--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/gst_plugins_base/gst-libs/gst/audio/multichannel.c Fri Jan 22 09:59:59 2010 +0200
@@ -0,0 +1,756 @@
+/* GStreamer Multichannel-Audio helper functions
+ * (c) 2004 Ronald Bultje <rbultje@ronald.bitfreak.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., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "multichannel.h"
+
+#define GST_AUDIO_CHANNEL_POSITIONS_FIELD_NAME "channel-positions"
+
+/*
+ * This function checks if basic assumptions apply:
+ * - does each position occur at most once?
+ * - do conflicting positions occur?
+ * + front_mono vs. front_left/right
+ * + front_center vs. front_left/right_of_center
+ * + rear_center vs. rear_left/right
+ * It also adds some hacks that 0.8.x needs for compatibility:
+ * - if channels == 1, are we really mono?
+ * - if channels == 2, are we really stereo?
+ */
+
+static gboolean
+gst_audio_check_channel_positions (const GstAudioChannelPosition * pos,
+ gint channels)
+{
+ gint i, n;
+ const struct
+ {
+ const GstAudioChannelPosition pos1[2];
+ const GstAudioChannelPosition pos2[1];
+ } conf[] = {
+ /* front: mono <-> stereo */
+ { {
+ GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
+ GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT}, {
+ GST_AUDIO_CHANNEL_POSITION_FRONT_MONO}},
+ /* front center: 2 <-> 1 */
+ { {
+ GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER,
+ GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER}, {
+ GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER}},
+ /* rear: 2 <-> 1 */
+ { {
+ GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
+ GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT}, {
+ GST_AUDIO_CHANNEL_POSITION_REAR_CENTER}}, { {
+ GST_AUDIO_CHANNEL_POSITION_INVALID}}
+ };
+
+ g_assert (pos != NULL && channels > 0);
+
+ /* check for invalid channel positions */
+ for (n = 0; n < channels; n++) {
+ if (pos[n] <= GST_AUDIO_CHANNEL_POSITION_INVALID ||
+ pos[n] >= GST_AUDIO_CHANNEL_POSITION_NUM) {
+ g_warning ("Channel position %d for channel %d is invalid", pos[n], n);
+ return FALSE;
+ }
+ }
+
+ /* either all channel positions are NONE or all are defined,
+ * but having only some channel positions NONE and others not
+ * is not allowed */
+ if (pos[0] == GST_AUDIO_CHANNEL_POSITION_NONE) {
+ for (n = 1; n < channels; ++n) {
+ if (pos[n] != GST_AUDIO_CHANNEL_POSITION_NONE) {
+ g_warning ("Either all channel positions must be defined, or all "
+ "be set to NONE, having only some defined is not allowed");
+ return FALSE;
+ }
+ }
+ /* all positions are NONE, we are done here */
+ return TRUE;
+ }
+
+ /* check for multiple position occurrences */
+ for (i = GST_AUDIO_CHANNEL_POSITION_INVALID + 1;
+ i < GST_AUDIO_CHANNEL_POSITION_NUM; i++) {
+ gint count = 0;
+
+ for (n = 0; n < channels; n++) {
+ if (pos[n] == i)
+ count++;
+ }
+
+ /* NONE may not occur mixed with other channel positions */
+ if (i == GST_AUDIO_CHANNEL_POSITION_NONE && count > 0) {
+ g_warning ("Either all channel positions must be defined, or all "
+ "be set to NONE, having only some defined is not allowed");
+ return FALSE;
+ }
+
+ if (count > 1) {
+ g_warning ("Channel position %d occurred %d times, not allowed",
+ i, count);
+ return FALSE;
+ }
+ }
+
+ /* check for position conflicts */
+ for (i = 0; conf[i].pos1[0] != GST_AUDIO_CHANNEL_POSITION_INVALID; i++) {
+ gboolean found1 = FALSE, found2 = FALSE;
+
+ for (n = 0; n < channels; n++) {
+ if (pos[n] == conf[i].pos1[0] || pos[n] == conf[i].pos1[1])
+ found1 = TRUE;
+ else if (pos[n] == conf[i].pos2[0])
+ found2 = TRUE;
+ }
+
+ if (found1 && found2) {
+ g_warning ("Found conflicting channel positions %d/%d and %d",
+ conf[i].pos1[0], conf[i].pos1[1], conf[i].pos2[0]);
+ return FALSE;
+ }
+ }
+
+ /* Throw warning if we encounter an unusual 2-channel configuration,
+ * at least until someone finds a reason why we should not */
+ if (channels == 2 && (pos[0] != GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT ||
+ pos[1] != GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT)) {
+ g_warning ("channels=2 implies stereo, but channel positions are "
+ "< %d, %d>", pos[0], pos[1]);
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/* FIXME: these default positions may or may not be correct. In any
+ * case, they are mostly just a fallback for buggy plugins, so it
+ * should not really matter too much */
+#define NUM_DEF_CHANS 8
+static const GstAudioChannelPosition
+ default_positions[NUM_DEF_CHANS][NUM_DEF_CHANS] = {
+ /* 1 channel */
+ {
+ GST_AUDIO_CHANNEL_POSITION_FRONT_MONO,
+ },
+ /* 2 channels */
+ {
+ GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
+ GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
+ },
+ /* 3 channels (2.1) */
+ {
+ GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
+ GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
+ GST_AUDIO_CHANNEL_POSITION_LFE, /* or FRONT_CENTER for 3.0? */
+ },
+ /* 4 channels (4.0 or 3.1?) */
+ {
+ GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
+ GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
+ GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
+ GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
+ },
+ /* 5 channels */
+ {
+ 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,
+ },
+ /* 6 channels */
+ {
+ 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_LFE,
+ },
+ /* 7 channels */
+ {
+ 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_LFE,
+ GST_AUDIO_CHANNEL_POSITION_REAR_CENTER,
+ },
+ /* 8 channels */
+ {
+ 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_LFE,
+ GST_AUDIO_CHANNEL_POSITION_SIDE_LEFT,
+ GST_AUDIO_CHANNEL_POSITION_SIDE_RIGHT,
+ }
+};
+
+/**
+ * gst_audio_get_channel_positions:
+ * @str: A #GstStructure to retrieve channel positions from.
+ *
+ * Retrieves a number of (fixed!) audio channel positions from
+ * the provided #GstStructure and returns it as a newly allocated
+ * array. The caller should g_free () this array. The caller
+ * should also check that the members in this #GstStructure are
+ * indeed "fixed" before calling this function.
+ *
+ * Returns: a newly allocated array containing the channel
+ * positions as provided in the given #GstStructure. Returns
+ * NULL on error.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+
+GstAudioChannelPosition *
+gst_audio_get_channel_positions (GstStructure * str)
+{
+ GstAudioChannelPosition *pos;
+ gint channels, n;
+ const GValue *pos_val_arr, *pos_val_entry;
+ gboolean res;
+ GType t;
+
+ /* get number of channels, general type checkups */
+ g_return_val_if_fail (str != NULL, NULL);
+ res = gst_structure_get_int (str, "channels", &channels);
+ g_return_val_if_fail (res, NULL);
+ g_return_val_if_fail (channels > 0, NULL);
+ pos_val_arr = gst_structure_get_value (str,
+ GST_AUDIO_CHANNEL_POSITIONS_FIELD_NAME);
+
+ /* The following checks are here to retain compatibility for plugins not
+ * implementing this field. They expect that channels=1 implies mono
+ * and channels=2 implies stereo, so we follow that. */
+ if (pos_val_arr == NULL) {
+ /* channel layouts for 1 and 2 channels are implicit, don't warn */
+ if (channels > 2) {
+ g_warning ("Failed to retrieve channel layout from caps. This usually "
+ "means there is a GStreamer element that does not implement "
+ "multichannel audio correctly. Please file a bug.");
+ }
+
+ /* just return some default channel layout if we have one */
+ if (channels >= 1 && channels <= NUM_DEF_CHANS) {
+ const GstAudioChannelPosition *p;
+
+ p = default_positions[channels - 1];
+ return g_memdup (p, channels * sizeof (GstAudioChannelPosition));
+ }
+
+ return NULL;
+ }
+
+ g_return_val_if_fail (gst_value_array_get_size (pos_val_arr) == channels,
+ NULL);
+ for (n = 0; n < channels; n++) {
+ t = G_VALUE_TYPE (gst_value_array_get_value (pos_val_arr, n));
+ g_return_val_if_fail (t == GST_TYPE_AUDIO_CHANNEL_POSITION, NULL);
+ }
+
+ /* ... and fill array */
+ pos = g_new (GstAudioChannelPosition, channels);
+ for (n = 0; n < channels; n++) {
+ pos_val_entry = gst_value_array_get_value (pos_val_arr, n);
+ pos[n] = g_value_get_enum (pos_val_entry);
+ }
+
+ if (!gst_audio_check_channel_positions (pos, channels)) {
+ g_free (pos);
+ return NULL;
+ }
+
+ return pos;
+}
+
+/**
+ * gst_audio_set_channel_positions:
+ * @str: A #GstStructure to set channel positions on.
+ * @pos: an array of channel positions. The number of members
+ * in this array should be equal to the (fixed!) number
+ * of the "channels" field in the given #GstStructure.
+ *
+ * Adds a "channel-positions" field to the given #GstStructure,
+ * which will represent the channel positions as given in the
+ * provided #GstAudioChannelPosition array.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+
+void
+gst_audio_set_channel_positions (GstStructure * str,
+ const GstAudioChannelPosition * pos)
+{
+ GValue pos_val_arr = { 0 }, pos_val_entry = {
+ 0};
+ gint channels, n;
+ gboolean res;
+
+ /* get number of channels, checkups */
+ g_return_if_fail (str != NULL);
+ g_return_if_fail (pos != NULL);
+ res = gst_structure_get_int (str, "channels", &channels);
+ g_return_if_fail (res);
+ g_return_if_fail (channels > 0);
+ if (!gst_audio_check_channel_positions (pos, channels))
+ return;
+
+ /* build gvaluearray from positions */
+ g_value_init (&pos_val_entry, GST_TYPE_AUDIO_CHANNEL_POSITION);
+ g_value_init (&pos_val_arr, GST_TYPE_ARRAY);
+ for (n = 0; n < channels; n++) {
+ g_value_set_enum (&pos_val_entry, pos[n]);
+ gst_value_array_append_value (&pos_val_arr, &pos_val_entry);
+ }
+ g_value_unset (&pos_val_entry);
+
+ /* add to structure */
+ gst_structure_set_value (str,
+ GST_AUDIO_CHANNEL_POSITIONS_FIELD_NAME, &pos_val_arr);
+ g_value_unset (&pos_val_arr);
+}
+
+/**
+ * gst_audio_set_structure_channel_positions_list:
+ * @str: #GstStructure to set the list of channel positions
+ * on.
+ * @pos: the array containing one or more possible audio
+ * channel positions that we should add in each value
+ * of the array in the given structure.
+ * @num_positions: the number of values in pos.
+ *
+ * Sets a (possibly non-fixed) list of possible audio channel
+ * positions (given in pos) on the given structure. The
+ * structure, after this function has been called, will contain
+ * a "channel-positions" field with an array of the size of
+ * the "channels" field value in the given structure (note
+ * that this means that the channels field in the provided
+ * structure should be fixed!). Each value in the array will
+ * contain each of the values given in the pos array.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+
+void
+gst_audio_set_structure_channel_positions_list (GstStructure * str,
+ const GstAudioChannelPosition * pos, gint num_positions)
+{
+ gint channels, n, c;
+ GValue pos_val_arr = { 0 }, pos_val_list = {
+ 0}, pos_val_entry = {
+ 0};
+ gboolean res;
+
+ /* get number of channels, general type checkups */
+ g_return_if_fail (str != NULL);
+ g_return_if_fail (num_positions > 0);
+ g_return_if_fail (pos != NULL);
+ res = gst_structure_get_int (str, "channels", &channels);
+ g_return_if_fail (res);
+ g_return_if_fail (channels > 0);
+
+ /* 0.8.x: channels=1 or channels=2 is mono/stereo, no positions needed
+ * there (we discard them anyway) */
+ if (channels == 1 || channels == 2)
+ return;
+
+ /* create the array of lists */
+ g_value_init (&pos_val_arr, GST_TYPE_ARRAY);
+ g_value_init (&pos_val_entry, GST_TYPE_AUDIO_CHANNEL_POSITION);
+ for (n = 0; n < channels; n++) {
+ g_value_init (&pos_val_list, GST_TYPE_LIST);
+ for (c = 0; c < num_positions; c++) {
+ g_value_set_enum (&pos_val_entry, pos[c]);
+ gst_value_list_append_value (&pos_val_list, &pos_val_entry);
+ }
+ gst_value_array_append_value (&pos_val_arr, &pos_val_list);
+ g_value_unset (&pos_val_list);
+ }
+ g_value_unset (&pos_val_entry);
+ gst_structure_set_value (str, GST_AUDIO_CHANNEL_POSITIONS_FIELD_NAME,
+ &pos_val_arr);
+ g_value_unset (&pos_val_arr);
+}
+
+/*
+ * Helper function for below. The structure will be conserved,
+ * but might be cut down. Any additional structures that were
+ * created will be stored in the returned caps.
+ */
+
+static GstCaps *
+add_list_to_struct (GstStructure * str,
+ const GstAudioChannelPosition * pos, gint num_positions)
+{
+ GstCaps *caps = gst_caps_new_empty ();
+ const GValue *chan_val;
+
+ chan_val = gst_structure_get_value (str, "channels");
+ if (G_VALUE_TYPE (chan_val) == G_TYPE_INT) {
+ gst_audio_set_structure_channel_positions_list (str, pos, num_positions);
+ } else if (G_VALUE_TYPE (chan_val) == GST_TYPE_LIST) {
+ gint size;
+ const GValue *sub_val;
+
+ size = gst_value_list_get_size (chan_val);
+ sub_val = gst_value_list_get_value (chan_val, 0);
+ gst_structure_set_value (str, "channels", sub_val);
+ gst_caps_append (caps, add_list_to_struct (str, pos, num_positions));
+ while (--size > 0) {
+ str = gst_structure_copy (str);
+ sub_val = gst_value_list_get_value (chan_val, size);
+ gst_structure_set_value (str, "channels", sub_val);
+ gst_caps_append (caps, add_list_to_struct (str, pos, num_positions));
+ gst_caps_append_structure (caps, str);
+ }
+ } else if (G_VALUE_TYPE (chan_val) == GST_TYPE_INT_RANGE) {
+ gint min, max;
+
+ min = gst_value_get_int_range_min (chan_val);
+ max = gst_value_get_int_range_max (chan_val);
+
+ gst_structure_set (str, "channels", G_TYPE_INT, min, NULL);
+ gst_audio_set_structure_channel_positions_list (str, pos, num_positions);
+ for (++min; min < max; min++) {
+ str = gst_structure_copy (str);
+ gst_structure_set (str, "channels", G_TYPE_INT, min, NULL);
+ gst_audio_set_structure_channel_positions_list (str, pos, num_positions);
+ gst_caps_append_structure (caps, str);
+ }
+ } else {
+ g_warning ("Unexpected value type '%s' for channels field",
+ GST_STR_NULL (g_type_name (G_VALUE_TYPE (chan_val))));
+ }
+
+ return caps;
+}
+
+/**
+ * gst_audio_set_caps_channel_positions_list:
+ * @caps: #GstCaps to set the list of channel positions on.
+ * @pos: the array containing one or more possible audio
+ * channel positions that we should add in each value
+ * of the array in the given structure.
+ * @num_positions: the number of values in pos.
+ *
+ * Sets a (possibly non-fixed) list of possible audio channel
+ * positions (given in pos) on the given caps. Each of the
+ * structures of the caps, after this function has been called,
+ * will contain a "channel-positions" field with an array.
+ * Each value in the array will contain each of the values given
+ * in the pos array. Note that the size of the caps might be
+ * increased by this, since each structure with a "channel-
+ * positions" field needs to have a fixed "channels" field.
+ * The input caps is not required to have this.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+
+void
+gst_audio_set_caps_channel_positions_list (GstCaps * caps,
+ const GstAudioChannelPosition * pos, gint num_positions)
+{
+ gint size, n;
+
+ /* get number of channels, general type checkups */
+ g_return_if_fail (caps != NULL);
+ g_return_if_fail (num_positions > 0);
+ g_return_if_fail (pos != NULL);
+
+ size = gst_caps_get_size (caps);
+ for (n = 0; n < size; n++) {
+ gst_caps_append (caps, add_list_to_struct (gst_caps_get_structure (caps,
+ n), pos, num_positions));
+ }
+}
+
+/**
+ * gst_audio_fixate_channel_positions:
+ * @str: a #GstStructure containing a (possibly unfixed)
+ * "channel-positions" field.
+ *
+ * Custom fixate function. Elements that implement some sort of
+ * channel conversion algorithm should use this function for
+ * fixating on GstAudioChannelPosition properties. It will take
+ * care of equal channel positioning (left/right). Caller g_free()s
+ * the return value. The input properties may be (and are supposed
+ * to be) unfixed.
+ * Note that this function is mostly a hack because we currently
+ * have no way to add default fixation functions for new GTypes.
+ *
+ * Returns: fixed values that the caller could use as a fixed
+ * set of #GstAudioChannelPosition values.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+
+GstAudioChannelPosition *
+gst_audio_fixate_channel_positions (GstStructure * str)
+{
+ GstAudioChannelPosition *pos;
+ gint channels, n, num_unfixed = 0, i, c;
+ const GValue *pos_val_arr, *pos_val_entry, *pos_val;
+ gboolean res, is_stereo = TRUE;
+ GType t;
+
+ /*
+ * We're going to do this cluelessly. We'll make an array of values that
+ * conflict with each other and, for each iteration in this array, pick
+ * either one until all unknown values are filled. This might not work in
+ * corner cases but should work OK for the general case.
+ */
+ const struct
+ {
+ const GstAudioChannelPosition pos1[2];
+ const GstAudioChannelPosition pos2[1];
+ } conf[] = {
+ /* front: mono <-> stereo */
+ { {
+ GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
+ GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT}, {
+ GST_AUDIO_CHANNEL_POSITION_FRONT_MONO}},
+ /* front center: 2 <-> 1 */
+ { {
+ GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER,
+ GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER}, {
+ GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER}},
+ /* rear: 2 <-> 1 */
+ { {
+ GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
+ GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT}, {
+ GST_AUDIO_CHANNEL_POSITION_REAR_CENTER}}, { {
+ GST_AUDIO_CHANNEL_POSITION_INVALID, GST_AUDIO_CHANNEL_POSITION_INVALID}, {
+ GST_AUDIO_CHANNEL_POSITION_LFE}}, { {
+ GST_AUDIO_CHANNEL_POSITION_SIDE_LEFT,
+ GST_AUDIO_CHANNEL_POSITION_SIDE_RIGHT}, {
+ GST_AUDIO_CHANNEL_POSITION_INVALID}}, { {
+ GST_AUDIO_CHANNEL_POSITION_INVALID, GST_AUDIO_CHANNEL_POSITION_INVALID}, {
+ GST_AUDIO_CHANNEL_POSITION_INVALID}}
+ };
+ struct
+ {
+ gint num_opt[3];
+ guint num_opts[3];
+ gboolean is_fixed[3];
+ gint choice; /* -1 is none, 0 is the two, 1 is the one */
+ } opt;
+
+ /* get number of channels, general type checkups */
+ g_return_val_if_fail (str != NULL, NULL);
+ res = gst_structure_get_int (str, "channels", &channels);
+ g_return_val_if_fail (res, NULL);
+ g_return_val_if_fail (channels > 0, NULL);
+
+ /* 0.8.x mono/stereo checks */
+ pos_val_arr = gst_structure_get_value (str,
+ GST_AUDIO_CHANNEL_POSITIONS_FIELD_NAME);
+ if (!pos_val_arr && (channels == 1 || channels == 2)) {
+ pos = g_new (GstAudioChannelPosition, channels);
+ if (channels == 1) {
+ pos[0] = GST_AUDIO_CHANNEL_POSITION_FRONT_MONO;
+ } else {
+ pos[0] = GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT;
+ pos[1] = GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT;
+ }
+ return pos;
+ }
+ g_return_val_if_fail (pos_val_arr != NULL, NULL);
+ g_return_val_if_fail (gst_value_array_get_size (pos_val_arr) == channels,
+ NULL);
+ for (n = 0; n < channels; n++) {
+ t = G_VALUE_TYPE (gst_value_array_get_value (pos_val_arr, n));
+ g_return_val_if_fail (t == GST_TYPE_LIST ||
+ t == GST_TYPE_AUDIO_CHANNEL_POSITION, NULL);
+ }
+
+ /* all unknown, to start with */
+ pos = g_new (GstAudioChannelPosition, channels);
+ for (n = 0; n < channels; n++)
+ pos[n] = GST_AUDIO_CHANNEL_POSITION_INVALID;
+ num_unfixed = channels;
+
+ /* Iterate the array of conflicting values */
+ for (i = 0; conf[i].pos1[0] != GST_AUDIO_CHANNEL_POSITION_INVALID ||
+ conf[i].pos2[0] != GST_AUDIO_CHANNEL_POSITION_INVALID; i++) {
+ /* front/center only important if not mono (obviously) */
+ if (conf[i].pos1[0] == GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER &&
+ !is_stereo)
+ continue;
+
+ /* init values */
+ for (n = 0; n < 3; n++) {
+ opt.num_opt[n] = -1;
+ opt.num_opts[n] = -1;
+ opt.is_fixed[n] = FALSE;
+ }
+
+ /* Now, we'll see for each channel if it allows for any of the values in
+ * the set of conflicting audio channel positions and keep scores. */
+ for (n = 0; n < channels; n++) {
+ /* if the channel is already taken, don't bother */
+ if (pos[n] != GST_AUDIO_CHANNEL_POSITION_INVALID)
+ continue;
+
+ pos_val_entry = gst_value_array_get_value (pos_val_arr, n);
+ t = G_VALUE_TYPE (pos_val_entry);
+ if (t == GST_TYPE_LIST) {
+ /* This algorhythm is suboptimal. */
+ for (c = 0; c < gst_value_list_get_size (pos_val_entry); c++) {
+ pos_val = gst_value_list_get_value (pos_val_entry, c);
+ if (g_value_get_enum (pos_val) == conf[i].pos1[0] &&
+ opt.num_opts[0] > gst_value_list_get_size (pos_val_entry) &&
+ !opt.is_fixed[0]) {
+ /* Now test if the old position of num_opt[0] also allows for
+ * the other channel (which was skipped previously). If so,
+ * keep score. */
+ if (opt.num_opt[0] != -1) {
+ gint c1;
+
+ pos_val_entry = gst_value_array_get_value (pos_val_arr,
+ opt.num_opt[0]);
+ if (G_VALUE_TYPE (pos_val_entry) == GST_TYPE_LIST) {
+ for (c1 = 0; c1 < gst_value_list_get_size (pos_val_entry); c1++) {
+ pos_val = gst_value_list_get_value (pos_val_entry, c1);
+ if (g_value_get_enum (pos_val) == conf[i].pos1[1] &&
+ opt.num_opts[1] > opt.num_opts[0] && !opt.is_fixed[1]) {
+ opt.num_opts[1] = opt.num_opts[0];
+ opt.num_opt[1] = opt.num_opt[0];
+ }
+ }
+ pos_val = gst_value_list_get_value (pos_val_entry, c);
+ }
+ pos_val_entry = gst_value_array_get_value (pos_val_arr, n);
+ }
+
+ /* and save values */
+ opt.num_opts[0] = gst_value_list_get_size (pos_val_entry);
+ opt.num_opt[0] = n;
+ } else if (g_value_get_enum (pos_val) == conf[i].pos1[1] &&
+ opt.num_opts[1] > gst_value_list_get_size (pos_val_entry) &&
+ !opt.is_fixed[1] && n != opt.num_opt[0]) {
+ opt.num_opts[1] = gst_value_list_get_size (pos_val_entry);
+ opt.num_opt[1] = n;
+ }
+
+ /* 2 goes separately, because 0/1 vs. 2 are separate */
+ if (g_value_get_enum (pos_val) == conf[i].pos2[0] &&
+ opt.num_opts[2] > gst_value_list_get_size (pos_val_entry) &&
+ !opt.is_fixed[2]) {
+ opt.num_opts[2] = gst_value_list_get_size (pos_val_entry);
+ opt.num_opt[2] = n;
+ }
+ }
+ } else {
+ if (g_value_get_enum (pos_val_entry) == conf[i].pos1[0]) {
+ opt.num_opt[0] = n;
+ opt.is_fixed[0] = TRUE;
+ } else if (g_value_get_enum (pos_val_entry) == conf[i].pos1[1]) {
+ opt.num_opt[1] = n;
+ opt.is_fixed[1] = TRUE;
+ } else if (g_value_get_enum (pos_val_entry) == conf[i].pos2[0]) {
+ opt.num_opt[2] = n;
+ opt.is_fixed[2] = TRUE;
+ }
+ }
+ }
+
+ /* check our results and choose either one */
+ if ((opt.is_fixed[0] || opt.is_fixed[1]) && opt.is_fixed[2]) {
+ g_warning ("Pre-fixated on both %d/%d and %d - conflict!",
+ conf[i].pos1[0], conf[i].pos1[1], conf[i].pos2[0]);
+ g_free (pos);
+ return NULL;
+ } else if ((opt.is_fixed[0] && opt.num_opt[1] == -1) ||
+ (opt.is_fixed[1] && opt.num_opt[0] == -1)) {
+ g_warning ("Pre-fixated one side, but other side n/a of %d/%d",
+ conf[i].pos1[0], conf[i].pos1[1]);
+ g_free (pos);
+ return NULL;
+ } else if (opt.is_fixed[0] || opt.is_fixed[1]) {
+ opt.choice = 0;
+ } else if (opt.is_fixed[2]) {
+ opt.choice = 1;
+ } else if (opt.num_opt[0] != -1 && opt.num_opt[1] != -1) {
+ opt.choice = 0;
+ } else if (opt.num_opt[2] != -1) {
+ opt.choice = 1;
+ } else {
+ opt.choice = -1;
+ }
+
+ /* stereo? Note that we keep is_stereo to TRUE if we didn't decide on
+ * any arrangement. The mono/stereo channels might be handled elsewhere
+ * which is clearly outside the scope of this element, so we cannot
+ * know and expect the application to handle that then. */
+ if (conf[i].pos2[0] == GST_AUDIO_CHANNEL_POSITION_FRONT_MONO &&
+ opt.choice == 1) {
+ is_stereo = FALSE;
+ }
+
+ /* now actually decide what we'll do and fixate on that */
+ if (opt.choice == 0) {
+ g_assert (conf[i].pos1[0] != GST_AUDIO_CHANNEL_POSITION_INVALID &&
+ conf[i].pos1[1] != GST_AUDIO_CHANNEL_POSITION_INVALID);
+ pos[opt.num_opt[0]] = conf[i].pos1[0];
+ pos[opt.num_opt[1]] = conf[i].pos1[1];
+ num_unfixed -= 2;
+ } else if (opt.choice == 1) {
+ g_assert (conf[i].pos2[0] != GST_AUDIO_CHANNEL_POSITION_INVALID);
+ pos[opt.num_opt[2]] = conf[i].pos2[0];
+ num_unfixed--;
+ }
+ }
+
+ /* safety check */
+ if (num_unfixed > 0) {
+ g_warning ("%d unfixed channel positions left after fixation!",
+ num_unfixed);
+ g_free (pos);
+ return NULL;
+ }
+
+ if (!gst_audio_check_channel_positions (pos, channels)) {
+ g_free (pos);
+ return NULL;
+ }
+
+ return pos;
+}