diff --git a/doc/libalsaaudio.rst b/doc/libalsaaudio.rst index 20d9b22..bdd2768 100644 --- a/doc/libalsaaudio.rst +++ b/doc/libalsaaudio.rst @@ -55,6 +55,8 @@ The :mod:`alsaaudio` module defines functions and classes for using ALSA. the `device` keyword argument is ignored. ``0`` is the first hardware sound card. + **Note:** This should not be used, as it bypasses most of ALSA's configuration. + * *device* - the name of the device on which the mixer resides. The default is ``'default'``. @@ -140,7 +142,10 @@ following arguments: ``PCM_FORMAT_U24_3BE`` Unsigned 24 bit samples for each channel (Big Endian byte order in 3 bytes) ========================= =============== - * *periodsize* - the period size in frames. Each write should consist of *periodsize* frames. The default value is 32. + * *periodsize* - the period size in frames. + Make sure you understand :ref:`the meaning of periods `. + The default value is 32, which is below the actual minimum of most devices, + and will therefore likely be larger in practice. * *device* - the name of the PCM device that should be used (for example a value from the output of :func:`pcms`). The default value is ``'default'``. @@ -149,6 +154,8 @@ following arguments: the `device` keyword argument is ignored. ``0`` is the first hardware sound card. + **Note:** This should not be used, as it bypasses most of ALSA's configuration. + This will construct a PCM object with the given settings. *Changed in 0.9:* @@ -317,6 +324,10 @@ PCM objects have the following methods: return value of zero, if the buffer is full. In this case, the data should be written at a later time. + Note that this call completing means only that the samples were buffered + in the kernel, and playout will continue afterwards. Make sure that the + stream is drained before discarding the PCM handle. + .. method:: PCM.pause([enable=True]) If *enable* is :const:`True`, playback or capture is paused. diff --git a/doc/terminology.rst b/doc/terminology.rst index 1347134..3c16d19 100644 --- a/doc/terminology.rst +++ b/doc/terminology.rst @@ -52,6 +52,8 @@ Data rate underrun (on playback) occurs; the term "xrun" is used to refer to either event. +.. _term-period: + Period The CPU processes sample data in chunks of frames, so-called periods (also called fragments by some systems). The operating system kernel's