gstreamer/ext/alsa/gstalsa.c
Takashi Iwai 76d807893c alsa: Add channel map API support
The initial support for the new ALSA chmap API.
Just translate the current chmap to GstAudioChannelPosition during the
setup.  No function to specify the channel map manually yet, so still
impossible to assign any non-standard positions or to configure in a
different order even if the hardware allows.

https://bugzilla.gnome.org/show_bug.cgi?id=709755
2013-10-09 19:05:53 +02:00

761 lines
22 KiB
C

/* Copyright (C) 2006 Tim-Philipp Müller <tim centricular net>
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include "gstalsa.h"
#include <gst/audio/audio.h>
static GstCaps *
gst_alsa_detect_rates (GstObject * obj, snd_pcm_hw_params_t * hw_params,
GstCaps * in_caps)
{
GstCaps *caps;
guint min, max;
gint err, dir, min_rate, max_rate, i;
GST_LOG_OBJECT (obj, "probing sample rates ...");
if ((err = snd_pcm_hw_params_get_rate_min (hw_params, &min, &dir)) < 0)
goto min_rate_err;
if ((err = snd_pcm_hw_params_get_rate_max (hw_params, &max, &dir)) < 0)
goto max_rate_err;
min_rate = min;
max_rate = max;
if (min_rate < 4000)
min_rate = 4000; /* random 'sensible minimum' */
if (max_rate <= 0)
max_rate = G_MAXINT; /* or maybe just use 192400 or so? */
else if (max_rate > 0 && max_rate < 4000)
max_rate = MAX (4000, min_rate);
GST_DEBUG_OBJECT (obj, "Min. rate = %u (%d)", min_rate, min);
GST_DEBUG_OBJECT (obj, "Max. rate = %u (%d)", max_rate, max);
caps = gst_caps_make_writable (in_caps);
for (i = 0; i < gst_caps_get_size (caps); ++i) {
GstStructure *s;
s = gst_caps_get_structure (caps, i);
if (min_rate == max_rate) {
gst_structure_set (s, "rate", G_TYPE_INT, min_rate, NULL);
} else {
gst_structure_set (s, "rate", GST_TYPE_INT_RANGE,
min_rate, max_rate, NULL);
}
}
return caps;
/* ERRORS */
min_rate_err:
{
GST_ERROR_OBJECT (obj, "failed to query minimum sample rate: %s",
snd_strerror (err));
gst_caps_unref (in_caps);
return NULL;
}
max_rate_err:
{
GST_ERROR_OBJECT (obj, "failed to query maximum sample rate: %s",
snd_strerror (err));
gst_caps_unref (in_caps);
return NULL;
}
}
static snd_pcm_format_t
gst_alsa_get_pcm_format (GstAudioFormat fmt)
{
switch (fmt) {
case GST_AUDIO_FORMAT_S8:
return SND_PCM_FORMAT_S8;
case GST_AUDIO_FORMAT_U8:
return SND_PCM_FORMAT_U8;
/* 16 bit */
case GST_AUDIO_FORMAT_S16LE:
return SND_PCM_FORMAT_S16_LE;
case GST_AUDIO_FORMAT_S16BE:
return SND_PCM_FORMAT_S16_BE;
case GST_AUDIO_FORMAT_U16LE:
return SND_PCM_FORMAT_U16_LE;
case GST_AUDIO_FORMAT_U16BE:
return SND_PCM_FORMAT_U16_BE;
/* 24 bit in low 3 bytes of 32 bits */
case GST_AUDIO_FORMAT_S24_32LE:
return SND_PCM_FORMAT_S24_LE;
case GST_AUDIO_FORMAT_S24_32BE:
return SND_PCM_FORMAT_S24_BE;
case GST_AUDIO_FORMAT_U24_32LE:
return SND_PCM_FORMAT_U24_LE;
case GST_AUDIO_FORMAT_U24_32BE:
return SND_PCM_FORMAT_U24_BE;
/* 24 bit in 3 bytes */
case GST_AUDIO_FORMAT_S24LE:
return SND_PCM_FORMAT_S24_3LE;
case GST_AUDIO_FORMAT_S24BE:
return SND_PCM_FORMAT_S24_3BE;
case GST_AUDIO_FORMAT_U24LE:
return SND_PCM_FORMAT_U24_3LE;
case GST_AUDIO_FORMAT_U24BE:
return SND_PCM_FORMAT_U24_3BE;
/* 32 bit */
case GST_AUDIO_FORMAT_S32LE:
return SND_PCM_FORMAT_S32_LE;
case GST_AUDIO_FORMAT_S32BE:
return SND_PCM_FORMAT_S32_BE;
case GST_AUDIO_FORMAT_U32LE:
return SND_PCM_FORMAT_U32_LE;
case GST_AUDIO_FORMAT_U32BE:
return SND_PCM_FORMAT_U32_BE;
default:
break;
}
return SND_PCM_FORMAT_UNKNOWN;
}
static gboolean
format_supported (const GValue * format_val, snd_pcm_format_mask_t * mask,
int endianness)
{
const GstAudioFormatInfo *finfo;
snd_pcm_format_t pcm_format;
GstAudioFormat format;
if (!G_VALUE_HOLDS_STRING (format_val))
return FALSE;
format = gst_audio_format_from_string (g_value_get_string (format_val));
if (format == GST_AUDIO_FORMAT_UNKNOWN)
return FALSE;
finfo = gst_audio_format_get_info (format);
if (GST_AUDIO_FORMAT_INFO_ENDIANNESS (finfo) != endianness)
return FALSE;
pcm_format = gst_alsa_get_pcm_format (format);
if (pcm_format == SND_PCM_FORMAT_UNKNOWN)
return FALSE;
return snd_pcm_format_mask_test (mask, pcm_format);
}
static GstCaps *
gst_alsa_detect_formats (GstObject * obj, snd_pcm_hw_params_t * hw_params,
GstCaps * in_caps, int endianness)
{
snd_pcm_format_mask_t *mask;
GstStructure *s;
GstCaps *caps;
gint i;
snd_pcm_format_mask_malloc (&mask);
snd_pcm_hw_params_get_format_mask (hw_params, mask);
caps = NULL;
for (i = 0; i < gst_caps_get_size (in_caps); ++i) {
const GValue *format;
GValue list = G_VALUE_INIT;
s = gst_caps_get_structure (in_caps, i);
if (!gst_structure_has_name (s, "audio/x-raw")) {
GST_DEBUG_OBJECT (obj, "skipping non-raw format");
continue;
}
format = gst_structure_get_value (s, "format");
if (format == NULL)
continue;
g_value_init (&list, GST_TYPE_LIST);
if (GST_VALUE_HOLDS_LIST (format)) {
gint i, len;
len = gst_value_list_get_size (format);
for (i = 0; i < len; i++) {
const GValue *val;
val = gst_value_list_get_value (format, i);
if (format_supported (val, mask, endianness))
gst_value_list_append_value (&list, val);
}
} else if (G_VALUE_HOLDS_STRING (format)) {
if (format_supported (format, mask, endianness))
gst_value_list_append_value (&list, format);
}
if (gst_value_list_get_size (&list) > 1) {
if (caps == NULL)
caps = gst_caps_new_empty ();
s = gst_structure_copy (s);
gst_structure_take_value (s, "format", &list);
gst_caps_append_structure (caps, s);
} else if (gst_value_list_get_size (&list) == 1) {
if (caps == NULL)
caps = gst_caps_new_empty ();
format = gst_value_list_get_value (&list, 0);
s = gst_structure_copy (s);
gst_structure_set_value (s, "format", format);
gst_caps_append_structure (caps, s);
g_value_unset (&list);
} else {
g_value_unset (&list);
}
}
snd_pcm_format_mask_free (mask);
gst_caps_unref (in_caps);
return caps;
}
/* we don't have channel mappings for more than this many channels */
#define GST_ALSA_MAX_CHANNELS 8
static GstStructure *
get_channel_free_structure (const GstStructure * in_structure)
{
GstStructure *s = gst_structure_copy (in_structure);
gst_structure_remove_field (s, "channels");
return s;
}
#define ONE_64 G_GUINT64_CONSTANT (1)
#define CHANNEL_MASK_STEREO ((ONE_64<<GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT) | (ONE_64<<GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT))
#define CHANNEL_MASK_2_1 (CHANNEL_MASK_STEREO | (ONE_64<<GST_AUDIO_CHANNEL_POSITION_LFE1))
#define CHANNEL_MASK_4_0 (CHANNEL_MASK_STEREO | (ONE_64<<GST_AUDIO_CHANNEL_POSITION_REAR_LEFT) | (ONE_64<<GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT))
#define CHANNEL_MASK_5_1 (CHANNEL_MASK_4_0 | (ONE_64<<GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER) | (ONE_64<<GST_AUDIO_CHANNEL_POSITION_LFE1))
#define CHANNEL_MASK_7_1 (CHANNEL_MASK_5_1 | (ONE_64<<GST_AUDIO_CHANNEL_POSITION_SIDE_LEFT) | (ONE_64<<GST_AUDIO_CHANNEL_POSITION_SIDE_RIGHT))
static GstCaps *
caps_add_channel_configuration (GstCaps * caps,
const GstStructure * in_structure, gint min_chans, gint max_chans)
{
GstStructure *s = NULL;
gint c;
if (min_chans == max_chans && max_chans == 1) {
s = get_channel_free_structure (in_structure);
gst_structure_set (s, "channels", G_TYPE_INT, 1, NULL);
caps = gst_caps_merge_structure (caps, s);
return caps;
}
g_assert (min_chans >= 1);
/* mono and stereo don't need channel configurations */
if (min_chans == 2) {
s = get_channel_free_structure (in_structure);
gst_structure_set (s, "channels", G_TYPE_INT, 2, "channel-mask",
GST_TYPE_BITMASK, CHANNEL_MASK_STEREO, NULL);
caps = gst_caps_merge_structure (caps, s);
} else if (min_chans == 1 && max_chans >= 2) {
s = get_channel_free_structure (in_structure);
gst_structure_set (s, "channels", G_TYPE_INT, 2, "channel-mask",
GST_TYPE_BITMASK, CHANNEL_MASK_STEREO, NULL);
caps = gst_caps_merge_structure (caps, s);
s = get_channel_free_structure (in_structure);
gst_structure_set (s, "channels", G_TYPE_INT, 1, NULL);
caps = gst_caps_merge_structure (caps, s);
}
/* don't know whether to use 2.1 or 3.0 here - but I suspect
* alsa might work around that/fix it somehow. Can we tell alsa
* what our channel layout is like? */
if (max_chans >= 3 && min_chans <= 3) {
s = get_channel_free_structure (in_structure);
gst_structure_set (s, "channels", G_TYPE_INT, 3, "channel-mask",
GST_TYPE_BITMASK, CHANNEL_MASK_2_1, NULL);
caps = gst_caps_merge_structure (caps, s);
}
/* everything else (4, 6, 8 channels) needs a channel layout */
for (c = MAX (4, min_chans); c <= 8; c += 2) {
if (max_chans >= c) {
guint64 channel_mask;
s = get_channel_free_structure (in_structure);
switch (c) {
case 4:
channel_mask = CHANNEL_MASK_4_0;
break;
case 6:
channel_mask = CHANNEL_MASK_5_1;
break;
case 8:
channel_mask = CHANNEL_MASK_7_1;
break;
default:
channel_mask = 0;
g_assert_not_reached ();
break;
}
gst_structure_set (s, "channels", G_TYPE_INT, c, "channel-mask",
GST_TYPE_BITMASK, channel_mask, NULL);
caps = gst_caps_merge_structure (caps, s);
}
}
/* NONE layouts for everything else */
for (c = MAX (9, min_chans); c <= max_chans; ++c) {
s = get_channel_free_structure (in_structure);
gst_structure_set (s, "channels", G_TYPE_INT, c, "channel-mask",
GST_TYPE_BITMASK, G_GUINT64_CONSTANT (0), NULL);
caps = gst_caps_merge_structure (caps, s);
}
return caps;
}
static GstCaps *
gst_alsa_detect_channels (GstObject * obj, snd_pcm_hw_params_t * hw_params,
GstCaps * in_caps)
{
GstCaps *caps;
guint min, max;
gint min_chans, max_chans;
gint err, i;
GST_LOG_OBJECT (obj, "probing channels ...");
if ((err = snd_pcm_hw_params_get_channels_min (hw_params, &min)) < 0)
goto min_chan_error;
if ((err = snd_pcm_hw_params_get_channels_max (hw_params, &max)) < 0)
goto max_chan_error;
/* note: the above functions may return (guint) -1 */
min_chans = min;
max_chans = max;
if (min_chans < 0) {
min_chans = 1;
max_chans = GST_ALSA_MAX_CHANNELS;
} else if (max_chans < 0) {
max_chans = GST_ALSA_MAX_CHANNELS;
}
if (min_chans > max_chans) {
gint temp;
GST_WARNING_OBJECT (obj, "minimum channels > maximum channels (%d > %d), "
"please fix your soundcard drivers", min, max);
temp = min_chans;
min_chans = max_chans;
max_chans = temp;
}
/* pro cards seem to return large numbers for min_channels */
if (min_chans > GST_ALSA_MAX_CHANNELS) {
GST_DEBUG_OBJECT (obj, "min_chans = %u, looks like a pro card", min_chans);
if (max_chans < min_chans) {
max_chans = min_chans;
} else {
/* only support [max_chans; max_chans] for these cards for now
* to avoid inflating the source caps with loads of structures ... */
min_chans = max_chans;
}
} else {
min_chans = MAX (min_chans, 1);
max_chans = MIN (GST_ALSA_MAX_CHANNELS, max_chans);
}
GST_DEBUG_OBJECT (obj, "Min. channels = %d (%d)", min_chans, min);
GST_DEBUG_OBJECT (obj, "Max. channels = %d (%d)", max_chans, max);
caps = gst_caps_new_empty ();
for (i = 0; i < gst_caps_get_size (in_caps); ++i) {
GstStructure *s;
GType field_type;
gint c_min = min_chans;
gint c_max = max_chans;
s = gst_caps_get_structure (in_caps, i);
/* the template caps might limit the number of channels (like alsasrc),
* in which case we don't want to return a superset, so hack around this
* for the two common cases where the channels are either a fixed number
* or a min/max range). Example: alsasrc template has channels = [1,2] and
* the detection will claim to support 8 channels for device 'plughw:0' */
field_type = gst_structure_get_field_type (s, "channels");
if (field_type == G_TYPE_INT) {
gst_structure_get_int (s, "channels", &c_min);
gst_structure_get_int (s, "channels", &c_max);
} else if (field_type == GST_TYPE_INT_RANGE) {
const GValue *val;
val = gst_structure_get_value (s, "channels");
c_min = CLAMP (gst_value_get_int_range_min (val), min_chans, max_chans);
c_max = CLAMP (gst_value_get_int_range_max (val), min_chans, max_chans);
} else {
c_min = min_chans;
c_max = max_chans;
}
caps = caps_add_channel_configuration (caps, s, c_min, c_max);
}
gst_caps_unref (in_caps);
return caps;
/* ERRORS */
min_chan_error:
{
GST_ERROR_OBJECT (obj, "failed to query minimum channel count: %s",
snd_strerror (err));
return NULL;
}
max_chan_error:
{
GST_ERROR_OBJECT (obj, "failed to query maximum channel count: %s",
snd_strerror (err));
return NULL;
}
}
snd_pcm_t *
gst_alsa_open_iec958_pcm (GstObject * obj, gchar * device)
{
char *iec958_pcm_name = NULL;
snd_pcm_t *pcm = NULL;
int res;
char devstr[256]; /* Storage for local 'default' device string */
/*
* Try and open our default iec958 device. Fall back to searching on card x
* if this fails, which should only happen on older alsa setups
*/
/* The string will be one of these:
* SPDIF_CON: Non-audio flag not set:
* spdif:{AES0 0x0 AES1 0x82 AES2 0x0 AES3 0x2}
* SPDIF_CON: Non-audio flag set:
* spdif:{AES0 0x2 AES1 0x82 AES2 0x0 AES3 0x2}
*/
sprintf (devstr,
"%s:{AES0 0x%02x AES1 0x%02x AES2 0x%02x AES3 0x%02x}",
device,
IEC958_AES0_CON_EMPHASIS_NONE | IEC958_AES0_NONAUDIO,
IEC958_AES1_CON_ORIGINAL | IEC958_AES1_CON_PCM_CODER,
0, IEC958_AES3_CON_FS_48000);
GST_DEBUG_OBJECT (obj, "Generated device string \"%s\"", devstr);
iec958_pcm_name = devstr;
res = snd_pcm_open (&pcm, iec958_pcm_name, SND_PCM_STREAM_PLAYBACK, 0);
if (G_UNLIKELY (res < 0)) {
GST_DEBUG_OBJECT (obj, "failed opening IEC958 device: %s",
snd_strerror (res));
pcm = NULL;
}
return pcm;
}
/*
* gst_alsa_probe_supported_formats:
*
* Takes the template caps and returns the subset which is actually
* supported by this device.
*
*/
GstCaps *
gst_alsa_probe_supported_formats (GstObject * obj, gchar * device,
snd_pcm_t * handle, const GstCaps * template_caps)
{
snd_pcm_hw_params_t *hw_params;
snd_pcm_stream_t stream_type;
GstCaps *caps;
gint err;
snd_pcm_hw_params_malloc (&hw_params);
if ((err = snd_pcm_hw_params_any (handle, hw_params)) < 0)
goto error;
stream_type = snd_pcm_stream (handle);
caps = gst_alsa_detect_formats (obj, hw_params,
gst_caps_copy (template_caps), G_BYTE_ORDER);
/* if there are no formats in native endianness, try non-native as well */
if (caps == NULL) {
GST_INFO_OBJECT (obj, "no formats in native endianness detected");
caps = gst_alsa_detect_formats (obj, hw_params,
gst_caps_copy (template_caps),
(G_BYTE_ORDER == G_LITTLE_ENDIAN) ? G_BIG_ENDIAN : G_LITTLE_ENDIAN);
if (caps == NULL)
goto subroutine_error;
}
if (!(caps = gst_alsa_detect_rates (obj, hw_params, caps)))
goto subroutine_error;
if (!(caps = gst_alsa_detect_channels (obj, hw_params, caps)))
goto subroutine_error;
/* Try opening IEC958 device to see if we can support that format (playback
* only for now but we could add SPDIF capture later) */
if (stream_type == SND_PCM_STREAM_PLAYBACK) {
snd_pcm_t *pcm = gst_alsa_open_iec958_pcm (obj, device);
if (G_LIKELY (pcm)) {
gst_caps_append (caps, gst_caps_from_string (PASSTHROUGH_CAPS));
snd_pcm_close (pcm);
}
}
snd_pcm_hw_params_free (hw_params);
return caps;
/* ERRORS */
error:
{
GST_ERROR_OBJECT (obj, "failed to query formats: %s", snd_strerror (err));
snd_pcm_hw_params_free (hw_params);
return NULL;
}
subroutine_error:
{
GST_ERROR_OBJECT (obj, "failed to query formats");
snd_pcm_hw_params_free (hw_params);
gst_caps_replace (&caps, NULL);
return NULL;
}
}
/* returns the card name when the device number is unknown or -1 */
static gchar *
gst_alsa_find_device_name_no_handle (GstObject * obj, const gchar * devcard,
gint device_num, snd_pcm_stream_t stream)
{
snd_ctl_card_info_t *info = NULL;
snd_ctl_t *ctl = NULL;
gchar *ret = NULL;
gint dev = -1;
GST_LOG_OBJECT (obj, "[%s] device=%d", devcard, device_num);
if (snd_ctl_open (&ctl, devcard, 0) < 0)
return NULL;
snd_ctl_card_info_malloc (&info);
if (snd_ctl_card_info (ctl, info) < 0)
goto done;
if (device_num != -1) {
while (snd_ctl_pcm_next_device (ctl, &dev) == 0 && dev >= 0) {
if (dev == device_num) {
snd_pcm_info_t *pcminfo;
snd_pcm_info_malloc (&pcminfo);
snd_pcm_info_set_device (pcminfo, dev);
snd_pcm_info_set_subdevice (pcminfo, 0);
snd_pcm_info_set_stream (pcminfo, stream);
if (snd_ctl_pcm_info (ctl, pcminfo) < 0) {
snd_pcm_info_free (pcminfo);
break;
}
ret = (gchar *) snd_pcm_info_get_name (pcminfo);
if (ret) {
ret = g_strdup (ret);
GST_LOG_OBJECT (obj, "name from pcminfo: %s", ret);
}
snd_pcm_info_free (pcminfo);
if (ret)
break;
}
}
}
if (ret == NULL) {
char *name = NULL;
gint card;
GST_LOG_OBJECT (obj, "trying card name");
card = snd_ctl_card_info_get_card (info);
snd_card_get_name (card, &name);
ret = g_strdup (name);
free (name);
}
done:
snd_ctl_card_info_free (info);
snd_ctl_close (ctl);
return ret;
}
gchar *
gst_alsa_find_card_name (GstObject * obj, const gchar * devcard,
snd_pcm_stream_t stream)
{
return gst_alsa_find_device_name_no_handle (obj, devcard, -1, stream);
}
gchar *
gst_alsa_find_device_name (GstObject * obj, const gchar * device,
snd_pcm_t * handle, snd_pcm_stream_t stream)
{
gchar *ret = NULL;
if (device != NULL) {
gchar *dev, *comma;
gint devnum;
GST_LOG_OBJECT (obj, "Trying to get device name from string '%s'", device);
/* only want name:card bit, but not devices and subdevices */
dev = g_strdup (device);
if ((comma = strchr (dev, ','))) {
*comma = '\0';
devnum = atoi (comma + 1);
ret = gst_alsa_find_device_name_no_handle (obj, dev, devnum, stream);
}
g_free (dev);
}
if (ret == NULL && handle != NULL) {
snd_pcm_info_t *info;
GST_LOG_OBJECT (obj, "Trying to get device name from open handle");
snd_pcm_info_malloc (&info);
snd_pcm_info (handle, info);
ret = g_strdup (snd_pcm_info_get_name (info));
snd_pcm_info_free (info);
}
GST_LOG_OBJECT (obj, "Device name for device '%s': %s",
GST_STR_NULL (device), GST_STR_NULL (ret));
return ret;
}
/* ALSA channel positions */
const GstAudioChannelPosition alsa_position[][8] = {
{
GST_AUDIO_CHANNEL_POSITION_MONO},
{
GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT},
{
GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
GST_AUDIO_CHANNEL_POSITION_LFE1},
{
GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT},
{
GST_AUDIO_CHANNEL_POSITION_INVALID,
GST_AUDIO_CHANNEL_POSITION_INVALID,
GST_AUDIO_CHANNEL_POSITION_INVALID,
GST_AUDIO_CHANNEL_POSITION_INVALID,
GST_AUDIO_CHANNEL_POSITION_INVALID,
GST_AUDIO_CHANNEL_POSITION_INVALID,
GST_AUDIO_CHANNEL_POSITION_INVALID,
GST_AUDIO_CHANNEL_POSITION_INVALID},
{
GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER,
GST_AUDIO_CHANNEL_POSITION_LFE1},
{
GST_AUDIO_CHANNEL_POSITION_INVALID,
GST_AUDIO_CHANNEL_POSITION_INVALID,
GST_AUDIO_CHANNEL_POSITION_INVALID,
GST_AUDIO_CHANNEL_POSITION_INVALID,
GST_AUDIO_CHANNEL_POSITION_INVALID,
GST_AUDIO_CHANNEL_POSITION_INVALID,
GST_AUDIO_CHANNEL_POSITION_INVALID,
GST_AUDIO_CHANNEL_POSITION_INVALID},
{
GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER,
GST_AUDIO_CHANNEL_POSITION_LFE1,
GST_AUDIO_CHANNEL_POSITION_SIDE_LEFT,
GST_AUDIO_CHANNEL_POSITION_SIDE_RIGHT}
};
#ifdef SND_CHMAP_API_VERSION
/* +1 is to make zero as holes */
#define ITEM(x, y) \
[SND_CHMAP_ ## x] = GST_AUDIO_CHANNEL_POSITION_ ## y + 1
static GstAudioChannelPosition gst_pos[SND_CHMAP_LAST + 1] = {
ITEM(MONO, MONO),
ITEM(FL, FRONT_LEFT),
ITEM(FR, FRONT_RIGHT),
ITEM(FC, FRONT_CENTER),
ITEM(RL, REAR_LEFT),
ITEM(RR, REAR_RIGHT),
ITEM(RC, REAR_CENTER),
ITEM(LFE, LFE1),
ITEM(SL, SIDE_LEFT),
ITEM(SR, SIDE_RIGHT),
ITEM(FLC, FRONT_LEFT_OF_CENTER),
ITEM(FRC, FRONT_RIGHT_OF_CENTER),
ITEM(FLW, WIDE_LEFT),
ITEM(FRW, WIDE_RIGHT),
ITEM(TC, TOP_CENTER),
ITEM(TFL, TOP_FRONT_LEFT),
ITEM(TFR, TOP_FRONT_RIGHT),
ITEM(TFC, TOP_FRONT_CENTER),
ITEM(TRL, TOP_REAR_LEFT),
ITEM(TRR, TOP_REAR_RIGHT),
ITEM(TRC, TOP_REAR_CENTER),
ITEM(LLFE, LFE1),
ITEM(RLFE, LFE2),
ITEM(BC, BOTTOM_FRONT_CENTER),
ITEM(BLC, BOTTOM_FRONT_LEFT),
ITEM(BRC, BOTTOM_FRONT_LEFT),
};
#undef ITEM
gboolean alsa_chmap_to_channel_positions (const snd_pcm_chmap_t *chmap,
GstAudioChannelPosition *pos)
{
int c;
for (c = 0; c < chmap->channels; c++) {
if (chmap->pos[c] > SND_CHMAP_LAST)
return FALSE;
pos[c] = gst_pos[chmap->pos[c]];
if (!pos[c])
return FALSE;
pos[c]--;
}
return TRUE;
}
#endif /* SND_CHMAP_API_VERSION */