mpeg4 -vtag DX50 -pass 2 -mbd 2 -trellis 2 -flags +cbp+mv0 -pre_dia_size 4 -dia_size 4 -precmp 4 -cmp 4 -subcmp 4 -preme 2 -qns 2 -b 3000k Transformers.3.Dark.of.the.Moon.avi}}
+
$ ffmpeg -i ''video''.VOB -acodec copy -vcodec mpeg4 -vtag DX50 -pass 2 -mbd 2 -trellis 2 \
 +
-flags +cbp+mv0 -pre_dia_size 4 -dia_size 4 -precmp 4 -cmp 4 -subcmp 4 -preme 2 -qns 2 \
 +
-b 3000k ''video''.avi
 
* Introducing {{ic|threads}}={{ic|n}}>{{ic|1}} for {{ic|-vcodec mpeg4}} may skew the effects of [[Wikipedia:Motion_estimation|motion estimation]] and lead to [http://ffmpeg.org/faq.html#Why-do-I-see-a-slight-quality-degradation-with-multithreaded-MPEG_002a-encoding_003f reduced video quality] and compression efficiency.
 
* Introducing {{ic|threads}}={{ic|n}}>{{ic|1}} for {{ic|-vcodec mpeg4}} may skew the effects of [[Wikipedia:Motion_estimation|motion estimation]] and lead to [http://ffmpeg.org/faq.html#Why-do-I-see-a-slight-quality-degradation-with-multithreaded-MPEG_002a-encoding_003f reduced video quality] and compression efficiency.
 
* The two-pass MPEG-4 example above also supports output to the [[Wikipedia:MPEG-4_Part_14|MP4]] container (replace {{ic|.avi}} with {{ic|.mp4}}).
 
* The two-pass MPEG-4 example above also supports output to the [[Wikipedia:MPEG-4_Part_14|MP4]] container (replace {{ic|.avi}} with {{ic|.mp4}}).
  
 
==== Determining bitrates with fixed output file sizes ====
 
==== Determining bitrates with fixed output file sizes ====
 +
 
* (Desired File Size in MB - Audio File Size in MB) '''x''' 8192 kb/MB '''/''' Length of Media in Seconds (s) '''=''' [[Wikipedia:Bitrate|Bitrate]] in kb/s
 
* (Desired File Size in MB - Audio File Size in MB) '''x''' 8192 kb/MB '''/''' Length of Media in Seconds (s) '''=''' [[Wikipedia:Bitrate|Bitrate]] in kb/s
 
:* (3900 MB - 275 MB) = 3625 MB '''x''' 8192 kb/MB '''/''' 8830 s = 3363 kb/s required to achieve an approximate total output file size of 3900 MB
 
:* (3900 MB - 275 MB) = 3625 MB '''x''' 8192 kb/MB '''/''' 8830 s = 3363 kb/s required to achieve an approximate total output file size of 3900 MB
 +
 +
=== Softsubs to hardsubs ===
 +
 +
If have a softsubbed video (eg. ASS/SSA subs in a mkv container like most anime) you can 'burn' these subs into a new file to be played on a device which does not support subs or is to weak to display complex subs.
 +
 +
* Install {{Pkg|mkvtoolnix-cli}} to pull out *.ass files from *.mkv files.
 +
 +
* Recompile '''ffmpeg''' with {{ic|--enable-libass}} if it is not already enabled in your ffmpeg build. See [[ABS]] for easy recompiling.
 +
 +
* Pull out subs from your file. This command assumes that track #2 is the ASS/SSA track. Use {{ic|mkvinfo}} if it is not.
 +
$ mkvextract tracks ''your file''.mkv 2:''your file''.ass
 +
 +
* Recode file with ffmpeg. See sections above for suitable options. It is very important to disable sub-recording and enable sub-rendering:
 +
$ ffmpeg ... -sn -vf ass=''subtitles''.ass
 +
 +
Output is set as *.mp4 since the default Android 4.2 player dislikes *.mkv. (But VLC on Android works with mkv). Example:
 +
$ ffmpeg -i ''video''.mkv -sn -vcodec libx264 -crf 18 -preset slow -vf ass=''subtitles''.ass -acodec copy ''output''.mp4
  
 
== Preset files ==
 
== Preset files ==
 +
 
=== Creating presets ===
 
=== Creating presets ===
 +
  
 
Populate {{ic|~/.ffmpeg}} with the default [http://ffmpeg.org/ffmpeg-doc.html#SEC13 preset files]:  
 
Populate {{ic|~/.ffmpeg}} with the default [http://ffmpeg.org/ffmpeg-doc.html#SEC13 preset files]:  
Line 73: Line 132:
 
Create new and/or modify the default preset files:
 
Create new and/or modify the default preset files:
  
{{hc|~/.ffmpeg/libavcodec-vhq.ffpreset|<nowiki>
+
{{hc|~/.ffmpeg/libavcodec-vhq.ffpreset|2=
vtag=DX50
+
vtag=DX50
mbd=2
+
mbd=2
trellis=2
+
trellis=2
flags=+cbp+mv0
+
flags=+cbp+mv0
pre_dia_size=4
+
pre_dia_size=4
dia_size=4
+
dia_size=4
precmp=4
+
precmp=4
cmp=4
+
cmp=4
subcmp=4
+
subcmp=4
preme=2
+
preme=2
qns=2</nowiki>}}
+
qns=2
 +
}}
  
 
=== Using preset files ===
 
=== Using preset files ===
Line 90: Line 150:
 
Enable the {{ic|-vpre}} option after declaring the desired  {{ic|-vcodec}}
 
Enable the {{ic|-vpre}} option after declaring the desired  {{ic|-vcodec}}
  
==== {{ic|libavcodec-vhq.ffpreset}} ====
+
==== libavcodec-vhq.ffpreset ====
  
 
* {{ic|libavcodec}} '''=''' Name of the vcodec/acodec
 
* {{ic|libavcodec}} '''=''' Name of the vcodec/acodec
Line 99: Line 159:
  
 
First pass of a multipass (bitrate) ratecontrol transcode:
 
First pass of a multipass (bitrate) ratecontrol transcode:
{{bc|ffmpeg -i 13.Assassins.2010.mpg -an -vcodec mpeg4 -pass 1 -vpre vhq -f rawvideo -y /dev/null}}
+
$ ffmpeg -i ''video''.mpg -an -vcodec mpeg4 -pass 1 -vpre vhq -f rawvideo -y /dev/null
 
Ratecontrol based on the video statistics logged from the first pass:  
 
Ratecontrol based on the video statistics logged from the first pass:  
{{bc|ffmpeg -i 13.Assassins.2010.mpg -acodec libvorbis -aq 8 -ar 48000 -vcodec mpeg4 -pass 2 -vpre vhq -b 3000k 13.Assassins.2010.mp4}}
+
$ ffmpeg -i ''video''.mpg -acodec libvorbis -aq 8 -ar 48000 -vcodec mpeg4 \
 +
-pass 2 -vpre vhq -b 3000k ''output''.mp4
  
 
* '''libvorbis quality settings (VBR)'''
 
* '''libvorbis quality settings (VBR)'''
Line 110: Line 171:
 
:* -aq 8 '''=''' 256 kb/s
 
:* -aq 8 '''=''' 256 kb/s
  
*[http://www.geocities.jp/aoyoume/aotuv/ aoTuV] is generally preferred over [http://vorbis.com/ libvorbis] provided by [http://www.xiph.org/ Xiph.Org] and is provided by [https://aur.archlinux.org/packages.php?ID=6155 libvorbis-aotuv] in the [[AUR]].
+
* [http://www.geocities.jp/aoyoume/aotuv/ aoTuV] is generally preferred over [http://vorbis.com/ libvorbis] provided by [http://www.xiph.org/ Xiph.Org] and is provided by [https://aur.archlinux.org/packages.php?ID=6155 libvorbis-aotuv] in the [[AUR]].
  
 
== Volume gain ==
 
== Volume gain ==
Line 122: Line 183:
  
 
To double the volume '''(512 = 200%)''' of an [[Wikipedia:Mp3|MP3]] file:
 
To double the volume '''(512 = 200%)''' of an [[Wikipedia:Mp3|MP3]] file:
  ffmpeg -i example.mp3 -vol 512 loud-example.mp3
+
  $ ffmpeg -i ''file''.mp3 -vol 512 ''louder file''.mp3
  
 
To quadruple the volume '''(1024 = 400%)''' of an [[Wikipedia:Ogg|Ogg]] file:
 
To quadruple the volume '''(1024 = 400%)''' of an [[Wikipedia:Ogg|Ogg]] file:
  ffmpeg -i example.ogg -vol 1024 loud-example.ogg
+
  $ ffmpeg -i ''file''.ogg -vol 1024 ''louder file''.ogg
  
 
Note that gain metadata is only written to the output file. Unlike mp3gain or ogggain, the source sound file is untouched.
 
Note that gain metadata is only written to the output file. Unlike mp3gain or ogggain, the source sound file is untouched.
Line 131: Line 192:
 
== Extracting audio ==
 
== Extracting audio ==
  
{{bc|$ ffmpeg -i The.Kings.Speech.mpg<br>
+
{{hc|$ ffmpeg -i ''video''.mpg|
Input #0, avi, from 'The.Kings.Speech.2010.mpg':<br>  Duration: 01:58:28.96, start: 0.000000, bitrate: 3000 kb/s<br>    Stream #0.0: Video: mpeg4, yuv420p, 720x480 [PAR 1:1 DAR 16:9], 29.97 tbr, 29.97 tbn, 29.97 tbc<br>    Stream #0.1: Audio: ac3, 48000 Hz, stereo, s16, 384 kb/s<br>    Stream #0.2: Audio: ac3, 48000 Hz, 5.1, s16, 448 kb/s<br>    Stream #0.3: Audio: dts, 48000 Hz, 5.1 768 kb/s}}
+
...
 +
Input #0, avi, from '''video''.mpg':
 +
  Duration: 01:58:28.96, start: 0.000000, bitrate: 3000 kb/s
 +
    Stream #0.0: Video: mpeg4, yuv420p, 720x480 [PAR 1:1 DAR 16:9], 29.97 tbr, 29.97 tbn, 29.97 tbc
 +
    Stream #0.1: Audio: ac3, 48000 Hz, stereo, s16, 384 kb/s
 +
    Stream #0.2: Audio: ac3, 48000 Hz, 5.1, s16, 448 kb/s
 +
    Stream #0.3: Audio: dts, 48000 Hz, 5.1 768 kb/s
 +
...
 +
}}
  
 
Extract the first ({{ic|-map 0:1}}) [[Wikipedia:Dolby_Digital|AC-3]] encoded audio stream exactly as it was multiplexed into the file:  
 
Extract the first ({{ic|-map 0:1}}) [[Wikipedia:Dolby_Digital|AC-3]] encoded audio stream exactly as it was multiplexed into the file:  
{{bc|ffmpeg -i The.Kings.Speech.mpg -map 0:1 -acodec copy -vn The.Kings.Speech.ac3}}
+
$ ffmpeg -i ''video''.mpg -map 0:1 -acodec copy -vn ''video''.ac3
 
Convert the third ({{ic|-map 0:3}}) [[Wikipedia:DTS_(sound_system)|DTS]] audio stream to an [[Wikipedia:Advanced_Audio_Coding|AAC]] file with a bitrate of 192 kb/s and a [[Wikipedia:Sampling_rate|sampling rate]] of 96000 Hz:
 
Convert the third ({{ic|-map 0:3}}) [[Wikipedia:DTS_(sound_system)|DTS]] audio stream to an [[Wikipedia:Advanced_Audio_Coding|AAC]] file with a bitrate of 192 kb/s and a [[Wikipedia:Sampling_rate|sampling rate]] of 96000 Hz:
{{bc|ffmpeg -i The.Kings.Speech.mpg -map 0:3 -acodec libvo-aacenc -ab 192k -ar 96000 -vn The.Kings.Speech.aac}}
+
$ ffmpeg -i ''video''.mpg -map 0:3 -acodec libvo-aacenc -ab 192k -ar 96000 -vn ''output''.aac
 
{{ic|-vn}} disables the processing of the video stream.
 
{{ic|-vn}} disables the processing of the video stream.
 +
 +
Extract audio stream with certain time interval:
 +
$ ffmpeg -ss 00:01:25 -t 00:00:05 -i ''video''.mpg -map 0:1 -acodec copy -vn ''output''.ac3
 +
{{ic|-ss}} specifies the start point, and {{ic|-t}} specifies the duration.
  
 
=== Stripping audio ===
 
=== Stripping audio ===
Line 144: Line 217:
 
# Copy the first video stream ({{ic|-map 0:0}}) along with the second AC-3 audio stream ({{ic|-map 0:2}}).
 
# Copy the first video stream ({{ic|-map 0:0}}) along with the second AC-3 audio stream ({{ic|-map 0:2}}).
 
# Convert the AC-3 audio stream to two-channel MP3 with a bitrate of 128 kb/s and a sampling rate of 48000 Hz.
 
# Convert the AC-3 audio stream to two-channel MP3 with a bitrate of 128 kb/s and a sampling rate of 48000 Hz.
{{bc|ffmpeg -i The.Kings.Speech.mpg -map 0:0 -map 0:2 -vcodec copy -acodec libmp3lame -ab 128k -ar 48000 -ac 2 The.Kings.Speech.mkv}}
+
$ ffmpeg -i ''video''.mpg -map 0:0 -map 0:2 -vcodec copy -acodec libmp3lame \
{{bc|$ ffmpeg -i The.Kings.Speech.mkv<br>
+
-ab 128k -ar 48000 -ac 2 ''video''.mkv
Input #0, avi, from 'The.Kings.Speech.2010.mpg':<br>  Duration: 01:58:28.96, start: 0.000000, bitrate: 3000 kb/s<br>    Stream #0.0: Video: mpeg4, yuv420p, 720x480 [PAR 1:1 DAR 16:9], 29.97 tbr, 29.97 tbn, 29.97 tbc<br>    Stream #0.1: Audio: mp3, 48000 Hz, stereo, s16, 128 kb/s}}
+
 
 +
{{hc|$ ffmpeg -i ''video''.mkv|
 +
...
 +
Input #0, avi, from '''video''.mpg':
 +
  Duration: 01:58:28.96, start: 0.000000, bitrate: 3000 kb/s
 +
    Stream #0.0: Video: mpeg4, yuv420p, 720x480 [PAR 1:1 DAR 16:9], 29.97 tbr, 29.97 tbn, 29.97 tbc
 +
    Stream #0.1: Audio: mp3, 48000 Hz, stereo, s16, 128 kb/s
 +
}}
 +
 
 
{{Note|Removing undesired audio streams allows for additional bits to be allocated towards improving video quality.}}
 
{{Note|Removing undesired audio streams allows for additional bits to be allocated towards improving video quality.}}
  
Line 155: Line 236:
 
== Recording webcam ==
 
== Recording webcam ==
  
FFmpeg supports grabbing input from Video4Linux2 devices.  The following command will record a video from the webcam, assuming that the webcam is correctly recognized under {{Ic|/dev/video0}}:
+
FFmpeg supports grabbing input from Video4Linux2 devices.  The following command will record a video from the webcam, assuming that the webcam is correctly recognized under {{ic|/dev/video0}}:
  
  $ ffmpeg -f v4l2 -s 640x480 -i /dev/video0 out.mpg
+
  $ ffmpeg -f v4l2 -s 640x480 -i /dev/video0 ''output''.mpg
  
The above produces a silent video. It is also possible to include audio sources from a microphone.  The following command will include a stream from the default [[Advanced Linux Sound Architecture|ALSA]] recording device into the video:
+
The above produces a silent video. It is also possible to include audio sources from a microphone.  The following command will include a stream from the default [[Advanced Linux Sound Architecture|ALSA]] recording device into the video:
  
  $ ffmpeg -f alsa -i default -f v4l2 -s 640x480 -i /dev/video0 out.mpg
+
  $ ffmpeg -f alsa -i default -f v4l2 -s 640x480 -i /dev/video0 ''output''.mpg
  
 
To use [[PulseAudio]] with an ALSA backend:
 
To use [[PulseAudio]] with an ALSA backend:
  
  $ ffmpeg -f alsa -i pulse -f v4l2 -s 640x480 -i /dev/video0 out.mpg
+
  $ ffmpeg -f alsa -i pulse -f v4l2 -s 640x480 -i /dev/video0 ''output''.mpg
  
 
For a higher quality capture, try encoding the output using higher quality codecs:
 
For a higher quality capture, try encoding the output using higher quality codecs:
  
  $ ffmpeg -f alsa -i default -f v4l2 -s 640x480 -i /dev/video0 -acodec flac -vcodec libx264 out.mkv
+
  $ ffmpeg -f alsa -i default -f v4l2 -s 640x480 -i /dev/video0 -acodec flac \
 +
-vcodec libx264 ''output''.mkv
  
 
== Package removal ==
 
== Package removal ==
Line 175: Line 257:
 
[[pacman]] will not [[Pacman#Removing_packages|remove]] configuration files outside of the defaults that were created during package installation. This includes user-created preset files.
 
[[pacman]] will not [[Pacman#Removing_packages|remove]] configuration files outside of the defaults that were created during package installation. This includes user-created preset files.
  
== Additional resources ==
+
== See also ==
* [http://mewiki.project357.com/wiki/X264_Settings x264 Settings] - MeWiki Documentation
+
 
* [http://ffmpeg.org/ffmpeg-doc.html FFmpeg Documentation] - Official Documentation
+
* [http://mewiki.project357.com/wiki/X264_Settings x264 Settings] - MeWiki documentation
* [http://www.mplayerhq.hu/DOCS/HTML/en/menc-feat-x264.html Encoding with the x264 Codec] - MEncoder Documentation
+
* [http://ffmpeg.org/ffmpeg-doc.html FFmpeg documentation] - official documentation
* [http://avidemux.org/admWiki/doku.php?id=tutorial:h.264 H.264 eEcoding Guide] - Avidemux Wiki
+
* [http://www.mplayerhq.hu/DOCS/HTML/en/menc-feat-x264.html Encoding with the x264 codec] - MEncoder documentation
* [http://howto-pages.org/ffmpeg/ Using FFmpeg] - Linux How To Pages
+
* [http://avidemux.org/admWiki/doku.php?id=tutorial:h.264 H.264 eEcoding guide] - Avidemux wiki
 +
* [http://howto-pages.org/ffmpeg/ Using FFmpeg] - Linux how to pages
 +
* [http://ffmpeg.org/general.html#Supported-File-Formats-and-Codecs List] of supported audio and video streams

Revision as of 20:34, 22 June 2013

Summary help replacing me
This article attempts to walk users through the installation, usage and configuration of FFmpeg.

From the FFmpeg homepage:

FFmpeg is a complete, cross-platform solution to record, convert and stream audio and video. It includes libavcodec - the leading audio/video codec library.

Package installation

Install ffmpeg from the official repositories.

Note: The version in the official repositories does not include all codecs due to license constraints. Notably, the Fraunhofer AAC codec and the AAC+ codec are not included. ffmpeg-fullAUR from AUR supplies all codecs.

A drop-in replacement fork called libavAUR is available in AUR. The binary it provides is called avconv instead of ffmpeg.

Encoding examples

Screen cast to .webm

Using x11grab to video grab your display and using ALSA for sound. First we create lossless raw file test.mkv.

$ ffmpeg -f x11grab -r 30 -i :0.0 -f alsa -i hw:0,0 -acodec flac -vcodec ffvhuff test.mkv

Then we process this test.mkv file into a smaller test.webm end product. Complex switches like c:a and c:v convert the stream into what's needed for WebM.

$ ffmpeg -y -i test.mkv -c:a libvorbis -q:a 3 -c:v libvpx -b:v 2000k test.webm

See https://github.com/kaihendry/recordmydesktop2.0/blob/master/r2d2.sh for a more fleshed out example.

VOB to any container

Concatenate the desired VOB files into a single VOB file:

$ cat video-1.VOB video-2.VOB video-3.VOB > output.VOB

Concatenate and then pipe the output VOB to FFmpeg to use a different format:

$ cat video-1.VOB video-2.VOB video-3.VOB > output.VOB | ffmpeg -i ...

x264 lossless

The ultrafast preset will provide the fastest encoding and is useful for quick capturing (such as screencasting):

$ ffmpeg -i input -vcodec libx264 -preset ultrafast -qp 0 -acodec copy output.mkv

On the opposite end of the preset spectrum is veryslow and will encode slower than ultrafast but provide a smaller output file size:

$ ffmpeg -i input -vcodec libx264 -preset veryslow -qp 0 -acodec copy output.mkv

Both examples will provide the same quality output.

Single-pass MPEG-2 (near lossless)

Allow FFmpeg to automatically set DVD standardized parameters. Encode to DVD MPEG-2 at a frame rate of 30 frames/second:

$ ffmpeg -i video.VOB -target ntsc-dvd -sameq output.mpg

Encode to DVD MPEG-2 at a frame rate of 24 frames/second:

$ ffmpeg -i video.VOB -target film-dvd -sameq output.mpg

x264: constant rate factor

Used when you want a specific quality output. General usage is to use the highest -crf value that still provides an acceptable quality. A sane range is 18-28 and 23 is default. 18 is considered to be visually lossless. Use the slowest -preset you have patience for. See the x264 Encoding Guide for more information.

$ ffmpeg -i video -vcodec libx264 -preset slow -crf 22 -acodec libmp3lame -aq 4 output.mkv

-tune option can be used to match the type and content of the of media being encoded.

YouTube

FFmpeg is very useful to encode videos and strip their size before you upload them on YouTube. The following single line of code takes an input file and outputs a mkv container.

$ ffmpeg -i video -c:v libx264 -crf 18 -preset slow -pix_fmt yuv420p -c:a copy output.mkv

For more information see the forums. You can also create a custom alias ytconvert which takes the name of the input file as first argument and the name of the .mkv container as second argument. To do so add the following to your ~/.bashrc:

youtubeConvert(){
ffmpeg -i $1 -c:v libx264 -crf 18 -preset slow -pix_fmt yuv420p -c:a copy $2.mkv
}
alias ytconvert=youtubeConvert

See also Arch Linux forum thread.

Two-pass x264 (very high-quality)

Audio deactivated as only video statistics are recorded during the first of multiple pass runs:

$ ffmpeg -i video.VOB -an -vcodec libx264 -pass 1  -preset veryslow \
-threads 0 -b 3000k -x264opts frameref=15:fast_pskip=0 -f rawvideo -y /dev/null

Container format is automatically detected and muxed into from the output file extenstion (.mkv):

$ ffmpeg -i video.VOB -acodec libvo-aacenc -ab 256k -ar 96000 -vcodec libx264 \
-pass 2 -preset veryslow -threads 0 -b 3000k -x264opts frameref=15:fast_pskip=0 video.mkv
Tip: If you receive Unknown encoder 'libvo-aacenc' error (given the fact that your ffmpeg is compiled with libvo-aacenc enabled), you may want to try -acodec libvo_aacenc, an underscore instead of hyphen.

Two-pass MPEG-4 (very high-quality)

Audio deactivated as only video statistics are logged during the first of multiple pass runs:

$ ffmpeg -i video.VOB -an -vcodec mpeg4 -pass 1 -mbd 2 -trellis 2 -flags +cbp+mv0 \
-pre_dia_size 4 -dia_size 4 -precmp 4 -cmp 4 -subcmp 4 -preme 2 -qns 2 -b 3000k \
-f rawvideo -y /dev/null

Container format is automatically detected and muxed into from the output file extenstion (.avi):

$ ffmpeg -i video.VOB -acodec copy -vcodec mpeg4 -vtag DX50 -pass 2 -mbd 2 -trellis 2 \
-flags +cbp+mv0 -pre_dia_size 4 -dia_size 4 -precmp 4 -cmp 4 -subcmp 4 -preme 2 -qns 2 \
-b 3000k video.avi
  • Introducing threads=n>1 for -vcodec mpeg4 may skew the effects of motion estimation and lead to reduced video quality and compression efficiency.
  • The two-pass MPEG-4 example above also supports output to the MP4 container (replace .avi with .mp4).

Determining bitrates with fixed output file sizes

  • (Desired File Size in MB - Audio File Size in MB) x 8192 kb/MB / Length of Media in Seconds (s) = Bitrate in kb/s
  • (3900 MB - 275 MB) = 3625 MB x 8192 kb/MB / 8830 s = 3363 kb/s required to achieve an approximate total output file size of 3900 MB

Softsubs to hardsubs

If have a softsubbed video (eg. ASS/SSA subs in a mkv container like most anime) you can 'burn' these subs into a new file to be played on a device which does not support subs or is to weak to display complex subs.

  • Recompile ffmpeg with --enable-libass if it is not already enabled in your ffmpeg build. See ABS for easy recompiling.
  • Pull out subs from your file. This command assumes that track #2 is the ASS/SSA track. Use mkvinfo if it is not.
$ mkvextract tracks your file.mkv 2:your file.ass
  • Recode file with ffmpeg. See sections above for suitable options. It is very important to disable sub-recording and enable sub-rendering:
$ ffmpeg ... -sn -vf ass=subtitles.ass

Output is set as *.mp4 since the default Android 4.2 player dislikes *.mkv. (But VLC on Android works with mkv). Example:

$ ffmpeg -i video.mkv -sn -vcodec libx264 -crf 18 -preset slow -vf ass=subtitles.ass -acodec copy output.mp4

Preset files

Creating presets

Populate ~/.ffmpeg with the default preset files:

$ cp -iR /usr/share/ffmpeg ~/.ffmpeg

Create new and/or modify the default preset files:

~/.ffmpeg/libavcodec-vhq.ffpreset
vtag=DX50
mbd=2
trellis=2
flags=+cbp+mv0
pre_dia_size=4
dia_size=4
precmp=4
cmp=4
subcmp=4
preme=2
qns=2

Using preset files

Enable the -vpre option after declaring the desired -vcodec

libavcodec-vhq.ffpreset

  • libavcodec = Name of the vcodec/acodec
  • vhq = Name of specific preset to be called out
  • ffpreset = FFmpeg preset filetype suffix
Two-pass MPEG-4 (very high quality)

First pass of a multipass (bitrate) ratecontrol transcode:

$ ffmpeg -i video.mpg -an -vcodec mpeg4 -pass 1 -vpre vhq -f rawvideo -y /dev/null

Ratecontrol based on the video statistics logged from the first pass:

$ ffmpeg -i video.mpg -acodec libvorbis -aq 8 -ar 48000 -vcodec mpeg4 \
-pass 2 -vpre vhq -b 3000k output.mp4
  • libvorbis quality settings (VBR)
  • -aq 4 = 128 kb/s
  • -aq 5 = 160 kb/s
  • -aq 6 = 192 kb/s
  • -aq 7 = 224 kb/s
  • -aq 8 = 256 kb/s

Volume gain

Change the audio volume in multiples of 256 where 256 = 100% (normal) volume. Additional values such as 400 are also valid options.

-vol 256  = 100%
-vol 512  = 200%
-vol 768  = 300%
-vol 1024 = 400%
-vol 2048 = 800%

To double the volume (512 = 200%) of an MP3 file:

$ ffmpeg -i file.mp3 -vol 512 louder file.mp3

To quadruple the volume (1024 = 400%) of an Ogg file:

$ ffmpeg -i file.ogg -vol 1024 louder file.ogg

Note that gain metadata is only written to the output file. Unlike mp3gain or ogggain, the source sound file is untouched.

Extracting audio

$ ffmpeg -i video.mpg
...
Input #0, avi, from 'video.mpg':
  Duration: 01:58:28.96, start: 0.000000, bitrate: 3000 kb/s
    Stream #0.0: Video: mpeg4, yuv420p, 720x480 [PAR 1:1 DAR 16:9], 29.97 tbr, 29.97 tbn, 29.97 tbc
    Stream #0.1: Audio: ac3, 48000 Hz, stereo, s16, 384 kb/s
    Stream #0.2: Audio: ac3, 48000 Hz, 5.1, s16, 448 kb/s
    Stream #0.3: Audio: dts, 48000 Hz, 5.1 768 kb/s
...

Extract the first (-map 0:1) AC-3 encoded audio stream exactly as it was multiplexed into the file:

$ ffmpeg -i video.mpg -map 0:1 -acodec copy -vn video.ac3

Convert the third (-map 0:3) DTS audio stream to an AAC file with a bitrate of 192 kb/s and a sampling rate of 96000 Hz:

$ ffmpeg -i video.mpg -map 0:3 -acodec libvo-aacenc -ab 192k -ar 96000 -vn output.aac

-vn disables the processing of the video stream.

Extract audio stream with certain time interval:

$ ffmpeg -ss 00:01:25 -t 00:00:05 -i video.mpg -map 0:1 -acodec copy -vn output.ac3

-ss specifies the start point, and -t specifies the duration.

Stripping audio

  1. Copy the first video stream (-map 0:0) along with the second AC-3 audio stream (-map 0:2).
  2. Convert the AC-3 audio stream to two-channel MP3 with a bitrate of 128 kb/s and a sampling rate of 48000 Hz.
$ ffmpeg -i video.mpg -map 0:0 -map 0:2 -vcodec copy -acodec libmp3lame \
-ab 128k -ar 48000 -ac 2 video.mkv
$ ffmpeg -i video.mkv
...
Input #0, avi, from 'video.mpg':
  Duration: 01:58:28.96, start: 0.000000, bitrate: 3000 kb/s
    Stream #0.0: Video: mpeg4, yuv420p, 720x480 [PAR 1:1 DAR 16:9], 29.97 tbr, 29.97 tbn, 29.97 tbc
    Stream #0.1: Audio: mp3, 48000 Hz, stereo, s16, 128 kb/s
Note: Removing undesired audio streams allows for additional bits to be allocated towards improving video quality.

Adding subtitles

FFmpeg does not currently support muxing subtitle files into existing streams. See MEncoder for subtitle muxing support.

Recording webcam

FFmpeg supports grabbing input from Video4Linux2 devices. The following command will record a video from the webcam, assuming that the webcam is correctly recognized under /dev/video0:

$ ffmpeg -f v4l2 -s 640x480 -i /dev/video0 output.mpg

The above produces a silent video. It is also possible to include audio sources from a microphone. The following command will include a stream from the default ALSA recording device into the video:

$ ffmpeg -f alsa -i default -f v4l2 -s 640x480 -i /dev/video0 output.mpg

To use PulseAudio with an ALSA backend:

$ ffmpeg -f alsa -i pulse -f v4l2 -s 640x480 -i /dev/video0 output.mpg

For a higher quality capture, try encoding the output using higher quality codecs:

$ ffmpeg -f alsa -i default -f v4l2 -s 640x480 -i /dev/video0 -acodec flac \
-vcodec libx264 output.mkv

Package removal

pacman will not remove configuration files outside of the defaults that were created during package installation. This includes user-created preset files.

See also