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* audio/out: make EOF handling properly event-basedwm42014-09-051-0/+9
| | | | | | | | | | | | | | | | | With --gapless-audio=no, changing from one file to the next apparently made it hang, until the player was woken up by unrelated events like input. The reason was that the AO doesn't notify the player of EOF properly. the played was querying ao_eof_reached(), and then just went to sleep, without anything waking it up. Make it event-based: the AO wakes up the playloop if the EOF state changes. We could have fixed this in a simpler way by synchronously draining the AO in these cases. But I think proper event handling is preferable. Fixes: #1069 CC: @mpv-player/stable (perhaps)
* Move compat/ and bstr/ directory contents somewhere elsewm42014-08-291-1/+1
| | | | | | | | | bstr.c doesn't really deserve its own directory, and compat had just a few files, most of which may as well be in osdep. There isn't really any justification for these extra directories, so get rid of them. The compat/libav.h was empty - just delete it. We changed our approach to API compatibility, and will likely not need it anymore.
* audio: don't wait for draining if pausedwm42014-07-131-0/+9
| | | | | | | | | | | | | Logic for this was missing from pull.c. For push.c it was missing if the driver didn't support it. But even if the driver supported it (such as with ao_alsa), strange behavior was observed by users. See issue #933. Always check explicitly whether the AO is in paused mode, and if so, don't drain. Possibly fixes #933. CC: @mpv-player/stable
* audio/out/pull: remove race conditionswm42014-05-291-34/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There were subtle and minor race conditions in the pull.c code, and AOs using it (jack, portaudio, sdl, wasapi). Attempt to remove these. There was at least a race condition in the ao_reset() implementation: mp_ring_reset() was called concurrently to the audio callback. While the ringbuffer uses atomics to allow concurrent access, the reset function wasn't concurrency-safe (and can't easily be made to). Fix this by stopping the audio callback before doing a reset. After that, we can do anything without needing synchronization. The callback is resumed when resuming playback at a later point. Don't call driver->pause, and make driver->resume and driver->reset start/stop the audio callback. In the initial state, the audio callback must be disabled. JackAudio of course is different. Maybe there is no way to suspend the audio callback without "disconnecting" it (what jack_deactivate() would do), so I'm not trying my luck, and implemented a really bad hack doing active waiting until we get the audio callback into a state where it won't interfere. Once the callback goes from AO_STATE_WAIT to NONE, we can be sure that the callback doesn't access the ringbuffer or anything else anymore. Since both sched_yield() and pthread_yield() apparently are not always available, use mp_sleep_us(1) to avoid burning CPU during active waiting. The ao_jack.c change also removes a race condition: apparently we didn't initialize _all_ ao fields before starting the audio callback. In ao_wasapi.c, I'm not sure whether reset really waits for the audio callback to return. Kovensky says it's not guaranteed, so disable the reset callback - for now the behavior of ao_wasapi.c is like with ao_jack.c, and active waiting is used to deal with the audio callback.
* atomics: switch to C11 stdatomic.hwm42014-05-211-27/+17
| | | | | | | | | | | | | | | | | | | | | | | | | In my opinion, we shouldn't use atomics at all, but ok. This switches the mpv code to use C11 stdatomic.h, and for compilers that don't support stdatomic.h yet, we emulate the subset used by mpv using the builtins commonly provided by gcc and clang. This supersedes an earlier similar attempt by Kovensky. That attempt unfortunately relied on a big copypasted freebsd header (which also depended on much more highly compiler-specific functionality, defined reserved symbols, etc.), so it had to be NIH'ed. Some issues: - C11 says default initialization of atomics "produces a valid state", but it's not sure whether the stored value is really 0. But we rely on this. - I'm pretty sure our use of the __atomic... builtins is/was incorrect. We don't use atomic load/store intrinsics, and access stuff directly. - Our wrapper actually does stricter typechecking than the stdatomic.h implementation by gcc 4.9. We make the atomic types incompatible with normal types by wrapping them into structs. (The FreeBSD wrapper does the same.) - I couldn't test on MinGW.
* audio: wake up the core when audio buffer is running low (2)wm42014-04-151-2/+9
| | | | | | | | | | | | | | Same change as in e2184fcb, but this time for pull based AOs. This is slightly controversial, because it will make a fast syscall from e.g. ao_jack. And according to JackAudio developers, syscalls are evil and will destroy realtime operation. But I don't think this is an issue at all. Still avoid locking a mutex. I'm not sure what jackaudio does in the worst case - but if they set the jackaudio thread (and only this thread) to realtime, we might run into deadlock situations due to priority inversion and such. I'm not quite sure whether this can happen, but I'll readily follow the cargo cult if it makes hack happy.
* audio/out: make draining a separate operationwm42014-03-091-2/+2
| | | | | | | | | | | | Until now, this was always conflated with uninit. This was ugly, and also many AOs emulated this manually (or just ignored it). Make draining an explicit operation, so AOs which support it can provide it, and for all others generic code will emulate it. For ao_wasapi, we keep it simple and basically disable the internal draining implementation (maybe it should be restored later). Tested on Linux only.
* audio/out: feed AOs from a separate threadwm42014-03-091-0/+219
This has 2 goals: - Ensure that AOs have always enough data, even if the device buffers are very small. - Reduce complexity in some AOs, which do their own buffering. One disadvantage is that performance is slightly reduced due to more copying. Implementation-wise, we don't change ao.c much, and instead "redirect" the driver's callback to an API wrapper in push.c. Additionally, we add code for dealing with AOs that have a pull API. These AOs usually do their own buffering (jack, coreaudio, portaudio), and adding a thread is basically a waste. The code in pull.c manages a ringbuffer, and allows callback-based AOs to read data directly.