X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=alsa_write.c;h=363e39301651bc47881f850f0235c13f6a016c62;hp=ba844db2b2b419363b01d1d1d21e28411ae92b37;hb=85ec8f30f6bef37a9a3bc2b84314654648f2f81c;hpb=3879481ddabc38236b9eee979a090c2a9bfa74d3 diff --git a/alsa_write.c b/alsa_write.c index ba844db2..363e3930 100644 --- a/alsa_write.c +++ b/alsa_write.c @@ -1,8 +1,4 @@ -/* - * Copyright (C) 2005-2013 Andre Noll - * - * Licensed under the GPL v2. For licencing details see COPYING. - */ +/* Copyright (C) 2005 Andre Noll , see file COPYING. */ /** \file alsa_write.c paraslash's alsa output plugin */ @@ -15,18 +11,16 @@ #include #include #include -#include +#include +#include "write_cmd.lsg.h" #include "para.h" #include "fd.h" #include "string.h" #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" /** Data specific to the alsa writer. */ @@ -35,17 +29,24 @@ struct private_alsa_write_data { snd_pcm_t *handle; /** Determined and set by alsa_init(). */ int bytes_per_frame; - /** - * The sample rate given by command line option or the decoder - * of the writer node group. + /* + * If the sample rate is not given at the command line and no wav + * header was detected, the btr exec mechanism is employed to query the + * ancestor buffer tree nodes for this information. In a typical setup + * the decoder passes the sample rate back to the alsa writer. + * + * \sa \ref btr_exec_up(). */ 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. + /* + * The sample format (8/16 bit, signed/unsigned, little/big endian) is + * determined in the same way as the \a sample_rate. */ + snd_pcm_format_t sample_format; + /* The number of channels, again determined like \a sample_rate. */ unsigned channels; + /* time until buffer underrun occurs, in milliseconds */ + unsigned buffer_time; struct timeval drain_barrier; /* File descriptor for select(). */ int poll_fd; @@ -65,25 +66,26 @@ static snd_pcm_format_t get_alsa_pcm_format(enum sample_format sf) } /* Install PCM software and hardware configuration. */ -static int alsa_init(struct private_alsa_write_data *pad, - struct alsa_write_args_info *conf) +static int alsa_init(struct writer_node *wn) { - snd_pcm_hw_params_t *hwparams; - snd_pcm_sw_params_t *swparams; + struct private_alsa_write_data *pad = wn->private_data; + snd_pcm_hw_params_t *hwparams = NULL; + snd_pcm_sw_params_t *swparams = NULL; snd_pcm_uframes_t start_threshold, stop_threshold; snd_pcm_uframes_t buffer_size, period_size; snd_output_t *output_log; - unsigned buffer_time; int ret; - const char *msg; + const char *msg, *dev = WRITE_CMD_OPT_STRING_VAL(ALSA, DEVICE, wn->lpr); + unsigned period_time; - PARA_INFO_LOG("opening %s\n", conf->device_arg); + PARA_INFO_LOG("opening %s\n", dev); msg = "unable to open pcm"; - ret = snd_pcm_open(&pad->handle, conf->device_arg, - SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK); + ret = snd_pcm_open(&pad->handle, dev, SND_PCM_STREAM_PLAYBACK, + SND_PCM_NONBLOCK); if (ret < 0) goto fail; - snd_pcm_hw_params_alloca(&hwparams); + ret = snd_pcm_hw_params_malloc(&hwparams); + assert(ret >= 0); msg = "Broken alsa configuration"; ret = snd_pcm_hw_params_any(pad->handle, hwparams); if (ret < 0) @@ -108,18 +110,22 @@ static int alsa_init(struct private_alsa_write_data *pad, &pad->sample_rate, NULL); if (ret < 0) goto fail; - msg = "unable to get buffer time"; - ret = snd_pcm_hw_params_get_buffer_time_max(hwparams, &buffer_time, - NULL); - if (ret < 0 || buffer_time == 0) - goto fail; - /* buffer at most 500 milliseconds */ - buffer_time = PARA_MIN(buffer_time, 500U * 1000U); + /* alsa wants microseconds */ + pad->buffer_time = 1000U * WRITE_CMD_OPT_UINT32_VAL(ALSA, BUFFER_TIME, + wn->lpr); msg = "could not set buffer time"; ret = snd_pcm_hw_params_set_buffer_time_near(pad->handle, hwparams, - &buffer_time, NULL); + &pad->buffer_time, NULL); + if (ret < 0) + goto fail; + pad->buffer_time /= 1000; /* we prefer milliseconds */ + period_time = pad->buffer_time * 250; /* buffer time / 4 */ + msg = "could not set period time"; + ret = snd_pcm_hw_params_set_period_time_near(pad->handle, hwparams, + &period_time, NULL); if (ret < 0) goto fail; + msg = "unable to install hw params"; ret = snd_pcm_hw_params(pad->handle, hwparams); if (ret < 0) @@ -131,7 +137,8 @@ static int alsa_init(struct private_alsa_write_data *pad, goto fail; /* software parameter setup */ - snd_pcm_sw_params_alloca(&swparams); + ret = snd_pcm_sw_params_malloc(&swparams); + assert(ret >= 0); snd_pcm_sw_params_current(pad->handle, swparams); snd_pcm_sw_params_set_avail_min(pad->handle, swparams, period_size); if (buffer_size < 1) @@ -165,33 +172,40 @@ static int alsa_init(struct private_alsa_write_data *pad, goto fail; ret = snd_output_buffer_open(&output_log); if (ret == 0) { - char *buf; - PARA_INFO_LOG("dumping alsa configuration\n"); + char *buf, *p; + size_t sz; + PARA_DEBUG_LOG("dumping alsa configuration\n"); snd_pcm_dump(pad->handle, output_log); - snd_output_buffer_string(output_log, &buf); - for (;;) { - char *p = strchr(buf, '\n'); - if (!p) /* omit last output line, it's empty */ + snd_pcm_hw_params_dump(hwparams, output_log); + sz = snd_output_buffer_string(output_log, &buf); + for (p = buf; p < buf + sz;) { + char *q = memchr(p, '\n', buf + sz - p); + if (!q) break; - *p = '\0'; - PARA_INFO_LOG("%s\n", buf); - buf = p + 1; + *q = '\0'; + PARA_DEBUG_LOG("%s\n", p); + p = q + 1; } snd_output_close(output_log); } - return 1; + ret = 1; + goto out; fail: if (ret < 0) PARA_ERROR_LOG("%s: %s\n", msg, snd_strerror(-ret)); else PARA_ERROR_LOG("%s\n", msg); - return -E_ALSA; + ret = -E_ALSA; +out: + snd_pcm_hw_params_free(hwparams); + snd_pcm_sw_params_free(swparams); + return ret; } -static void alsa_write_pre_select(struct sched *s, struct task *t) +static void alsa_write_pre_select(struct sched *s, void *context) { struct pollfd pfd; - struct writer_node *wn = container_of(t, struct writer_node, task); + struct writer_node *wn = context; struct private_alsa_write_data *pad = wn->private_data; int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF); @@ -207,11 +221,12 @@ static void alsa_write_pre_select(struct sched *s, struct task *t) sched_request_barrier_or_min_delay(&pad->drain_barrier, s); return; } + /* wait at most 50% of the buffer time */ + sched_request_timeout_ms(pad->buffer_time / 2, s); ret = snd_pcm_poll_descriptors(pad->handle, &pfd, 1); if (ret < 0) { PARA_ERROR_LOG("could not get alsa poll fd: %s\n", snd_strerror(-ret)); - t->error = -E_ALSA; return; } pad->poll_fd = pfd.fd; @@ -236,10 +251,9 @@ static void alsa_close(struct writer_node *wn) free(pad); } -static void alsa_write_post_select(__a_unused struct sched *s, - struct task *t) +static int alsa_write_post_select(__a_unused struct sched *s, void *context) { - struct writer_node *wn = container_of(t, struct writer_node, task); + struct writer_node *wn = context; struct private_alsa_write_data *pad = wn->private_data; struct btr_node *btrn = wn->btrn; char *data; @@ -247,13 +261,13 @@ static void alsa_write_post_select(__a_unused struct sched *s, snd_pcm_sframes_t frames; int ret; - ret = task_get_notification(t); + ret = task_get_notification(wn->task); if (ret < 0) goto err; again: ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF); if (ret == 0) - return; + return 0; btr_merge(btrn, wn->min_iqs); bytes = btr_next_buffer(btrn, &data); if (ret < 0 || bytes < wn->min_iqs) { /* eof */ @@ -266,18 +280,18 @@ again: PARA_DEBUG_LOG("waiting for device to drain\n"); tv_add(now, &(struct timeval)EMBRACE(0, 200 * 1000), &pad->drain_barrier); - return; + return 0; } if (tv_diff(now, &pad->drain_barrier, NULL) > 0) goto err; - return; + return 0; } if (!pad) { int32_t val; if (bytes == 0) /* no data available */ - return; - pad = para_calloc(sizeof(*pad)); + return 0; + pad = wn->private_data = para_calloc(sizeof(*pad)); get_btr_sample_rate(btrn, &val); pad->sample_rate = val; get_btr_channels(btrn, &val); @@ -285,33 +299,25 @@ again: get_btr_sample_format(btrn, &val); pad->sample_format = get_alsa_pcm_format(val); - PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, + PARA_INFO_LOG("%u channel(s), %uHz\n", pad->channels, pad->sample_rate); - ret = alsa_init(pad, wn->conf); + ret = alsa_init(wn); if (ret < 0) { - free(pad); + free(wn->private_data); + wn->private_data = NULL; goto err; } - wn->private_data = pad; wn->min_iqs = pad->bytes_per_frame; goto again; } - if (pad->poll_fd < 0 || !FD_ISSET(pad->poll_fd, &s->rfds)) - return; frames = bytes / pad->bytes_per_frame; frames = snd_pcm_writei(pad->handle, data, frames); if (frames == 0 || frames == -EAGAIN) { - /* - * The alsa poll fd was ready for IO but we failed to write to - * the alsa handle. This means another event is pending. We - * don't care about that but we have to dispatch the event in - * order to avoid a busy loop. So we simply read from the poll - * fd. - */ char buf[100]; - if (read(pad->poll_fd, buf, 100)) - do_nothing; - return; + if (pad->poll_fd >= 0 && FD_ISSET(pad->poll_fd, &s->rfds)) + if (read(pad->poll_fd, buf, 100)) + do_nothing; + return 0; } if (frames > 0) { btr_consume(btrn, frames * pad->bytes_per_frame); @@ -320,50 +326,19 @@ again: if (frames == -EPIPE) { PARA_WARNING_LOG("underrun (tried to write %zu bytes)\n", bytes); snd_pcm_prepare(pad->handle); - return; + return 0; } PARA_ERROR_LOG("alsa write error: %s\n", snd_strerror(-frames)); ret = -E_ALSA; err: assert(ret < 0); btr_remove_node(&wn->btrn); - t->error = ret; + return ret; } -__malloc static void *alsa_parse_config_or_die(int argc, char **argv) -{ - struct alsa_write_args_info *conf = para_calloc(sizeof(*conf)); - - /* exits on errors */ - alsa_write_cmdline_parser(argc, argv, conf); - return conf; -} +struct writer lsg_write_cmd_com_alsa_user_data = { -static void alsa_free_config(void *conf) -{ - alsa_write_cmdline_parser_free(conf); -} - -/** - * The init function of the alsa writer. - * - * \param w Pointer to the writer to initialize. - * - * \sa struct \ref writer. - */ -void alsa_write_init(struct writer *w) -{ - struct alsa_write_args_info dummy; - - alsa_write_cmdline_parser_init(&dummy); - w->close = alsa_close; - w->pre_select = alsa_write_pre_select; - w->post_select = alsa_write_post_select; - w->parse_config_or_die = alsa_parse_config_or_die; - 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 - }; - alsa_write_cmdline_parser_free(&dummy); -} + .pre_select = alsa_write_pre_select, + .post_select = alsa_write_post_select, + .close = alsa_close, +};