Difference between revisions of "MEncoder"

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(Two-pass xvid (very high-quality))
(Two-pass xvid (very high-quality))
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* Recent versions of mencoder enable {{Filename|bvhq}}={{Filename|1}} as a default setting.  
* Recent versions of mencoder enable {{Filename|bvhq}}={{Filename|1}} as a default setting.  
* Xvid does not accept {{Filename|bitrate}} settings on the first of multiple-pass encodings.
* Xvid does not accept {{Filename|bitrate}} settings on the first of multiple-pass encodings.
* {{Filename|max_bframes}}={{Filename|0}} can be set so long as the bitrate is high enough.
* {{Filename|subfont-text-scale 2-3}} helps with proper sizing with 16:9 format screens.
* {{Filename|subfont-text-scale 2-3}} helps with proper sizing with 16:9 format screens.
* {{Filename|max_bframes}}={{Filename|0}} can be set so long as the bitrate is high enough.
====Three-pass [[Wikipedia:Libavcodec|lavc]] (very high-quality mpeg4) ====
====Three-pass [[Wikipedia:Libavcodec|lavc]] (very high-quality mpeg4) ====

Revision as of 02:31, 13 June 2011

Summary help replacing me
An overview of the video encoding/decoding tool provided by MPlayer.
DVD Ripping

MEncoder is part of the Template:Package Official package. See MPlayer for details. Template:Package Official does not include MEncoder.


The basic syntax for a conversion is

mencoder original_video.mpg -o new_video.avi -ovc output_video_codec -oac output_audio_codec

So to convert movie.mpg to movie.avi with MPEG-4 Part 2 video and MP2 audio, the command is

mencoder movie.mpg -o movie.avi -ovc lavc -oac lavc

The default output formats without any options are MPEG-4 for video and MP2 for audio.

This is basically how one converts a video. However, there are MANY more options available.

For input formats, MEncoder can use any format that MPlayer can play, so to verify whether it will work with your video, just try playing it in MPlayer.

To list output video codecs, run

$ mencoder -ovc help

Similarly, to list output audio codecs, run

$ mencoder -oac help

This information can also be found here where it better explained, although non-specific.

There are many more options available (e.g. you can define bit rates and expected sizes). Template:Gentoo


This approach allows one to make a .mkv file with an H.264-encoded video and any number of Vorbis-encoded audio tracks.

We will use mencoder (part of mplayer package) for ripping and encoding and mkvmerge (part of mkvtoolnix package) for making the .mkv file itself.

Ripping and encoding the video

The H.264 encoder is usually used in two passes: the first reads informations about the movie, the second uses that information to encode. We will not extract any audio for now.

Commands follow; remember to replace the variables with the proper values:

# First pass: we are just collecting information, so the normal output is thrown away.
mencoder -dvd-device "$ISO" dvd://"$TITLE" -chapter "$CHAPTER" -o /dev/null -nosound -ovc x264 \
-x264encopts direct=auto:pass=1:turbo:bitrate=900:bframes=1:\
me=umh:partitions=all:trellis=1:qp_step=4:qcomp=0.7:direct_pred=auto:keyint=300 \
-vf scale=-1:-10,harddup
# Second pass: here we compress the video track using the information from the first step.
mencoder -dvd-device "$ISO" dvd://"$TITLE" -chapter "$CHAPTER" -nosound -ovc x264 \
-x264encopts direct=auto:pass=2:bitrate=900:frameref=5:bframes=1:\
me=umh:partitions=all:trellis=1:qp_step=4:qcomp=0.7:direct_pred=auto:keyint=300 \
-vf scale=-1:-10,harddup -o video.avi

This will create a video.avi file containing the video. You can play with the -x264encopts options and the -vf filters to improve the quality or reduce the file size. For example, a movie with a black border should be cropped with -vf crop=$X:$Y,scale=-1:-10,harddup with the proper values instead of $X and $Y (see cropdetect in the MEncoder manual). You may want to scale down the movie with -vf scale=$WIDTH:-10,harddup the width of the movie will become $WIDTH (keep $WIDTH a multiple of 16: 640, 480, or 320 are usually fine), the height will be correctly calculated in order to keep the aspect ratio.

You can also use any other of the filters MEncoder has to offer, like pullup,softskip or you can change the frame rate using -ofps. (If you do so, remember to use the same frame rate everywhere including in the commands to rip audio.)

It is important that you use harddup as the last filter: it will force MEncoder to write every frame (even duplicate ones) in the output. Also, it is necessary to use scale=$WIDTH,-10 with $WIDTH as -1 to keep the original width or a new, usually smaller, width: it is necessary since the H.264 codec uses square pixels and DVDs instead use rectangular pixels.

Ripping and encoding the audio

You can extract audio tracks as needed. Here we compress with the Vorbis algorithm, but you may want to check the MEncoder manual in order to see alternatives.

The command follows (replace the variables with desired values):

# Here we rip and compress the audio.
mencoder -dvd-device "$ISO" dvd://"$TITLE" -alang "$AUDIOLANG" -chapter "$CHAPTER" -ovc frameno \
-oac lavc -lavcopts acodec=vorbis:abitrate=224 -channels 2 -srate 48000 -o "$AUDIOLANG".avi

You should repeat the command for every audio track you want, so we will have .avi files with the audio track.

You may also want to use -channels 6 to exact all the channels of a 5.1 DVD or changing the bit rate. As with the video, you can use audio filters via -af but it is not necessary.

Making the final .mkv file

Putting it all together in a single file is simple. Add other audio tracks if needed:

mkvmerge -D audio.avi -A video.avi -o mymovie.mkv

The .mkv file will contain everything, so you can store your movie keeping all the audio track you want. Even if you are not interested in keeping multiple sound tracks, the H.264/Vorbis format pair should ensure great quality.

Of course to make the work easier, you should write every command in a single file and execute it.

See Dvd2Avi for a sample script.

Encoding video mp4 for Nokia 5800 XM and Nokia N97

In 2 passes with small bitrates (640kbps video vbitrate and 96kbps audio abitrate) yields pretty watchable video mp4 for nokia 5800 xm and Nokia N97 phones' default video player. Let's assume that we have a video.avi file (replace video.avi with your video file)

mkv to mp4 (nokia 97, 5800 compatible)

# step 1: convert the mkv to mpg ; many mkv files do not directly get converted to mp4
mencoder "$1" -ovc lavc -lavcopts vcodec=mpeg1video -aid 0 -oac pcm -o delete_me.mpg
# step 2: convert the mpg file to mp4
mencoder -of lavf -lavfopts format=mp4 -oac lavc -ovc lavc -lavcopts \
aglobal=1:vglobal=1:acodec=libfaac:vcodec=mpeg4:abitrate=128:vbitrate=640:keyint=250:mbd=1:vqmax=10:lmax=10:turbo  -af lavcresample=44100 \
-vf harddup,scale=640:-3 "delete_me.mpg" -o "$1.mp4"
# step 3: delete the temporary huge sized mpg file 
rm "delete_me.mpg"

replace "$1" with the .mkv video filename. e.g., sample.mkv; here -aid 0 = first audio track in mkv;

Converting an avi to mp4 (nokia 97, 5800 compatible) using multipass (2 passes)

# First pass:
mencoder -of lavf -lavfopts format=mp4 -oac lavc -ovc lavc -lavcopts \
aglobal=1:vglobal=1:acodec=libfaac:vcodec=mpeg4:abitrate=96:vbitrate=640:keyint=250:mbd=1:vqmax=10:lmax=10:vpass=1:turbo  -af lavcresample=44100 \
-vf harddup,scale=640:-3 "video.avi" -o "video.mp4"
# Second pass:
mencoder -of lavf -lavfopts format=mp4 -oac lavc -ovc lavc -lavcopts \
aglobal=1:vglobal=1:acodec=libfaac:vcodec=mpeg4:abitrate=96:vbitrate=640:keyint=250:mbd=1:vqmax=10:lmax=10:vpass=2 -af lavcresample=44100 \
-vf harddup,scale=640:-3 "video.avi" -o "video.mp4"

After the 2nd pass is done, copy the video.mp4 to nokia 5800 xm or n97's memory card and open the file using file manager of nokia after removing the device from the computer.

we need to run the above two commands in the folder where video.avi is present. play around with abitrate, vbitrate, and scale values to get video quality and size of your liking. alternate formatfactory is a mencoder gpl application for windows which runs in wine, can also convert all-to-mp4.

scale=640:-3 will try to keep the video width to 640 and resize the video height accordingly. Do use the "original" aspect in nokia's mp4 player "option->aspect" for 16:9 and 4:3 aspect ratio videos.

Encoding a multi audio / multi language MKV video to an MP4 with different audio streams

to encode multi-audio file to mp4 we need to use the "-aid <audio stream number>" like -map 0:1 in ffmpeg)

1. To extract video+audio stream1 (usually english) of mkv file:

mencoder -oac copy -ovc copy -aid 0 sample.mkv -o sample.mp4 

2. To extract video+audio stream2 (usually non-english, like Hindi, French, etc.) of mkv file:

mencoder -oac copy -ovc copy -aid 1 sample.mkv -o sample.mp4

Adding SubRip subtitles to a file

The following output video codec (-ovc) options are suggested as very-high quality settings and should suffice for most transcodings, including the additon of subtitles to a stream.

Two-pass x264 (very high-quality)

mencoder original_video.avi -oac copy -ovc x264 -x264encopts pass=1:preset=veryslow:frameref=5:tune=film:bitrate=2400:threads=auto -sub original_video.srt -subfont-text-scale 3 -o /dev/null
mencoder original_video.avi -oac copy -ovc x264 -x264encopts pass=2:preset=veryslow:frameref=5:tune=film:bitrate=2400:threads=auto -sub original_video.srt -subfont-text-scale 3 -o output_video.avi

Single-pass x264 (very high-quality)

mencoder original_video.avi -oac copy -ovc x264 -x264encopts pass=2:preset=veryslow:frameref=5:tune=film:crf=15:threads=auto -sub original_video.srt -subfont-text-scale 3 -o output_video.avi
  • The following example uses the option Template:Filename to mux the output into a Matroska container which is autodetected from the output file extension .mkv
mencoder original_video.avi -oac copy -of lavc -ovc x264 -x264encopts pass=2:preset=veryslow:frameref=5:tune=film:crf=15:global_header:threads=auto -sub original_video.srt -subfont-text-scale 3 -o output_video.mkv
  • Template:Filename writes global video headers to extradata, or in front of keyframes and is typically required for .mp4 and .mkv containers.

Two-pass xvid (very high-quality)

mencoder original_video.avi -oac copy -ovc xvid -xvidencopts pass=1:chroma_opt:vhq=4:max_bframes=1:quant_type=mpeg:threads=6 -sub original_video.srt -subfont-text-scale 3 -o /dev/null
mencoder original_video.avi -oac copy -ovc xvid -xvidencopts pass=2:chroma_opt:vhq=4:max_bframes=1:quant_type=mpeg:bitrate=2400:threads=6 -sub original_video.srt -subfont-text-scale 3 -o output_video.avi

Three-pass lavc (very high-quality mpeg4)

mencoder original_video.avi -oac copy -ffourcc DX50 -ovc lavc -lavcopts vpass=1:mbd=2:mv0:trell:v4mv:cbp:predia=6:dia=6:precmp=6:cmp=6:subcmp=6:preme=2:qns=2:vbitrate=2400 -sub original_video.srt -subfont-text-scale 3 -o output_video.avi
mencoder original_video.avi -oac copy -ffourcc DX50 -ovc lavc -lavcopts vpass=3:mbd=2:mv0:trell:v4mv:cbp:predia=6:dia=6:precmp=6:cmp=6:subcmp=6:preme=2:qns=2:vbitrate=2400 -sub original_video.srt -subfont-text-scale 3 -o output_video.avi
mencoder original_video.avi -oac copy -ffourcc DX50 -ovc lavc -lavcopts vpass=3:mbd=2:mv0:trell:v4mv:cbp:predia=6:dia=6:precmp=6:cmp=6:subcmp=6:preme=:qns=2:vbitrate=2400 -sub original_video.srt -subfont-text-scale 3 -o output_video.avi

mp2 vs. mp3lame vs. aac

  • toolame is recommended over ffmpeg lavc for mp2 encoding.
  • mp3lame is recommended over faac (not fully developed) encoding.