gstreamer/ext/hal/hal.c

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/* GStreamer
* Copyright (C) <2002> Thomas Vander Stichele <thomas@apestaart.org>
* Copyright (C) <2006> Jürg Billeter <j@bitron.ch>
* Copyright (C) <2007> Sebastian Dröge <slomo@circular-chaos.org>
*
* 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.
*/
/*
* this library handles interaction with Hal
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include <glib.h>
#include "hal.h"
GST_DEBUG_CATEGORY_EXTERN (hal_debug);
#define GST_CAT_DEFAULT hal_debug
/* compat for older libhal */
#ifndef LIBHAL_FREE_DBUS_ERROR
#define LIBHAL_FREE_DBUS_ERROR(e) dbus_error_free (e)
#endif
/**
* gst_hal_get_alsa_element:
* @ctx: a #LibHalContext which should be used for querying HAL.
* @udi: a #gchar corresponding to the UDI you want to get.
* @device_type: a #GstHalDeviceType specifying the wanted device type.
*
* Get Hal UDI @udi's string value.
*
* Returns: a newly allocated #gchar string containing the appropriate pipeline
* for UDI @udi, or NULL in the case of an error..
*/
static gchar *
gst_hal_get_alsa_element (LibHalContext * ctx, const gchar * udi,
GstHalDeviceType device_type)
{
char *type, *element = NULL, *string = NULL;
DBusError error;
dbus_error_init (&error);
if (!libhal_device_query_capability (ctx, udi, "alsa", &error)) {
if (dbus_error_is_set (&error)) {
GST_DEBUG ("Failed querying %s for alsa capability: %s: %s",
udi, error.name, error.message);
LIBHAL_FREE_DBUS_ERROR (&error);
} else {
GST_DEBUG ("UDI %s has no alsa capability", udi);
}
return NULL;
}
type = libhal_device_get_property_string (ctx, udi, "alsa.type", &error);
if (dbus_error_is_set (&error)) {
GST_DEBUG ("UDI %s has alsa capabilities but no alsa.type property: %s, %s",
udi, error.name, error.message);
LIBHAL_FREE_DBUS_ERROR (&error);
return NULL;
} else if (!type) {
GST_DEBUG ("UDI %s has empty alsa.type property", udi);
return NULL;
}
if (strcmp (type, "playback") == 0 && device_type == GST_HAL_AUDIOSINK)
element = "alsasink";
else if (strcmp (type, "capture") == 0 && device_type == GST_HAL_AUDIOSRC)
element = "alsasrc";
libhal_free_string (type);
if (element) {
int card, device;
card = libhal_device_get_property_int (ctx, udi, "alsa.card", &error);
if (dbus_error_is_set (&error)) {
GST_DEBUG ("UDI %s has no alsa.card property: %s: %s", udi, error.name,
error.message);
LIBHAL_FREE_DBUS_ERROR (&error);
return NULL;
} else if (card == -1) {
GST_DEBUG ("UDI %s has no alsa.card property", udi);
return NULL;
}
device = libhal_device_get_property_int (ctx, udi, "alsa.device", &error);
if (dbus_error_is_set (&error)) {
GST_DEBUG ("UDI %s has no alsa.device property: %s: %s", udi, error.name,
error.message);
LIBHAL_FREE_DBUS_ERROR (&error);
return NULL;
} else if (device == -1) {
GST_DEBUG ("UDI %s has no alsa.device property", udi);
return NULL;
}
if (device == 0) {
/* handle default device specially to use
* dmix, dsnoop, and softvol if appropriate */
string = g_strdup_printf ("%s device=default:%d", element, card);
} else {
string =
g_strdup_printf ("%s device=plughw:%d,%d", element, card, device);
}
}
return string;
}
/**
* gst_hal_get_oss_element:
* @ctx: a #LibHalContext which should be used for querying HAL.
* @udi: a #gchar corresponding to the UDI you want to get.
* @device_type: a #GstHalDeviceType specifying the wanted device type.
*
* Get Hal UDI @udi's string value.
*
* Returns: a newly allocated #gchar string containing the appropriate pipeline
* for UDI @udi, or NULL in the case of an error..
*/
static gchar *
gst_hal_get_oss_element (LibHalContext * ctx, const gchar * udi,
GstHalDeviceType device_type)
{
char *type, *element = NULL, *string = NULL;
DBusError error;
dbus_error_init (&error);
if (!libhal_device_query_capability (ctx, udi, "oss", &error)) {
if (dbus_error_is_set (&error)) {
GST_DEBUG ("Failed querying %s for oss capability: %s: %s", udi,
error.name, error.message);
LIBHAL_FREE_DBUS_ERROR (&error);
} else {
GST_DEBUG ("UDI %s has no oss capability", udi);
}
return NULL;
}
type = libhal_device_get_property_string (ctx, udi, "oss.type", &error);
if (dbus_error_is_set (&error)) {
GST_DEBUG ("UDI %s has oss capabilities but no oss.type property: %s, %s",
udi, error.name, error.message);
LIBHAL_FREE_DBUS_ERROR (&error);
return NULL;
} else if (!type) {
GST_DEBUG ("UDI %s has empty oss.type property", udi);
return NULL;
}
if (strcmp (type, "pcm") == 0) {
if (device_type == GST_HAL_AUDIOSINK)
element = "osssink";
else if (device_type == GST_HAL_AUDIOSRC)
element = "osssrc";
}
libhal_free_string (type);
if (element) {
char *device = NULL;
device =
libhal_device_get_property_string (ctx, udi, "oss.device_file", &error);
if (dbus_error_is_set (&error)) {
GST_DEBUG
("UDI %s has oss capabilities but no oss.device_file property: %s, %s",
udi, error.name, error.message);
LIBHAL_FREE_DBUS_ERROR (&error);
return NULL;
} else if (!device) {
GST_DEBUG ("UDI %s has empty oss.device_file property", udi);
return NULL;
}
string = g_strdup_printf ("%s device=%s", element, device);
libhal_free_string (device);
}
return string;
}
/**
* gst_hal_get_string:
* @udi: a #gchar corresponding to the UDI you want to get.
* @device_type: a #GstHalDeviceType specifying the wanted device type.
*
* Get Hal UDI @udi's string value.
*
* Returns: a newly allocated #gchar string containing the appropriate pipeline
* for UDI @udi, or NULL in the case of an error..
*/
static gchar *
gst_hal_get_string (const gchar * udi, GstHalDeviceType device_type)
{
DBusError error;
LibHalContext *ctx;
char *string = NULL;
/* Don't query HAL for NULL UDIs. Passing NULL as UDI to HAL gives
* an assertion failure in D-Bus when running with
* DBUS_FATAL_WARNINGS=1. */
if (!udi)
return NULL;
dbus_error_init (&error);
ctx = libhal_ctx_new ();
/* Should only happen on OOM */
g_return_val_if_fail (ctx != NULL, NULL);
if (!libhal_ctx_set_dbus_connection (ctx, dbus_bus_get (DBUS_BUS_SYSTEM,
&error))) {
GST_DEBUG ("Unable to set DBus connection: %s: %s", error.name,
error.message);
LIBHAL_FREE_DBUS_ERROR (&error);
goto ctx_free;
}
if (!libhal_ctx_init (ctx, &error)) {
GST_DEBUG ("Unable to set init HAL context: %s: %s", error.name,
error.message);
LIBHAL_FREE_DBUS_ERROR (&error);
goto ctx_free;
}
/* Now first check if UDI is an alsa device, then oss and then
* check the childs of the given device. If there are alsa and oss
* children the first alsa one is used. */
string = gst_hal_get_alsa_element (ctx, udi, device_type);
if (!string)
string = gst_hal_get_oss_element (ctx, udi, device_type);
if (!string) {
int num_childs;
char **childs = NULL;
/* now try if one of the direct subdevices supports ALSA or OSS */
childs =
libhal_manager_find_device_string_match (ctx, "info.parent", udi,
&num_childs, &error);
if (dbus_error_is_set (&error)) {
GST_DEBUG ("Unable to retrieve childs of %s: %s: %s", udi, error.name,
error.message);
LIBHAL_FREE_DBUS_ERROR (&error);
goto ctx_shutdown;
}
if (childs && num_childs > 0) {
int i;
char *alsa_string = NULL, *oss_string = NULL;
for (i = 0; i < num_childs && !alsa_string; i++) {
alsa_string = gst_hal_get_alsa_element (ctx, childs[i], device_type);
if (!oss_string)
oss_string = gst_hal_get_oss_element (ctx, childs[i], device_type);
}
if (alsa_string) {
string = alsa_string;
g_free (oss_string);
} else if (oss_string) {
string = oss_string;
}
}
libhal_free_string_array (childs);
}
ctx_shutdown:
if (!libhal_ctx_shutdown (ctx, &error)) {
GST_DEBUG ("Closing connection to HAL failed: %s: %s", error.name,
error.message);
LIBHAL_FREE_DBUS_ERROR (&error);
}
ctx_free:
libhal_ctx_free (ctx);
if (string == NULL) {
GST_WARNING ("Problem finding a HAL audio device for udi %s", udi);
}
return string;
}
/* external functions */
/**
* gst_hal_render_bin_from_udi:
* @udi: a #gchar string corresponding to a Hal UDI.
*
* Render bin from Hal UDI @udi.
*
* Returns: a #GstElement containing the rendered bin.
*/
GstElement *
gst_hal_render_bin_from_udi (const gchar * udi, GstHalDeviceType type)
{
GstElement *bin = NULL;
gchar *value;
value = gst_hal_get_string (udi, type);
if (value)
bin = gst_parse_bin_from_description (value, TRUE, NULL);
g_free (value);
return bin;
}
/**
* gst_hal_get_audio_sink:
* @udi: a #gchar string corresponding to a Hal UDI.
*
* Render audio output bin from GStreamer Hal UDI.
* If no device with the specified UDI exists or @udi is NULL,
* the default audio sink for the platform is used
* (typically alsasink, osssink or sunaudiosink).
*
* Returns: a #GstElement containing the audio output bin, or NULL if
* everything failed.
*/
GstElement *
gst_hal_get_audio_sink (const gchar * udi)
{
GstElement *ret = NULL;
if (udi)
ret = gst_hal_render_bin_from_udi (udi, GST_HAL_AUDIOSINK);
if (!ret) {
ret = gst_element_factory_make (DEFAULT_AUDIOSINK, NULL);
if (!ret)
GST_ERROR ("Hal audio sink and %s don't work", DEFAULT_AUDIOSINK);
}
return ret;
}
/**
* gst_hal_get_audio_src:
* @udi: a #gchar string corresponding to a Hal UDI.
*
* Render audio acquisition bin from GStreamer Hal UDI.
* If no device with the specified UDI exists or @udi is NULL,
* the default audio source for the plaform is used
* (typically alsasrc, osssrc or sunaudiosrc).
*
* Returns: a #GstElement containing the audio source bin, or NULL if
* everything failed.
*/
GstElement *
gst_hal_get_audio_src (const gchar * udi)
{
GstElement *ret = NULL;
if (udi)
ret = gst_hal_render_bin_from_udi (udi, GST_HAL_AUDIOSRC);
if (!ret) {
ret = gst_element_factory_make (DEFAULT_AUDIOSRC, NULL);
if (!ret)
GST_ERROR ("Hal audio src and %s don't work", DEFAULT_AUDIOSRC);
}
return ret;
}