In ALSA PCM interface, before configuring hardware actually, applications
can request available set of hardware parameters for runtime of PCM
substream. The set of parameters are represented and delivered by a
structure.
In alsa-lib PCM API, the above design is abstracted by a series of
snd_pcm_hw_params_xxx() functions. An actual layout of the structure is
hidden from applications by an opaque pointer.
In aplay, '--dump-hw-params' option is for this purpose. With this option,
the command output available set of the hardware parameters.
This commit adds support for the option. Unlike aplay, this commit takes
this program to finish after dumping the parameters for simplicity of
usage.
I note that all of combinations in the set are not necessarily available
when the PCM substream includes dependencies of parameters described by
constraints and rules.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
In current aplay, some informative output is available as a default. This
can be suppressed by a quiet option. This commit adds support for it.
An original aplay implementation has no effect of this option in a case
to handle multiple files. However, in a point of usability, this commit
support this case.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
In aplay, many command-line options are supported. Some of them have
dependency or conflicts. Furthemore, some of them are just for
runtime configuration of alsa-lib(libasound), and some options can
be used by several xfer backends commonly; e.g. options for file name,
sample format and sampling rate.
This commit adds a parser for the common options below.
* --help (-h)
* Just output 'help' string (not written yet).
* --verbose (-v)
* For verbose output, including information about xfer, mapper and
container.
* --format (-f): string. format literals or one of ['cd'|'cdr'|'dat']
* For sample format supported by ALSA PCM interface. Special format
can be used. For playback, this is auto-detected according to actual
file format.
* --channels (-c)
* For the number of samples included in one data frame. For playback,
this is auto-detected according to actual file format, except for
'raw' format. This option can conflict to above format option.
* --rate (-r)
* For the number of data frames transferred in one second. For playback,
this is auto-detected according to actual file format, except for
'raw' format. This option can conflict to format option above.
* --file-type (-f): string. one of ['wav'|'au'|'voc'|'raw']
* For format of files of given paths. For playback, this is optional
because the format is auto-detected. For capture, this is optional too
because the format is decided according to suffix of given path.
Anyway, this option is used for cases to fail to detect or decide.
* --separate-channels (-I)
* When using several files as source or destination for transmission
of data frame, this option can be used with several file paths.
When '--separate-channels' option is used, users can give several file
paths to source/destination of data transmission, else they can give single
file path for the purpose. When multiple files are handled by this option,
for playback, data frames in first channel is used to construct buffer for
data transmission with multi channel. For capture, data frames in each
channel of buffer are written to each of given path. Furthermore, when a
single path is given for capture, file paths are auto-generated according
to available number of channels. For example, 'name.wav' is given for
2 channels capture, 'name-0.wav' and 'name-1.wav' are generated. In a
case of no suffix, 'name-0' and 'name-1' are generated.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
