para_server: Don't link with stat.o.
[paraslash.git] / alsa_write.c
index 8e8b693..cf0f335 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -21,6 +21,7 @@
 #include "string.h"
 #include "list.h"
 #include "sched.h"
+#include "ggo.h"
 #include "write.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 */
+/** Data specific to the alsa writer. */
 struct private_alsa_write_data {
-       /** the alsa handle */
+       /** The alsa handle */
        snd_pcm_t *handle;
-       /** determined and set by alsa_open() */
-       size_t bytes_per_frame;
-       /** don't write anything until this time */
+       /** Determined and set by alsa_open(). */
+       int bytes_per_frame;
+       /** Don't write anything until this time. */
        struct timeval next_chunk;
-       /** the return value of snd_pcm_hw_params_get_buffer_time_max() */
+       /** The approximate maximum buffer duration in us. */
        unsigned buffer_time;
        /**
-        * the samplerate given by command line option or the decoder
-        * of the writer node group
-        */
+        * The samplerate given by command line option or the decoder
+        * of the writer node group.
+        */
        unsigned samplerate;
        /**
-        * the number of channels, also given by command line option or the
-        * decoder of the writer node group
+        * The number of channels, given by command line option or the
+        * decoder of the writer node group.
         */
        unsigned channels;
 };
 
-/*
- * open and prepare the PCM handle for writing
- *
- * Install PCM software and hardware configuration. Exit on errors.
- */
-static int alsa_open(struct writer_node *w)
+/* 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;
-       int err;
-       snd_pcm_info_t *info;
        snd_pcm_uframes_t period_size;
-       struct private_alsa_write_data *pad = para_calloc(sizeof(struct
-               private_alsa_write_data));
-       struct alsa_write_args_info *conf = w->conf;
-       struct writer_node_group *wng = w->wng;
+       int err;
 
-       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);
-       w->private_data = pad;
-       snd_pcm_info_alloca(&info);
        err = snd_pcm_open(&pad->handle, conf->device_arg,
                SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
        if (err < 0)
                return -E_PCM_OPEN;
-       if ((err = snd_pcm_info(pad->handle, info)) < 0)
-               return -E_SND_PCM_INFO;
 
        snd_pcm_hw_params_alloca(&hwparams);
        snd_pcm_sw_params_alloca(&swparams);
@@ -121,7 +101,8 @@ static int alsa_open(struct writer_node *w)
        if (buffer_size < 1)
                start_threshold = 1;
        else
-               start_threshold = buffer_size;
+               start_threshold = PARA_MIN(buffer_size,
+                       (snd_pcm_uframes_t)pad->samplerate);
        if (snd_pcm_sw_params_set_start_threshold(pad->handle, swparams,
                        start_threshold) < 0)
                return -E_START_THRESHOLD;
@@ -130,12 +111,36 @@ static int alsa_open(struct writer_node *w)
                        stop_threshold) < 0)
                return -E_STOP_THRESHOLD;
        if (snd_pcm_sw_params(pad->handle, swparams) < 0)
-               return -E_SW_PARAMS;
+               PARA_WARNING_LOG("unable to install sw params\n");
        pad->bytes_per_frame = snd_pcm_format_physical_width(FORMAT)
                * pad->channels / 8;
+       if (pad->bytes_per_frame <= 0)
+               return -E_PHYSICAL_WIDTH;
+       PARA_INFO_LOG("bytes per frame: %d\n", pad->bytes_per_frame);
        if (snd_pcm_nonblock(pad->handle, 1))
-               PARA_ERROR_LOG("%s\n", "failed to set nonblock mode");
-       return period_size * pad->bytes_per_frame;
+               PARA_ERROR_LOG("failed to set nonblock mode\n");
+       return 1;
+}
+
+/* Open an instance of the alsa writer. */
+static int alsa_open(struct writer_node *wn)
+{
+       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));
+
+       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;
 }
 
 static int alsa_write_pre_select(struct sched *s, struct writer_node *wn)
@@ -144,7 +149,7 @@ static int alsa_write_pre_select(struct sched *s, struct writer_node *wn)
        struct writer_node_group *wng = wn->wng;
        struct timeval diff;
 
-       if (*wng->loaded < pad->bytes_per_frame)
+       if (!*wng->loaded)
                return 1;
        if (tv_diff(now, &pad->next_chunk, &diff) < 0) {
                if (tv_diff(&s->timeout, &diff, NULL) > 0)
@@ -154,7 +159,6 @@ static int alsa_write_pre_select(struct sched *s, struct writer_node *wn)
                s->timeout.tv_usec = 1;
        }
        return 1;
-//     PARA_INFO_LOG("timeout: %lu\n", tv2ms(&s->timeout));
 }
 
 static int alsa_write_post_select(__a_unused struct sched *s,
@@ -162,57 +166,72 @@ static int alsa_write_post_select(__a_unused struct sched *s,
 {
        struct private_alsa_write_data *pad = wn->private_data;
        struct writer_node_group *wng = wn->wng;
-       size_t frames = (*wng->loaded - wn->written) / pad->bytes_per_frame;
-       snd_pcm_sframes_t ret;
-       unsigned char *data = (unsigned char*)wng->buf + wn->written;
+       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;
 
-//     PARA_INFO_LOG("%zd frames\n", frames);
-       if (!frames) {
-               if (*wng->input_error)
-                       wn->written = *wng->loaded;
-               return 1;
+       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 1;
-       ret = snd_pcm_writei(pad->handle, data, frames);
-       if (ret == -EPIPE) {
-               PARA_WARNING_LOG("EPIPE\n");
-               snd_pcm_prepare(pad->handle);
-               return 1;
+               return 0;
+       if (!pad->handle) {
+               int err = alsa_init(pad, wn->conf);
+               if (err < 0)
+                       return err;
        }
-       if (ret < 0 && ret != -EAGAIN) {
-               PARA_WARNING_LOG("alsa error (%zu frames, ret = %d\n",
-                       frames, (int)ret);
+       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;
+               }
+               if (ret == -EAGAIN)
+                       goto delay;
                return -E_ALSA_WRITE;
        }
-       if (ret == -EAGAIN) { /* try again in 5ms */
-               PARA_WARNING_LOG("EAGAIN\n");
-               ms2tv(5, &tv);
-       } else {
-               wn->written += ret * pad->bytes_per_frame;
-               ms2tv(pad->buffer_time / 4000, &tv);
-       }
-       tv_add(now, &tv, &pad->next_chunk);
+       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;
 }
 
 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);
-       snd_pcm_drain(pad->handle);
-       snd_pcm_close(pad->handle);
-       snd_config_update_free_global();
+
+       if (pad->handle) {
+               snd_pcm_drain(pad->handle);
+               snd_pcm_close(pad->handle);
+               snd_config_update_free_global();
+       }
        free(pad);
 }
 
 __malloc static void *alsa_parse_config(const char *options)
 {
+       int ret;
        struct alsa_write_args_info *conf
                = para_calloc(sizeof(struct alsa_write_args_info));
+
        PARA_INFO_LOG("options: %s, %zd\n", options, strcspn(options, " \t"));
-       int ret = alsa_cmdline_parser_string(options, conf, "alsa_write");
+       ret = alsa_cmdline_parser_string(options, conf, "alsa_write");
        if (ret)
                goto err_out;
        PARA_INFO_LOG("help given: %d\n", conf->help_given);
@@ -231,10 +250,17 @@ err_out:
  */
 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->shutdown = NULL; /* nothing to do */
+       w->help = (struct ggo_help) {
+               .short_help = alsa_write_args_info_help,
+               .detailed_help = alsa_write_args_info_detailed_help
+       };
 }