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media formats: re-architect handling of media for performance improvements

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In the old times media formats were represented using a bit field. This was
fast but had a few limitations.
 1. Asterisk was limited in how many formats it could handle.
 2. Formats, being a bit field, could not include any attribute information.
    A format was strictly its type, e.g., "this is ulaw".
This was changed in Asterisk 10 (see
https://wiki.asterisk.org/wiki/display/AST/Media+Architecture+Proposal for
notes on that work) which led to the creation of the ast_format structure.
This structure allowed Asterisk to handle attributes and bundle information
with a format.

Additionally, ast_format_cap was created to act as a container for multiple
formats that, together, formed the capability of some entity. Another
mechanism was added to allow logic to be registered which performed format
attribute negotiation. Everywhere throughout the codebase Asterisk was
changed to use this strategy.

Unfortunately, in software, there is no free lunch. These new capabilities
came at a cost.

Performance analysis and profiling showed that we spend an inordinate
amount of time comparing, copying, and generally manipulating formats and
their related structures. Basic prototyping has shown that a reasonably
large performance improvement could be made in this area. This patch is the
result of that project, which overhauled the media format architecture
and its usage in Asterisk to improve performance.

Generally, the new philosophy for handling formats is as follows:
 * The ast_format structure is reference counted. This removed a large amount
   of the memory allocations and copying that was done in prior versions.
 * In order to prevent race conditions while keeping things performant, the
   ast_format structure is immutable by convention and lock-free. Violate this
   tenet at your peril!
 * Because formats are reference counted, codecs are also reference counted.
   The Asterisk core generally provides built-in codecs and caches the
   ast_format structures created to represent them. Generally, to prevent
   inordinate amounts of module reference bumping, codecs and formats can be
   added at run-time but cannot be removed.
 * All compatibility with the bit field representation of codecs/formats has
   been moved to a compatibility API. The primary user of this representation
   is chan_iax2, which must continue to maintain its bit-field usage of formats
   for interoperability concerns.
 * When a format is negotiated with attributes, or when a format cannot be
   represented by one of the cached formats, a new format object is created or
   cloned from an existing format. That format may have the same codec
   underlying it, but is a different format than a version of the format with
   different attributes or without attributes.
 * While formats are reference counted objects, the reference count maintained
   on the format should be manipulated with care. Formats are generally cached
   and will persist for the lifetime of Asterisk and do not explicitly need
   to have their lifetime modified. An exception to this is when the user of a
   format does not know where the format came from *and* the user may outlive
   the provider of the format. This occurs, for example, when a format is read
   from a channel: the channel may have a format with attributes (hence,
   non-cached) and the user of the format may last longer than the channel (if
   the reference to the channel is released prior to the format's reference).

For more information on this work, see the API design notes:
  https://wiki.asterisk.org/wiki/display/AST/Media+Format+Rewrite

Finally, this work was the culmination of a large number of developer's
efforts. Extra thanks goes to Corey Farrell, who took on a large amount of the
work in the Asterisk core, chan_sip, and was an invaluable resource in peer
reviews throughout this project.

There were a substantial number of patches contributed during this work; the
following issues/patch names simply reflect some of the work (and will cause
the release scripts to give attribution to the individuals who work on them).

Reviews:
 https://reviewboard.asterisk.org/r/3814
 https://reviewboard.asterisk.org/r/3808
 https://reviewboard.asterisk.org/r/3805
 https://reviewboard.asterisk.org/r/3803
 https://reviewboard.asterisk.org/r/3801
 https://reviewboard.asterisk.org/r/3798
 https://reviewboard.asterisk.org/r/3800
 https://reviewboard.asterisk.org/r/3794
 https://reviewboard.asterisk.org/r/3793
 https://reviewboard.asterisk.org/r/3792
 https://reviewboard.asterisk.org/r/3791
 https://reviewboard.asterisk.org/r/3790
 https://reviewboard.asterisk.org/r/3789
 https://reviewboard.asterisk.org/r/3788
 https://reviewboard.asterisk.org/r/3787
 https://reviewboard.asterisk.org/r/3786
 https://reviewboard.asterisk.org/r/3784
 https://reviewboard.asterisk.org/r/3783
 https://reviewboard.asterisk.org/r/3778
 https://reviewboard.asterisk.org/r/3774
 https://reviewboard.asterisk.org/r/3775
 https://reviewboard.asterisk.org/r/3772
 https://reviewboard.asterisk.org/r/3761
 https://reviewboard.asterisk.org/r/3754
 https://reviewboard.asterisk.org/r/3753
 https://reviewboard.asterisk.org/r/3751
 https://reviewboard.asterisk.org/r/3750
 https://reviewboard.asterisk.org/r/3748
 https://reviewboard.asterisk.org/r/3747
 https://reviewboard.asterisk.org/r/3746
 https://reviewboard.asterisk.org/r/3742
 https://reviewboard.asterisk.org/r/3740
 https://reviewboard.asterisk.org/r/3739
 https://reviewboard.asterisk.org/r/3738
 https://reviewboard.asterisk.org/r/3737
 https://reviewboard.asterisk.org/r/3736
 https://reviewboard.asterisk.org/r/3734
 https://reviewboard.asterisk.org/r/3722
 https://reviewboard.asterisk.org/r/3713
 https://reviewboard.asterisk.org/r/3703
 https://reviewboard.asterisk.org/r/3689
 https://reviewboard.asterisk.org/r/3687
 https://reviewboard.asterisk.org/r/3674
 https://reviewboard.asterisk.org/r/3671
 https://reviewboard.asterisk.org/r/3667
 https://reviewboard.asterisk.org/r/3665
 https://reviewboard.asterisk.org/r/3625
 https://reviewboard.asterisk.org/r/3602
 https://reviewboard.asterisk.org/r/3519
 https://reviewboard.asterisk.org/r/3518
 https://reviewboard.asterisk.org/r/3516
 https://reviewboard.asterisk.org/r/3515
 https://reviewboard.asterisk.org/r/3512
 https://reviewboard.asterisk.org/r/3506
 https://reviewboard.asterisk.org/r/3413
 https://reviewboard.asterisk.org/r/3410
 https://reviewboard.asterisk.org/r/3387
 https://reviewboard.asterisk.org/r/3388
 https://reviewboard.asterisk.org/r/3389
 https://reviewboard.asterisk.org/r/3390
 https://reviewboard.asterisk.org/r/3321
 https://reviewboard.asterisk.org/r/3320
 https://reviewboard.asterisk.org/r/3319
 https://reviewboard.asterisk.org/r/3318
 https://reviewboard.asterisk.org/r/3266
 https://reviewboard.asterisk.org/r/3265
 https://reviewboard.asterisk.org/r/3234
 https://reviewboard.asterisk.org/r/3178

ASTERISK-23114 #close
Reported by: mjordan
  media_formats_translation_core.diff uploaded by kharwell (License 6464)
  rb3506.diff uploaded by mjordan (License 6283)
  media_format_app_file.diff uploaded by kharwell (License 6464) 
  misc-2.diff uploaded by file (License 5000)
  chan_mild-3.diff uploaded by file (License 5000) 
  chan_obscure.diff uploaded by file (License 5000) 
  jingle.diff uploaded by file (License 5000) 
  funcs.diff uploaded by file (License 5000) 
  formats.diff uploaded by file (License 5000) 
  core.diff uploaded by file (License 5000) 
  bridges.diff uploaded by file (License 5000) 
  mf-codecs-2.diff uploaded by file (License 5000) 
  mf-app_fax.diff uploaded by file (License 5000) 
  mf-apps-3.diff uploaded by file (License 5000) 
  media-formats-3.diff uploaded by file (License 5000) 

ASTERISK-23715
  rb3713.patch uploaded by coreyfarrell (License 5909)
  rb3689.patch uploaded by mjordan (License 6283)
  
ASTERISK-23957
  rb3722.patch uploaded by mjordan (License 6283) 
  mf-attributes-3.diff uploaded by file (License 5000) 

ASTERISK-23958
Tested by: jrose
  rb3822.patch uploaded by coreyfarrell (License 5909) 
  rb3800.patch uploaded by jrose (License 6182)
  chan_sip.diff uploaded by mjordan (License 6283) 
  rb3747.patch uploaded by jrose (License 6182)

ASTERISK-23959 #close
Tested by: sgriepentrog, mjordan, coreyfarrell
  sip_cleanup.diff uploaded by opticron (License 6273)
  chan_sip_caps.diff uploaded by mjordan (License 6283) 
  rb3751.patch uploaded by coreyfarrell (License 5909) 
  chan_sip-3.diff uploaded by file (License 5000) 

ASTERISK-23960 #close
Tested by: opticron
  direct_media.diff uploaded by opticron (License 6273) 
  pjsip-direct-media.diff uploaded by file (License 5000) 
  format_cap_remove.diff uploaded by opticron (License 6273) 
  media_format_fixes.diff uploaded by opticron (License 6273) 
  chan_pjsip-2.diff uploaded by file (License 5000) 

ASTERISK-23966 #close
Tested by: rmudgett
  rb3803.patch uploaded by rmudgetti (License 5621)
  chan_dahdi.diff uploaded by file (License 5000) 
  
ASTERISK-24064 #close
Tested by: coreyfarrell, mjordan, opticron, file, rmudgett, sgriepentrog, jrose
  rb3814.patch uploaded by rmudgett (License 5621) 
  moh_cleanup.diff uploaded by opticron (License 6273) 
  bridge_leak.diff uploaded by opticron (License 6273) 
  translate.diff uploaded by file (License 5000) 
  rb3795.patch uploaded by rmudgett (License 5621) 
  tls_fix.diff uploaded by mjordan (License 6283) 
  fax-mf-fix-2.diff uploaded by file (License 5000) 
  rtp_transfer_stuff uploaded by mjordan (License 6283) 
  rb3787.patch uploaded by rmudgett (License 5621) 
  media-formats-explicit-translate-format-3.diff uploaded by file (License 5000) 
  format_cache_case_fix.diff uploaded by opticron (License 6273) 
  rb3774.patch uploaded by rmudgett (License 5621) 
  rb3775.patch uploaded by rmudgett (License 5621) 
  rtp_engine_fix.diff uploaded by opticron (License 6273) 
  rtp_crash_fix.diff uploaded by opticron (License 6273) 
  rb3753.patch uploaded by mjordan (License 6283) 
  rb3750.patch uploaded by mjordan (License 6283) 
  rb3748.patch uploaded by rmudgett (License 5621) 
  media_format_fixes.diff uploaded by opticron (License 6273) 
  rb3740.patch uploaded by mjordan (License 6283) 
  rb3739.patch uploaded by mjordan (License 6283) 
  rb3734.patch uploaded by mjordan (License 6283) 
  rb3689.patch uploaded by mjordan (License 6283) 
  rb3674.patch uploaded by coreyfarrell (License 5909) 
  rb3671.patch uploaded by coreyfarrell (License 5909) 
  rb3667.patch uploaded by coreyfarrell (License 5909) 
  rb3665.patch uploaded by mjordan (License 6283) 
  rb3625.patch uploaded by coreyfarrell (License 5909) 
  rb3602.patch uploaded by coreyfarrell (License 5909) 
  format_compatibility-2.diff uploaded by file (License 5000) 
  core.diff uploaded by file (License 5000) 
  


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@419044 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Matthew Jordan
2014-07-20 22:06:33 +00:00
parent b299052e20
commit a2c912e997
205 changed files with 14244 additions and 9839 deletions
Download Patch File Download Diff File Expand all files Collapse all files

129
include/asterisk/rtp_engine.h
View File

@@ -1,4 +1,4 @@
/*
/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 1999 - 2009, Digium, Inc.
@@ -71,10 +71,12 @@ extern "C" {
#include "asterisk/astobj2.h"
#include "asterisk/frame.h"
#include "asterisk/format_cap.h"
#include "asterisk/netsock2.h"
#include "asterisk/sched.h"
#include "asterisk/res_srtp.h"
#include "asterisk/stasis.h"
#include "asterisk/vector.h"
/* Maximum number of payloads supported */
#if defined(LOW_MEMORY)
@@ -245,7 +247,7 @@ struct ast_rtp_payload_type {
int asterisk_format;
/*! If asterisk_format is set, this is the internal
* asterisk format represented by the payload */
struct ast_format format;
struct ast_format *format;
/*! Actual internal RTP specific value of the payload */
int rtp_code;
/*! Actual payload number */
@@ -526,8 +528,6 @@ struct ast_rtp_engine {
void (*prop_set)(struct ast_rtp_instance *instance, enum ast_rtp_property property, int value);
/*! Callback for setting a payload. If asterisk is to be used, asterisk_format will be set, otherwise value in code is used. */
void (*payload_set)(struct ast_rtp_instance *instance, int payload, int asterisk_format, struct ast_format *format, int code);
/*! Callback for setting packetization preferences */
void (*packetization_set)(struct ast_rtp_instance *instance, struct ast_codec_pref *pref);
/*! Callback for setting the remote address that RTP is to be sent to */
void (*remote_address_set)(struct ast_rtp_instance *instance, struct ast_sockaddr *sa);
/*! Callback for changing DTMF mode */
@@ -575,11 +575,16 @@ struct ast_rtp_engine {
/*! Structure that represents codec and packetization information */
struct ast_rtp_codecs {
/*! Payloads present */
struct ao2_container *payloads;
/*! Codec packetization preferences */
struct ast_codec_pref pref;
AST_VECTOR(, struct ast_rtp_payload_type *) payloads;
/*! The framing for this media session */
unsigned int framing;
/*! RW lock that protects elements in this structure */
ast_rwlock_t codecs_lock;
};
#define AST_RTP_CODECS_NULL_INIT \
{ .payloads = { 0, }, .framing = 0, .codecs_lock = AST_RWLOCK_INIT_VALUE, }
/*! Structure that represents the glue that binds an RTP instance to a channel */
struct ast_rtp_glue {
/*! Name of the channel driver that this glue is responsible for */
@@ -622,6 +627,18 @@ struct ast_rtp_glue {
AST_RWLIST_ENTRY(ast_rtp_glue) entry;
};
/*!
* \brief Allocation routine for \ref ast_rtp_payload_type
*
* \retval NULL on error
* \retval An ao2 ref counted \c ast_rtp_payload_type on success.
*
* \note The \c ast_rtp_payload_type returned by this function is an
* ao2 ref counted object.
*
*/
struct ast_rtp_payload_type *ast_rtp_engine_alloc_payload_type(void);
#define ast_rtp_engine_register(engine) ast_rtp_engine_register2(engine, ast_module_info->self)
/*!
@@ -1116,25 +1133,6 @@ void ast_rtp_codecs_payloads_destroy(struct ast_rtp_codecs *codecs);
*/
void ast_rtp_codecs_payloads_clear(struct ast_rtp_codecs *codecs, struct ast_rtp_instance *instance);
/*!
* \brief Set payload information on an RTP instance to the default
*
* \param codecs The codecs structure to set defaults on
* \param instance Optionally the instance that the codecs structure belongs to
*
* Example usage:
*
* \code
* struct ast_rtp_codecs codecs;
* ast_rtp_codecs_payloads_default(&codecs, NULL);
* \endcode
*
* This sets the default payloads on the codecs structure.
*
* \since 1.8
*/
void ast_rtp_codecs_payloads_default(struct ast_rtp_codecs *codecs, struct ast_rtp_instance *instance);
/*!
* \brief Copy payload information from one RTP instance to another
*
@@ -1249,20 +1247,36 @@ void ast_rtp_codecs_payloads_unset(struct ast_rtp_codecs *codecs, struct ast_rtp
* \param codecs Codecs structure to look in
* \param payload Numerical payload to look up
*
* \retval Payload information
* \retval Payload information.
* \retval NULL if payload does not exist.
*
* \note The payload returned by this function has its reference count increased.
* Callers are responsible for decrementing the reference count.
*
* Example usage:
*
* \code
* struct ast_rtp_payload_type payload_type;
* payload_type = ast_rtp_codecs_payload_lookup(&codecs, 0);
* struct ast_rtp_payload_type *payload_type;
* payload_type = ast_rtp_codecs_get_payload(&codecs, 0);
* \endcode
*
* This looks up the information for payload '0' from the codecs structure.
*
* \since 1.8
*/
struct ast_rtp_payload_type ast_rtp_codecs_payload_lookup(struct ast_rtp_codecs *codecs, int payload);
struct ast_rtp_payload_type *ast_rtp_codecs_get_payload(struct ast_rtp_codecs *codecs, int payload);
/*!
* \brief Update the format associated with a payload in a codecs structure
*
* \param codecs Codecs structure to operate on
* \param payload Numerical payload to look up
* \param format The format to replace the existing one
*
* \retval 0 success
* \retval -1 failure
*
* \since 13
*/
int ast_rtp_codecs_payload_replace_format(struct ast_rtp_codecs *codecs, int payload, struct ast_format *format);
/*!
* \brief Retrieve the actual ast_format stored on the codecs structure for a specific payload
@@ -1273,10 +1287,34 @@ struct ast_rtp_payload_type ast_rtp_codecs_payload_lookup(struct ast_rtp_codecs
* \retval pointer to format structure on success
* \retval NULL on failure
*
* \note The format returned by this function has its reference count increased.
* Callers are responsible for decrementing the reference count.
*
* \since 10.0
*/
struct ast_format *ast_rtp_codecs_get_payload_format(struct ast_rtp_codecs *codecs, int payload);
/*!
* \brief Set the framing used for a set of codecs
*
* \param codecs Codecs structure to set framing on
* \param framing The framing value to set on the codecs
*
* \since 13.0.0
*/
void ast_rtp_codecs_set_framing(struct ast_rtp_codecs *codecs, unsigned int framing);
/*!
* \brief Get the framing used for a set of codecs
*
* \param codecs Codecs structure to get the framing from
*
* \retval The framing to be used for the media stream associated with these codecs
*
* \since 13.0.0
*/
unsigned int ast_rtp_codecs_get_framing(struct ast_rtp_codecs *codecs);
/*!
* \brief Get the sample rate associated with known RTP payload types
*
@@ -1393,8 +1431,8 @@ const char *ast_rtp_lookup_mime_subtype2(const int asterisk_format, struct ast_f
* char buf[256] = "";
* struct ast_format tmp_fmt;
* struct ast_format_cap *cap = ast_format_cap_alloc_nolock();
* ast_format_cap_add(cap, ast_format_set(&tmp_fmt, AST_FORMAT_ULAW, 0));
* ast_format_cap_add(cap, ast_format_set(&tmp_fmt, AST_FORMAT_GSM, 0));
* ast_format_cap_append(cap, ast_format_set(&tmp_fmt, AST_FORMAT_ULAW, 0));
* ast_format_cap_append(cap, ast_format_set(&tmp_fmt, AST_FORMAT_GSM, 0));
* char *mime = ast_rtp_lookup_mime_multiple2(&buf, sizeof(buf), cap, 0, 1, 0);
* ast_format_cap_destroy(cap);
* \endcode
@@ -1405,25 +1443,6 @@ const char *ast_rtp_lookup_mime_subtype2(const int asterisk_format, struct ast_f
*/
char *ast_rtp_lookup_mime_multiple2(struct ast_str *buf, struct ast_format_cap *ast_format_capability, int rtp_capability, const int asterisk_format, enum ast_rtp_options options);
/*!
* \brief Set codec packetization preferences
*
* \param codecs Codecs structure to muck with
* \param instance Optionally the instance that the codecs structure belongs to
* \param prefs Codec packetization preferences
*
* Example usage:
*
* \code
* ast_rtp_codecs_packetization_set(&codecs, NULL, &prefs);
* \endcode
*
* This sets the packetization preferences pointed to by prefs on the codecs structure pointed to by codecs.
*
* \since 1.8
*/
void ast_rtp_codecs_packetization_set(struct ast_rtp_codecs *codecs, struct ast_rtp_instance *instance, struct ast_codec_pref *prefs);
/*!
* \brief Begin sending a DTMF digit
*
@@ -2111,12 +2130,12 @@ struct ast_srtp *ast_rtp_instance_get_srtp(struct ast_rtp_instance *instance);
/*! \brief Custom formats declared in codecs.conf at startup must be communicated to the rtp_engine
* so their mime type can payload number can be initialized. */
int ast_rtp_engine_load_format(const struct ast_format *format);
int ast_rtp_engine_load_format(struct ast_format *format);
/*! \brief Formats requiring the use of a format attribute interface must have that
* interface registered in order for the rtp engine to handle it correctly. If an
* attribute interface is unloaded, this function must be called to notify the rtp_engine. */
int ast_rtp_engine_unload_format(const struct ast_format *format);
int ast_rtp_engine_unload_format(struct ast_format *format);
/*!
* \brief Obtain a pointer to the ICE support present on an RTP instance