For the complete list of available MEncoder options and examples, please see the man page.
2-pass encoding: the name comes from the fact that this method encodes the file twice. The first encoding (dubbed pass) creates some temporary files (*.log) with a size of few megabytes, do not delete them yet (you can delete the AVI). In the second pass, the 2-pass output file is created, using the bitrate data from the temporary files. The resulting file will have much better image quality. If this is the first time you heard about this, you should consult some guides available on the Net.
This example shows how to encode a DVD to a 2-pass MPEG-4 ("DIVX") AVI. Just
two commands are needed:
rm frameno.avi - remove this file, which
can come from a previous 3-pass encoding (it interferes with current
one)
mencoder -dvd 2 -ovc lavc -lavcopts
vcodec=mpeg4:vpass=1 -oac copy -o movie.avi
mencoder -dvd 2 -ovc lavc -lavcopts
vcodec=mpeg4:vpass=2 -oac copy -o movie.avi
3-pass encoding: this is an extension of 2-pass encoding, where the audio encoding takes place in a separate pass. This method enables estimation of recommended video bitrate in order to fit on a CD. Also, the audio is encoded only once, unlike in 2-pass mode. The schematics:
rm frameno.avi
mencoder <file/DVD> -ovc frameno -oac mp3lame -lameopts vbr=3 -o frameno.avi
An audio-only avi file will be created, containing
only the requested audio stream. Don't forget -lameopts,
if you need to set it. If you were encoding a long movie, MEncoder
prints the recommended bitrate values for 650Mb, 700Mb, and 800Mb
destination sizes, after this pass finishes.
mencoder <file/DVD> -oac copy
-ovc lavc -lavcopts vcodec=mpeg4:vpass=1:vbitrate=<bitrate>
This is the first pass of video encoding. Optionally specify the video bitrate MEncoder printed at the end of the previous pass.
mencoder <file/DVD> -oac copy
-ovc lavc -lavcopts vcodec=mpeg4:vpass=2:vbitrate=<bitrate>
This is the second pass of video encoding.
Specify the same bitrate as in the previous pass unless you really know
what you are doing. In this pass, audio from frameno.avi
will be inserted into the destination file.. and it's all ready!
rm frameno.avi - remove this file,
which can come from a previous 3-pass encoding (it interferes with current
one)
mencoder -dvd 2 -ovc frameno
-o frameno.avi -oac mp3lame -lameopts vbr=3
mencoder -dvd 2 -ovc lavc
-lavcopts vcodec=mpeg4:vpass=1 -oac copy -o movie.avi
mencoder -dvd 2 -ovc lavc
-lavcopts vcodec=mpeg4:vpass=2 -oac copy -o movie.avi
Often the need to resize movie images' size emerges. Its reasons can be many: decreasing file size, network bandwidth, etc. Most people even do rescaling when converting DVDs or SVCDs to DivX AVI. This is bad. Instead of even you doing so, read the Preserving aspect ratio section.
The scaling process is handled by the 'scale' video filter:
-vop scale=widht:height. Its quality can be set with the
-sws option. If it's not specified, MEncoder will use 0:
fast bilinear.
mencoder input.mpg -ovc lavc -lavcopts
vcodec=mpeg4 -vop scale=640:480 -oac copy -o
output.avi
MEncoder can handle input streams in two ways: encode or copy them. This section is about copying.
-ovc copy): nice stuff can be
done :)-oac copy): straightforward.
It is possible to take an external audio file (MP3, Vorbis) and mux it
into the output stream. Use the -audiofile <filename>
option for this.Easiest thing. We simply copy the video and audio streams, and
MEncoder generates the index. Of course this cannot fix possible bugs
in the video and/or audio streams. It also fixes files with broken
interleaving, thus the -ni option won't be needed for them
anymore.
Command: mencoder -idx input.avi -ovc copy -oac copy -o output.avi
libavcodec provides simple encoding to a lot of interesting video and audio formats (currently its audio codecs are unsupported). You can encode to the following codecs:
The first column contains the codec names that should be passed after the
vcodec config, like: -lavcopts vcodec=msmpeg4
An example, with MJPEG compression:
mencoder -dvd 2 -o title2.avi -ovc lavc
-lavcopts vcodec=mjpeg -oac copy
MEncoder is capable of creating movies from one or more JPEG, PNG or TGA files. With simple framecopy it can create MJPEG (Motion JPEG), MPNG (Motion PNG) or MTGA (Motion TGA) files.
Explanation of the process:libjpeg (when decoding PNGs, it will use libpng).The explanation of the -mf option can be found below in the
global Options section and in the man page.
Creating a DivX4 file from all the JPEG files in the current dir:
mencoder \*.jpg -mf on:w=800:h=600:fps=25 -ovc divx4
-o output.avi
Creating a DivX4 file from some JPEG files in the current dir:
mencoder frame001.jpg,frame002.jpg -mf on:w=800:h=600:fps=25
-ovc divx4 -o output.avi
Creating a Motion JPEG (MJPEG) file from all the JPEG files in the current dir:
mencoder \*.jpg -mf on:w=800:h=600:fps=25 -ovc copy
-o output.avi
Creating an uncompressed file from all the PNG files in the current dir:
mencoder \*.png -mf on:w=800:h=600:fps=25:type=png -ovc raw
-o output.avi
Creating a Motion PNG (MPNG) file from all the PNG files in the current dir:
mencoder \*.png -mf on:w=800:h=600:fps=25:type=png -ovc copy
-o output.avi
Creating a Motion TGA (MTGA) file from all the TGA files in the current dir:
mencoder \*.tga -mf on:w=800:h=600:fps=25:type=tga -ovc copy
-o output.avi
MEncoder is capable of extracting subtitles from a DVD into
Vobsub fomat files. They consist of a pair of files ending in
.idx and .sub and are usually packaged in a single
.rar archive. MPlayer can play these with the
-vobsub and -vobsubid options.
You specify the basename (i.e without the .idx or
.sub extension) of the output files with -vobsubout
and the index for this subtitle in the resulting files with
-vobsuboutindex.
If the input is not from a DVD you should use -ifo to
indicate the .ifo file needed to construct the resulting
.idx file.
If the input is not from a DVD and you do not have the .ifo
file you will need to use the -vobsubid option to let it know
what language id to put in the .idx file.
Each run will append the running subtitle if the .idx and
.sub files already exist. So you should remove any before
starting.
Copying two subtitles from a DVD while doing 3-pass encoding
rm subtitles.idx subtitles.sub
mencoder -dvd 1 -vobsubout subtitles -vobsuboutindex 0
-sid 2 -o frameno.avi -ovc frameno -oac mp3lame -lameopts vbr=3
mencoder -dvd 1 -oac copy -ovc divx4 -divx4opts pass=1
mencoder -dvd 1 -oac copy -ovc divx4 -divx4opts pass=2 -vobsubout
subtitles -vobsuboutindex 1 -sid 5
Copying a french subtitle from an MPEG file
rm subtitles.idx subtitles.sub
mencoder movie.mpg -ifo movie.ifo -vobsubout subtitles
-vobsuboutindex 0 -vobsuboutid fr -sid 1
DVDs and SVCDs (i.e. MPEG1/2) files contain an aspect ratio value, which describes how should the player scale the video stream, so humans won't have egg heads (ex.: 480x480 + 4:3 = 640x480). However when encoding to AVI (DivX) files, you have be aware that AVI headers don't store this value. Rescaling the movie is disgusting and time consuming, there must be a better feature!
There is.
MPEG4 has an unique feature: the video stream can contain its needed aspect ratio. Yes, just like MPEG1/2 files (DVD, SVCD). Regretfully, there are no video players outside which support this attribute. Except MPlayer.
This feature can be used only with libavcodec's mpeg4
codec. Keep in mind: although MPlayer will correctly play the created file,
other players will use the wrong aspect ratio.
You seriously should crop the black bands over and below the movie image.
See the manpage about the usage of the cropdetect and
crop filters.
$ mencoder sample-svcd.mpg -ovc lavc -lavcopts
vcodec=mpeg4:aspect=16.0/9.0 -vop crop=714:548:0:14 -oac copy -o output.avi