Basic usage of MEncoder
For the complete list of available MEncoder options
and examples, please see the man page. For a series of hands-on examples and
detailed guides on using several encoding parameters, read the
encoding-tips that were
collected from several mailing list threads on MPlayer-users. Search the
archives
for a wealth of discussions about all aspects of and problems related to
encoding with MEncoder.
Selecting codecs and container formats
Audio and video codecs for encoding are selected with the
and options, respectively.
Type for instance:
mencoder -ovc help
to list all video codecs supported by the version of
MEncoder on your machine.
The following choices are available:
Audio Codecs:
Audio codec nameDescriptionmp3lameEncode to VBR, ABR or CBR MP3 with LAMElavcUse one of libavcodec's audio codecs
faacFAAC AAC audio encodertoolameMPEG Audio Layer 2 encodertwolameMPEG Audio Layer 2 encoder based on tooLAMEpcmUncompressed PCM audiocopyDo not reencode, just copy compressed frames
Video codecs:
Video codec nameDescriptionlavcUse one of libavcodec's video codecs
xvidXviD, MPEG-4 Advanced Simple Profile (ASP) codecx264x264, MPEG-4 Advanced Video Coding (AVC), AKA H.264 codecnuvnuppel video, used by some realtime applicationsrawUncompressed video framescopyDo not reencode, just copy compressed framesframenoUsed for 3-pass encoding (not recommended)
Output container formats are selected with the
option.
Type:
mencoder -of help
to list all containers supported by the version of
MEncoder on your machine.
The following choices are available:
Container formats:
Container format nameDescriptionlavfOne of the containers supported by
libavformataviAudio-Video InterleavedmpegMPEG-1 and MPEG-2 PSrawvideoraw video stream (no muxing - one video stream only)rawaudioraw audio stream (no muxing - one audio stream only)
The AVI container is the native container format for
MEncoder, which means that it's the one that
is best handled, and the one for which MEncoder
was designed.
As noted above, other container formats are usable, but you may
experience problems when using them.
libavformat containers:
If you selected libavformat
to do the muxing of the output file (by using the ),
the appropriate container format will be determined by the file extension
of the output file.
You may force a particular container format with
libavformat's
option.
libavformat container nameDescriptionmpgMPEG-1 and MPEG-2 PSasfAdvanced Streaming FormataviAudio-Video InterleavedwavWaveform AudioswfMacromedia FlashflvMacromedia Flash videormRealMediaauSUN AUnutNUT open container (experimental and not yet spec-compliant)movQuickTimemp4MPEG-4 formatdvSony Digital Video container
As you can see, libavformat
allows MEncoder to mux into a considerable
variety of containers.
Unfortunately, as MEncoder was not designed
from the beginning to support container formats other than AVI,
your should really be paranoid about the resulting file.
Please check to be sure that the audio/video synchronization is OK
and that the file can be played correctly by players other than
MPlayer.
Example:
Creating a Macromedia Flash video suitable for playback in a web browser
with the Macromedia Flash plugin:
mencoder input.avi -o output.flv -of lavf -oac mp3lame -lameopts abr:br=56 -ovc lavc \
-lavcopts vcodec=flv:vbitrate=500:mbd=2:mv0:trell:v4mv:cbp:last_pred=3 \
-srate 22050
Selecting input file or deviceMEncoder can encode from files or directly
from a DVD or VCD disc.
Simply include the filename on the command line to encode from a file,
or titlenumber or
tracknumber to encode
from a DVD title or VCD track.
If you have already copied a DVD to your hard drive (you can use a tool
such as dvdbackup, available on most systems),
and wish to encode from the copy, you should still use the
syntax, along with
followed by the path to the copied DVD root.
The and
options can also be used to override the paths to the device nodes
for reading directly from disc, if the defaults of
/dev/dvd and /dev/cdrom do
not work on your system.
When encoding from DVD, it is often desirable to select a chapter or
range of chapters to encode.
You can use the option for this purpose.
For example, 1-4
will only encode chapters 1 through 4 from the DVD.
This is especially useful if you will be making a 1400 MB encode
targetted for two CDs, since you can ensure the split occurs exactly
at a chapter boundary rather than in the middle of a scene.
If you have a supported TV capture card, you can also encode from the
TV-in device.
Use channelnumber as
the filename, and to configure various capture
settings.
DVB input works similarly.
Encoding two pass MPEG-4 ("DivX")
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 or rather just not create any video by
redirecting it into /dev/null).
In the second pass, the two 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.
copy audio track
Two pass encode of the second track a DVD to an MPEG-4 ("DivX")
AVI while copying the audio track.
mencoder dvd://2 -ovc lavc -lavcopts vcodec=mpeg4:vpass=1 -oac copy -o /dev/null
mencoder dvd://2 -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell:vpass=2 -oac copy -o output.aviencode audio track
Two pass encode of a DVD to an MPEG-4 ("DivX") AVI while encoding
the audio track to MP3.
Be careful using this method as it may lead to audio/video desync in
some cases.
mencoder dvd://2 -ovc lavc -lavcopts vcodec=mpeg4:vpass=1 -oac mp3lame -lameopts vbr=3 -o /dev/null
mencoder dvd://2 -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell:vpass=2 -oac mp3lame -lameopts vbr=3 -o output.aviEncoding to Sony PSP video formatMEncoder supports encoding to Sony PSP's video
format, but, depending on the revision of the PSP software, the constraints
may differ.
You should be safe if you respect the following constraints:
Bitrate: it should not exceed 1500kbps,
however, past versions supported pretty much any bitrate as long as the
header claimed it was not too high.
Dimensions: the width and height of the
PSP video should be multiples of 16, and the product width * height must
be <= 64000.
Under some circumstances, it may be possible for the PSP to play higher
resolutions.
Audio: its samplerate should be 24khz
for MPEG-4 videos, and 48khz for H.264.
Example
mencoder -oac lavc -ovc lavc -of lavf -lavcopts aglobal=1:vglobal=1:vcodec=mpeg4:acodec=aac \
-af lavcresample=24000 -vf harddup -lavfopts format=psp:i_certify_that_my_video_stream_does_not_use_b_frames \
-ofps 30000/1001 input.video -o output.psp
Note that you can set the title of the video with
.
Encoding to MPEG formatMEncoder can create MPEG (MPEG-PS) format output
files.
Usually, when you are using MPEG-1 or MPEG-2 video, it is because you are
encoding for a constrained format such as SVCD, VCD, or DVD.
The specific requirements for these formats are explained in the
VCD and DVD creation guide
section.
To change MEncoder's output file format,
use the option.
Example:
mencoder input.avi -of mpeg -ovc lavc -lavcopts vcodec=mpeg1video -oac copy other_options -o output.mpg
Creating an MPEG-1 file suitable to be played on systems with minimal
multimedia support, such as default Windows installs:
mencoder input.avi -of mpeg -mpegopts format=mpeg1:tsaf:muxrate=2000 -o output.mpg -oac lavc -ovc lavc \
-lavcopts acodec=mp2:abitrate=224:vcodec=mpeg1video:vbitrate=1152:keyint=15:mbd=2:aspect=4/3
Hint:
If for some reason the video quality of the second pass did not
satisfy you, you may re-run your video encode with a different target
bitrate, provided that you saved the statistics file of the previous
pass.
This is possible because the statistics file's primary goal is to
record the complexity of each frame, which doesn't depend heavily on
bitrate. You should note, though, that you'll get the best results if
all passes are run with target bitrates that do not differ very much.
Rescaling movies
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. If you wish to rescale,
read the Preserving aspect ratio section.
The scaling process is handled by the scale video filter:
.
Its quality can be set with the option.
If it is not specified, MEncoder will use 2: bicubic.
Usage:
mencoder input.mpg -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell -vf scale=640:480 -o output.aviStream copyingMEncoder can handle input streams in two ways:
encode or copy
them. This section is about copying.
Video stream (option ):
nice stuff can be done :) Like, putting (not converting!) FLI or VIVO or
MPEG-1 video into an AVI file! Of course only
MPlayer can play such files :) And it probably
has no real life value at all. Rationally: video stream copying can be
useful for example when only the audio stream has to be encoded (like,
uncompressed PCM to MP3).
Audio stream (option ):
straightforward. It is possible to take an external audio file (MP3,
WAV) and mux it into the output stream. Use the
option
for this.
Using to copy from one container format to
another may require the use of to keep the
audio format tag of the original file.
For example, if you are converting an NSV file with AAC audio to an AVI
container, the audio format tag will be incorrect and it will have to
be changed. For a list of audio format tags, check
codecs.conf.
Example:
mencoder input.nsv -oac copy -fafmttag 0x706D -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell -o output.aviEncoding from multiple input image files (JPEG, PNG, TGA, SGI)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:MEncoderdecodes the input image(s) with
libjpeg (when decoding PNGs, it
will use libpng).
MEncoder then feeds the decoded image to the
chosen video compressor (DivX4, XviD, FFmpeg msmpeg4, etc.).
Examples
The explanation of the option is in the man page.
Creating an MPEG-4 file from all the JPEG files in the current directory:
mencoder mf://*.jpg -mf w=800:h=600:fps=25:type=jpg -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell -oac copy -o output.avi
Creating an MPEG-4 file from some JPEG files in the current directory:
mencoder mf://frame001.jpg,frame002.jpg -mf w=800:h=600:fps=25:type=jpg -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell -oac copy -o output.avi
Creating an MPEG-4 file from explicit list of JPEG files (list.txt in current directory
contains the list of files to use as source, one per line):
mencoder mf://@list.txt -mf w=800:h=600:fps=25:type=jpg \
-ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell -oac copy -o output.avi
Creating a Motion JPEG (MJPEG) file from all the JPEG files in the current
directory:
mencoder mf://*.jpg -mf w=800:h=600:fps=25:type=jpg -ovc copy -oac copy -o output.avi
Creating an uncompressed file from all the PNG files in the current directory:
mencoder mf://*.png -mf w=800:h=600:fps=25:type=png -ovc raw -oac copy -o output.avi
Width must be integer multiple of 4, it is a limitation of the RAW RGB AVI format.
Creating a Motion PNG (MPNG) file from all the PNG files in the current
directory:
mencoder mf://*.png -mf w=800:h=600:fps=25:type=png -ovc copy -oac copy -o output.avi
Creating a Motion TGA (MTGA) file from all the TGA files in the current
directory:
mencoder mf://*.tga -mf w=800:h=600:fps=25:type=tga -ovc copy -oac copy -o output.aviExtracting DVD subtitles to VOBsub fileMEncoder is capable of extracting subtitles from
a DVD into VOBsub formatted 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
and options.
You specify the basename (i.e without the .idx or
.sub extension) of the output files with
and the index for this subtitle in the
resulting files with .
If the input is not from a DVD you should use 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
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 two pass encoding
rm subtitles.idx subtitles.sub
mencoder dvd://1 -oac copy -ovc lavc -lavcopts vcodec=mpeg4:vpass=1 -vobsubout subtitles -vobsuboutindex 0 -sid 2
mencoder dvd://1 -oac copy -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell:vpass=2 -vobsubout subtitles -vobsuboutindex 1 -sid 5Copying 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 -nosound -ovc copy
Preserving aspect ratio
DVDs and SVCDs (i.e. MPEG-1/2) files contain an aspect ratio value, which
describes how the player should scale the video stream, so humans will not
have egg heads (ex.: 480x480 + 4:3 = 640x480). However when encoding to AVI
(DivX) files, you have to be aware that AVI headers do not store this value.
Rescaling the movie is disgusting and time consuming, there has to be a better
way!
There is
MPEG-4 has a unique feature: the video stream can contain its needed aspect
ratio. Yes, just like MPEG-1/2 (DVD, SVCD) and H.263 files. Regretfully, there are
few video players apart from MPlayer that support this
MPEG-4 attribute.
This feature can be used only with
libavcodec's
mpeg4 codec. Keep in mind: although
MPlayer will correctly play the created file,
other players may use the wrong aspect ratio.
You seriously should crop the black bands over and below the movie image.
See the man page for the usage of the cropdetect and
crop filters.
Usage
mencoder sample-svcd.mpg -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell:autoaspect -vf crop=714:548:0:14 -oac copy -o output.avi