snd_pcm_avail_delay() is expected to report avail and delay values
in atomic fashion. However the function does two separate syscalls
and it cannot guarantee the avail value is the same as was used
to calculate the delay. This is a problem as the reported delay is
always relative to avail frames value.
If application (like e.g. alsa_conformance_test) uses snd_pcm_avail_delay()
to estimate the effective play position, it can observe bogus delay
values (and effective play position going backwards) if
snd_pcm_avail_delay() is called during a DMA burst where hw_ptr
moves quickly.
This commit adds a loop similar to that used in snd_pcm_hw_htimestamp()
to wait until we get a stable avail reading, and only then extract
the delay. This will avoid bogus values if function is called during
DMA bursts.
Closes: https://github.com/alsa-project/alsa-lib/pull/469
Closes: https://github.com/alsa-project/alsa-lib/issues/468
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Try to explain more the output value and its relation between
format and sample bits defined by the format.
Link: https://github.com/larsimmisch/pyalsaaudio/pull/146
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
I'm not sure this is the best way to describe the interaction, but I think
this needs to be mentioned in some form at least.
Closes: https://github.com/alsa-project/alsa-lib/pull/381
Signed-off-by: Zeno Endemann <zeno.endemann@mailbox.org>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
In some places samples and frames are used interchangeably, which may
be a little confusing, so update it to say 'frames' where it could matter.
Closes: https://github.com/alsa-project/alsa-lib/pull/375
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
The start_treshold is defined as unsigned, so fix the condition
to allow using values avobe LONG_MAX.
Also, fix the documentation for the 64-bit platforms (INTMAX -> LONG_MAX).
Fixes: https://github.com/alsa-project/alsa-lib/issues/374
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
As noted in the github issue, the poll descriptors may change depending
on the stream parameters.
Fixes: cd04da2b ("pcm: clarify documentation of poll descriptor usage")
Fixes: https://github.com/alsa-project/alsa-lib/issues/372
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
This is based on my understanding of the intended behavior, the
test/pcm.c example code, as well as the github pull request
discussion (#370).
There needs to be more clarifiaction regarding the exact semantics
of the value of the revents output parameter of
snd_pcm_poll_descriptors_revents, since there are events that do
not necessarily correspond to POLLIN or POLLOUT (such as period
events), but I believe this is a lot less obvious and needs
confirmation first.
Closes: https://github.com/alsa-project/alsa-lib/pull/370
Signed-off-by: Zeno Endemann <zeno.endemann@mailbox.org>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Update snd_pcm_subformat_t getters and setters so they no longer throw
warnings when building.
Closes: https://github.com/alsa-project/alsa-lib/pull/342
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Improve granularity of format selection for S32/U32 formats by adding
masks representing 20, 24 and 32 most significant bits.
Closes: https://github.com/alsa-project/alsa-lib/pull/342
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Allow userspace applications to select subformats easily just like in
snd_pcm_format_t case - by string conversion.
Closes: https://github.com/alsa-project/alsa-lib/pull/342
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
config.h may contain defines like _FILE_OFFSET_BITS which influence
the system wide include files (off_t types, open -> open64 function
usage etc.).
Related: https://github.com/alsa-project/alsa-lib/pull/333
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Add possibility to return -EINTR instead waiting for the event. The
applications may want to handle -EINTR condition themselves.
BugLink: https://github.com/alsa-project/alsa-lib/issues/228
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
The snd_pcm_wait() function is called also internally from
the various plugins to wait for the drain with -1 and from i/o
routines in pcm.c.
Define two special negative timeout values to distinguish the
drain and i/o wait and calculate the maximal timeout according
the wait place.
Fixes: https://github.com/alsa-project/alsa-lib/issues/228
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
The application may not require to touch the playback
sample stream for the drain operation at all. In this case,
the application is responsible to setup a silencing mechanism
for the playback or another graceful stop (like using the
rewind operation).
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Handle the driver informing us that it is not necessary to set up
silencing upon playback draining. This will be the case for drivers
which are guaranteed to not read any samples beyond the application
pointer.
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
The fast_ops callback invocation must always pass the fast_op_arg
as the pcm argument. Plugins expect that.
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
This commit allows to define private alsa-lib's configuration. When
the configuration is present, the device values ("PlaybackCTL",
"CaptureCTL", "PlaybackMixer", "CaptureMixer", "CapturePCM")
are prefixed with '_ucmHEXA.' string where HEXA is replaced by the
unique hexadecimal number identifying the opened ucm manager handle.
Syntax 4
LibraryConfig.a_label.SubstiConfig {
# substituted library configuration like:
usr_share_dir "${ConfLibDir}"
}
LibraryConfig.b_label.Config {
# non-substituted library configuration like:
usr_share_dir "/usr/share/alsa"
}
The File counterparts:
LibraryConfig.c_label.SubstiFile "/some/path"
LibraryConfig.d_label.File "/some/path"
Note that for files the contents is substituted on the request,
but the file name is always substituted (useful for ${ConfDir} etc.).
The private configuration is not saved or preserved. It's life time
belongs to the opened ucm manager handle.
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
It seems that the commit "pcm: ioplug: Transfer all available data"
introduced new regressions (wrong memory access). The second issue
is that the avail_update in ioplug does not move appl_ptr nor hw_ptr,
so it's possible that the transfers may be repetitive.
This patch moves the transfer calls to mmap_begin callback where it
should be. The pointer wraps are handled by design now.
Fixes: 1714332719 ("pcm: ioplug: Transfer all available data")
BugLink: https://github.com/alsa-project/alsa-lib/pull/103
Tested-by: Andreas Pape <apape@de.adit-jv.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
The pthread_mutexattr_t object should be destroyed by calling
pthread_mutexattr_destroy(), otherwise it may cause a potential
memory leak due to the different implement of pthread_mutexattr_init()
Signed-off-by: chunxu.li <chunxuxiao@gmail.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
This error code can be used e.g. with echo reference PCM devices
(the SND_USE_CASE_MOD_ECHO_REF UCM token).
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
In commit b906db19ef, the snd_dlopen()
implements the automatic lookup to the ALSA_PLUGIN_DIR directory.
It is not necessary to add the absolute paths in callers now.
The plugin names are also searched in ld.so.conf paths as the fallback now,
but it should not be a big problem.
BugLink: https://github.com/alsa-project/alsa-lib/issues/34
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
once draining is done, the pcm enters the SETUP state, which ought to
be valid for snd_pcm_drain()
signed-off-by: Sylvain BERTRAND <sylvain.bertrand@legeek.net>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Most of PCM API functions have snd_pcm_lock()/unlock() wraps for the
actual calls of ops, and some plugins try to unlock/relock internally
for the given PCM object. This, unfortunately, causes a problem in
some configurations and leads to the unexpected behavior or deadlock.
The main problem is that we call snd_pcm_lock() with the given PCM
object, while calling the ops with pcm->op_arg or pcm->fast_op_arg as
the slave PCM object. Meanwhile the plugin code assumes that the
passed PCM object is already locked, and calls snd_pcm_unlock().
This bug doesn't hit always because in most cases pcm->op_arg and
fast_op_arg are identical with pcm itself. But in some configurations
they have different values, so the problem surfaces.
This patch is an attempt to resolve these inconsistencies. It
replaces most of snd_pcm_lock()/unlock() calls with either pcm->op_arg
or pcm->fast_op_arg, depending on the call pattern, so that the plugin
code can safely run snd_pcm_unlock() to the given PCM object.
Fixes: 54931e5a54 ("pcm: Add thread-safety to PCM API")
Reported-by: Ben Russell <thematrixeatsyou@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
snd_pcm_set_chmap() leaks the memory returned from snd_pcm_get_chmap()
without releasing. Add the missing free() call as well as a slight
code refactoring.
Reported-by: Conrad Jones
BugLink: https://github.com/alsa-project/alsa-lib/pull/11
Fixes: d20e24e5d1 ("chmap: Always succeed setting the map to what it already is")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
function is allowed to continue until it checks for error variable, as to
not conflict with original implementation flow
for simple functions involving only one line, return error immediately in
case callback is NULL
Signed-off-by: Adam Miartus <amiartus@de.adit-jv.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
main motivation for adding the callback is to use it to enable operation
on mmaped buffer before user access for pcm_file plugin
support for MMAP read access with masking by data from input file is not
implemented for pcm_file plugin, by adding this callback implementing
such feature can be done by rewriting next continuous portion of buffer
on each mmap_begin call
plugins like softvol use pcm_plugin interface and overwrite the buffer by
looping around it in avail_update callback, this patch hopes to simplify
the task by adding new api callback, removing the need for rewriting
pcm_file (to use pcm_plugin callbacks) and careful checking when looping
around whole mmaped buffer
Signed-off-by: Adam Miartus <amiartus@de.adit-jv.com>
Reviewed-by: Timo Wischer <twischer@de.adit-jv.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The hw_ptr might be updated during the snd_pcm_may_wait_for_avail_min() call,
so even if it returns zero (OK), the avail must be updated again.
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
snd_pcm_wait() & co checks the current avail value and returns
immediately if it satisfies <= avail_min condition. It's good in
general except for one situation: draining. When the draining is
being performed in the non-blocking mode, apps are supposed to wait
via poll(), typically via snd_pcm_wait(). So this ends up with the
busy loop because of the immediate return from snd_pcm_wait().
A simple workaround is to put the PCM state check and ignore the
avail_min condition if it's DRAINING state. The equivalent check is
found in the kernel xfer code, too.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The already existing areas_copy functions do not care about the end of
the source and destination buffer.
Therefore the caller has to take care that the requested offset+size
is not exceeding any buffer limit.
This additional function will take care about the end of an buffer
and will continue at the beginning of the buffer.
For example this is required when copying between buffers with
different sizes (not multiple of).
This is often the case in IO plugins like the JACK plugin.
Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Without this commit compiling fails when THREAD_SAFE_API is not
enabled.
Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
