Ffmpeg2theora

From LinuxReviews

ffmpeg2theora is a command line converter which can create Ogg Theora videofiles using most common videoformats (mpg, dv, etc)^[1]

Usage

$ ffmpeg2theora -h          
ffmpeg2theora 0.19

  Usage: ffmpeg2theora [options] input

General output options:
  -o, --output           alternative output filename
  -k, --skeleton         outputs ogg skeleton metadata
  -s, --starttime        start encoding at this time (in sec.)
  -e, --endtime          end encoding at this time (in sec.)
  -p, --v2v-preset       encode file with v2v preset.
                          Right now there is preview and pro. Run
                          'ffmpeg2theora -p info' for more informations

Video output options:
  -v, --videoquality     [0 to 10] encoding quality for video (default: 5)
  -V, --videobitrate     [1 to 16778] encoding bitrate for video (kb/s)
      --optimize         optimize video output filesize (slower)
  -x, --width            scale to given width (in pixels)
  -y, --height           scale to given height (in pixels)
      --aspect           define frame aspect ratio: i.e. 4:3 or 16:9
  -F, --framerate        output framerate e.g 25:2 or 16
      --croptop, --cropbottom, --cropleft, --cropright
                         crop input by given pixels before resizing
  -S, --sharpness        [0 to 2] sharpness of images (default: 2).
                          Note: lower values make the video sharper.
  -K, --keyint           [8 to 65536] keyframe interval (default: 64)

Video transfer options:
  -C, --contrast         [0.1 to 10.0] contrast correction (default: 1.0)
                          Note: lower values make the video darker.
  -B, --brightness       [-1.0 to 1.0] brightness correction (default: 0.0)
                          Note: lower values make the video darker.
  -G, --gamma            [0.1 to 10.0] gamma correction (default: 1.0)
                          Note: lower values make the video darker.
  -Z, --saturation       [0.1 to 10.0] saturation correction (default: 1.0)
                          Note: lower values make the video grey.

Audio output options:
  -a, --audioquality     [-2 to 10] encoding quality for audio (default: 1)
  -A, --audiobitrate     [32 to 500] encoding bitrate for audio (kb/s)
  -c, --channels         set number of output channels
  -H, --samplerate       set output samplerate (in Hz)
      --nosound          disable the sound from input

Input options:
      --deinterlace      force deinterlace, otherwise only material
                          marked as interlaced will be deinterlaced
      --vhook            you can use ffmpeg's vhook system, example:
        ffmpeg2theora --vhook '/path/watermark.so -f wm.gif' input.dv
  -f, --format           specify input format
      --v4l /dev/video0  read data from v4l device /dev/video0
                          you have to specifiy an output file with -o
      --inputfps fps     override input fps
      --audiostream id   by default the last audio stream is selected,
                          use this to select another audio stream
      --sync             use A/V sync from input container. Since this does
                          not work with all input format you have to manually
                          enable it if you have issues with A/V sync

Metadata options:
      --artist           Name of artist (director)
      --title            Title
      --date             Date
      --location         Location
      --organization     Name of organization (studio)
      --copyright        Copyright
      --license          License

Other options:
      --nice n           set niceness to n
  -P, --pid fname        write the process' id to a file
  -h, --help             this message

Examples:
  ffmpeg2theora videoclip.avi (will write output to videoclip.ogg)

  cat something.dv | ffmpeg2theora -f dv -o output.ogg -

  Live streaming from V4L Device:
  ffmpeg2theora --v4l /dev/video0 --inputfps 15 -x 160 -y 128 -o - \
   | oggfwd iccast2server 8000 password /theora.ogg

  Live encoding from a DV camcorder (needs a fast machine):
  dvgrab - | ffmpeg2theora -f dv -x 352 -y 288 -o output.ogg -

  Live encoding and streaming to icecast server:
  dvgrab --format raw - | \
   ffmpeg2theora -f dv -x 160 -y 128 -o /dev/stdout - | \
   oggfwd iccast2server 8000 password /theora.ogg

Usage tips

It should be mentioned that you can pipe multiple files. Example:

cat *.mpeg | \
ffmpeg2theora -f mpg --optimize -o /pub/local/video/GNU/stallman.ogg -

Performance

It must be mentioned that ffmpeg2theora is extremely slow and uses ages compared to encoding MPEG-4 ASP using mencoder and it's version of the Xvid codec.

You likely want to encode your flies using fmpeg2theora regardless if you prefer freedom over slavery simply because Ogg Theora is not subject to software patents (which Xvid isn't^[1]).

It should also be mentioned that --optimize creates signifficantly smaller files (at the price of way longer encoding time).

ffmpeg2theora manual page

Limitations

You can't set target size to get a output file which is exactly 350 MB or something like that.

References