matches the audio format with the given mask (i.e. one
...
...
@@ -423,7 +424,9 @@ Querying :program:`MPD`'s status
- ``xfade``: ``crossfade`` in seconds
- ``mixrampdb``: ``mixramp`` threshold in dB
- ``mixrampdelay``: ``mixrampdelay`` in seconds
- ``audio``: The format emitted by the decoder plugin during playback, format: ``*samplerate:bits:channels*``. Check the user manual for a detailed explanation.
- ``audio``: The format emitted by the decoder plugin during
playback, format: ``samplerate:bits:channels``. See
:ref:`audio_output_format` for a detailed explanation.
- ``updating_db``: ``job id``
- ``error``: if there is an error, returns message here
@@ -402,14 +402,9 @@ The following table lists the audio_output options valid for all plugins:
- The name of the plugin
* - **name**
- The name of the audio output. It is visible to the client. Some plugins also use it internally, e.g. as a name registered in the PULSE server.
* - **format**
- Always open the audio output with the specified audio format samplerate:bits:channels), regardless of the format of the input file. This is optional for most plugins.
Any of the three attributes may be an asterisk to specify that this attribute should not be enforced, example: 48000:16:*. *:*:* is equal to not having a format specification.
The following values are valid for bits: 8 (signed 8 bit integer samples), 16, 24 (signed 24 bit integer samples padded to 32 bit), 32 (signed 32 bit integer samples), f (32 bit floating point, -1.0 to 1.0), "dsd" means DSD (Direct Stream Digital). For DSD, there are special cases such as "dsd64", which allows you to omit the sample rate (e.g. dsd512:2 for stereo DSD512, i.e. 22.5792 MHz).
The sample rate is special for DSD: :program:`MPD` counts the number of bytes, not bits. Thus, a DSD "bit" rate of 22.5792 MHz (DSD512) is 2822400 from :program:`MPD`'s point of view (44100*512/8).
* - **format samplerate:bits:channels**
- Always open the audio output with the specified audio format, regardless of the format of the input file. This is optional for most plugins.
See :ref:`audio_output_format` for a detailed description of the value.
* - **enabed yes|no**
- Specifies whether this audio output is enabled when :program:`MPD` is started. By default, all audio outputs are enabled. This is just the default setting when there is no state file; with a state file, the previous state is restored.
* - **tags yes|no**
...
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@@ -504,10 +499,31 @@ reference.
Audio Format Settings
---------------------
.. _audio_output_format:
Global Audio Format
~~~~~~~~~~~~~~~~~~~
The setting audio_output_format forces :program:`MPD` to use one audio format for all outputs. Doing that is usually not a good idea. The values are the same as in format in the audio_output section.
The setting ``audio_output_format`` forces :program:`MPD` to use one
audio format for all outputs. Doing that is usually not a good idea.
The value is specified as ``samplerate:bits:channels``.
Any of the three attributes may be an asterisk to specify that this
attribute should not be enforced, example: ``48000:16:*``.
``*:*:*`` is equal to not having a format specification.
The following values are valid for bits: ``8`` (signed 8 bit integer
samples), ``16``, ``24`` (signed 24 bit integer samples padded to 32
bit), ``32`` (signed 32 bit integer samples), ``f`` (32 bit floating
point, -1.0 to 1.0), ``dsd`` means DSD (Direct Stream Digital). For
DSD, there are special cases such as ``dsd64``, which allows you to
omit the sample rate (e.g. ``dsd512:2`` for stereo DSD512,
i.e. 22.5792 MHz).
The sample rate is special for DSD: :program:`MPD` counts the number
of bytes, not bits. Thus, a DSD "bit" rate of 22.5792 MHz (DSD512) is
2822400 from :program:`MPD`'s point of view (44100*512/8).
Resampler
~~~~~~~~~
...
...
@@ -885,7 +901,7 @@ To verify if :program:`MPD` converts the audio format, enable verbose logging, a
.. code-block:: none
decoder: audio_format=44100:24:2, seekable=true
output: opened plugin=alsa name="An ALSA output"audio_format=44100:16:2
output: opened plugin=alsa name="An ALSA output"audio_format=44100:16:2
output: converting from 44100:24:2
This example shows that a 24 bit file is being played, but the sound chip cannot play 24 bit. It falls back to 16 bit, discarding 8 bit.
...
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@@ -912,7 +928,7 @@ Check list for bit-perfect playback:
device (:samp:`hw:0,0` or similar).
* Don't use software volume (setting :code:`mixer_type`).
* Don't force :program:`MPD` to use a specific audio format (settings
* Verify that you are really doing bit-perfect playback using :program:`MPD`'s verbose log and :file:`/proc/asound/card*/pcm*p/sub*/hw_params`. Some DACs can also indicate the audio format.
