1 files changed, 124 insertions, 0 deletions
diff --git a/src/polypcore/alsa-util.c b/src/polypcore/alsa-util.c
new file mode 100644
index 00000000..7528ee0b
--- /dev/null
+++ b/src/polypcore/alsa-util.c
@@ -0,0 +1,124 @@
+/* $Id$ */
+
+/***
+  This file is part of polypaudio.
+ 
+  polypaudio is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as published
+  by the Free Software Foundation; either version 2 of the License,
+  or (at your option) any later version.
+ 
+  polypaudio is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+ 
+  You should have received a copy of the GNU Lesser General Public License
+  along with polypaudio; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <sys/types.h>
+#include <asoundlib.h>
+
+#include "alsa-util.h"
+#include <polyp/sample.h>
+#include "xmalloc.h"
+#include "log.h"
+
+/* Set the hardware parameters of the given ALSA device. Returns the
+ * selected fragment settings in *period and *period_size */
+int pa_alsa_set_hw_params(snd_pcm_t *pcm_handle, const pa_sample_spec *ss, uint32_t *periods, snd_pcm_uframes_t *period_size) {
+    int ret = -1;
+    snd_pcm_uframes_t buffer_size;
+    snd_pcm_hw_params_t *hwparams = NULL;
+    static const snd_pcm_format_t format_trans[] = {
+        [PA_SAMPLE_U8] = SND_PCM_FORMAT_U8,
+        [PA_SAMPLE_ALAW] = SND_PCM_FORMAT_A_LAW,
+        [PA_SAMPLE_ULAW] = SND_PCM_FORMAT_MU_LAW,
+        [PA_SAMPLE_S16LE] = SND_PCM_FORMAT_S16_LE,
+        [PA_SAMPLE_S16BE] = SND_PCM_FORMAT_S16_BE,
+        [PA_SAMPLE_FLOAT32LE] = SND_PCM_FORMAT_FLOAT_LE,
+        [PA_SAMPLE_FLOAT32BE] = SND_PCM_FORMAT_FLOAT_BE,
+    };
+    assert(pcm_handle && ss && periods && period_size);
+    
+    if (snd_pcm_hw_params_malloc(&hwparams) < 0 ||
+        snd_pcm_hw_params_any(pcm_handle, hwparams) < 0 ||
+        snd_pcm_hw_params_set_access(pcm_handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED) < 0 ||
+        snd_pcm_hw_params_set_format(pcm_handle, hwparams, format_trans[ss->format]) < 0 ||
+        snd_pcm_hw_params_set_rate_near(pcm_handle, hwparams, &ss->rate, NULL) < 0 ||
+        snd_pcm_hw_params_set_channels(pcm_handle, hwparams, ss->channels) < 0 ||
+        (*periods > 0 && snd_pcm_hw_params_set_periods_near(pcm_handle, hwparams, periods, NULL) < 0) || 
+        (*period_size > 0 && snd_pcm_hw_params_set_period_size_near(pcm_handle, hwparams, period_size, NULL) < 0) || 
+        snd_pcm_hw_params(pcm_handle, hwparams) < 0)
+        goto finish;
+    
+    if (snd_pcm_prepare(pcm_handle) < 0)
+        goto finish;
+
+    if (snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size) < 0 ||
+        snd_pcm_hw_params_get_period_size(hwparams, period_size, NULL) < 0)
+        goto finish;
+    
+    assert(buffer_size > 0);
+    assert(*period_size > 0);
+    *periods = buffer_size / *period_size;
+    assert(*periods > 0);
+    
+    ret = 0;
+    
+finish:
+    if (hwparams)
+        snd_pcm_hw_params_free(hwparams);
+    
+    return ret;
+}
+
+/* Allocate an IO event for every ALSA poll descriptor for the
+ * specified ALSA device. Return a pointer to such an array in
+ * *io_events. Store the length of that array in *n_io_events. Use the
+ * specified callback function and userdata. The array has to be freed
+ * with pa_free_io_events(). */
+int pa_create_io_events(snd_pcm_t *pcm_handle, pa_mainloop_api* m, pa_io_event ***io_events, unsigned *n_io_events, void (*cb)(pa_mainloop_api*a, pa_io_event *e, int fd, pa_io_event_flags_t events, void *userdata), void *userdata) {
+    unsigned i;
+    struct pollfd *pfds, *ppfd;
+    pa_io_event **ios;
+    assert(pcm_handle && m && io_events && n_io_events && cb);
+
+    *n_io_events = snd_pcm_poll_descriptors_count(pcm_handle);
+
+    pfds = pa_xmalloc(sizeof(struct pollfd) * *n_io_events);
+    if (snd_pcm_poll_descriptors(pcm_handle, pfds, *n_io_events) < 0) {
+        pa_xfree(pfds);
+        return -1;
+    }
+    
+    *io_events = pa_xmalloc(sizeof(void*) * *n_io_events);
+
+    for (i = 0, ios = *io_events, ppfd = pfds; i < *n_io_events; i++, ios++, ppfd++) {
+        *ios = m->io_new(m, ppfd->fd,
+                            ((ppfd->events & POLLIN) ? PA_IO_EVENT_INPUT : 0) |
+                            ((ppfd->events & POLLOUT) ? PA_IO_EVENT_OUTPUT : 0), cb, userdata);
+        assert(*ios);
+    }
+
+    pa_xfree(pfds);
+    return 0;
+}
+
+/* Free the memory allocated by pa_create_io_events() */
+void pa_free_io_events(pa_mainloop_api* m, pa_io_event **io_events, unsigned n_io_events) {
+    unsigned i;
+    pa_io_event **ios;
+    assert(m && io_events);
+    
+    for (ios = io_events, i = 0; i < n_io_events; i++, ios++)
+        m->io_free(*ios);
+    pa_xfree(io_events);
+}