1 files changed, 381 insertions, 0 deletions
diff --git a/main/codec.c b/main/codec.c
new file mode 100644
index 000000000..e060efe3e
--- /dev/null
+++ b/main/codec.c
@@ -0,0 +1,381 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2014, Digium, Inc.
+ *
+ * Joshua Colp <jcolp@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 Codecs API
+ *
+ * \author Joshua Colp <jcolp@digium.com>
+ */
+
+/*** MODULEINFO
+	<support_level>core</support_level>
+ ***/
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#include "asterisk/logger.h"
+#include "asterisk/codec.h"
+#include "asterisk/format.h"
+#include "asterisk/frame.h"
+#include "asterisk/astobj2.h"
+#include "asterisk/strings.h"
+#include "asterisk/module.h"
+#include "asterisk/cli.h"
+
+/*! \brief Number of buckets to use for codecs (should be prime for performance reasons) */
+#define CODEC_BUCKETS 53
+
+/*! \brief Current identifier value for newly registered codec */
+static int codec_id = 1;
+
+/*! \brief Registered codecs */
+static struct ao2_container *codecs;
+
+static int codec_hash(const void *obj, int flags)
+{
+	const struct ast_codec *codec;
+	const char *key;
+
+	switch (flags & OBJ_SEARCH_MASK) {
+	case OBJ_SEARCH_KEY:
+		key = obj;
+		return ast_str_hash(key);
+	case OBJ_SEARCH_OBJECT:
+		codec = obj;
+		return ast_str_hash(codec->name);
+	default:
+		/* Hash can only work on something with a full key. */
+		ast_assert(0);
+		return 0;
+	}
+}
+
+static int codec_cmp(void *obj, void *arg, int flags)
+{
+	const struct ast_codec *left = obj;
+	const struct ast_codec *right = arg;
+	const char *right_key = arg;
+	int cmp;
+
+	switch (flags & OBJ_SEARCH_MASK) {
+	case OBJ_SEARCH_OBJECT:
+		right_key = right->name;
+		cmp = strcmp(left->name, right_key);
+
+		if (right->type != AST_MEDIA_TYPE_UNKNOWN) {
+			cmp |= (right->type != left->type);
+		}
+
+		/* BUGBUG: this will allow a match on a codec by name only.
+		 * This is particularly useful when executed by the CLI; if
+		 * that is not needed in translate.c, this can be removed.
+		 */
+		if (right->sample_rate) {
+			cmp |= (right->sample_rate != left->sample_rate);
+		}
+		break;
+	case OBJ_SEARCH_KEY:
+		cmp = strcmp(left->name, right_key);
+		break;
+	case OBJ_SEARCH_PARTIAL_KEY:
+		cmp = strncmp(left->name, right_key, strlen(right_key));
+		break;
+	default:
+		ast_assert(0);
+		cmp = 0;
+		break;
+	}
+	if (cmp) {
+		return 0;
+	}
+
+	return CMP_MATCH;
+}
+
+static char *show_codecs(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
+{
+	struct ao2_iterator i;
+	struct ast_codec *codec;
+
+	switch (cmd) {
+	case CLI_INIT:
+		e->command = "core show codecs [audio|video|image|text]";
+		e->usage =
+			"Usage: core show codecs [audio|video|image|text]\n"
+			"       Displays codec mapping\n";
+		return NULL;
+	case CLI_GENERATE:
+		return NULL;
+	}
+
+	if ((a->argc < 3) || (a->argc > 4)) {
+		return CLI_SHOWUSAGE;
+	}
+
+	if (!ast_opt_dont_warn) {
+		ast_cli(a->fd, "Disclaimer: this command is for informational purposes only.\n"
+				"\tIt does not indicate anything about your configuration.\n");
+	}
+
+	ast_cli(a->fd, "%8s %5s %8s %s\n","ID","TYPE","NAME","DESCRIPTION");
+	ast_cli(a->fd, "-----------------------------------------------------------------------------------\n");
+
+	ao2_rdlock(codecs);
+	i = ao2_iterator_init(codecs, AO2_ITERATOR_DONTLOCK);
+
+	for (; (codec = ao2_iterator_next(&i)); ao2_ref(codec, -1)) {
+		if (a->argc == 4) {
+			if (!strcasecmp(a->argv[3], "audio")) {
+				if (codec->type != AST_MEDIA_TYPE_AUDIO) {
+					continue;
+				}
+			} else if (!strcasecmp(a->argv[3], "video")) {
+				if (codec->type != AST_MEDIA_TYPE_VIDEO) {
+					continue;
+				}
+			} else if (!strcasecmp(a->argv[3], "image")) {
+				if (codec->type != AST_MEDIA_TYPE_IMAGE) {
+					continue;
+				}
+			} else if (!strcasecmp(a->argv[3], "text")) {
+				if (codec->type != AST_MEDIA_TYPE_TEXT) {
+					continue;
+				}
+			} else {
+				continue;
+			}
+		}
+
+		ast_cli(a->fd, "%8u %5s %8s (%s)\n",
+			codec->id,
+			ast_codec_media_type2str(codec->type),
+			codec->name,
+			codec->description);
+	}
+
+	ao2_iterator_destroy(&i);
+	ao2_unlock(codecs);
+
+	return CLI_SUCCESS;
+}
+
+/*! \brief Callback function for getting a codec based on unique identifier */
+static int codec_id_cmp(void *obj, void *arg, int flags)
+{
+	struct ast_codec *codec = obj;
+	int *id = arg;
+
+	return (codec->id == *id) ? CMP_MATCH | CMP_STOP : 0;
+}
+
+static char *show_codec(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
+{
+	int type_punned_codec;
+	struct ast_codec *codec;
+
+	switch (cmd) {
+	case CLI_INIT:
+		e->command = "core show codec";
+		e->usage =
+			"Usage: core show codec <number>\n"
+			"       Displays codec mapping\n";
+		return NULL;
+	case CLI_GENERATE:
+		return NULL;
+	}
+
+	if (a->argc != 4) {
+		return CLI_SHOWUSAGE;
+	}
+
+	if (sscanf(a->argv[3], "%30d", &type_punned_codec) != 1) {
+		return CLI_SHOWUSAGE;
+	}
+
+	codec = ao2_callback(codecs, 0, codec_id_cmp, &type_punned_codec);
+	if (!codec) {
+		ast_cli(a->fd, "Codec %d not found\n", type_punned_codec);
+		return CLI_SUCCESS;
+	}
+
+	ast_cli(a->fd, "%11u %s\n", (unsigned int) codec->id, codec->description);
+
+	ao2_ref(codec, -1);
+
+	return CLI_SUCCESS;
+}
+
+/* Builtin Asterisk CLI-commands for debugging */
+static struct ast_cli_entry codec_cli[] = {
+	AST_CLI_DEFINE(show_codecs, "Displays a list of registered codecs"),
+	AST_CLI_DEFINE(show_codec, "Shows a specific codec"),
+};
+
+/*! \brief Function called when the process is shutting down */
+static void codec_shutdown(void)
+{
+	ast_cli_unregister_multiple(codec_cli, ARRAY_LEN(codec_cli));
+	ao2_cleanup(codecs);
+	codecs = NULL;
+}
+
+int ast_codec_init(void)
+{
+	codecs = ao2_container_alloc_options(AO2_ALLOC_OPT_LOCK_RWLOCK, CODEC_BUCKETS, codec_hash, codec_cmp);
+	if (!codecs) {
+		return -1;
+	}
+
+	ast_cli_register_multiple(codec_cli, ARRAY_LEN(codec_cli));
+	ast_register_atexit(codec_shutdown);
+
+	return 0;
+}
+
+static void codec_dtor(void *obj)
+{
+	struct ast_codec *codec;
+
+	codec = obj;
+
+	ast_module_unref(codec->mod);
+}
+
+int __ast_codec_register(struct ast_codec *codec, struct ast_module *mod)
+{
+	SCOPED_AO2WRLOCK(lock, codecs);
+	struct ast_codec *codec_new;
+
+	/* Some types have specific requirements */
+	if (codec->type == AST_MEDIA_TYPE_UNKNOWN) {
+		ast_log(LOG_ERROR, "A media type must be specified for codec '%s'\n", codec->name);
+		return -1;
+	} else if (codec->type == AST_MEDIA_TYPE_AUDIO) {
+		if (!codec->sample_rate) {
+			ast_log(LOG_ERROR, "A sample rate must be specified for codec '%s' of type '%s'\n",
+				codec->name, ast_codec_media_type2str(codec->type));
+			return -1;
+		}
+	}
+
+	codec_new = ao2_find(codecs, codec, OBJ_SEARCH_OBJECT | OBJ_NOLOCK);
+	if (codec_new) {
+		ast_log(LOG_ERROR, "A codec with name '%s' of type '%s' and sample rate '%u' is already registered\n",
+			codec->name, ast_codec_media_type2str(codec->type), codec->sample_rate);
+		ao2_ref(codec_new, -1);
+		return -1;
+	}
+
+	codec_new = ao2_t_alloc_options(sizeof(*codec_new), codec_dtor,
+		AO2_ALLOC_OPT_LOCK_NOLOCK, S_OR(codec->description, ""));
+	if (!codec_new) {
+		ast_log(LOG_ERROR, "Could not allocate a codec with name '%s' of type '%s' and sample rate '%u'\n",
+			codec->name, ast_codec_media_type2str(codec->type), codec->sample_rate);
+		return -1;
+	}
+	*codec_new = *codec;
+	codec_new->id = codec_id++;
+
+	ao2_link_flags(codecs, codec_new, OBJ_NOLOCK);
+
+	/* Once registered a codec can not be unregistered, and the module must persist */
+	ast_module_ref(mod);
+
+	ast_verb(2, "Registered '%s' codec '%s' at sample rate '%u' with id '%u'\n",
+		ast_codec_media_type2str(codec->type), codec->name, codec->sample_rate, codec_new->id);
+
+	ao2_ref(codec_new, -1);
+
+	return 0;
+}
+
+struct ast_codec *ast_codec_get(const char *name, enum ast_media_type type, unsigned int sample_rate)
+{
+	struct ast_codec codec = {
+		.name = name,
+		.type = type,
+		.sample_rate = sample_rate,
+	};
+
+	return ao2_find(codecs, &codec, OBJ_SEARCH_OBJECT);
+}
+
+struct ast_codec *ast_codec_get_by_id(int id)
+{
+	return ao2_callback(codecs, 0, codec_id_cmp, &id);
+}
+
+int ast_codec_get_max(void)
+{
+	return codec_id;
+}
+
+const char *ast_codec_media_type2str(enum ast_media_type type)
+{
+	switch (type) {
+	case AST_MEDIA_TYPE_AUDIO:
+		return "audio";
+	case AST_MEDIA_TYPE_VIDEO:
+		return "video";
+	case AST_MEDIA_TYPE_IMAGE:
+		return "image";
+	case AST_MEDIA_TYPE_TEXT:
+		return "text";
+	default:
+		return "<unknown>";
+	}
+}
+
+unsigned int ast_codec_samples_count(struct ast_frame *frame)
+{
+	struct ast_codec *codec;
+	unsigned int samples = 0;
+
+	if ((frame->frametype != AST_FRAME_VOICE) &&
+		(frame->frametype != AST_FRAME_VIDEO) &&
+		(frame->frametype != AST_FRAME_IMAGE)) {
+		return 0;
+	}
+
+	/* BUGBUG - why not just get the codec pointer off the format?
+	This is a bit roundabout
+	*/
+	codec = ast_codec_get_by_id(ast_format_get_codec_id(frame->subclass.format));
+
+	if (codec->samples_count) {
+		samples = codec->samples_count(frame);
+	} else {
+		ast_log(LOG_WARNING, "Unable to calculate samples for codec %s\n",
+			ast_format_get_name(frame->subclass.format));
+	}
+
+	ao2_ref(codec, -1);
+	return samples;
+}
+
+unsigned int ast_codec_determine_length(const struct ast_codec *codec, unsigned int samples)
+{
+	if (!codec->get_length) {
+		return 0;
+	}
+
+	return codec->get_length(samples);
+}