• Here are some commands to get information about the nature of a video:

    1 $ ffmpeg -i ./video.avi
    2 $ file ./video.avi
    3 $ avprobe ./video.avi
    4 $ mplayer -frames 0 -identify ./video.avi

FFmpeg

  • Remux a Flash video to an MP4 container without transcoding:

    1 $ ffmpeg -i ./input.flv -vcodec copy -acodec copy ./output.mp4
  • Remove audio:

    1 $ ffmpeg -i ./input.mp4 -vcodec copy -an ./input-no-audio.mp4
  • Start audio 1.5 seconds later:

    1 $ ffmpeg -i ./input.mkv -itsoffset 1.5 -i ./input.mkv -map 0:v -vcodec copy -map 1:a -acodec copy ./video-fixed.mkv
  • Start audio 1.5 seconds earlier (notice the difference in -map index value compared to CLI above):

    1 $ ffmpeg -i ./input.mkv -itsoffset 1.5 -i ./input.mkv -map 1:v -vcodec copy -map 0:a -acodec copy ./video-fixed.mkv
  • Transcode the audio track into AAC but keep the video and subtitles as-is:

    1 $ ffmpeg -i ./input.mkv -vcodec copy -acodec aac -scodec copy ./output.mkv
  • Transcode a video to H.265/HEVC video with a CRF of 20 and a slow profile, and AAC audio mono channel at 64 kBit/s. The extra -tag:v hvc1 option is for compatibility with Apple, while the -movflags use_metadata_tags option transfer all metadata from the input file to the output file:

    1 $ ffmpeg -i ./MVI_5547.MOV -movflags use_metadata_tags -c:v libx265 -crf 20 -preset slow -tag:v hvc1 -c:a aac -ac 1 -b:a 64k ./MVI_5547-2.mp4
  • Transcode all audio tracks to AAC (-map 0:a & -acodec aac) but keep all video streams as-is (-map 0:v & -vcodec copy). Introduce a negative 128.5 seconds delay on the sole subtitle track using the srt Python package as an intermediate step. The -map 1:s option ensure only the original subtitle tracks are ignored:

     1 $ pip install srt
     2 $ ffmpeg -i ./input.mkv ./subtitle.srt
     3 (...)
     4 $ srt fixed-timeshift --input ./subtitle.srt --inplace --seconds -128.5
     5 (...)
     6 $ ffmpeg -i ./input.mkv -i ./subtitle.srt -map 0:v -vcodec copy -map 0:a -acodec aac -map 1:s -scodec copy ./video-fixed.mkv
     7 (...)
     8 Input #0, matroska,webm, from 'input.mkv':
     9     Stream #0:0(eng): Video: h264 (High), yuv420p(progressive), 1280x720, SAR 1:1 DAR 16:9, 25 fps, 25 tbr, 1k tbn, 50 tbc (default)
    10     Stream #0:1(ger): Audio: dts (DTS), 48000 Hz, 5.1(side), fltp, 1536 kb/s (default)
    11     Stream #0:2(eng): Subtitle: subrip (default)
    12     (...)
    13 Input #1, srt, from 'subtitle.srt':
    14     Stream #1:0: Subtitle: subrip
    15     (...)
    16 Stream mapping:
    17   Stream #0:0 -> #0:0 (copy)
    18   Stream #0:1 -> #0:1 (dts (dca) -> aac (native))
    19   Stream #1:0 -> #0:2 (copy)
    20   (...)
    21 Output #0, matroska, to 'video-fixed.mkv':
    22     Stream #0:0(eng): Video: h264 (High) (H264 / 0x34363248), yuv420p(progressive), 1280x720 [SAR 1:1 DAR 16:9], q=2-31, 25 fps, 25 tbr, 1k tbn, 1k tbc (default)
    23     Stream #0:1(ger): Audio: aac (LC) ([255][0][0][0] / 0x00FF), 48000 Hz, 5.1(side), fltp, 394 kb/s (default)
    24     Stream #0:2: Subtitle: subrip
  • Concatenate a series of videos and transcode the audio output to a flac file. This only works with certain multimedia container (MPEG-1, MPEG-2 PS, DV):

    1 $ cat ./M2U01802.MPG ./M2U01803.MPG ./M2U01804.MPG | ffmpeg -i - -acodec flac ./output.flac
  • Remove the first 16 seconds of video and change container to Matroska:

    1 $ ffmpeg -ss 16 -i ./MVI_8763.MOV -vcodec copy -acodec copy ./MVI_8763.mkv
  • Extract the first frame of a video (great to generate image preview):

    1 $ ffmpeg -i ./video.mov -r 1 -t 00:00:01 -f image2 ./images%05d.png
  • Extract a frame every 10 seconds:

    1 $ ffmpeg -i ./video.mov -f image2 -r 1/10 ./preview-%04d.png
  • Transcode the video stream to the lossless HuffYUV codec:

    1 $ ffmpeg -i ./MVI_1714.MOV -vcodec huffyuv -sameq ./MVI_1714-lossless.avi
  • Produce a dummy 10 seconds video of a solid pink background at 1080p/60fps:

    1 $ ffmpeg -f lavfi -i "color=color=pink:size=1920x1080" -r 60 -t 10 -c:v libx264 ./dummy.mp4
  • Produce a video from a static image and an audio file. That’s the way I produced Cool Cavemen’s video tracks for YouTube. Hence the special video filter option which crop the image to a square (thanks to arithmetic operators) and scale it to a 1080x1080 pixels video:

    1 $ ffmpeg -loop 1 -y -i ./album-front-cover.jpg -i ./track-01.flac -c:v libx264 -tune stillimage -vf "crop='min(in_h,in_w)':'min(in_h,in_w)',scale=-2:1080" -c:a copy -shortest ./track-01-video.mkv
  • Same as above but instead of cropping, pad with either vertical or horizontal black bars to fit a typical Full HD 1080p steam of 1920x1080 pixels:

    1 $ ffmpeg -loop 1 -y -i ./album-front-cover.jpg -i ./track-01.flac -c:v libx264 -tune stillimage -vf "scale=-2:1080:force_original_aspect_ratio=1,pad=1920:1080:(ow-iw)/2:(oh-ih)/2:black" -c:a copy -shortest ./track-01-video.mkv
  • Extract a segment of a video and produce a gif animation out of it. The extracted fragment is from the absolute time reference of 00:24:52.4 to 00:24:57.0. The first video stream is selected ([0:v]), and the audio naturraly discarded. Framerate is reduced to 12 fps, and horizontal size to 480 pixels while keeping the aspect ratio. It use special filters to generate a global optimized color palette limited to 64 colors. The first subtitle track (si=0) embedded in the original source.mp4 file is burned down, in a bold Arial Black font at 26pt (as per ASS specs).

    1 $ ffmpeg -i ./source.mp4 -ss 00:24:52.4 -to 00:24:57.0 -filter_complex "[0:v] fps=12,scale=width=480:height=-1:flags=lanczos,subtitles=source.mp4:si=0:force_style='FontName=Arial Black,Bold=-1,FontSize=26',split [a][b];[a] palettegen=64 [p];[b][p] paletteuse" ./meme.gif

    To pinpoint the right moment to cut your segment, here is a variation of the above to produce a set of timecoded frames with embedded subtitles for preview:

    1 $ ffmpeg -i ./source.mp4 -ss 00:24:52.700 -to 00:24:57.371 -filter_complex "drawtext=text='%{pts\:hms}': fontcolor=black: fontsize=32: box=1: boxcolor=white,subtitles=source.mp4:si=0" -f image2 "%04d.jpg"

VLC

  • Transcode the first video stream found in a m3u playlist to a 384 kbps MPEG-2 video and 48 kHz Vorbis audio, and serve the resulting stream ina Ogg container to http://localhost:8888. To save bandwidth we reduce by two the size of the video:

    1 $ vlc -vvv https://mafreebox.freebox.fr/freeboxtv/playlist.m3u --sout '#transcode{vcodec=mp2v,vb=384,scale=0.5,acodec=vorbis,ab=48,channels=1}:standard{access=http,mux=ogg,url=:8888}' -I ncurses 2> /dev/null

libAV

  • Re-encode a yuv422p video into a lossless h264, but this time in yuv420p:

    1 $ avconv -i yuv422p.mkv -c:v libx264 -pix_fmt yuv420p -preset veryslow -qp 0 yuv420p.mkv
  • Re-encode a lossless h264 video with a lower bitrate:

    1 $ avconv -i lossless.mkv -b:v 45M -preset veryfast lower-bitrate.mkv

Mplayer / Mencoder

  • Change the aspect ratio of a film for the playback. Standard aspect ratio are : 1.33 (4:3), 1.66 (1.66:1), 1.77 (16:9) and 2.35 (2.35:1):

    1 $ mplayer -aspect 2:1 ./video.avi
  • Play the video with subtitles:

    1 $ mplayer -sub ./subtitle_file.txt ./video.avi
  • This will extract audio track no. 128, downmix the AC3 sound to PCM and write the results to file.wav:

    1 $ mplayer -vo null -hardframedrop -aid 128 -ao pcm -aofile file.wav dvd://1
  • This will extract the audio, convert it to PCM and write the resulting wave file to audio.wav:

    1 $ mplayer -vo null -hardframedrop -ao pcm:file=audio.wav myvideo.avi
  • Show all subtitles streams:

    1 $ mplayer -vo null -ao null -frames 0 -v 2 dvd://1 >&1 | grep sid
  • Create a rotated copy of the file.avi video (rotate=1: clockwise; rotate=2: anti-clockwise):

    1 $ mencoder -vop rotate=2 -oac pcm -ovc lavc ./source.avi -o ./dest.avi
  • Preview a video composed of all jpeg files from the current folder at 15fps (mplayer only support jpeg, png, tga and sgi formats):

    1 $ mplayer "mf://*.jpg" -mf fps=15
  • Create a 15fps video from all jpeg files of the current folder:

    1 $ mencoder "mf://*.jpg" -mf fps=15 -ovc lavc -o ./dest.avi
  • Encode a SVCD to AVI file:

    1 $ mencoder -oac lavc -ovc lavc vcd://1 -o ./svcd.avi
  • Transcode video to raw format (be careful: usually the output video got annoying audio delay):

    1 $ mencoder -oac pcm -ovc raw -ofps 25 -noskip ./video.wmv -o ./video.avi
  • Encode a video using the default mpeg4 codec at 400 kbps for video and mp3 codec at constant 32 kbps bitrate for audio:

    1 $ mencoder -oac mp3lame -lameopts cbr:preset=32 -ovc lavc -lavcopts vbitrate=400 in.avi -o out.avi
  • Enhance the sharpness of the video:

    1 $ mplayer video.avi -vf smartblur=.6:-.5:0,unsharp=l5x5:.8:c5x5:.4
  • Cut a video to keep the first 5.4 seconds:

    1 $ mencoder big-file.avi -ss 0 -endpos 5.4 -ovc copy -oac copy -o cut.avi
  • Cut a video to keep everything except the first 5.4 seconds:

    1 $ mencoder big-file.avi -ss 5.4 -ovc copy -oac copy -o cut.avi
  • Show all mplayer filter list:

    1 $ mplayer -vf help
  • Get help of a particular filter (eq2 in this example):

    1 $ mplayer -vf eq2=help
  • Here is the filter I use to light up a video taken in the dark with my cheap camera. Of course it add noise but thanks to this we can distinguish shapes in the dark.

    1 $ mencoder -vf eq2=1.61:1.95:0.54:2.43 -oac pcm -ovc lavc video.avi -o bright-vid.avi
  • And this is the command to preview the result of the filter used above:

    1 $ mplayer video.avi -vf eq2=1.61:1.95:0.54:2.43
  • This is how I convert raw videos taken with my digital camera into ISO standard MPEG-4 (DivX 5, XVID compatible) videos (to encode in grayscale, add :gray option to -lavcopts):

    1 $ mencoder source.avi -ovc lavc -oac lavc -ffourcc DX50 -lavcopts vcodec=mpeg4:vbitrate=400:v4mv:mbd=2:trell:autoaspect:dia=2:acodec=mp3:abitrate=32:vpass=1 -vf hqdn3d -o output.avi
    2 $ mencoder source.avi -ovc lavc -oac lavc -ffourcc DX50 -lavcopts vcodec=mpeg4:vbitrate=400:v4mv:mbd=2:trell:autoaspect:dia=2:acodec=mp3:abitrate=32:vpass=2 -vf hqdn3d -o output.avi
  • Play all videos of the current folder fullscreen at 4x speed with 50% more brightness:

    1 $ mplayer -speed 4 -brightness 50 -fs ./*.avi
  • Extract audio stream from a video:

    1 $ mplayer -dumpaudio -dumpfile audio.ac3 video_source.mpg

Others

  • List MLT audio codecs:

    1 $ melt -query "audio_codecs"
  • Extract to chapter.txt the chapter file of the track n°1 of the DVD:

    1 $ dvdxchap -t 1 /mnt/cdrom > chapter.txt
  • Test XV video driver output via gstreamer v0.10:

    1 $ gst-launch-0.10 videotestsrc ! xvimagesink