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authorDimitri Sokolyuk <demon@dim13.org>2013-07-02 15:30:29 +0000
committerDimitri Sokolyuk <demon@dim13.org>2013-07-02 15:30:29 +0000
commit59d91966e83f7bbe6231eec945e2f93d17b2e3e2 (patch)
tree2e8df9ea3fce8caf22bc7b75304a16945bc58d3d /alsa.c
parenta8655ac4cb70abe872361e3f2978d6edf591cfad (diff)
add linux support
Diffstat (limited to 'alsa.c')
-rw-r--r--alsa.c102
1 files changed, 102 insertions, 0 deletions
diff --git a/alsa.c b/alsa.c
new file mode 100644
index 0000000..a1b8a3c
--- /dev/null
+++ b/alsa.c
@@ -0,0 +1,102 @@
+/* $Id$ */
+/*
+ * Copyright (c) 2013 Dimitri Sokolyuk <demon@dim13.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <err.h>
+#include <stdlib.h>
+#include <alsa/asoundlib.h>
+
+#define RCHAN 2
+
+struct sio {
+ int16_t *buffer;
+ size_t bufsz;
+ snd_pcm_t *handle;
+ snd_pcm_hw_params_t *params;
+ snd_pcm_uframes_t frames;
+};
+
+struct sio *
+init_sio(void)
+{
+ struct sio *sio;
+ unsigned int rate = 48000;
+ int rc;
+
+
+ sio = malloc(sizeof(struct sio));
+ if (!sio)
+ errx(1, "malloc failed");
+
+ rc = snd_pcm_open(&sio->handle, "default", SND_PCM_STREAM_CAPTURE, 0);
+ if (rc < 0)
+ errx(1, "unable to open pcm device: %s", snd_strerror(rc));
+
+ snd_pcm_hw_params_malloc(&sio->params);
+ snd_pcm_hw_params_any(sio->handle, sio->params);
+ snd_pcm_hw_params_set_access(sio->handle, sio->params, SND_PCM_ACCESS_RW_INTERLEAVED);
+ snd_pcm_hw_params_set_format(sio->handle, sio->params, SND_PCM_FORMAT_S16_LE);
+ snd_pcm_hw_params_set_rate_near(sio->handle, sio->params, &rate, NULL);
+ snd_pcm_hw_params_set_channels(sio->handle, sio->params, RCHAN);
+
+ rc = snd_pcm_hw_params(sio->handle, sio->params);
+ if (rc < 0)
+ errx(1, "unable to set hw parameters: %s", snd_strerror(rc));
+
+ snd_pcm_hw_params_get_period_size(sio->params, &sio->frames, NULL);
+ snd_pcm_hw_params_free(sio->params);
+ snd_pcm_prepare(sio->handle);
+
+ sio->bufsz = sio->frames * RCHAN * sizeof(int16_t);
+ sio->buffer = malloc(sio->bufsz);
+
+ if (!sio->buffer)
+ errx(1, "malloc failed");
+
+ return sio;
+}
+
+unsigned int
+get_round(struct sio *sio)
+{
+ return sio->frames;
+}
+
+int16_t *
+read_sio(struct sio *sio)
+{
+ int rc;
+
+ rc = snd_pcm_readi(sio->handle, sio->buffer, sio->frames);
+ if (rc == -EPIPE) {
+ warnx("overrun occured");
+ snd_pcm_prepare(sio->handle);
+ } else if (rc < 0)
+ warnx("error from read: %s", snd_strerror(rc));
+ else if (rc != sio->frames)
+ warnx("shor read, read %d frames", rc);
+
+ return sio->buffer;
+}
+
+void
+del_sio(struct sio *sio)
+{
+ snd_pcm_drain(sio->handle);
+ snd_pcm_close(sio->handle);
+ free(sio->buffer);
+ free(sio);
+}