aboutsummaryrefslogtreecommitdiffstats
path: root/res/res_format_attr_silk.c
diff options
context:
space:
mode:
Diffstat (limited to 'res/res_format_attr_silk.c')
-rw-r--r--res/res_format_attr_silk.c215
1 files changed, 215 insertions, 0 deletions
diff --git a/res/res_format_attr_silk.c b/res/res_format_attr_silk.c
new file mode 100644
index 000000000..49122fe80
--- /dev/null
+++ b/res/res_format_attr_silk.c
@@ -0,0 +1,215 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2011, Digium, Inc.
+ *
+ * David Vossel <dvossel@digium.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*!
+ * \file
+ * \brief SILK format attribute interface
+ *
+ * \author David Vossel <dvossel@digium.com>
+ */
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#include "asterisk/module.h"
+#include "asterisk/format.h"
+
+/*!
+ * \brief SILK attribute structure.
+ *
+ * \note The only attribute that affects compatibility here is the sample rate.
+ */
+struct silk_attr {
+ unsigned int samplerate;
+ unsigned int maxbitrate;
+ unsigned int dtx;
+ unsigned int fec;
+ unsigned int packetloss_percentage;
+};
+
+static enum ast_format_cmp_res silk_cmp(const struct ast_format_attr *fattr1, const struct ast_format_attr *fattr2)
+{
+ struct silk_attr *attr1 = (struct silk_attr *) fattr1;
+ struct silk_attr *attr2 = (struct silk_attr *) fattr2;
+
+ if (attr1->samplerate == attr2->samplerate) {
+ return AST_FORMAT_CMP_EQUAL;
+ }
+ return AST_FORMAT_CMP_NOT_EQUAL;
+}
+
+static int silk_get_val(const struct ast_format_attr *fattr, int key, void *result)
+{
+ const struct silk_attr *attr = (struct silk_attr *) fattr;
+ int *val = result;
+
+ switch (key) {
+ case SILK_ATTR_KEY_SAMP_RATE:
+ *val = attr->samplerate;
+ break;
+ case SILK_ATTR_KEY_MAX_BITRATE:
+ *val = attr->maxbitrate;
+ break;
+ case SILK_ATTR_KEY_DTX:
+ *val = attr->dtx;
+ break;
+ case SILK_ATTR_KEY_FEC:
+ *val = attr->fec;
+ break;
+ case SILK_ATTR_KEY_PACKETLOSS_PERCENTAGE:
+ *val = attr->packetloss_percentage;
+ break;
+ default:
+ return -1;
+ ast_log(LOG_WARNING, "unknown attribute type %d\n", key);
+ }
+ return 0;
+}
+
+static int silk_isset(const struct ast_format_attr *fattr, va_list ap)
+{
+ enum silk_attr_keys key;
+ const struct silk_attr *attr = (struct silk_attr *) fattr;
+
+ for (key = va_arg(ap, int);
+ key != AST_FORMAT_ATTR_END;
+ key = va_arg(ap, int))
+ {
+ switch (key) {
+ case SILK_ATTR_KEY_SAMP_RATE:
+ if (attr->samplerate != (va_arg(ap, int))) {
+ return -1;
+ }
+ break;
+ case SILK_ATTR_KEY_MAX_BITRATE:
+ if (attr->maxbitrate != (va_arg(ap, int))) {
+ return -1;
+ }
+ break;
+ case SILK_ATTR_KEY_DTX:
+ if (attr->dtx != (va_arg(ap, int))) {
+ return -1;
+ }
+ break;
+ case SILK_ATTR_KEY_FEC:
+ if (attr->fec != (va_arg(ap, int))) {
+ return -1;
+ }
+ break;
+ case SILK_ATTR_KEY_PACKETLOSS_PERCENTAGE:
+ if (attr->packetloss_percentage != (va_arg(ap, int))) {
+ return -1;
+ }
+ break;
+ default:
+ return -1;
+ ast_log(LOG_WARNING, "unknown attribute type %d\n", key);
+ }
+ }
+ return 0;
+}
+static int silk_getjoint(const struct ast_format_attr *fattr1, const struct ast_format_attr *fattr2, struct ast_format_attr *result)
+{
+ struct silk_attr *attr1 = (struct silk_attr *) fattr1;
+ struct silk_attr *attr2 = (struct silk_attr *) fattr2;
+ struct silk_attr *attr_res = (struct silk_attr *) result;
+ int joint = -1;
+
+ attr_res->samplerate = attr1->samplerate & attr2->samplerate;
+ /* sample rate is the only attribute that has any bearing on if joint capabilities exist or not */
+ if (attr_res->samplerate) {
+ joint = 0;
+ }
+ /* Take the lowest max bitrate */
+ attr_res->maxbitrate = MIN(attr1->maxbitrate, attr2->maxbitrate);
+
+ /* Only do dtx if both sides want it. DTX is a trade off between
+ * computational complexity and bandwidth. */
+ attr_res->dtx = attr1->dtx && attr2->dtx ? 1 : 0;
+
+ /* Only do FEC if both sides want it. If a peer specifically requests not
+ * to receive with FEC, it may be a waste of bandwidth. */
+ attr_res->fec = attr1->fec && attr2->fec ? 1 : 0;
+
+ /* Use the maximum packetloss percentage between the two attributes. This affects how
+ * much redundancy is used in the FEC. */
+ attr_res->packetloss_percentage = MAX(attr1->packetloss_percentage, attr2->packetloss_percentage);
+ return joint;
+}
+
+static void silk_set(struct ast_format_attr *fattr, va_list ap)
+{
+ enum silk_attr_keys key;
+ struct silk_attr *attr = (struct silk_attr *) fattr;
+
+ for (key = va_arg(ap, int);
+ key != AST_FORMAT_ATTR_END;
+ key = va_arg(ap, int))
+ {
+ switch (key) {
+ case SILK_ATTR_KEY_SAMP_RATE:
+ attr->samplerate = (va_arg(ap, int));
+ break;
+ case SILK_ATTR_KEY_MAX_BITRATE:
+ attr->maxbitrate = (va_arg(ap, int));
+ break;
+ case SILK_ATTR_KEY_DTX:
+ attr->dtx = (va_arg(ap, int));
+ break;
+ case SILK_ATTR_KEY_FEC:
+ attr->fec = (va_arg(ap, int));
+ break;
+ case SILK_ATTR_KEY_PACKETLOSS_PERCENTAGE:
+ attr->packetloss_percentage = (va_arg(ap, int));
+ break;
+ default:
+ ast_log(LOG_WARNING, "unknown attribute type %d\n", key);
+ }
+ }
+}
+
+static struct ast_format_attr_interface silk_interface = {
+ .id = AST_FORMAT_SILK,
+ .format_attr_cmp = silk_cmp,
+ .format_attr_get_joint = silk_getjoint,
+ .format_attr_set = silk_set,
+ .format_attr_isset = silk_isset,
+ .format_attr_get_val = silk_get_val,
+};
+
+static int load_module(void)
+{
+ if (ast_format_attr_reg_interface(&silk_interface)) {
+ return AST_MODULE_LOAD_DECLINE;
+ }
+
+ return AST_MODULE_LOAD_SUCCESS;
+}
+
+static int unload_module(void)
+{
+ ast_format_attr_unreg_interface(&silk_interface);
+ return 0;
+}
+
+AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "SILK Format Attribute Module",
+ .load = load_module,
+ .unload = unload_module,
+ .load_pri = AST_MODPRI_CHANNEL_DEPEND,
+);