asterisk/main/codec.c

415 lines
10 KiB
C

/*
* 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"
#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;
/*!
* \internal
* \brief Internal codec structure
*
* External codecs won't know about the format_name field so the public
* ast_codec structure has to leave it out. This structure will be used
* for the internal codecs.
*
*/
struct internal_ast_codec {
/*! \brief Public codec structure. Must remain first. */
struct ast_codec external;
/*! \brief A format name for a default sane format using this codec */
const char *format_name;
};
/*!
* \internal
* \brief Internal function for registration with format name
*
* This function is only used by codec.c and codec_builtin.c and
* will be removed in Asterisk 14
*/
int __ast_codec_register_with_format(struct ast_codec *codec, const char *format_name,
struct ast_module *mod);
AO2_STRING_FIELD_HASH_FN(ast_codec, name)
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 internal_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 %-12s %-16s %s\n","ID","TYPE","NAME","FORMAT","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->external.type != AST_MEDIA_TYPE_AUDIO) {
continue;
}
} else if (!strcasecmp(a->argv[3], "video")) {
if (codec->external.type != AST_MEDIA_TYPE_VIDEO) {
continue;
}
} else if (!strcasecmp(a->argv[3], "image")) {
if (codec->external.type != AST_MEDIA_TYPE_IMAGE) {
continue;
}
} else if (!strcasecmp(a->argv[3], "text")) {
if (codec->external.type != AST_MEDIA_TYPE_TEXT) {
continue;
}
} else {
continue;
}
}
ast_cli(a->fd, "%8u %-5s %-12s %-16s (%s)\n",
codec->external.id,
ast_codec_media_type2str(codec->external.type),
codec->external.name,
S_OR(codec->format_name, "no cached format"),
codec->external.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 internal_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 (%s)\n", (unsigned int) codec->external.id, codec->external.description,
S_OR(codec->format_name, "no format"));
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_hash(AO2_ALLOC_OPT_LOCK_RWLOCK, 0, CODEC_BUCKETS,
ast_codec_hash_fn, NULL, codec_cmp);
if (!codecs) {
return -1;
}
ast_cli_register_multiple(codec_cli, ARRAY_LEN(codec_cli));
ast_register_cleanup(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)
{
return __ast_codec_register_with_format(codec, NULL, mod);
}
int __ast_codec_register_with_format(struct ast_codec *codec, const char *format_name, struct ast_module *mod)
{
SCOPED_AO2WRLOCK(lock, codecs);
struct internal_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->external = *codec;
codec_new->format_name = format_name;
codec_new->external.id = codec_id++;
ao2_link_flags(codecs, codec_new, OBJ_NOLOCK);
/* Once registered a codec can not be unregistered, and the module must persist until shutdown */
ast_module_shutdown_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->external.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>";
}
}
enum ast_media_type ast_media_type_from_str(const char *media_type_str)
{
if (!strcasecmp(media_type_str, "audio")) {
return AST_MEDIA_TYPE_AUDIO;
} else if (!strcasecmp(media_type_str, "video")) {
return AST_MEDIA_TYPE_VIDEO;
} else if (!strcasecmp(media_type_str, "image")) {
return AST_MEDIA_TYPE_IMAGE;
} else if (!strcasecmp(media_type_str, "text")) {
return AST_MEDIA_TYPE_TEXT;
} else {
return AST_MEDIA_TYPE_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;
}
codec = ast_format_get_codec(frame->subclass.format);
if (codec->samples_count) {
samples = codec->samples_count(frame);
if ((int) samples < 0) {
ast_log(LOG_WARNING, "Codec %s returned invalid number of samples.\n",
ast_format_get_name(frame->subclass.format));
samples = 0;
}
} 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);
}