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Removes the section "menc-feat-fix-avi" as part of it was wrong and the other
belonged to the faq. Does a bit of reformating and spellings fixes. git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@15114 b3059339-0415-0410-9bf9-f77b7e298cf2
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@ -140,47 +140,6 @@ them. This section is about <emphasis role="bold">copying</emphasis>.
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</sect1>
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<sect1 id="menc-feat-fix-avi">
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<title>Fixing AVIs with broken index or interleaving</title>
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<para>
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Easiest thing. We simply copy the video and audio streams, and
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<application>MEncoder</application> generates the index. Of course this cannot fix possible bugs in
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the video and/or audio streams. It also fixes files with broken interleaving,
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thus the <option>-ni</option> option won't be needed for them anymore.
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</para>
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<para>
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Command:
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<screen>
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mencoder -idx <replaceable>input.avi</replaceable> -ovc copy -oac copy -o <replaceable>output.avi</replaceable><!--
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--></screen>
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</para>
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<sect2 id="menc-feat-appending">
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<title>Appending multiple AVI files</title>
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<para>
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As a side-effect, the broken AVI fixer function enables <application>MEncoder</application>
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to append 2 (or more) AVI files:
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</para>
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<para>
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Command:
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<screen>cat <replaceable>1.avi</replaceable> <replaceable>2.avi</replaceable> > <replaceable>3.avi</replaceable>
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mencoder -noidx -ovc copy -oac copy -o <replaceable>output.avi</replaceable> <replaceable>3.avi</replaceable></screen>
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</para>
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<note><para>
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This expects <filename>1.avi</filename> and <filename>2.avi</filename> to use
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the same codecs, resolution, stream rate etc, and at least <filename>1.avi</filename>
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must not be broken. You may need to fix your input AVI files first, as described
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<link linkend="menc-feat-fix-avi">above</link>.
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</para></note>
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</sect2>
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</sect1>
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<sect1 id="menc-feat-enc-libavcodec">
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<title>Encoding with the <systemitem class="library">libavcodec</systemitem>
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codec family</title>
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@ -660,14 +619,17 @@ vcodec=mpeg2video:intra_matrix=8,9,12,22,26,27,29,34,9,10,14,26,27,29,34,37,
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audio track(s), so you should <link linkend="menc-feat-dvd-mpeg4-audio">rip
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those</link> first.
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You can compute the bitrate with the following equation:
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bitrate = (target_size_in_Mbytes - sound_size_in_Mbytes) * 1024 * 1024 / length_in_secs * 8 / 1000
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<equation>bitrate = (target_size_in_Mbytes - sound_size_in_Mbytes) *
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1024 * 1024 / length_in_secs * 8 / 1000</equation>
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For instance, to squeeze a two-hour movie onto a 702MB CD, with 60MB
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of audio track, the video bitrate will have to be
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(702 - 60) * 1024 * 1024 / (120*60) * 8 / 1000 = 740kbps.
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of audio track, the video bitrate will have to be:
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<equation>(702 - 60) * 1024 * 1024 / (120*60) * 8 / 1000
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= 740kbps</equation>
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</para>
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</sect2>
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<sect2 id="menc-feat-dvd-mpeg4-crop">
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<title>Cropping and Scaling</title>
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@ -721,7 +683,7 @@ vcodec=mpeg2video:intra_matrix=8,9,12,22,26,27,29,34,9,10,14,26,27,29,34,37,
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<para>
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First, you should compute the encoded aspect ratio:
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ARc = (Wc x (ARa / PRdvd )) / Hc
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<equation>ARc = (Wc x (ARa / PRdvd )) / Hc</equation>
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<itemizedlist>
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<title>where:</title>
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<listitem><para>
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@ -739,8 +701,8 @@ vcodec=mpeg2video:intra_matrix=8,9,12,22,26,27,29,34,9,10,14,26,27,29,34,37,
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<para>
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Then, you can compute the X and Y resolution, according to a certain
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Compression Quality (CQ) factor:
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ResY = INT( SQRT(1000 * Bitrate / 25 / ARc / CQ) / 16 ) * 16
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ResX = INT( ResY * ARc / 16) * 16
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<equation>ResY = INT(SQRT( 1000*Bitrate/25/ARc/CQ )/16) * 16</equation>
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<equation>ResX = INT( ResY * ARc / 16) * 16</equation>
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</para>
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<para>
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@ -751,6 +713,9 @@ vcodec=mpeg2video:intra_matrix=8,9,12,22,26,27,29,34,9,10,14,26,27,29,34,37,
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However, if you have a target size for your movie (1 or 2 CDs for instance),
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there's a limited total number of bits that you can spend; therefore it's
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necessary to find a good tradeoff between compressibility and quality.
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</para>
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<para>
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The CQ depends both on the bitrate and the movie resolution.
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In order to raise the CQ, typically you'd downscale the movie given that the
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bitrate is computed in function of the target size and the length of the
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@ -762,7 +727,10 @@ vcodec=mpeg2video:intra_matrix=8,9,12,22,26,27,29,34,9,10,14,26,27,29,34,37,
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visible).
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It's therefore wise to take a CQ ranging from 0.20 to 0.22 for a 1 CD rip,
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and 0.26-0.28 for 2 CDs.
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Please thake note that the CQ is just an indicative figure, as depending on
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</para>
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<para>
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Please take note that the CQ is just an indicative figure, as depending on
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the encoded content, a CQ of 0.18 may look just fine for a Bergman, contrary
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to a movie such as The Matrix, which contains many high-motion scenes.
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On the other hand, it's worthless to raise CQ higher than 0.30 as you'd
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@ -820,8 +788,11 @@ vcodec=mpeg2video:intra_matrix=8,9,12,22,26,27,29,34,9,10,14,26,27,29,34,37,
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will encode destination_sound.wav with the encoding quality 1, which is
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roughly equivalent to 80Kb/s, and is the minimum quality at which you
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should encode if you care about quality.
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Please note that MEncoder currently cannot mux Ogg Vorbis files
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into a video stream because it can only create AVI and MPEG files.
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Please note that MEncoder currently cannot mux Vorbis audio tracks
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into the output file because it only supports AVI and MPEG
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containers as an output, each of which may lead to audio/video
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playback synchronization problems with some players when the AVI file
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contain VBR audio streams such as Vorbis.
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Don't worry, this document will show you how you can do that with third
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party programs.
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</para>
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@ -915,8 +886,8 @@ vcodec=mpeg2video:intra_matrix=8,9,12,22,26,27,29,34,9,10,14,26,27,29,34,37,
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</sect2>
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<sect2 id="menc-feat-dvd-mpeg4-encoding-options">
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<title>Encoding options</title>
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<sect2 id="menc-feat-dvd-mpeg4-lavc-encoding-options">
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<title>Encoding options of libavcodec</title>
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<para>
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Ideally, you'd probably want to be able to just tell the encoder to switch
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@ -1299,7 +1270,7 @@ vcodec=mpeg2video:intra_matrix=8,9,12,22,26,27,29,34,9,10,14,26,27,29,34,37,
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document are <emphasis role="bold">not</emphasis> intended for
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actual use. They are simply the bare minimum required to encode the
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pertaining video category. How to make good DVD rips or fine-tune
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<systemitem class="library">libavcodec</systemitem> for maximum
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<systemitem class="library">libavcodec</systemitem> for maximal
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quality is not within the scope of this document.
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</para></listitem>
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<listitem><para>
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