mpv/DOCS/encoding.rst

General usage
=============

::

  mpv infile --o=outfile [--of=outfileformat] [--ofopts=formatoptions] [--orawts] \
    [(any other mpv options)] \
    --ovc=outvideocodec [--ovcopts=outvideocodecoptions] \
    --oac=outaudiocodec [--oacopts=outaudiocodecoptions]

Help for these options is provided if giving help as parameter, as in::

  mpv --ovc=help

The suboptions of these generally are identical to ffmpeg's (as option parsing
is simply delegated to ffmpeg). The option --ocopyts enables copying timestamps
from the source as-is, instead of fixing them to match audio playback time
(note: this doesn't work with all output container formats); --orawts even turns
off discontinuity fixing.

Note that if neither --ofps nor --oautofps is specified, VFR encoding is assumed
and the time base is 24000fps. --oautofps sets --ofps to a guessed fps number
from the input video. Note that not all codecs and not all formats support VFR
encoding, and some which do have bugs when a target bitrate is specified - use
--ofps or --oautofps to force CFR encoding in these cases.

Of course, the options can be stored in a profile, like this .config/mpv/mpv.conf
section::

  [myencprofile]
  vf-add = scale=480:-2
  ovc = libx264
  ovcopts-add = preset=medium
  ovcopts-add = tune=fastdecode
  ovcopts-add = crf=23
  ovcopts-add = maxrate=1500k
  ovcopts-add = bufsize=1000k
  ovcopts-add = rc_init_occupancy=900k
  ovcopts-add = refs=2
  ovcopts-add = profile=baseline
  oac = aac
  oacopts-add = b=96k

It's also possible to define default encoding options by putting them into
the section named ``[encoding]``.

One can then encode using this profile using the command::

  mpv infile --o=outfile.mp4 --profile=myencprofile

Some example profiles are provided in a file
etc/encoding-profiles.conf; as for this, see below.


Encoding examples
=================

These are some examples of encoding targets this code has been used and tested
for.

Typical MPEG-4 Part 2 ("ASP", "DivX") encoding, AVI container::

  mpv infile --o=outfile.avi \
    --vf=fps=25 \
    --ovc=mpeg4 --ovcopts=qscale=4 \
    --oac=libmp3lame --oacopts=b=128k

Note: AVI does not support variable frame rate, so the fps filter must be used.
The frame rate should ideally match the input (25 for PAL, 24000/1001 or
30000/1001 for NTSC)

Typical MPEG-4 Part 10 ("AVC", "H.264") encoding, Matroska (MKV) container::

  mpv infile --o=outfile.mkv \
    --ovc=libx264 --ovcopts=preset=medium,crf=23,profile=baseline \
    --oac=libopus --oacopts=qscale=3

Typical MPEG-4 Part 10 ("AVC", "H.264") encoding, MPEG-4 (MP4) container::

  mpv infile --o=outfile.mp4 \
    --ovc=libx264 --ovcopts=preset=medium,crf=23,profile=baseline \
    --oac=aac --oacopts=b=128k

Typical VP8 encoding, WebM (restricted Matroska) container::

  mpv infile -o outfile.mkv \
    --of=webm \
    --ovc=libvpx --ovcopts=qmin=6,b=1000000k \
    --oac=libopus --oacopts=qscale=3


Device targets
==============

As the options for various devices can get complex, profiles can be used.

An example profile file for encoding is provided in
etc/encoding-profiles.conf in the source tree. mpv will read any file
named ``encoding-profiles.conf`` in either the local or system
configuration directories.

Keep in mind that the default profile is the playback one. If you want to add
options that apply only in encoding mode, put them into a ``[encoding]``
section.

Refer to the top of that file for more comments - in a nutshell, the following
options are added by it::

  --profile=enc-to-dvdpal      # DVD-Video PAL, use dvdauthor -v pal+4:3 -a ac3+en
  --profile=enc-to-dvdntsc     # DVD-Video NTSC, use dvdauthor -v ntsc+4:3 -a ac3+en
  --profile=enc-to-bb-9000     # MP4 for Blackberry Bold 9000
  --profile=enc-to-nok-6300    # 3GP for Nokia 6300
  --profile=enc-to-psp         # MP4 for PlayStation Portable
  --profile=enc-to-iphone      # MP4 for iPhone
  --profile=enc-to-iphone-4    # MP4 for iPhone 4 (double res)
  --profile=enc-to-iphone-5    # MP4 for iPhone 5 (even larger res)

You can encode using these with a command line like::

  mpv infile --o=outfile.mp4 --profile=enc-to-bb-9000

Of course, you are free to override options set by these profiles by specifying
them after the -profile option.


What works
==========

* Encoding at variable frame rate (default)
* Encoding at constant frame rate using --vf=fps=RATE
* 2-pass encoding (specify flags=+pass1 in the first pass's --ovcopts, specify
  flags=+pass2 in the second pass)
* Hardcoding subtitles using vobsub, ass or srt subtitle rendering (just
  configure mpv for the subtitles as usual)
* Hardcoding any other mpv OSD (e.g. time codes, using --osdlevel=3 and
  --vf=expand=::::1)
* Encoding directly from a DVD, network stream, webcam, or any other source
  mpv supports
* Using x264 presets/tunings/profiles (by using profile=, tune=, preset= in the
  --ovcopts)
* Deinterlacing/Inverse Telecine with any of mpv's filters for that
* Audio file converting: mpv --o=outfile.m4a infile.flac --no-video
  --oac=aac --oacopts=b=320k

What does not work yet
======================

* 3-pass encoding (ensuring constant total size and bitrate constraints while
  having VBR audio; mencoder calls this "frameno")
* Direct stream copy