gstreamer/ext/alsa/gstalsasrc.c

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/*
* Copyright (C) 2001 CodeFactory AB
* Copyright (C) 2001 Thomas Nyberg <thomas@codefactory.se>
* Copyright (C) 2001-2002 Andy Wingo <apwingo@eos.ncsu.edu>
* Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstalsasrc.h"
#include "gstalsaclock.h"
/* elementfactory information */
static GstElementDetails gst_alsa_src_details = GST_ELEMENT_DETAILS ("Alsa Src",
"Source/Audio",
"Read from a sound card via ALSA",
"Thomas Nyberg <thomas@codefactory.se>, "
"Andy Wingo <apwingo@eos.ncsu.edu>, "
"Benjamin Otte <in7y118@public.uni-hamburg.de>");
static GstPadTemplate *gst_alsa_src_pad_factory (void);
static void gst_alsa_src_base_init (gpointer g_class);
static void gst_alsa_src_class_init (gpointer g_class, gpointer class_data);
static void gst_alsa_src_init (GstAlsaSrc * this);
static int gst_alsa_src_mmap (GstAlsa * this, snd_pcm_sframes_t * avail);
static int gst_alsa_src_read (GstAlsa * this, snd_pcm_sframes_t * avail);
static void gst_alsa_src_loop (GstElement * element);
static void gst_alsa_src_flush (GstAlsaSrc * src);
static GstElementStateReturn gst_alsa_src_change_state (GstElement * element);
static GstClockTime gst_alsa_src_get_time (GstAlsa * this);
static GstAlsa *src_parent_class = NULL;
static GstPadTemplate *
gst_alsa_src_pad_factory (void)
{
static GstPadTemplate *template = NULL;
if (!template)
template = gst_pad_template_new ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
gst_alsa_caps (SND_PCM_FORMAT_UNKNOWN, -1, -1));
return template;
}
GType
gst_alsa_src_get_type (void)
{
static GType alsa_src_type = 0;
if (!alsa_src_type) {
static const GTypeInfo alsa_src_info = {
sizeof (GstAlsaSrcClass),
gst_alsa_src_base_init,
NULL,
gst_alsa_src_class_init,
NULL,
NULL,
sizeof (GstAlsaSrc),
0,
(GInstanceInitFunc) gst_alsa_src_init,
};
alsa_src_type =
g_type_register_static (GST_TYPE_ALSA_MIXER, "GstAlsaSrc",
&alsa_src_info, 0);
}
return alsa_src_type;
}
static void
gst_alsa_src_base_init (gpointer g_class)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
gst_element_class_add_pad_template (element_class,
gst_alsa_src_pad_factory ());
gst_element_class_set_details (element_class, &gst_alsa_src_details);
}
static void
gst_alsa_src_class_init (gpointer g_class, gpointer class_data)
{
GObjectClass *object_class;
GstElementClass *element_class;
GstAlsaClass *alsa_class;
GstAlsaSrcClass *klass;
klass = (GstAlsaSrcClass *) g_class;
object_class = (GObjectClass *) klass;
element_class = (GstElementClass *) klass;
alsa_class = (GstAlsaClass *) klass;
if (src_parent_class == NULL)
src_parent_class = g_type_class_ref (GST_TYPE_ALSA_MIXER);
alsa_class->stream = SND_PCM_STREAM_CAPTURE;
alsa_class->transmit_mmap = gst_alsa_src_mmap;
alsa_class->transmit_rw = gst_alsa_src_read;
element_class->change_state = gst_alsa_src_change_state;
}
static void
gst_alsa_src_init (GstAlsaSrc * src)
{
GstAlsa *this = GST_ALSA (src);
this->pad[0] = gst_pad_new_from_template (gst_alsa_src_pad_factory (), "src");
gst_pad_set_link_function (this->pad[0], gst_alsa_link);
gst_pad_set_getcaps_function (this->pad[0], gst_alsa_get_caps);
gst_element_add_pad (GST_ELEMENT (this), this->pad[0]);
this->clock =
gst_alsa_clock_new ("alsasrcclock", gst_alsa_src_get_time, this);
/* we hold a ref to our clock until we're disposed */
gst_object_ref (GST_OBJECT (this->clock));
gst_object_sink (GST_OBJECT (this->clock));
gst_element_set_loop_function (GST_ELEMENT (this), gst_alsa_src_loop);
}
static int
gst_alsa_src_mmap (GstAlsa * this, snd_pcm_sframes_t * avail)
{
snd_pcm_uframes_t offset;
snd_pcm_channel_area_t *dst;
const snd_pcm_channel_area_t *src;
int i, err, width = snd_pcm_format_physical_width (this->format->format);
GstAlsaSrc *alsa_src = GST_ALSA_SRC (this);
/* areas points to the memory areas that belong to gstreamer. */
dst = g_malloc0 (this->format->channels * sizeof (snd_pcm_channel_area_t));
if (((GstElement *) this)->numpads == 1) {
/* interleaved */
for (i = 0; i < this->format->channels; i++) {
dst[i].addr = alsa_src->buf[0]->data;
dst[i].first = i * width;
dst[i].step = this->format->channels * width;
}
} else {
/* noninterleaved */
for (i = 0; i < this->format->channels; i++) {
dst[i].addr = alsa_src->buf[i]->data;
dst[i].first = 0;
dst[i].step = width;
}
}
if ((err = snd_pcm_mmap_begin (this->handle, &src, &offset, avail)) < 0) {
GST_ERROR_OBJECT (this, "mmap failed: %s", snd_strerror (err));
return -1;
}
if (*avail > 0
&& (err =
snd_pcm_areas_copy (dst, 0, src, offset, this->format->channels,
*avail, this->format->format)) < 0) {
snd_pcm_mmap_commit (this->handle, offset, 0);
GST_ERROR_OBJECT (this, "data copy failed: %s", snd_strerror (err));
return -1;
}
if ((err = snd_pcm_mmap_commit (this->handle, offset, *avail)) < 0) {
GST_ERROR_OBJECT (this, "mmap commit failed: %s", snd_strerror (err));
return -1;
}
return err;
}
static int
gst_alsa_src_read (GstAlsa * this, snd_pcm_sframes_t * avail)
{
void *channels[this->format->channels];
int err, i;
GstAlsaSrc *src = GST_ALSA_SRC (this);
if (((GstElement *) this)->numpads == 1) {
/* interleaved */
err = snd_pcm_readi (this->handle, src->buf[0]->data, *avail);
} else {
/* noninterleaved */
for (i = 0; i < this->format->channels; i++) {
channels[i] = src->buf[i]->data;
}
err = snd_pcm_readn (this->handle, channels, *avail);
}
/* error handling */
if (err < 0) {
if (err == -EPIPE) {
gst_alsa_xrun_recovery (this);
return 0;
}
GST_ERROR_OBJECT (this, "error on data access: %s", snd_strerror (err));
}
return err;
}
static inline gint
gst_alsa_src_adjust_rate (gint rate, gboolean aggressive)
{
static gint rates[] = { 96000, 48000, 44100, 22050, 8000 };
gint i;
if (aggressive)
return rate;
for (i = 0; i < G_N_ELEMENTS (rates); i++) {
if (rate >= rates[i])
return rates[i];
}
return 0;
}
static gboolean
gst_alsa_src_set_caps (GstAlsaSrc * src, gboolean aggressive)
{
GstCaps *all_caps, *caps;
GstStructure *structure, *walk;
gint channels, min_channels, max_channels;
gint rate, min_rate, max_rate;
gint i, endian, width, depth;
gboolean sign;
GstAlsa *this = GST_ALSA (src);
all_caps = gst_alsa_get_caps (this->pad[0]);
if (all_caps == NULL)
return FALSE;
/* now intersect this with all caps of the peers... */
for (i = 0; i < GST_ELEMENT (src)->numpads; i++) {
all_caps =
gst_caps_intersect (all_caps, gst_pad_get_allowed_caps (this->pad[i]));
if (all_caps == NULL) {
GST_DEBUG ("No compatible caps found in alsasrc (%s)",
GST_ELEMENT_NAME (this));
return FALSE;
}
}
/* construct caps */
caps = gst_caps_new_simple ("audio/x-raw-int", NULL);
g_assert (gst_caps_get_size (caps) == 1);
structure = gst_caps_get_structure (caps, 0);
/* now try to find the best match */
for (i = 0; i < gst_caps_get_size (all_caps); i++) {
walk = gst_caps_get_structure (all_caps, i);
if (!(gst_structure_get_int (walk, "signed", &sign) &&
gst_structure_get_int (walk, "width", &width) &&
gst_structure_get_int (walk, "depth", &depth))) {
GST_ERROR_OBJECT (src, "couldn't parse my own format. Huh?");
continue;
}
if (!gst_structure_get_int (walk, "endianness", &endian)) {
endian = G_BYTE_ORDER;
}
gst_structure_set (structure,
"endianness", G_TYPE_INT, endian,
"width", G_TYPE_INT, width,
"depth", G_TYPE_INT, depth, "signed", G_TYPE_BOOLEAN, sign, NULL);
min_rate =
gst_value_get_int_range_min (gst_structure_get_value (walk, "rate"));
max_rate =
gst_value_get_int_range_max (gst_structure_get_value (walk, "rate"));
min_channels =
gst_value_get_int_range_min (gst_structure_get_value (walk,
"channels"));
max_channels =
gst_value_get_int_range_max (gst_structure_get_value (walk,
"channels"));
for (rate = max_rate;; rate--) {
if ((rate = gst_alsa_src_adjust_rate (rate, aggressive)) < min_rate)
break;
gst_structure_set (structure, "rate", G_TYPE_INT, rate, NULL);
for (channels = aggressive ? max_channels : MIN (max_channels, 2);
channels >= min_channels; channels--) {
gst_structure_set (structure, "channels", G_TYPE_INT, channels, NULL);
GST_DEBUG
("trying new caps: %ssigned, endianness: %d, width %d, depth %d, channels %d, rate %d",
sign ? "" : "un", endian, width, depth, channels, rate);
if (gst_pad_try_set_caps (this->pad[0], caps) != GST_PAD_LINK_REFUSED)
gst_alsa_link (this->pad[0], caps);
if (this->format) {
/* try to set caps here */
return TRUE;
}
}
}
}
if (!aggressive)
return gst_alsa_src_set_caps (src, TRUE);
return FALSE;
}
/* we transmit buffers of period_size frames */
static void
gst_alsa_src_loop (GstElement * element)
{
snd_pcm_sframes_t avail, copied;
gint i;
GstAlsa *this = GST_ALSA (element);
GstAlsaSrc *src = GST_ALSA_SRC (element);
/* set the caps on all pads */
if (!this->format) {
if (!gst_alsa_src_set_caps (src, FALSE)) {
GST_ELEMENT_ERROR (element, CORE, NEGOTIATION, (NULL),
("ALSA format not negotiated"));
return;
}
}
/* the cast to long is explicitly needed;
* with avail = -32 and period_size = 100, avail < period_size is false */
while ((avail = gst_alsa_update_avail (this)) < (long) this->period_size) {
if (avail == -EPIPE) {
GST_DEBUG_OBJECT (this, "got EPIPE when checking for available bytes");
continue;
}
if (avail < 0) {
GST_DEBUG_OBJECT (this,
"got error %s (%d) when checking for available bytes",
snd_strerror (avail));
return;
}
if (snd_pcm_state (this->handle) != SND_PCM_STATE_RUNNING) {
if (!gst_alsa_start (this))
return;
continue;
};
/* wait */
if (gst_alsa_pcm_wait (this) == FALSE)
return;
}
g_assert (avail >= this->period_size);
/* make sure every pad has a buffer */
for (i = 0; i < element->numpads; i++) {
if (src->buf[i])
gst_data_unref (GST_DATA (src->buf[i]));
src->buf[i] =
gst_buffer_new_and_alloc (gst_alsa_samples_to_bytes (this, avail));
}
/* fill buffer with data */
if ((copied = this->transmit (this, &avail)) <= 0)
return;
/* push the buffers out and let them have fun */
for (i = 0; i < element->numpads; i++) {
GstBuffer *buf;
if (!src->buf[i])
return;
if (copied != this->period_size)
GST_BUFFER_SIZE (src->buf[i]) = gst_alsa_samples_to_bytes (this, copied);
GST_BUFFER_TIMESTAMP (src->buf[i]) =
gst_alsa_samples_to_timestamp (this, this->transmitted);
GST_BUFFER_DURATION (src->buf[i]) =
gst_alsa_samples_to_timestamp (this, copied);
buf = src->buf[i];
src->buf[i] = NULL;
gst_pad_push (this->pad[i], GST_DATA (buf));
}
this->transmitted += copied;
}
static void
gst_alsa_src_flush (GstAlsaSrc * src)
{
gint i;
for (i = 0; i < GST_ELEMENT (src)->numpads; i++) {
if (src->buf[i]) {
gst_buffer_unref (src->buf[i]);
src->buf[i] = NULL;
}
}
}
static GstElementStateReturn
gst_alsa_src_change_state (GstElement * element)
{
GstAlsaSrc *src;
g_return_val_if_fail (element != NULL, FALSE);
src = GST_ALSA_SRC (element);
switch (GST_STATE_TRANSITION (element)) {
case GST_STATE_NULL_TO_READY:
case GST_STATE_READY_TO_PAUSED:
case GST_STATE_PAUSED_TO_PLAYING:
case GST_STATE_PLAYING_TO_PAUSED:
break;
case GST_STATE_PAUSED_TO_READY:
gst_alsa_src_flush (src);
break;
case GST_STATE_READY_TO_NULL:
break;
default:
g_assert_not_reached ();
}
if (GST_ELEMENT_CLASS (src_parent_class)->change_state)
return GST_ELEMENT_CLASS (src_parent_class)->change_state (element);
return GST_STATE_SUCCESS;
}
static GstClockTime
gst_alsa_src_get_time (GstAlsa * this)
{
snd_pcm_sframes_t delay;
if (snd_pcm_delay (this->handle, &delay) == 0 && this->format) {
return GST_SECOND * (this->transmitted + delay) / this->format->rate;
} else {
return 0;
}
}