--- /dev/null
+#include <assert.h>
+#include <stdio.h>
+#include <sys/poll.h>
+
+#include <asoundlib.h>
+
+#include "module.h"
+#include "core.h"
+#include "memchunk.h"
+#include "sink.h"
+#include "modargs.h"
+#include "util.h"
+#include "sample-util.h"
+
+struct userdata {
+ snd_pcm_t *pcm_handle;
+ struct pa_sink *sink;
+ void **io_sources;
+ unsigned n_io_sources;
+
+ size_t frame_size, fragment_size;
+ struct pa_memchunk memchunk, silence;
+};
+
+static const char* const valid_modargs[] = {
+ "device",
+ "sink_name",
+ NULL
+};
+
+#define DEFAULT_SINK_NAME "alsa_output"
+#define DEFAULT_DEVICE "plughw:0,0"
+
+static void xrun_recovery(struct userdata *u) {
+ assert(u);
+
+ fprintf(stderr, "*** XRUN ***\n");
+
+ if (snd_pcm_prepare(u->pcm_handle) < 0)
+ fprintf(stderr, "snd_pcm_prepare() failed\n");
+}
+
+static void do_write(struct userdata *u) {
+ assert(u);
+
+ for (;;) {
+ struct pa_memchunk *memchunk = NULL;
+ snd_pcm_sframes_t frames;
+
+ if (u->memchunk.memblock)
+ memchunk = &u->memchunk;
+ else {
+ if (pa_sink_render(u->sink, u->fragment_size, &u->memchunk) < 0)
+ memchunk = &u->silence;
+ else
+ memchunk = &u->memchunk;
+ }
+
+ assert(memchunk->memblock && memchunk->memblock->data && memchunk->length && memchunk->memblock->length && (memchunk->length % u->frame_size) == 0);
+
+ assert(u->pcm_handle);
+ assert(memchunk->memblock);
+ assert(memchunk->memblock->data);
+ assert(memchunk->length);
+ assert(u->frame_size);
+
+ if ((frames = snd_pcm_writei(u->pcm_handle, memchunk->memblock->data + memchunk->index, memchunk->length / u->frame_size)) < 0) {
+ if (frames == -EPIPE) {
+ xrun_recovery(u);
+ continue;
+ }
+
+ fprintf(stderr, "snd_pcm_writei() failed\n");
+ return;
+ }
+
+ if (memchunk == &u->memchunk) {
+ memchunk->index += frames * u->frame_size;
+ memchunk->length -= frames * u->frame_size;
+
+ if (memchunk->length == 0) {
+ pa_memblock_unref(memchunk->memblock);
+ memchunk->memblock = NULL;
+ memchunk->index = memchunk->length = 0;
+ }
+ }
+
+ break;
+ }
+}
+
+static void io_callback(struct pa_mainloop_api*a, void *id, int fd, enum pa_mainloop_api_io_events events, void *userdata) {
+ struct userdata *u = userdata;
+ assert(u && a && id);
+
+ if (snd_pcm_state(u->pcm_handle) == SND_PCM_STATE_XRUN)
+ xrun_recovery(u);
+
+ do_write(u);
+}
+
+static uint32_t sink_get_latency_cb(struct pa_sink *s) {
+ struct userdata *u = s->userdata;
+ snd_pcm_sframes_t frames;
+ assert(s && u && u->sink);
+
+ if (snd_pcm_delay(u->pcm_handle, &frames) < 0) {
+ fprintf(stderr, __FILE__": failed to get delay\n");
+ s->get_latency = NULL;
+ return 0;
+ }
+
+ if (frames < 0)
+ frames = 0;
+
+ return pa_samples_usec(frames * u->frame_size, &s->sample_spec);
+}
+
+int pa_module_init(struct pa_core *c, struct pa_module*m) {
+ struct pa_modargs *ma = NULL;
+ int ret = -1;
+ struct userdata *u = NULL;
+ snd_pcm_hw_params_t *hwparams;
+ const char *dev;
+ struct pollfd *pfds, *ppfd;
+ struct pa_sample_spec ss;
+ unsigned i, periods;
+ snd_pcm_uframes_t buffer_size;
+ void ** ios;
+
+ if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
+ fprintf(stderr, __FILE__": failed to parse module arguments\n");
+ goto fail;
+ }
+
+ u = malloc(sizeof(struct userdata));
+ assert(u);
+ memset(u, 0, sizeof(struct userdata));
+ m->userdata = u;
+
+ if (snd_pcm_open(&u->pcm_handle, dev = pa_modargs_get_value(ma, "device", DEFAULT_DEVICE), SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK) < 0) {
+ fprintf(stderr, "Error opening PCM device %s\n", dev);
+ goto fail;
+ }
+
+ ss.format = PA_SAMPLE_S16LE;
+ ss.rate = 44100;
+ ss.channels = 2;
+
+ periods = 12;
+ buffer_size = periods*256;
+
+ snd_pcm_hw_params_alloca(&hwparams);
+ if (snd_pcm_hw_params_any(u->pcm_handle, hwparams) < 0 ||
+ snd_pcm_hw_params_set_access(u->pcm_handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED) < 0 ||
+ snd_pcm_hw_params_set_format(u->pcm_handle, hwparams, SND_PCM_FORMAT_S16_LE) < 0 ||
+ snd_pcm_hw_params_set_rate_near(u->pcm_handle, hwparams, &ss.rate, NULL) < 0 ||
+ snd_pcm_hw_params_set_channels(u->pcm_handle, hwparams, ss.channels) < 0 ||
+ snd_pcm_hw_params_set_periods_near(u->pcm_handle, hwparams, &periods, NULL) < 0 ||
+ snd_pcm_hw_params_set_buffer_size_near(u->pcm_handle, hwparams, &buffer_size) < 0 ||
+ snd_pcm_hw_params(u->pcm_handle, hwparams) < 0) {
+ fprintf(stderr, "Error setting HW params.\n");
+ goto fail;
+ }
+
+ u->sink = pa_sink_new(c, pa_modargs_get_value(ma, "sink_name", DEFAULT_SINK_NAME), 0, &ss);
+ assert(u->sink);
+
+ u->sink->get_latency = sink_get_latency_cb;
+ u->sink->userdata = u;
+ pa_sink_set_owner(u->sink, m);
+ u->sink->description = pa_sprintf_malloc("Advanced Linux Sound Architecture PCM on '%s'", dev);
+
+ u->n_io_sources = snd_pcm_poll_descriptors_count(u->pcm_handle);
+
+ pfds = malloc(sizeof(struct pollfd) * u->n_io_sources);
+ assert(pfds);
+ if (snd_pcm_poll_descriptors(u->pcm_handle, pfds, u->n_io_sources) < 0) {
+ printf("Unable to obtain poll descriptors for playback.\n");
+ free(pfds);
+ goto fail;
+ }
+
+ u->io_sources = malloc(sizeof(void*) * u->n_io_sources);
+ assert(u->io_sources);
+
+ for (i = 0, ios = u->io_sources, ppfd = pfds; i < u->n_io_sources; i++, ios++, ppfd++) {
+ *ios = c->mainloop->source_io(c->mainloop, ppfd->fd,
+ ((ppfd->events & POLLIN) ? PA_MAINLOOP_API_IO_EVENT_INPUT : 0) |
+ ((ppfd->events & POLLOUT) ? PA_MAINLOOP_API_IO_EVENT_OUTPUT : 0), io_callback, u);
+ assert(*ios);
+ }
+
+ free(pfds);
+
+ u->frame_size = pa_sample_size(&ss);
+ u->fragment_size = buffer_size*u->frame_size/periods;
+
+ fprintf(stderr, __FILE__": using %u fragments of size %u bytes.\n", periods, u->fragment_size);
+
+ u->silence.memblock = pa_memblock_new(u->silence.length = u->fragment_size);
+ assert(u->silence.memblock);
+ pa_silence_memblock(u->silence.memblock, &ss);
+ u->silence.index = 0;
+
+ u->memchunk.memblock = NULL;
+ u->memchunk.index = u->memchunk.length = 0;
+
+ ret = 0;
+
+finish:
+ if (ma)
+ pa_modargs_free(ma);
+
+ return ret;
+
+fail:
+
+ if (u)
+ pa_module_done(c, m);
+
+ goto finish;
+}
+
+void pa_module_done(struct pa_core *c, struct pa_module*m) {
+ struct userdata *u;
+ assert(c && m);
+
+ if ((u = m->userdata)) {
+ unsigned i;
+ void **ios;
+
+ pa_sink_free(u->sink);
+
+ for (ios = u->io_sources, i = 0; i < u->n_io_sources; i++, ios++)
+ c->mainloop->cancel_io(c->mainloop, *ios);
+ free(u->io_sources);
+
+ if (u->pcm_handle) {
+ snd_pcm_drop(u->pcm_handle);
+ snd_pcm_close(u->pcm_handle);
+ }
+
+ if (u->memchunk.memblock)
+ pa_memblock_unref(u->memchunk.memblock);
+ if (u->silence.memblock)
+ pa_memblock_unref(u->silence.memblock);
+
+ free(u);
+ }
+}
+