X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=alsa_write.c;h=d649341837d3284f7aaf9b1fc83ab22f217826b6;hp=ae8bed6d339724563e86eb899d9aa96a46f6f8e7;hb=fa578bf1d070161cafcbcc69ca7b810414ee1a4b;hpb=271c83d4fd9411be628fa650ce595ac79754d22e diff --git a/alsa_write.c b/alsa_write.c index ae8bed6d..d6493418 100644 --- a/alsa_write.c +++ b/alsa_write.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2005-2009 Andre Noll + * Copyright (C) 2005-2011 Andre Noll * * Licensed under the GPL v2. For licencing details see COPYING. */ @@ -16,6 +16,8 @@ #include #include #include +#include +#include #include "para.h" #include "fd.h" @@ -23,45 +25,60 @@ #include "list.h" #include "sched.h" #include "ggo.h" +#include "buffer_tree.h" #include "write.h" +#include "write_common.h" #include "alsa_write.cmdline.h" #include "error.h" -/** always use 16 bit little endian */ -#define FORMAT SND_PCM_FORMAT_S16_LE - /** Data specific to the alsa writer. */ struct private_alsa_write_data { /** The alsa handle */ snd_pcm_t *handle; - /** Determined and set by alsa_open(). */ + /** Determined and set by alsa_init(). */ int bytes_per_frame; - /** Don't write anything until this time. */ - struct timeval next_chunk; /** The approximate maximum buffer duration in us. */ unsigned buffer_time; + /* Number of frames that fit into the buffer. */ + snd_pcm_uframes_t buffer_frames; /** - * The samplerate given by command line option or the decoder + * The sample rate given by command line option or the decoder * of the writer node group. */ - unsigned samplerate; + unsigned sample_rate; + snd_pcm_format_t sample_format; /** * The number of channels, given by command line option or the * decoder of the writer node group. */ unsigned channels; + struct timeval drain_barrier; }; +static snd_pcm_format_t get_alsa_pcm_format(enum sample_format sf) +{ + switch (sf) { + case SF_S8: return SND_PCM_FORMAT_S8; + case SF_U8: return SND_PCM_FORMAT_U8; + case SF_S16_LE: return SND_PCM_FORMAT_S16_LE; + case SF_S16_BE: return SND_PCM_FORMAT_S16_BE; + case SF_U16_LE: return SND_PCM_FORMAT_U16_LE; + case SF_U16_BE: return SND_PCM_FORMAT_U16_BE; + default: return SND_PCM_FORMAT_S16_LE; + } +} + /* Install PCM software and hardware configuration. */ static int alsa_init(struct private_alsa_write_data *pad, struct alsa_write_args_info *conf) { snd_pcm_hw_params_t *hwparams; snd_pcm_sw_params_t *swparams; - snd_pcm_uframes_t buffer_size, start_threshold, stop_threshold; + snd_pcm_uframes_t start_threshold, stop_threshold; snd_pcm_uframes_t period_size; int err; + PARA_INFO_LOG("opening %s\n", conf->device_arg); err = snd_pcm_open(&pad->handle, conf->device_arg, SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK); if (err < 0) @@ -74,46 +91,48 @@ static int alsa_init(struct private_alsa_write_data *pad, if (snd_pcm_hw_params_set_access(pad->handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED) < 0) return -E_ACCESS_TYPE; - if (snd_pcm_hw_params_set_format(pad->handle, hwparams, FORMAT) < 0) + if (snd_pcm_hw_params_set_format(pad->handle, hwparams, + pad->sample_format) < 0) return -E_SAMPLE_FORMAT; if (snd_pcm_hw_params_set_channels(pad->handle, hwparams, pad->channels) < 0) return -E_CHANNEL_COUNT; if (snd_pcm_hw_params_set_rate_near(pad->handle, hwparams, - &pad->samplerate, 0) < 0) + &pad->sample_rate, NULL) < 0) return -E_SET_RATE; - err = snd_pcm_hw_params_get_buffer_time_max(hwparams, &pad->buffer_time, 0); + err = snd_pcm_hw_params_get_buffer_time_max(hwparams, + &pad->buffer_time, NULL); if (err < 0 || !pad->buffer_time) return -E_GET_BUFFER_TIME; PARA_INFO_LOG("buffer time: %d\n", pad->buffer_time); if (snd_pcm_hw_params_set_buffer_time_near(pad->handle, hwparams, - &pad->buffer_time, 0) < 0) + &pad->buffer_time, NULL) < 0) return -E_SET_BUFFER_TIME; if (snd_pcm_hw_params(pad->handle, hwparams) < 0) return -E_HW_PARAMS; - snd_pcm_hw_params_get_period_size(hwparams, &period_size, 0); - snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size); - PARA_INFO_LOG("buffer size: %lu, period_size: %lu\n", buffer_size, + snd_pcm_hw_params_get_period_size(hwparams, &period_size, NULL); + snd_pcm_hw_params_get_buffer_size(hwparams, &pad->buffer_frames); + PARA_INFO_LOG("buffer size: %lu, period_size: %lu\n", pad->buffer_frames, period_size); - if (period_size == buffer_size) + if (period_size == pad->buffer_frames) return -E_BAD_PERIOD; snd_pcm_sw_params_current(pad->handle, swparams); snd_pcm_sw_params_set_avail_min(pad->handle, swparams, period_size); - if (buffer_size < 1) + if (pad->buffer_frames < 1) start_threshold = 1; else - start_threshold = PARA_MIN(buffer_size, - (snd_pcm_uframes_t)pad->samplerate); + start_threshold = PARA_MIN(pad->buffer_frames, + (snd_pcm_uframes_t)pad->sample_rate); if (snd_pcm_sw_params_set_start_threshold(pad->handle, swparams, start_threshold) < 0) return -E_START_THRESHOLD; - stop_threshold = buffer_size; + stop_threshold = pad->buffer_frames; if (snd_pcm_sw_params_set_stop_threshold(pad->handle, swparams, stop_threshold) < 0) return -E_STOP_THRESHOLD; if (snd_pcm_sw_params(pad->handle, swparams) < 0) PARA_WARNING_LOG("unable to install sw params\n"); - pad->bytes_per_frame = snd_pcm_format_physical_width(FORMAT) + pad->bytes_per_frame = snd_pcm_format_physical_width(pad->sample_format) * pad->channels / 8; if (pad->bytes_per_frame <= 0) return -E_PHYSICAL_WIDTH; @@ -123,143 +142,168 @@ static int alsa_init(struct private_alsa_write_data *pad, return 1; } -/* Open an instance of the alsa writer. */ -static int alsa_open(struct writer_node *wn) +static void alsa_write_pre_select(struct sched *s, struct task *t) { - struct alsa_write_args_info *conf = wn->conf; - struct writer_node_group *wng = wn->wng; - struct private_alsa_write_data *pad = para_calloc(sizeof(*pad)); + struct writer_node *wn = container_of(t, struct writer_node, task); + struct private_alsa_write_data *pad = wn->private_data; + struct timeval tv; + snd_pcm_sframes_t avail, underrun; + int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF); - wn->private_data = pad; - if (!conf->samplerate_given && wng->samplerate) - pad->samplerate = *wng->samplerate; - else - pad->samplerate = conf->samplerate_arg; - if (!conf->channels_given && wng->channels) - pad->channels = *wng->channels; - else - pad->channels = conf->channels_arg; - PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate); - tv_add(now, &(struct timeval){0, 100 * 1000}, &pad->next_chunk); - return 1; + if (ret == 0) + return; + if (ret < 0 || !pad) + return sched_min_delay(s); + /* + * Data is available to be written to the alsa handle. Compute number + * of milliseconds until next buffer underrun would occur. + * + * snd_pcm_avail_update() updates the current available count of + * samples for writing. It is a light method to obtain current stream + * position, because it does not require the user <-> kernel context + * switch, but the value is less accurate, because ring buffer pointers + * are updated in kernel drivers only when an interrupt occurs. + */ + avail = snd_pcm_avail_update(pad->handle); + if (avail < 0) + avail = 0; + underrun = (pad->buffer_frames - avail) * pad->buffer_time + / pad->buffer_frames / 1000; + if (underrun < 50) + underrun = 50; + underrun -= 50; + ms2tv(underrun, &tv); + sched_request_timeout(&tv, s); } -static int alsa_write_pre_select(struct sched *s, struct writer_node *wn) +static void alsa_close(struct writer_node *wn) { struct private_alsa_write_data *pad = wn->private_data; - struct writer_node_group *wng = wn->wng; - struct timeval diff; + PARA_INFO_LOG("closing writer node %p\n", wn); - if (!*wng->loaded) - return 1; - if (tv_diff(now, &pad->next_chunk, &diff) < 0) { - if (tv_diff(&s->timeout, &diff, NULL) > 0) - s->timeout = diff; - } else { - s->timeout.tv_sec = 0; - s->timeout.tv_usec = 1; - } - return 1; + if (!pad) + return; + /* + * It's OK to have a blocking operation here because we already made + * sure that the PCM output buffer is (nearly) empty. + */ + snd_pcm_nonblock(pad->handle, 0); + snd_pcm_drain(pad->handle); + snd_pcm_close(pad->handle); + snd_config_update_free_global(); + free(pad); } -static int alsa_write_post_select(__a_unused struct sched *s, - struct writer_node *wn) +static void alsa_write_post_select(__a_unused struct sched *s, + struct task *t) { + struct writer_node *wn = container_of(t, struct writer_node, task); struct private_alsa_write_data *pad = wn->private_data; - struct writer_node_group *wng = wn->wng; - size_t bytes = *wng->loaded - wn->written; - unsigned char *data = (unsigned char*)*wng->bufp + wn->written; - struct timeval tv; - snd_pcm_sframes_t ret, frames, avail; + struct btr_node *btrn = wn->btrn; + char *data; + size_t bytes; + snd_pcm_sframes_t frames; + int ret; - if (*wng->input_error < 0 && (!pad->handle || bytes < pad->bytes_per_frame)) { - wn->written = *wng->loaded; - return *wng->input_error; - } - if (!bytes) /* no data available */ - return 0; - if (tv_diff(now, &pad->next_chunk, NULL) < 0) - return 0; - if (!pad->handle) { - int err = alsa_init(pad, wn->conf); - if (err < 0) - return err; - } - frames = bytes / pad->bytes_per_frame; - if (!frames) /* less than a single frame available */ - return 0; - avail = snd_pcm_avail_update(pad->handle); - if (avail <= 0) - goto delay; - frames = PARA_MIN(frames, avail); - ret = snd_pcm_writei(pad->handle, data, frames); - if (ret < 0) { - PARA_WARNING_LOG("%s\n", snd_strerror(-ret)); - if (ret == -EPIPE) { - snd_pcm_prepare(pad->handle); - return 0; +again: + t->error = 0; + ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF); + if (ret == 0) + return; + btr_merge(btrn, wn->min_iqs); + bytes = btr_next_buffer(btrn, &data); + if (ret < 0 || bytes < wn->min_iqs) { /* eof */ + assert(btr_no_parent(btrn)); + ret = -E_ALSA_EOF; + if (!pad) + goto err; + /* wait until pending frames are played */ + if (pad->drain_barrier.tv_sec == 0) { + PARA_DEBUG_LOG("waiting for device to drain\n"); + tv_add(now, &(struct timeval)EMBRACE(0, 200 * 1000), + &pad->drain_barrier); + return; } - if (ret == -EAGAIN) - goto delay; - return -E_ALSA_WRITE; + if (tv_diff(now, &pad->drain_barrier, NULL) > 0) + goto err; + return; } - wn->written += ret * pad->bytes_per_frame; - return 1; -delay: - /* wait until 50% buffer space is available */ - ms2tv(pad->buffer_time / 2000, &tv); - tv_add(now, &tv, &pad->next_chunk); - return 0; -} + if (!pad) { + int32_t val; -static void alsa_close(struct writer_node *wn) -{ - struct private_alsa_write_data *pad = wn->private_data; - PARA_INFO_LOG("closing writer node %p\n", wn); + pad = para_calloc(sizeof(*pad)); + wn->private_data = pad; + if (bytes == 0) /* no data available */ + return; + get_btr_sample_rate(btrn, &val); + pad->sample_rate = val; + get_btr_channels(btrn, &val); + pad->channels = val; + get_btr_sample_format(btrn, &val); + pad->sample_format = get_alsa_pcm_format(val); - if (pad->handle) { - snd_pcm_drain(pad->handle); - snd_pcm_close(pad->handle); - snd_config_update_free_global(); + PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, + pad->sample_rate); + ret = alsa_init(pad, wn->conf); + if (ret < 0) + goto err; + wn->min_iqs = pad->bytes_per_frame; + goto again; } - free(pad); + frames = bytes / pad->bytes_per_frame; + frames = snd_pcm_writei(pad->handle, data, frames); + if (frames >= 0) { + btr_consume(btrn, frames * pad->bytes_per_frame); + goto again; + } + if (frames == -EPIPE) { + PARA_WARNING_LOG("underrun (tried to write %zu bytes)\n", bytes); + snd_pcm_prepare(pad->handle); + return; + } + if (frames == -EAGAIN) + return; + PARA_WARNING_LOG("%s\n", snd_strerror(-frames)); + ret = -E_ALSA_WRITE; +err: + assert(ret < 0); + btr_remove_node(btrn); + t->error = ret; } -__malloc static void *alsa_parse_config(const char *options) +__malloc static void *alsa_parse_config_or_die(const char *options) { - int ret; - struct alsa_write_args_info *conf - = para_calloc(sizeof(struct alsa_write_args_info)); + struct alsa_write_args_info *conf = para_calloc(sizeof(*conf)); PARA_INFO_LOG("options: %s, %zd\n", options, strcspn(options, " \t")); - ret = alsa_cmdline_parser_string(options, conf, "alsa_write"); - if (ret) - goto err_out; - PARA_INFO_LOG("help given: %d\n", conf->help_given); + /* exits on errors */ + alsa_cmdline_parser_string(options, conf, "alsa_write"); return conf; -err_out: - free(conf); - return NULL; +} + +static void alsa_free_config(void *conf) +{ + alsa_cmdline_parser_free(conf); } /** - * the init function of the alsa writer + * The init function of the alsa writer. * - * \param w pointer to the writer to initialize + * \param w Pointer to the writer to initialize. * - * \sa struct writer + * \sa struct \ref writer. */ void alsa_write_init(struct writer *w) { struct alsa_write_args_info dummy; alsa_cmdline_parser_init(&dummy); - w->open = alsa_open; w->close = alsa_close; w->pre_select = alsa_write_pre_select; w->post_select = alsa_write_post_select; - w->parse_config = alsa_parse_config; + w->parse_config_or_die = alsa_parse_config_or_die; w->shutdown = NULL; /* nothing to do */ + w->free_config = alsa_free_config; w->help = (struct ggo_help) { .short_help = alsa_write_args_info_help, .detailed_help = alsa_write_args_info_detailed_help