tips¶
Cmds¶
$ ffmpeg -formats # print the list of supported file formats
$ ffmpeg -codecs # print the list of supported codecs (E=encode,D=decode)
$ ffmpeg --help
-i set the input file. Multiple -i switchs can be used
-f set video format (for the input if before of -i, for output otherwise)
-an ignore audio
-vn ignore video
-ar set audio rate (in Hz)
-ac set the number of channels
-ab set audio bitrate
-acodec choose audio codec or use “copy” to bypass audio encoding
-vcodec choose video codec or use “copy” to bypass video encoding
-r video fps. You can also use fractional values like 30000/1001 instead of 29.97
-s frame size (w x h, ie: 320x240)
-aspect set the aspect ratio i.e: 4:3 or 16:9
-sameq ffmpeg tries to keep the visual quality of the input
-t N encode only N seconds of video (you can use also the hh:mm:ss.ddd format)
-croptop, -cropleft, -cropright, -cropbottom crop input video frame on each side
-y automatic overwrite of the output file
-ss select the starting time in the source file
-vol change the volume of the audio
-g Gop size (distance between keyframes)
-b Video bitrate
-bt Video bitrate tolerance
-metadata add a key=value metadata
Compile¶
Compile FFMPEG
Requirement libraries:
$ aptitude install libfdk-aac-dev \
libmp3lame-dev \
libtheora-dev \
libvorbis-dev \
libvpx-dev \
libx264-dev
Also you can download libfdk_aac from http://sourceforge.net/projects/opencore-amr/?source=dlp and compile it:
$ ./configure
$ make
$ make install
then download ffpmeg from http://www.ffmpeg.org/download.html#releases
$./configure --enable-gpl --enable-nonfree \
--enable-libmp3lame \
--enable-libfdk_aac \
--enable-libvorbis \
--enable-libtheora \
--enable-libx264 \
--enable-libvpx
$ make
$ make install
FFmpeg Static Builds¶
Links¶
https://sonnati.wordpress.com/2011/07/11/ffmpeg-the-swiss-army-knife-of-internet-streaming-part-i/
FFmpeg on Windows¶
How to Watermark an image into the video¶
# Top left
$ ffmpeg –i source.avi -vf "movie=watermark.png [watermark]; [in][watermark] overlay=10:10 [out]" output.flv
# Top right
$ ffmpeg –i source.avi -vf "movie=watermark.png [watermark]; [in][watermark] overlay=main_w-overlay_w-10:10 [out]" output.flv
# Bottom left
$ ffmpeg –i source.avi -vf "movie=watermark.png [watermark]; [in][watermark] overlay=10:main_h-overlay_h-10 [out]" output.flv
# Bottom right
$ ffmpeg –i source.avi -vf "movie=watermark.png [watermark]; [in][watermark] overlay=main_w-overlay_w-10:main_h-overlay_h-10 [out]" output.flv
# Center
$ ffmpeg –i source.avi -vf "movie=watermark.png [watermark]; [in][watermark] overlay=main_w/2-overlay_w/2:main_h/2-overlay_h/2 [out]" output.flv
http://www.digitalwhores.net/ffmpeg/ffmpeg-watermark-positions/
Burn subtitles into video¶
$ ffmpeg -i video.avi -vf subtitles=subtitle.srt out.avi
Reduce the size of a video¶
$ ffmpeg -i input.mp4 -r 30 -s 960x540 output.mp4
GUI Video editor¶
$ apt-get install kdenlive
Convert an animated gif to an mp4 file¶
$ ffmpeg -i input.gif -movflags faststart -pix_fmt yuv420p -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" output.mp4
movflags – This option optimizes the structure of the MP4 file so the browser can load it as quickly as possible.
- pix_fmt – MP4 videos store pixels in different formats.
We include this option to specify a specific format which has maximum compatibility across all browsers.
vf – MP4 videos using H.264 need to have a dimensions that are divisible by 2. This option ensures that’s the case.
$ ffmpeg -f gif -i input.gif output.mp4
Extract screen shot for a video at a given time¶
$ ffmpeg -ss 00:00:03 -i input.mp4 -vframes 1 -q:v 2 output.jpg