Tag Archive for 'audio'

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

  mplayer -frames 0 -identify ./video.avi
  tcprobe -i ./video.avi
  ffmpeg -i ./video.avi
  file ./video.avi
  

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):

  mplayer -aspect 2:1 ./video.avi
  

• Play the video with subtitles:

  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:

  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:

  mplayer -vo null -hardframedrop -ao pcm:file=audio.wav myvideo.avi
  

• Show all subtitles streams:

  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):

  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):

  mplayer "mf://*.jpg" -mf fps=15
  

• Create a 15fps video from all jpeg files of the current folder:

  mencoder "mf://*.jpg" -mf fps=15 -ovc lavc -o ./dest.avi
  

• Encode a SVCD to AVI file:

  mencoder -oac lavc -ovc lavc vcd://1 -o ./svcd.avi
  

• Transcode video to raw format (be carefull: usually the output video got annoying audio delay):

  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:

  mencoder -oac mp3lame -lameopts cbr:preset=32 -ovc lavc -lavcopts vbitrate=400 in.avi -o out.avi
  

• Enhance the sharpness of the video:

  mplayer video.avi -vf smartblur=.6:-.5:0,unsharp=l5x5:.8:c5x5:.4
  

• Cut a video to keep the first 5.4 seconds:

  mencoder big-file.avi -ss 0 -endpos 5.4 -ovc copy -oac copy -o cutted.avi
  

• Cut a video to keep everything exept the first 5.4 seconds:

  mencoder big-file.avi -ss 5.4 -ovc copy -oac copy -o cutted.avi
  

• Show all mplayer filter list:

  mplayer -vf help
  

• Get help of a particular filter (eq2 in this example):

  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.

  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:

  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]:

  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
  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:

  mplayer -speed 4 -brightness 50 -fs ./*.avi
  

• Extract audio stream from a video:

  mplayer -dumpaudio -dumpfile audio.ac3 video_source.mpg
  

Transcode

• Merge multiple video into one:

  avimerge -i part1.avi part2.avi -o big-file.avi
  

• Extract the raw subtitle stream. The -a 0x21 option correspond to the subtitle stream’s hexadecimal number (= 0×20 + id of the stream):

  tccat -i /space/st-tng/dic1/ -T 1 -L | tcextract -x ps1 -t vob -a 0x22 > subs-en
  

Others

• Extract to chapter.txt the chapter file of the track n°1 of the DVD:

  dvdxchap -t 1 /mnt/cdrom > chapter.txt
  

• Test XV video driver output via gstreamer v0.10:

  gst-launch-0.10 videotestsrc ! xvimagesink