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| -rw-r--r-- | doc/mpd.conf.5 | 47 | ||||
| -rw-r--r-- | doc/user.xml | 144 |
2 files changed, 143 insertions, 48 deletions
diff --git a/doc/mpd.conf.5 b/doc/mpd.conf.5 index 3c48b5f30..d92033179 100644 --- a/doc/mpd.conf.5 +++ b/doc/mpd.conf.5 @@ -136,53 +136,6 @@ for the format of this parameter. Multiple audio_output sections may be specified. If no audio_output section is specified, then MPD will scan for a usable audio output. .TP -.B audio_output_format <sample_rate:bits:channels> -This specifies the sample rate, bits per sample, and number of channels of -audio that is sent to each audio output. Note that audio outputs may specify -their own audio format which will be used for actual output to the audio -device. An example is "44100:16:2" for 44100Hz, 16 bits, and 2 channels. The -default is to use the audio format of the input file. -Any of the three attributes may be an asterisk to specify that this -attribute should not be enforced -.TP -.B samplerate_converter <integer or prefix> -This specifies the libsamplerate converter to use. The supplied value should -either be an integer or a prefix of the name of a converter. The default is -"Fastest Sinc Interpolator". - -At the time of this writing, the following converters are available: -.RS -.TP -Best Sinc Interpolator (0) - -Band limited sinc interpolation, best quality, 97dB SNR, 96% BW. -.TP -Medium Sinc Interpolator (1) - -Band limited sinc interpolation, medium quality, 97dB SNR, 90% BW. -.TP -Fastest Sinc Interpolator (2) - -Band limited sinc interpolation, fastest, 97dB SNR, 80% BW. -.TP -ZOH Interpolator (3) - -Zero order hold interpolator, very fast, very poor quality with audible -distortions. -.TP -Linear Interpolator (4) - -Linear interpolator, very fast, poor quality. -.TP -internal - -Poor quality, no floating point operations. This is the default (and -only choice) if MPD was compiled without libsamplerate. -.RE -.IP -For an up-to-date list of available converters, please see the libsamplerate -documentation (available online at <\fBhttp://www.mega\-nerd.com/SRC/\fP>). -.TP .B replaygain <off or album or track or auto> If specified, mpd will adjust the volume of songs played using ReplayGain tags (see <\fBhttp://www.replaygain.org/\fP>). Setting this to "album" will adjust diff --git a/doc/user.xml b/doc/user.xml index 5c810dc70..a74c1ce27 100644 --- a/doc/user.xml +++ b/doc/user.xml @@ -393,7 +393,7 @@ systemctl start mpd.socket</programlisting> a name registered in the PULSE server. </entry> </row> - <row> + <row id="ao_format"> <entry> <varname>format</varname> </entry> @@ -607,6 +607,148 @@ systemctl start mpd.socket</programlisting> </tgroup> </informaltable> </section> + + <section> + <title>Audio Format Settings</title> + + <section> + <title>Global Audio Format</title> + + <para> + The setting <varname>audio_output_format</varname> forces + MPD to use one audio format for all outputs. Doing that is + usually not a good idea. The values are the same as in + <link linkend="ao_format"><varname>format</varname> in the + <varname>audio_output</varname> section</link>. + </para> + </section> + + <section> + <title>Resampler</title> + + <para> + Sometimes, music needs to be resampled before it can be + played; for example, CDs use a sample rate of 44,100 Hz + while many cheap audio chips can only handle 48,000 Hz. + Resampling reduces the quality and consumes a lot of CPU. + There are different options, some of them optimized for high + quality and others for low CPU usage, but you can't have + both at the same time. Often, the resampler is the + component that is responsible for most of MPD's CPU usage. + Since MPD comes with high quality defaults, it may appear + that MPD consumes more CPU than other software. + </para> + + <para> + The following resamplers are available (if enabled at + compile time): + </para> + + <itemizedlist> + <listitem> + <para> + <ulink + url="http://www.mega-nerd.com/SRC/">libsamplerate</ulink> + a.k.a. Secret Rabbit Code (SRC). + </para> + </listitem> + + <listitem> + <para> + internal: low CPU usage, but very poor quality. This is + the fallback if MPD was compiled without an external + resampler. + </para> + </listitem> + </itemizedlist> + + <para> + The setting <varname>samplerate_converter</varname> controls + how MPD shall resample music. Possible values: + </para> + + <informaltable> + <tgroup cols="2"> + <thead> + <row> + <entry> + Value + </entry> + <entry> + Description + </entry> + </row> + </thead> + <tbody> + <row> + <entry> + "<parameter>internal</parameter>" + </entry> + <entry> + The internal resampler. Low CPU usage, but very + poor quality. + </entry> + </row> + + <row> + <entry> + "<parameter>Best Sinc Interpolator</parameter>" or + "<parameter>0</parameter>" + </entry> + <entry> + libsamplerate: Band limited sinc interpolation, best + quality, 97dB SNR, 96% BW. + </entry> + </row> + + <row> + <entry> + "<parameter>Medium Sinc Interpolator</parameter>" or + "<parameter>1</parameter>" + </entry> + <entry> + libsamplerate: Band limited sinc interpolation, + medium quality, 97dB SNR, 90% BW. + </entry> + </row> + + <row> + <entry> + "<parameter>Fastest Sinc Interpolator</parameter>" or + "<parameter>2</parameter>" + </entry> + <entry> + libsamplerate: Band limited sinc interpolation, + fastest, 97dB SNR, 80% BW. + </entry> + </row> + + <row> + <entry> + "<parameter>ZOH Sinc Interpolator</parameter>" or + "<parameter>3</parameter>" + </entry> + <entry> + libsamplerate: Zero order hold interpolator, very + fast, very poor quality with audible distortions. + </entry> + </row> + + <row> + <entry> + "<parameter>Linear Interpolator</parameter>" or + "<parameter>4</parameter>" + </entry> + <entry> + libsamplerate: Linear interpolator, very fast, poor + quality. + </entry> + </row> + </tbody> + </tgroup> + </informaltable> + </section> + </section> </chapter> <chapter> |