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diff --git a/DOCS/xml/en/mencoder.xml b/DOCS/xml/en/mencoder.xml index a91c422740..344e59c5f1 100644 --- a/DOCS/xml/en/mencoder.xml +++ b/DOCS/xml/en/mencoder.xml @@ -4,776 +4,7 @@ <title>Basic usage of <application>MEncoder</application></title> <para> -For the complete list of available <application>MEncoder</application> 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 -<ulink url="../../tech/encoding-tips.txt">encoding-tips</ulink> that were -collected from several mailing list threads on MPlayer-users. Search the archives -<ulink url="http://lists.mplayerhq.hu/pipermail/mencoder-users/">here</ulink> -and especially for older things also -<ulink url="http://lists.mplayerhq.hu/pipermail/mplayer-users/">here</ulink> -for a wealth of discussions about all aspects of and problems related to -encoding with <application>MEncoder</application>. +OUTDATED CONTENT REMOVED </para> - -<!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --> - - -<sect1 id="menc-feat-selecting-codec"> -<title>Selecting codecs and container formats</title> - -<para> -Audio and video codecs for encoding are selected with the -<option>-oac</option> and <option>-ovc</option> options, respectively. -Type for instance: -<screen>mencoder -ovc help</screen> -to list all video codecs supported by the version of -<application>MEncoder</application> on your machine. -The following choices are available: -</para> - -<para> -Audio Codecs: -<informaltable frame="all"> -<tgroup cols="2"> -<thead> -<row><entry>Audio codec name</entry><entry>Description</entry></row> -</thead> -<tbody> -<row> - <entry>mp3lame</entry> - <entry>encode to VBR, ABR or CBR MP3 with LAME</entry> -</row> -<row> - <entry>lavc</entry> - <entry>use one of <link linkend="menc-feat-enc-libavcodec-audio-codecs"><systemitem class="library">libavcodec</systemitem>'s audio codecs</link></entry> -</row> -<row> - <entry>faac</entry> - <entry>FAAC AAC audio encoder</entry> -</row> -<row> - <entry>toolame</entry> - <entry>MPEG Audio Layer 2 encoder</entry> -</row> -<row> - <entry>twolame</entry> - <entry>MPEG Audio Layer 2 encoder based on tooLAME</entry> -</row> -<row> - <entry>pcm</entry> - <entry>uncompressed PCM audio</entry> -</row> -<row> - <entry>copy</entry> - <entry>do not reencode, just copy compressed frames</entry> -</row> -</tbody> -</tgroup> -</informaltable> -</para> - -<para> -Video codecs: -<informaltable frame="all"> -<tgroup cols="2"> -<thead> -<row><entry>Video codec name</entry><entry>Description</entry></row> -</thead> -<tbody> -<row> - <entry>lavc</entry> - <entry>use one of <link linkend="menc-feat-enc-libavcodec-video-codecs"><systemitem class="library">libavcodec</systemitem>'s video codecs</link></entry> -</row> -<row> - <entry>xvid</entry> - <entry>Xvid, MPEG-4 Advanced Simple Profile (ASP) codec</entry> -</row> -<row> - <entry>x264</entry> - <entry>x264, MPEG-4 Advanced Video Coding (AVC), AKA H.264 codec</entry> -</row> -<row> - <entry>nuv</entry> - <entry>nuppel video, used by some realtime applications</entry> -</row> -<row> - <entry>raw</entry> - <entry>uncompressed video frames</entry> -</row> -<row> - <entry>copy</entry> - <entry>do not reencode, just copy compressed frames</entry> -</row> -<row> - <entry>frameno</entry> - <entry>used for 3-pass encoding (not recommended)</entry> -</row> -</tbody> -</tgroup> -</informaltable> -</para> - -<para> -Output container formats are selected with the <option>-of</option> -option. -Type: -<screen>mencoder -of help</screen> -to list all containers supported by the version of -<application>MEncoder</application> on your machine. -The following choices are available: -</para> - -<para> -Container formats: -<informaltable frame="all"> -<tgroup cols="2"> -<thead> -<row><entry>Container format name</entry><entry>Description</entry></row> -</thead> -<tbody> -<row> - <entry>lavf</entry> - <entry>one of the containers supported by - <systemitem class="library">libavformat</systemitem></entry> -</row> -<row> - <entry>avi</entry> - <entry>Audio-Video Interleaved</entry> -</row> -<row> - <entry>mpeg</entry> - <entry>MPEG-1 and MPEG-2 PS</entry> -</row> -<row> - <entry>rawvideo</entry> - <entry>raw video stream (no muxing - one video stream only)</entry> -</row> -<row> - <entry>rawaudio</entry> - <entry>raw audio stream (no muxing - one audio stream only)</entry> -</row> -</tbody> -</tgroup> -</informaltable> -The AVI container is the native container format for -<application>MEncoder</application>, which means that it's the one that -is best handled, and the one for which <application>MEncoder</application> -was designed. -As noted above, other container formats are usable, but you may -experience problems when using them. -</para> - -<para> -<systemitem class="library">libavformat</systemitem> containers: -</para> - -<para> -If you selected <systemitem class="library">libavformat</systemitem> -to do the muxing of the output file (by using the <option>-of lavf</option>), -the appropriate container format will be determined by the file extension -of the output file. -You may force a particular container format with -<systemitem class="library">libavformat</systemitem>'s -<option>format</option> option. - -<informaltable frame="all"> -<tgroup cols="2"> -<thead><row> -<entry><systemitem class="library">libavformat</systemitem> container name</entry> -<entry>Description</entry> -</row></thead> -<tbody> -<row> - <entry>mpg</entry> - <entry>MPEG-1 and MPEG-2 PS</entry> -</row> -<row> - <entry>asf</entry> - <entry>Advanced Streaming Format</entry> -</row> -<row> - <entry>avi</entry> - <entry>Audio-Video Interleaved</entry> -</row> -<row> - <entry>wav</entry> - <entry>Waveform Audio</entry> -</row> -<row> - <entry>swf</entry> - <entry>Macromedia Flash</entry> -</row> -<row> - <entry>flv</entry> - <entry>Macromedia Flash video</entry> -</row> -<row> - <entry>rm</entry> - <entry>RealMedia</entry> -</row> -<row> - <entry>au</entry> - <entry>SUN AU</entry> -</row> -<row> - <entry>nut</entry> - <entry>NUT open container (experimental and not yet spec-compliant)</entry> -</row> -<row> - <entry>mov</entry> - <entry>QuickTime</entry> -</row> -<row> - <entry>mp4</entry> - <entry>MPEG-4 format</entry> -</row> -<row> - <entry>dv</entry> - <entry>Sony Digital Video container</entry> -</row> -<row> - <entry>mkv</entry> - <entry>Matroska open audio/video container</entry> -</row> -</tbody> -</tgroup> -</informaltable> -As you can see, <systemitem class="library">libavformat</systemitem> -allows <application>MEncoder</application> to mux into a considerable -variety of containers. -Unfortunately, as <application>MEncoder</application> 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 -<application>MPlayer</application>. -</para> - -<example id="encode_to_macromedia_flash_format"> -<title>encode to Macromedia Flash format</title> -<para> -Creating a Macromedia Flash video suitable for playback in a web browser -with the Macromedia Flash plugin: -<screen> -mencoder <replaceable>input.avi</replaceable> -o <replaceable>output.flv</replaceable> -of lavf \ - -oac mp3lame -lameopts abr:br=56 -srate 22050 -ovc lavc \ - -lavcopts vcodec=flv:vbitrate=500:mbd=2:mv0:trell:v4mv:cbp:last_pred=3 -</screen> -</para> -</example> - -</sect1> - - -<!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --> - - -<sect1 id="menc-feat-selecting-input"> -<title>Selecting input file or device</title> - -<para> -<application>MEncoder</application> 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 <option>dvd://</option><replaceable>titlenumber</replaceable> or -<option>vcd://</option><replaceable>tracknumber</replaceable> 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 <application>dvdbackup</application>, available on most systems), -and wish to encode from the copy, you should still use the -<option>dvd://</option> syntax, along with <option>-dvd-device</option> -followed by the path to the copied DVD root. - -The <option>-dvd-device</option> and <option>-cdrom-device</option> -options can also be used to override the paths to the device nodes -for reading directly from disc, if the defaults of -<filename>/dev/dvd</filename> and <filename>/dev/cdrom</filename> do -not work on your system. -</para> - -<para> -When encoding from DVD, it is often desirable to select a chapter or -range of chapters to encode. -You can use the <option>-chapter</option> option for this purpose. -For example, <option>-chapter</option> <replaceable>1-4</replaceable> -will only encode chapters 1 through 4 from the DVD. -This is especially useful if you will be making a 1400 MB encode -targeted for two CDs, since you can ensure the split occurs exactly -at a chapter boundary rather than in the middle of a scene. -</para> - -<para> -If you have a supported TV capture card, you can also encode from the -TV-in device. -Use <option>tv://</option><replaceable>channelnumber</replaceable> as -the filename, and <option>-tv</option> to configure various capture -settings. -DVB input works similarly. -</para> -</sect1> - - -<!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --> - - -<sect1 id="menc-feat-mpeg4"> -<title>Encoding two pass MPEG-4 ("DivX")</title> - -<para> -The name comes from the fact that this method encodes the file -<emphasis>twice</emphasis>. The first encoding (dubbed pass) creates some -temporary files (<filename>*.log</filename>) 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 <filename>/dev/null</filename> -or on Windows into <filename>NUL</filename>). -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. -</para> - -<example id="copy_audio_track"> -<title>copy audio track</title> -<para> -Two pass encode of the second track a DVD to an MPEG-4 ("DivX") -AVI while copying the audio track. -<screen> -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 <replaceable>output.avi</replaceable> -</screen> -</para> -</example> - -<example id="encode_audio_track"> -<title>encode audio track</title> -<para> -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. -<screen> -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 <replaceable>output.avi</replaceable> -</screen> -</para> -</example> -</sect1> - - -<!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --> - - -<sect1 id="menc-feat-handheld-psp"> -<title>Encoding to Sony PSP video format</title> - -<para> -<application>MEncoder</application> 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: -<itemizedlist> -<listitem><para> - <emphasis role="bold">Bitrate</emphasis>: it should not exceed 1500kbps, - however, past versions supported pretty much any bitrate as long as the - header claimed it was not too high. -</para></listitem> -<listitem><para> - <emphasis role="bold">Dimensions</emphasis>: 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. -</para></listitem> -<listitem><para> - <emphasis role="bold">Audio</emphasis>: its samplerate should be 24kHz - for MPEG-4 videos, and 48kHz for H.264. -</para></listitem> -</itemizedlist> -</para> - -<example id="encode_for_psp"> -<title>encode for PSP</title> -<para> -<screen> -mencoder -ofps 30000/1001 -af lavcresample=24000 -vf harddup -oac lavc \ - -ovc lavc -lavcopts aglobal=1:vglobal=1:vcodec=mpeg4:acodec=libfaac \ - -of lavf -lavfopts format=psp \ - <replaceable>input.video</replaceable> -o <replaceable>output.psp</replaceable> -</screen> -Note that you can set the title of the video with -<option>-info name=<replaceable>MovieTitle</replaceable></option>. -</para> -</example> -</sect1> - - -<!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --> - - -<sect1 id="menc-feat-mpeg"> -<title>Encoding to MPEG format</title> - -<para> -<application>MEncoder</application> 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 -<link linkend="menc-feat-vcd-dvd"> VCD and DVD creation guide</link> -section. -</para> - -<para> -To change <application>MEncoder</application>'s output file format, -use the <option>-of mpeg</option> option. -</para> - -<informalexample> -<para> -Example: -<screen> -mencoder <replaceable>input.avi</replaceable> -of mpeg -ovc lavc -lavcopts vcodec=mpeg1video \ - -oac copy <replaceable>other_options</replaceable> -o <replaceable>output.mpg</replaceable> -</screen> -Creating an MPEG-1 file suitable to be played on systems with minimal -multimedia support, such as default Windows installs: -<screen> -mencoder <replaceable>input.avi</replaceable> -of mpeg -mpegopts format=mpeg1:tsaf:muxrate=2000 \ - -o <replaceable>output.mpg</replaceable> -oac lavc -lavcopts acodec=mp2:abitrate=224 -ovc lavc \ - -lavcopts vcodec=mpeg1video:vbitrate=1152:keyint=15:mbd=2:aspect=4/3 -</screen> -Same, but using <systemitem class="library">libavformat</systemitem> MPEG muxer: -<screen> -mencoder <replaceable>input.avi</replaceable> -o <replaceable>VCD.mpg</replaceable> -ofps 25 -vf scale=352:288,harddup -of lavf \ - -lavfopts format=mpg -oac lavc -lavcopts acodec=mp2:abitrate=224 -ovc lavc \ - -lavcopts vcodec=mpeg1video:vrc_buf_size=327:keyint=15:vrc_maxrate=1152:vbitrate=1152:vmax_b_frames=0 -</screen> -</para> -</informalexample> - -<note><title>Hint:</title> -<para> -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. -</para> -</note> -</sect1> - - -<!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --> - - -<sect1 id="menc-feat-rescale"> -<title>Rescaling movies</title> - -<para> -Often the need to resize movie images emerges. The 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 <link linkend="aspect">Preserving aspect ratio</link> section. -</para> - -<para> -The scaling process is handled by the <literal>scale</literal> video filter: -<option>-vf scale=<replaceable>width</replaceable>:<replaceable>height</replaceable></option>. -Its quality can be set with the <option>-sws</option> option. -If it is not specified, <application>MEncoder</application> will use 2: bicubic. -</para> - -<para> -Usage: -<screen> -mencoder <replaceable>input.mpg</replaceable> -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell \ - -vf scale=640:480 -o <replaceable>output.avi</replaceable> -</screen> -</para> -</sect1> - - -<!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --> - - -<sect1 id="menc-feat-streamcopy"> -<title>Stream copying</title> - -<para> -<application>MEncoder</application> can handle input streams in two ways: -<emphasis role="bold">encode</emphasis> or <emphasis role="bold">copy</emphasis> -them. This section is about <emphasis role="bold">copying</emphasis>. -</para> - -<itemizedlist> -<listitem><para> - <emphasis role="bold">Video stream</emphasis> (option <option>-ovc copy</option>): - nice stuff can be done :) Like, putting (not converting!) FLI or VIVO or - MPEG-1 video into an AVI file! Of course only - <application>MPlayer</application> 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). -</para></listitem> -<listitem><para> - <emphasis role="bold">Audio stream</emphasis> (option <option>-oac copy</option>): - straightforward. It is possible to take an external audio file (MP3, - WAV) and mux it into the output stream. Use the - <option>-audiofile <replaceable>filename</replaceable></option> option - for this. -</para></listitem> -</itemizedlist> - -<para> -Using <option>-oac copy</option> to copy from one container format to -another may require the use of <option>-fafmttag</option> 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 -<filename>codecs.conf</filename>. -</para> - -<para> -Example: -<screen> -mencoder <replaceable>input.nsv</replaceable> -oac copy -fafmttag 0x706D \ - -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell -o <replaceable>output.avi</replaceable> -</screen> -</para> -</sect1> - - -<!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --> - - -<sect1 id="menc-feat-enc-images"> -<title>Encoding from multiple input image files (JPEG, PNG, TGA, etc.)</title> - -<para> -<application>MEncoder</application> is capable of creating movies from one -or more JPEG, PNG, TGA, or other image files. With simple framecopy it can -create MJPEG (Motion JPEG), MPNG (Motion PNG) or MTGA (Motion TGA) files. -</para> - -<orderedlist> -<title>Explanation of the process:</title> -<listitem><para> - <application>MEncoder</application> <emphasis>decodes</emphasis> the input - image(s) with <systemitem class="library">libjpeg</systemitem> (when decoding - PNGs, it will use <systemitem class="library">libpng</systemitem>). -</para></listitem> -<listitem><para> - <application>MEncoder</application> then feeds the decoded image to the - chosen video compressor (DivX4, Xvid, FFmpeg msmpeg4, etc.). -</para></listitem> -</orderedlist> - -<formalpara> -<title>Examples</title> -<para> -The explanation of the <option>-mf</option> option is in the man page. - -<informalexample> -<para> -Creating an MPEG-4 file from all the JPEG files in the current directory: -<screen> -mencoder mf://*.jpg -mf w=800:h=600:fps=25:type=jpg -ovc lavc \ - -lavcopts vcodec=mpeg4:mbd=2:trell -oac copy -o <replaceable>output.avi</replaceable> -</screen> -</para> -</informalexample> - -<informalexample> -<para> -Creating an MPEG-4 file from some JPEG files in the current directory: -<screen> -mencoder mf://<replaceable>frame001.jpg,frame002.jpg</replaceable> -mf w=800:h=600:fps=25:type=jpg \ - -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell -oac copy -o <replaceable>output.avi</replaceable> -</screen> -</para> -</informalexample> - -<informalexample> -<para> -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): -<screen> -mencoder mf://<replaceable>@list.txt</replaceable> -mf w=800:h=600:fps=25:type=jpg \ - -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell -oac copy -o <replaceable>output.avi</replaceable> -</screen> -</para> -</informalexample> - -You can mix different types of images, regardless of the method you use -— individual filenames, wildcard or file with list — provided of -course they have the same dimensions. -So you can e.g. take title frame from PNG file, -and then put a slideshow of your JPEG photos. - -<informalexample> -<para> -Creating a Motion JPEG (MJPEG) file from all the JPEG files in the current -directory: -<screen> -mencoder mf://*.jpg -mf w=800:h=600:fps=25:type=jpg -ovc copy -oac copy -o <replaceable>output.avi</replaceable> -</screen> -</para> -</informalexample> - -<informalexample> -<para> -Creating an uncompressed file from all the PNG files in the current directory: -<screen> -mencoder mf://*.png -mf w=800:h=600:fps=25:type=png -ovc raw -oac copy -o <replaceable>output.avi</replaceable> -</screen> -</para> -</informalexample> - -<note><para> -Width must be integer multiple of 4, it is a limitation of the RAW RGB AVI -format. -</para></note> - -<informalexample> -<para> -Creating a Motion PNG (MPNG) file from all the PNG files in the current -directory: -<screen> -mencoder mf://*.png -mf w=800:h=600:fps=25:type=png -ovc copy -oac copy -o <replaceable>output.avi</replaceable><!-- ---></screen> -</para> -</informalexample> - -<informalexample> -<para> -Creating a Motion TGA (MTGA) file from all the TGA files in the current -directory: -<screen> -mencoder mf://*.tga -mf w=800:h=600:fps=25:type=tga -ovc copy -oac copy -o <replaceable>output.avi</replaceable><!-- ---></screen> -</para> -</informalexample> -</para> -</formalpara> -</sect1> - - -<!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --> - - -<sect1 id="menc-feat-extractsub"> -<title>Extracting DVD subtitles to VOBsub file</title> - -<para> -<application>MEncoder</application> is capable of extracting subtitles from -a DVD into VOBsub formatted files. They consist of a pair of files ending in -<filename>.idx</filename> and <filename>.sub</filename> and are usually -packaged in a single <filename>.rar</filename> archive. -<application>MPlayer</application> can play these with the -<option>-vobsub</option> and <option>-vobsubid</option> options. -</para> - -<para> -You specify the basename (i.e without the <filename>.idx</filename> or -<filename>.sub</filename> extension) of the output files with -<option>-vobsubout</option> and the index for this subtitle in the -resulting files with <option>-vobsuboutindex</option>. -</para> - -<para> -If the input is not from a DVD you should use <option>-ifo</option> to -indicate the <filename>.ifo</filename> file needed to construct the -resulting <filename>.idx</filename> file. -</para> - -<para> -If the input is not from a DVD and you do not have the -<filename>.ifo</filename> file you will need to use the -<option>-vobsubid</option> option to let it know what language id to put in -the <filename>.idx</filename> file. -</para> - -<para> -Each run will append the running subtitle if the <filename>.idx</filename> -and <filename>.sub</filename> files already exist. So you should remove any -before starting. -</para> - -<example id="copying_two_subtitles_from_a_dvd_while_doing_two_pass_encoding"> -<title>Copying two subtitles from a DVD while doing two pass encoding</title> -<screen> -rm <replaceable>subtitles.idx</replaceable> <replaceable>subtitles.sub</replaceable> -mencoder dvd://1 -oac copy -ovc lavc -lavcopts vcodec=mpeg4:vpass=1 \ - -vobsubout <replaceable>subtitles</replaceable> -vobsuboutindex 0 -sid 2 -mencoder dvd://1 -oac copy -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell:vpass=2 \ - -vobsubout <replaceable>subtitles</replaceable> -vobsuboutindex 1 -sid 5<!-- ---></screen> -</example> - -<example id="copying_a_french_subtitle_from_an_mpeg_file"> -<title>Copying a French subtitle from an MPEG file</title> -<screen> -rm <replaceable>subtitles.idx</replaceable> <replaceable>subtitles.sub</replaceable> -mencoder <replaceable>movie.mpg</replaceable> -ifo <replaceable>movie.ifo</replaceable> -vobsubout <replaceable>subtitles</replaceable> -vobsuboutindex 0 \ - -vobsuboutid fr -sid 1 -nosound -ovc copy -</screen> -</example> -</sect1> - - -<!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --> - - -<sect1 id="aspect"> -<title>Preserving aspect ratio</title> - -<para> -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! -</para> - -<para>There is</para> - -<para> -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 <application>MPlayer</application> that -support this MPEG-4 attribute. -</para> - -<para> -This feature can be used only with -<systemitem class="library">libavcodec</systemitem>'s -<systemitem>mpeg4</systemitem> codec. Keep in mind: although -<application>MPlayer</application> will correctly play the created file, -other players may use the wrong aspect ratio. -</para> - -<para> -You seriously should crop the black bands over and below the movie image. -See the man page for the usage of the <systemitem>cropdetect</systemitem> and -<systemitem>crop</systemitem> filters. -</para> - -<para> -Usage -<screen>mencoder <replaceable>sample-svcd.mpg</replaceable> -vf crop=714:548:0:14 -oac copy -ovc lavc \ - -lavcopts vcodec=mpeg4:mbd=2:trell:autoaspect -o <replaceable>output.avi</replaceable></screen> -</para> -</sect1> - </chapter> |