gstreamer/subprojects/gst-plugins-good/sys/oss/gstossdeviceprovider.c
Matthieu Volat d228b8d96f oss: add a GstDeviceProvider plugin
Based on Alsa's GstDeviceProvider structure, relies on sndstat
file for OSS device enumeration but uses already existing utils
to query caps and names.

Reviewed and thanks to @slomo

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4879>
2023-06-27 09:34:33 +03:00

303 lines
8.1 KiB
C

/* GStreamer
* Copyright (C) 2023 Matthieu Volat <matthieu.volat@ensimag.fr>
*
* ossdeviceprovider.c: OSS device probing and monitoring
*
* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstossdeviceprovider.h"
#include "gstosshelper.h"
#include <glib/gstdio.h>
#include <gst/gst.h>
#include <fcntl.h>
#include <unistd.h>
static GstDevice *gst_oss_device_new (const gchar * device_name, GstCaps * caps,
const gchar * device, GstOssDeviceType type);
G_DEFINE_TYPE (GstOssDeviceProvider, gst_oss_device_provider,
GST_TYPE_DEVICE_PROVIDER);
static GstDevice *
add_device (GstDeviceProvider * provider, GstOssDeviceType type, gint devno)
{
gchar devpath[64];
gchar mixpath[64];
gint fd;
GstCaps *caps;
gchar *name;
GstDevice *device;
snprintf (devpath, sizeof (devpath), "/dev/dsp%u", devno);
snprintf (mixpath, sizeof (mixpath), "/dev/mixer%u", devno);
switch (type) {
case GST_OSS_DEVICE_TYPE_SOURCE:
fd = open (devpath, O_RDONLY);
break;
case GST_OSS_DEVICE_TYPE_SINK:
fd = open (devpath, O_WRONLY);
break;
default:
g_assert_not_reached ();
break;
}
if (fd == -1) {
GST_WARNING_OBJECT (provider, "Could open device %s for introspection",
devpath);
return NULL;
}
caps = gst_oss_helper_probe_caps (fd);
close (fd);
name = gst_oss_helper_get_card_name (mixpath);
device = gst_oss_device_new (name, caps, devpath, type);
g_free (name);
return device;
}
static GList *
gst_oss_device_provider_probe (GstDeviceProvider * provider)
{
FILE *sndstat_handle;
gchar *sndstat_line = NULL;
size_t sndstat_line_len = 0;
gint sndstat_device_section = 0;
gint ossdevno;
gboolean play, rec;
GstDevice *device;
GList *list = NULL;
GST_INFO_OBJECT (provider, "Probing OSS devices");
if (((sndstat_handle = fopen ("/dev/sndstat", "r")) == NULL)
&& ((sndstat_handle = fopen ("/proc/sndstat", "r")) == NULL)
&& ((sndstat_handle = fopen ("/proc/asound/sndstat", "r")) == NULL)) {
/* Cannot evaluate OSS devices without this file */
GST_WARNING_OBJECT (provider, "No sndstat file found");
goto beach;
}
while (!feof (sndstat_handle)) {
if (getline (&sndstat_line, &sndstat_line_len, sndstat_handle) == -1) {
break;
}
g_strstrip (sndstat_line);
if (!sndstat_device_section) {
sndstat_device_section = g_str_equal (sndstat_line, "Audio devices:")
|| g_str_equal (sndstat_line, "Installed devices:")
|| g_str_equal (sndstat_line, "Installed devices from userspace:");
continue;
}
if ((sscanf (sndstat_line, "pcm%u:", &ossdevno) == 1)
|| (sscanf (sndstat_line, "%u:", &ossdevno) == 1)) {
/* At least on FreeBSD, these keywords can be different if hw.snd.verbose is not 0 */
if (strstr (sndstat_line, "(play/rec)") != NULL) {
play = rec = TRUE;
} else if (strstr (sndstat_line, "(play)") != NULL) {
play = TRUE, rec = FALSE;
} else if (strstr (sndstat_line, "(rec)") != NULL) {
play = FALSE, rec = TRUE;
} else {
play = rec = FALSE; /* Or should we assume play/rec? */
}
if (play) {
device = add_device (provider, GST_OSS_DEVICE_TYPE_SINK, ossdevno);
if (device != NULL) {
list = g_list_append (list, device);
}
}
if (rec) {
device = add_device (provider, GST_OSS_DEVICE_TYPE_SOURCE, ossdevno);
if (device != NULL) {
list = g_list_append (list, device);
}
}
}
}
free (sndstat_line);
fclose (sndstat_handle);
beach:
return list;
}
static void
gst_oss_device_provider_class_init (GstOssDeviceProviderClass * klass)
{
GstDeviceProviderClass *dm_class = GST_DEVICE_PROVIDER_CLASS (klass);
dm_class->probe = gst_oss_device_provider_probe;
gst_device_provider_class_set_static_metadata (dm_class,
"OSS Device Provider", "Sink/Source/Audio",
"List and provides OSS source and sink devices",
"Matthieu Volat <matthieu.volat@ensimag.fr>");
}
static void
gst_oss_device_provider_init (GstOssDeviceProvider * self)
{
}
/*** GstOssDevice implementation ******/
enum
{
PROP_DEVICE_PATH = 1,
};
G_DEFINE_TYPE (GstOssDevice, gst_oss_device, GST_TYPE_DEVICE);
static GstElement *
gst_oss_device_create_element (GstDevice * device, const gchar * name)
{
GstOssDevice *oss_dev = GST_OSS_DEVICE (device);
GstElement *elem;
elem = gst_element_factory_make (oss_dev->element, name);
g_object_set (elem, "device", oss_dev->device_path, NULL);
return elem;
}
static gboolean
gst_oss_device_reconfigure_element (GstDevice * device, GstElement * element)
{
GstOssDevice *oss_dev = GST_OSS_DEVICE (device);
g_object_set (element, "device", oss_dev->device_path, NULL);
return TRUE;
}
static void
gst_oss_device_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstOssDevice *device;
device = GST_OSS_DEVICE_CAST (object);
switch (prop_id) {
case PROP_DEVICE_PATH:
g_value_set_string (value, device->device_path);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_oss_device_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstOssDevice *device;
device = GST_OSS_DEVICE_CAST (object);
switch (prop_id) {
case PROP_DEVICE_PATH:
device->device_path = g_value_dup_string (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_oss_device_finalize (GObject * object)
{
GstOssDevice *device = GST_OSS_DEVICE (object);
g_free (device->device_path);
G_OBJECT_CLASS (gst_oss_device_parent_class)->finalize (object);
}
static void
gst_oss_device_class_init (GstOssDeviceClass * klass)
{
GstDeviceClass *dev_class = GST_DEVICE_CLASS (klass);
GObjectClass *object_class = G_OBJECT_CLASS (klass);
dev_class->create_element = gst_oss_device_create_element;
dev_class->reconfigure_element = gst_oss_device_reconfigure_element;
object_class->get_property = gst_oss_device_get_property;
object_class->set_property = gst_oss_device_set_property;
object_class->finalize = gst_oss_device_finalize;
g_object_class_install_property (object_class, PROP_DEVICE_PATH,
g_param_spec_string ("device-path", "OSS device path",
"The path of the OSS device", "",
G_PARAM_STATIC_STRINGS | G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
}
static void
gst_oss_device_init (GstOssDevice * device)
{
}
static GstDevice *
gst_oss_device_new (const gchar * device_name,
GstCaps * caps, const gchar * device_path, GstOssDeviceType type)
{
GstOssDevice *gstdev;
const gchar *element = NULL;
const gchar *klass = NULL;
g_return_val_if_fail (device_name, NULL);
g_return_val_if_fail (device_path, NULL);
g_return_val_if_fail (caps, NULL);
switch (type) {
case GST_OSS_DEVICE_TYPE_SOURCE:
element = "osssrc";
klass = "Audio/Source";
break;
case GST_OSS_DEVICE_TYPE_SINK:
element = "osssink";
klass = "Audio/Sink";
break;
default:
g_assert_not_reached ();
break;
}
gstdev = g_object_new (GST_TYPE_OSS_DEVICE,
"display-name", device_name, "caps", caps, "device-class", klass,
"device-path", device_path, NULL);
gstdev->element = element;
gst_caps_unref (caps);
return GST_DEVICE (gstdev);
}