diff options
author | David Vossel <dvossel@digium.com> | 2011-04-20 20:52:15 +0000 |
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committer | David Vossel <dvossel@digium.com> | 2011-04-20 20:52:15 +0000 |
commit | 18d591cb48730b8eeff0daa5946fbc6684285088 (patch) | |
tree | 06af1a8a399ca5ee4a8e7f72c41e07dfebd0c927 /funcs | |
parent | 3b52f36551331fbae62c82e5e0f7f1a250b6c17d (diff) |
Introduction of the JITTERBUFFER dialplan function.
Review: https://reviewboard.asterisk.org/r/1157/
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@314509 65c4cc65-6c06-0410-ace0-fbb531ad65f3
Diffstat (limited to 'funcs')
-rw-r--r-- | funcs/func_jitterbuffer.c | 369 |
1 files changed, 369 insertions, 0 deletions
diff --git a/funcs/func_jitterbuffer.c b/funcs/func_jitterbuffer.c new file mode 100644 index 000000000..e613e6a23 --- /dev/null +++ b/funcs/func_jitterbuffer.c @@ -0,0 +1,369 @@ +/* + * 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 Put a jitterbuffer on the read side of a channel + * + * \author David Vossel <dvossel@digium.com> + * + * \ingroup functions + */ + +#include "asterisk.h" + +ASTERISK_FILE_VERSION(__FILE__, "$Revision$") + +#include "asterisk/module.h" +#include "asterisk/channel.h" +#include "asterisk/framehook.h" +#include "asterisk/pbx.h" +#include "asterisk/abstract_jb.h" +#include "asterisk/timing.h" +#include "asterisk/app.h" + +/*** DOCUMENTATION + <function name="JITTERBUFFER" language="en_US"> + <synopsis> + Add a Jitterbuffer to the Read side of the channel. This dejitters the audio stream before it reaches the Asterisk core. This is a write only function. + </synopsis> + <syntax> + <parameter name="jitterbuffer type" required="true"> + <para>Jitterbuffer type can be either <literal>fixed</literal> or <literal>adaptive</literal>.</para> + <para>Used as follows. </para> + <para>Set(JITTERBUFFER(type)=max_size[,resync_threshold[,target_extra]])</para> + <para>Set(JITTERBUFFER(type)=default) </para> + </parameter> + </syntax> + <description> + <para>max_size: Defaults to 200 ms</para> + <para>Length in milliseconds of buffer.</para> + <para> </para> + <para>resync_threshold: Defaults to 1000ms </para> + <para>The length in milliseconds over which a timestamp difference will result in resyncing the jitterbuffer. </para> + <para> </para> + <para>target_extra: Defaults to 40ms</para> + <para>This option only affects the adaptive jitterbuffer. It represents the amount time in milliseconds by which the new jitter buffer will pad its size.</para> + <para> </para> + <para>Examples:</para> + <para>exten => 1,1,Set(JITTERBUFFER(fixed)=default);Fixed with defaults. </para> + <para>exten => 1,1,Set(JITTERBUFFER(fixed)=200);Fixed with max size 200ms, default resync threshold and target extra. </para> + <para>exten => 1,1,Set(JITTERBUFFER(fixed)=200,1500);Fixed with max size 200ms resync threshold 1500. </para> + <para>exten => 1,1,Set(JITTERBUFFER(adaptive)=default);Adaptive with defaults. </para> + <para>exten => 1,1,Set(JITTERBUFFER(adaptive)=200,,60);Adaptive with max size 200ms, default resync threshold and 40ms target extra. </para> + </description> + </function> + ***/ + +#define DEFAULT_TIMER_INTERVAL 20 +#define DEFAULT_SIZE 200 +#define DEFAULT_TARGET_EXTRA 40 +#define DEFAULT_RESYNC 1000 +#define DEFAULT_TYPE AST_JB_FIXED + +struct jb_framedata { + const struct ast_jb_impl *jb_impl; + struct ast_jb_conf jb_conf; + struct timeval start_tv; + struct ast_format last_format; + struct ast_timer *timer; + int timer_interval; /* ms between deliveries */ + int timer_fd; + int first; + void *jb_obj; +}; + +static void jb_framedata_destroy(struct jb_framedata *framedata) +{ + if (framedata->timer) { + ast_timer_close(framedata->timer); + framedata->timer = NULL; + } + if (framedata->jb_impl && framedata->jb_obj) { + struct ast_frame *f; + while (framedata->jb_impl->remove(framedata->jb_obj, &f) == AST_JB_IMPL_OK) { + ast_frfree(f); + } + framedata->jb_impl->destroy(framedata->jb_obj); + framedata->jb_obj = NULL; + } + ast_free(framedata); +} + +static void jb_conf_default(struct ast_jb_conf *conf) +{ + conf->max_size = DEFAULT_SIZE; + conf->resync_threshold = DEFAULT_RESYNC; + ast_copy_string(conf->impl, "fixed", sizeof(conf->impl)); + conf->target_extra = DEFAULT_TARGET_EXTRA; +} + +/* set defaults */ +static int jb_framedata_init(struct jb_framedata *framedata, const char *data, const char *value) +{ + int jb_impl_type = DEFAULT_TYPE; + + /* Initialize defaults */ + framedata->timer_fd = -1; + jb_conf_default(&framedata->jb_conf); + if (!(framedata->jb_impl = ast_jb_get_impl(jb_impl_type))) { + return -1; + } + if (!(framedata->timer = ast_timer_open())) { + return -1; + } + framedata->timer_fd = ast_timer_fd(framedata->timer); + framedata->timer_interval = DEFAULT_TIMER_INTERVAL; + ast_timer_set_rate(framedata->timer, 1000 / framedata->timer_interval); + framedata->start_tv = ast_tvnow(); + + + + /* Now check user options to see if any of the defaults need to change. */ + if (!ast_strlen_zero(data)) { + if (!strcasecmp(data, "fixed")) { + jb_impl_type = AST_JB_FIXED; + } else if (!strcasecmp(data, "adaptive")) { + jb_impl_type = AST_JB_ADAPTIVE; + } else { + ast_log(LOG_WARNING, "Unknown Jitterbuffer type %s. Failed to create jitterbuffer.\n", data); + return -1; + } + ast_copy_string(framedata->jb_conf.impl, data, sizeof(framedata->jb_conf.impl)); + } + + if (!ast_strlen_zero(value) && strcasecmp(value, "default")) { + char *parse = ast_strdupa(value); + int res = 0; + AST_DECLARE_APP_ARGS(args, + AST_APP_ARG(max_size); + AST_APP_ARG(resync_threshold); + AST_APP_ARG(target_extra); + ); + + AST_STANDARD_APP_ARGS(args, parse); + if (!ast_strlen_zero(args.max_size)) { + res |= ast_jb_read_conf(&framedata->jb_conf, + "jbmaxsize", + args.max_size); + } + if (!ast_strlen_zero(args.resync_threshold)) { + res |= ast_jb_read_conf(&framedata->jb_conf, + "jbresyncthreshold", + args.resync_threshold); + } + if (!ast_strlen_zero(args.target_extra)) { + res |= ast_jb_read_conf(&framedata->jb_conf, + "jbtargetextra", + args.target_extra); + } + if (res) { + ast_log(LOG_WARNING, "Invalid jitterbuffer parameters %s\n", value); + } + } + + /* now that all the user parsing is done and nothing will change, create the jb obj */ + framedata->jb_obj = framedata->jb_impl->create(&framedata->jb_conf, framedata->jb_conf.resync_threshold); + return 0; +} + +static void datastore_destroy_cb(void *data) { + ast_free(data); + ast_debug(1, "JITTERBUFFER datastore destroyed\n"); +} + +static const struct ast_datastore_info jb_datastore = { + .type = "jitterbuffer", + .destroy = datastore_destroy_cb +}; + +static void hook_destroy_cb(void *framedata) +{ + ast_debug(1, "JITTERBUFFER hook destroyed\n"); + jb_framedata_destroy((struct jb_framedata *) framedata); +} + +static struct ast_frame *hook_event_cb(struct ast_channel *chan, struct ast_frame *frame, enum ast_framehook_event event, void *data) +{ + struct jb_framedata *framedata = data; + struct timeval now_tv; + unsigned long now; + + switch (event) { + case AST_FRAMEHOOK_EVENT_READ: + break; + case AST_FRAMEHOOK_EVENT_ATTACHED: + case AST_FRAMEHOOK_EVENT_DETACHED: + case AST_FRAMEHOOK_EVENT_WRITE: + return frame; + } + + if (chan->fdno == AST_JITTERBUFFER_FD && framedata->timer) { + ast_timer_ack(framedata->timer, 1); + } + + if (!frame) { + return frame; + } + + now_tv = ast_tvnow(); + now = ast_tvdiff_ms(now_tv, framedata->start_tv); + + if (frame->frametype == AST_FRAME_VOICE) { + int res; + struct ast_frame *jbframe; + + if (!ast_test_flag(frame, AST_FRFLAG_HAS_TIMING_INFO) || frame->len < 2 || frame->ts < 0) { + /* only frames with timing info can enter the jitterbuffer */ + return frame; + } + + jbframe = ast_frisolate(frame); + ast_format_copy(&framedata->last_format, &frame->subclass.format); + + if (frame->len && (frame->len != framedata->timer_interval)) { + framedata->timer_interval = frame->len; + ast_timer_set_rate(framedata->timer, 1000 / framedata->timer_interval); + } + if (!framedata->first) { + framedata->first = 1; + res = framedata->jb_impl->put_first(framedata->jb_obj, jbframe, now); + } else { + res = framedata->jb_impl->put(framedata->jb_obj, jbframe, now); + } + if (res == AST_JB_IMPL_OK) { + frame = &ast_null_frame; + } + } + + if (frame->frametype == AST_FRAME_NULL) { + int res; + long next = framedata->jb_impl->next(framedata->jb_obj); + + if (now < next) { + return frame; + } + res = framedata->jb_impl->get(framedata->jb_obj, &frame, now, framedata->timer_interval); + switch (res) { + case AST_JB_IMPL_OK: + /* got it, and pass it through */ + break; + case AST_JB_IMPL_DROP: + ast_frfree(frame); + frame = &ast_null_frame; + break; + case AST_JB_IMPL_INTERP: + if (framedata->last_format.id) { + struct ast_frame tmp = { 0, }; + tmp.frametype = AST_FRAME_VOICE; + ast_format_copy(&tmp.subclass.format, &framedata->last_format); + /* example: 8000hz / (1000 / 20ms) = 160 samples */ + tmp.samples = ast_format_rate(&framedata->last_format) / (1000 / framedata->timer_interval); + tmp.delivery = ast_tvadd(framedata->start_tv, ast_samp2tv(next, 1000)); + tmp.offset = AST_FRIENDLY_OFFSET; + tmp.src = "func_jitterbuffer interpolation"; + frame = ast_frdup(&tmp); + break; + } + /* else fall through */ + case AST_JB_IMPL_NOFRAME: + frame = &ast_null_frame; + break; + } + } + + return frame; +} + +static int jb_helper(struct ast_channel *chan, const char *cmd, char *data, const char *value) +{ + struct jb_framedata *framedata; + struct ast_datastore *datastore = NULL; + struct ast_framehook_interface interface = { + .version = AST_FRAMEHOOK_INTERFACE_VERSION, + .event_cb = hook_event_cb, + .destroy_cb = hook_destroy_cb, + }; + int i = 0; + + if (!(framedata = ast_calloc(1, sizeof(*framedata)))) { + return 0; + } + + if (jb_framedata_init(framedata, data, value)) { + jb_framedata_destroy(framedata); + return 0; + } + + interface.data = framedata; + + ast_channel_lock(chan); + i = ast_framehook_attach(chan, &interface); + if (i >= 0) { + int *id; + if ((datastore = ast_channel_datastore_find(chan, &jb_datastore, NULL))) { + id = datastore->data; + ast_framehook_detach(chan, *id); + ast_channel_datastore_remove(chan, datastore); + } + + if (!(datastore = ast_datastore_alloc(&jb_datastore, NULL))) { + ast_framehook_detach(chan, i); + ast_channel_unlock(chan); + return 0; + } + + if (!(id = ast_calloc(1, sizeof(int)))) { + ast_datastore_free(datastore); + ast_framehook_detach(chan, i); + ast_channel_unlock(chan); + return 0; + } + + *id = i; /* Store off the id. The channel is still locked so it is safe to access this ptr. */ + datastore->data = id; + ast_channel_datastore_add(chan, datastore); + + ast_channel_set_fd(chan, AST_JITTERBUFFER_FD, framedata->timer_fd); + } else { + jb_framedata_destroy(framedata); + framedata = NULL; + } + ast_channel_unlock(chan); + + return 0; +} + +static struct ast_custom_function jb_function = { + .name = "JITTERBUFFER", + .write = jb_helper, +}; + +static int unload_module(void) +{ + return ast_custom_function_unregister(&jb_function); +} + +static int load_module(void) +{ + int res = ast_custom_function_register(&jb_function); + return res ? AST_MODULE_LOAD_DECLINE : AST_MODULE_LOAD_SUCCESS; +} + +AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Jitter buffer for read side of channel."); + |