diff options
author | gabucino <gabucino@b3059339-0415-0410-9bf9-f77b7e298cf2> | 2001-12-01 11:30:22 +0000 |
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committer | gabucino <gabucino@b3059339-0415-0410-9bf9-f77b7e298cf2> | 2001-12-01 11:30:22 +0000 |
commit | 0a6dd6d81bcea2805fbe6130c295f67c5ce540ea (patch) | |
tree | 65af00cfe82898cab155a6c0e128eaef1567c830 /DOCS/codecs.html | |
parent | 3fcf9132796c86f2dda66ed38df750ecff864a71 (diff) |
"Software AC3 decoding" section. Patch by Stephen Davies <steve@daviesfam.org>
(doxized)
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@3240 b3059339-0415-0410-9bf9-f77b7e298cf2
Diffstat (limited to 'DOCS/codecs.html')
-rw-r--r-- | DOCS/codecs.html | 36 |
1 files changed, 33 insertions, 3 deletions
diff --git a/DOCS/codecs.html b/DOCS/codecs.html index 9a8c8569e0..008542c965 100644 --- a/DOCS/codecs.html +++ b/DOCS/codecs.html @@ -207,7 +207,37 @@ outputs, in contrary to the Win32 codec which supports only RGB.</P> </UL></P> -<P><B><A NAME=2.2.2.1>2.2.2.1. Hardware AC3 decoding</A></B></P> +<P><B><A NAME=2.2.2.1>2.2.2.1. Software AC3 decoding</A></B></P> + +<P>This is the default decoder used for files with AC3 audio.</P> + +<P>The AC3 decoder can create output audio mixes for 2, 4, or 6 +speakers. When configured for 6 speakers, this decoder provides +separate output of all the AC3 channels to the soundcard driver, +allowing the full "surround sound" experience without the external AC3 +decoder required to use the hwac3 codec.</P> + +<P>Use the <CODE>-channels</CODE> option to select the number of output channels. +Use <CODE>-channels 2</CODE> for a stereo downmix. For a 4 channel downmix (Left +Front, Right Front, Left Surround and Right Surround outputs), use +<CODE>-channels 4</CODE>. In this case, any Centre channel will be mixed +equally to the front channels. Lastly, "-channels 6" will output all the AC3 +channels as they are encoded - in the order Left, Right, Left Surround, Right +Surround, Centre and LFE.</P> + +<P>The default number of output channels is 2.</P> + +<P>To use more than 2 output channels, you'll need to be using OSS, +and to have a soundcard driver that supports the appropriate number of +output channels via the SNDCTL_DSP_CHANNELS ioctl. For example, a +version of the emu10k1 driver (used with the SB Live cards) newer than +August 2001 should be suitable.</P> + +<P>Output mixes of more than 2 channels should be considered +experimental.</P> + + +<P><B><A NAME=2.2.2.2>2.2.2.2. Hardware AC3 decoding</A></B></P> <P>You'll need an AC3 capable soundcard, with digital out (SP/DIF). The card's driver must support the AFMT_AC3 format (like SB Live! does). @@ -215,7 +245,7 @@ Connect your AC3 decoder to the SP/DIF output, and use the '-ac hwac3' option. It may or may not work (experimental). (probably won't...)</P> -<P><B><A NAME=2.2.2.2>2.2.2.2. libmad support</A></B></P> +<P><B><A NAME=2.2.2.3>2.2.2.3. libmad support</A></B></P> <P><A HREF="http://mad.sourceforge.net">libmad</A> is a multiplatform MPEG audio decoding library. If you don't know why is it good, you probably don't need it.</P> @@ -224,7 +254,7 @@ decoding library. If you don't know why is it good, you probably don't need it.< option.</P> -<P><B><A NAME=2.2.2.3>2.2.2.3. VIVO audio</A></B></P> +<P><B><A NAME=2.2.2.4>2.2.2.4. VIVO audio</A></B></P> <P>The audio codec used in VIVO files depends on whether it's a VIVO/1.0 or VIVO/2.0 file. VIVO/1.0 files have <B>g.723</B> audio, and VIVO/2.0 files |