diff options
Diffstat (limited to 'pd/portaudio/pa_linux_alsa/callback_thread.c')
| -rw-r--r-- | pd/portaudio/pa_linux_alsa/callback_thread.c | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/pd/portaudio/pa_linux_alsa/callback_thread.c b/pd/portaudio/pa_linux_alsa/callback_thread.c new file mode 100644 index 00000000..483557b6 --- /dev/null +++ b/pd/portaudio/pa_linux_alsa/callback_thread.c @@ -0,0 +1,374 @@ + +#include <sys/poll.h> +#include <limits.h> +#include <math.h> /* abs() */ + +#include <alsa/asoundlib.h> + +#include "pa_linux_alsa.h" + +#define MIN(x,y) ( (x) < (y) ? (x) : (y) ) + +static int wait( PaAlsaStream *stream ) +{ + int need_capture; + int need_playback; + int capture_avail = INT_MAX; + int playback_avail = INT_MAX; + int common_avail; + + if( stream->pcm_capture ) + need_capture = 1; + else + need_capture = 0; + + if( stream->pcm_playback ) + need_playback = 1; + else + need_playback = 0; + + while( need_capture || need_playback ) + { + int playback_pfd_offset=0; + int total_fds = 0; + + /* if the main thread has requested that we stop, do so now */ + pthread_testcancel(); + + /*printf("still polling...\n"); + if( need_capture ) + printf("need capture.\n"); + if( need_playback ) + printf("need playback.\n"); */ + + /* get the fds, packing all applicable fds into a single array, + * so we can check them all with a single poll() call */ + + if( need_capture ) + { + snd_pcm_poll_descriptors( stream->pcm_capture, stream->pfds, + stream->capture_nfds ); + total_fds += stream->capture_nfds; + } + + if( need_playback ) + { + playback_pfd_offset = total_fds; + snd_pcm_poll_descriptors( stream->pcm_playback, + stream->pfds + playback_pfd_offset, + stream->playback_nfds ); + total_fds += stream->playback_nfds; + } + + /* now poll on the combination of playback and capture fds. + * TODO: handle interrupt and/or failure */ + poll( stream->pfds, total_fds, 1000 ); + + /* check the return status of our pfds */ + if( need_capture ) + { + short revents; + snd_pcm_poll_descriptors_revents( stream->pcm_capture, stream->pfds, + stream->capture_nfds, &revents ); + if( revents == POLLIN ) + need_capture = 0; + } + + if( need_playback ) + { + short revents; + snd_pcm_poll_descriptors_revents( stream->pcm_playback, + stream->pfds + playback_pfd_offset, + stream->playback_nfds, &revents ); + //if( revents & POLLOUT ) + //if( revents & POLLERR ) + // printf("polling error!"); + if( revents == POLLOUT ) + need_playback = 0; + } + } + + /* we have now established that there are buffers ready to be + * operated on. Now determine how many frames are available. */ + if( stream->pcm_capture ) + capture_avail = snd_pcm_avail_update( stream->pcm_capture ); + + if( stream->pcm_playback ) + playback_avail = snd_pcm_avail_update( stream->pcm_playback ); + + common_avail = MIN(capture_avail, playback_avail); + common_avail -= common_avail % stream->frames_per_period; + + return common_avail; +} + +static int setup_buffers( PaAlsaStream *stream, int frames_avail ) +{ + int i; + int capture_frames_avail = INT_MAX; + int playback_frames_avail = INT_MAX; + int common_frames_avail; + + if( stream->pcm_capture ) + { + const snd_pcm_channel_area_t *capture_areas; + const snd_pcm_channel_area_t *area; + snd_pcm_uframes_t frames = frames_avail; + + /* I do not understand this code fragment yet, it is copied out of the + * alsa-devel archives... */ + snd_pcm_mmap_begin( stream->pcm_capture, &capture_areas, + &stream->capture_offset, &frames); + + if( stream->capture_interleaved ) + { + void *interleaved_capture_buffer; + area = &capture_areas[0]; + interleaved_capture_buffer = area->addr + + (area->first + area->step * stream->capture_offset) / 8; + PaUtil_SetInterleavedInputChannels( &stream->bufferProcessor, + 0, /* starting at channel 0 */ + interleaved_capture_buffer, + 0 /* default numInputChannels */ + ); + } + else + { + /* noninterleaved */ + void *noninterleaved_capture_buffers[1000]; + for( i = 0; i < stream->capture_channels; i++ ) + { + area = &capture_areas[i]; + noninterleaved_capture_buffers[i] = area->addr + + (area->first + area->step * stream->capture_offset) / 8; + PaUtil_SetNonInterleavedInputChannel( &stream->bufferProcessor, + i, + noninterleaved_capture_buffers[i]); + } + } + + capture_frames_avail = frames; + } + + if( stream->pcm_playback ) + { + const snd_pcm_channel_area_t *playback_areas; + const snd_pcm_channel_area_t *area; + snd_pcm_uframes_t frames = frames_avail; + + /* I do not understand this code fragment yet, it is copied out of the + * alsa-devel archives... */ + snd_pcm_mmap_begin( stream->pcm_playback, &playback_areas, + &stream->playback_offset, &frames); + + if( stream->playback_interleaved ) + { + void *interleaved_playback_buffer; + area = &playback_areas[0]; + interleaved_playback_buffer = area->addr + + (area->first + area->step * stream->playback_offset) / 8; + PaUtil_SetInterleavedOutputChannels( &stream->bufferProcessor, + 0, /* starting at channel 0 */ + interleaved_playback_buffer, + 0 /* default numInputChannels */ + ); + } + else + { + /* noninterleaved */ + void *noninterleaved_playback_buffers[1000]; + for( i = 0; i < stream->playback_channels; i++ ) + { + area = &playback_areas[i]; + noninterleaved_playback_buffers[i] = area->addr + + (area->first + area->step * stream->playback_offset) / 8; + PaUtil_SetNonInterleavedOutputChannel( &stream->bufferProcessor, + i, + noninterleaved_playback_buffers[i]); + } + } + + playback_frames_avail = frames; + } + + + common_frames_avail = MIN(capture_frames_avail, playback_frames_avail); + common_frames_avail -= common_frames_avail % stream->frames_per_period; + //printf( "%d capture frames available\n", capture_frames_avail ); + //printf( "%d frames playback available\n", playback_frames_avail ); + //printf( "%d frames available\n", common_frames_avail ); + + if( stream->pcm_capture ) + PaUtil_SetInputFrameCount( &stream->bufferProcessor, common_frames_avail ); + + if( stream->pcm_playback ) + PaUtil_SetOutputFrameCount( &stream->bufferProcessor, common_frames_avail ); + + return common_frames_avail; +} + +void *CallbackThread( void *userData ) +{ + PaAlsaStream *stream = (PaAlsaStream*)userData; + + if( stream->pcm_capture ) + snd_pcm_start( stream->pcm_capture ); + if( stream->pcm_playback ) + snd_pcm_start( stream->pcm_playback ); + + while(1) + { + int frames_avail; + int frames_got; + + PaStreamCallbackTimeInfo timeInfo = {0,0,0}; /* IMPLEMENT ME */ + int callbackResult; + int framesProcessed; + + pthread_testcancel(); + { + /* calculate time info */ + snd_timestamp_t capture_timestamp; + snd_timestamp_t playback_timestamp; + snd_pcm_status_t *capture_status; + snd_pcm_status_t *playback_status; + snd_pcm_status_alloca( &capture_status ); + snd_pcm_status_alloca( &playback_status ); + + if( stream->pcm_capture ) + { + snd_pcm_status( stream->pcm_capture, capture_status ); + snd_pcm_status_get_tstamp( capture_status, &capture_timestamp ); + } + if( stream->pcm_playback ) + { + snd_pcm_status( stream->pcm_playback, playback_status ); + snd_pcm_status_get_tstamp( playback_status, &playback_timestamp ); + } + + /* Hmm, we potentially have both a playback and a capture timestamp. + * Hopefully they are the same... */ + if( stream->pcm_capture && stream->pcm_playback ) + { + float capture_time = capture_timestamp.tv_sec + + ((float)capture_timestamp.tv_usec/1000000); + float playback_time= playback_timestamp.tv_sec + + ((float)playback_timestamp.tv_usec/1000000); + if( fabsf(capture_time-playback_time) > 0.01 ) + printf("Capture time and playback time differ by %f\n", fabsf(capture_time-playback_time)); + timeInfo.currentTime = capture_time; + } + else if( stream->pcm_playback ) + { + timeInfo.currentTime = playback_timestamp.tv_sec + + ((float)playback_timestamp.tv_usec/1000000); + } + else + { + timeInfo.currentTime = capture_timestamp.tv_sec + + ((float)capture_timestamp.tv_usec/1000000); + } + + if( stream->pcm_capture ) + { + snd_pcm_sframes_t capture_delay = snd_pcm_status_get_delay( capture_status ); + timeInfo.inputBufferAdcTime = timeInfo.currentTime - + (float)capture_delay / stream->streamRepresentation.streamInfo.sampleRate; + } + + if( stream->pcm_playback ) + { + snd_pcm_sframes_t playback_delay = snd_pcm_status_get_delay( playback_status ); + timeInfo.outputBufferDacTime = timeInfo.currentTime + + (float)playback_delay / stream->streamRepresentation.streamInfo.sampleRate; + } + } + + + /* + IMPLEMENT ME: + - handle buffer slips + */ + + /* + depending on whether the host buffers are interleaved, non-interleaved + or a mixture, you will want to call PaUtil_ProcessInterleavedBuffers(), + PaUtil_ProcessNonInterleavedBuffers() or PaUtil_ProcessBuffers() here. + */ + + frames_avail = wait( stream ); + //printf( "%d frames available\n", frames_avail ); + + /* Now we know the soundcard is ready to produce/receive at least + * one period. We just need to get the buffers for the client + * to read/write. */ + PaUtil_BeginBufferProcessing( &stream->bufferProcessor, &timeInfo ); + + frames_got = setup_buffers( stream, frames_avail ); + + if( frames_avail == frames_got ) + ;//printf("good, they were both %d\n", frames_avail ); + else + printf("damn, they were different: avail: %d, got: %d\n", frames_avail, frames_got ); + + /* this calls the callback */ + + PaUtil_BeginCpuLoadMeasurement( &stream->cpuLoadMeasurer ); + + framesProcessed = PaUtil_EndBufferProcessing( &stream->bufferProcessor, + &callbackResult ); + + PaUtil_EndCpuLoadMeasurement( &stream->cpuLoadMeasurer, framesProcessed ); + + /* inform ALSA how many frames we wrote */ + + if( stream->pcm_capture ) + snd_pcm_mmap_commit( stream->pcm_capture, stream->capture_offset, frames_avail ); + + if( stream->pcm_playback ) + snd_pcm_mmap_commit( stream->pcm_playback, stream->playback_offset, frames_avail ); + + + /* + If you need to byte swap outputBuffer, you can do it here using + routines in pa_byteswappers.h + */ + + if( callbackResult == paContinue ) + { + /* nothing special to do */ + } + else if( callbackResult == paAbort ) + { + stream->callback_finished = 1; + + if( stream->pcm_capture ) + { + snd_pcm_drop( stream->pcm_capture ); + } + + if( stream->pcm_playback ) + { + snd_pcm_drop( stream->pcm_playback ); + } + pthread_exit(NULL); + } + else + { + stream->callback_finished = 1; + + if( stream->pcm_capture ) + { + snd_pcm_drain( stream->pcm_capture ); + } + + if( stream->pcm_playback ) + { + snd_pcm_drain( stream->pcm_playback ); + } + pthread_exit(NULL); + } + + } +} + |