mirror of
https://github.com/asterisk/asterisk.git
synced 2025-10-12 15:45:18 +00:00
Streams: Add features for Advanced Codec Negotiation
The Streams API becomes the home for the core ACN capabilities. These include... * Parsing and formatting of codec negotation preferences. * Resolving pending streams and topologies with those configured using configured preferences. * Utility functions for creating string representations of streams, topologies, and negotiation preferences. For codec negotiation preferences: * Added ast_stream_codec_prefs_parse() which takes a string representation of codec negotiation preferences, which may come from a pjsip endpoint for example, and populates a ast_stream_codec_negotiation_prefs structure. * Added ast_stream_codec_prefs_to_str() which does the reverse. * Added many functions to parse individual parameter name and value strings to their respectrive enum values, and the reverse. For streams: * Added ast_stream_create_resolved() which takes a "live" stream and resolves it with a configured stream and the negotiation preferences to create a new stream. * Added ast_stream_to_str() which create a string representation of a stream suitable for debug or display purposes. For topology: * Added ast_stream_topology_create_resolved() which takes a "live" topology and resolves it, stream by stream, with a configured topology stream and the negotiation preferences to create a new topology. * Added ast_stream_topology_to_str() which create a string representation of a topology suitable for debug or display purposes. * Renamed ast_format_caps_from_topology() to ast_stream_topology_get_formats() to be more consistent with the existing ast_stream_get_formats(). Additional changes: * A new function ast_format_cap_append_names() appends the results to the ast_str buffer instead of replacing buffer contents. Change-Id: I2df77dedd0c72c52deb6e329effe057a8e06cd56
This commit is contained in:
George Joseph
committed by
Friendly Automation
Friendly Automation
parent
7440fd0397
commit
8d1064eaaf
@@ -310,6 +310,17 @@ int ast_format_cap_has_type(const struct ast_format_cap *cap, enum ast_media_typ
|
||||
*/
|
||||
const char *ast_format_cap_get_names(const struct ast_format_cap *cap, struct ast_str **buf);
|
||||
|
||||
/*!
|
||||
* \brief Append the names of codecs of a set of formats to an ast_str buffer
|
||||
* \since 18
|
||||
*
|
||||
* \param cap The capabilities structure containing the formats
|
||||
* \param buf A \c ast_str buffer to append the names of the formats to
|
||||
*
|
||||
* \return The contents of the buffer in \c buf
|
||||
*/
|
||||
const char *ast_format_cap_append_names(const struct ast_format_cap *cap, struct ast_str **buf);
|
||||
|
||||
#ifndef AST_FORMAT_CAP_NAMES_LEN
|
||||
/*! Buffer size for callers of ast_format_cap_get_names to allocate. */
|
||||
#define AST_FORMAT_CAP_NAMES_LEN 384
|
||||
|
||||
@@ -29,6 +29,23 @@
|
||||
#include "asterisk/codec.h"
|
||||
#include "asterisk/vector.h"
|
||||
|
||||
/*!
|
||||
* \brief Internal macro to assist converting enums to strings
|
||||
* \internal
|
||||
* \since 18
|
||||
*
|
||||
* This macro checks that _value is in the bounds
|
||||
* of the enum/string map.
|
||||
*/
|
||||
#define _stream_maps_to_str(_mapname, _value) \
|
||||
({ \
|
||||
const char *_rtn = ""; \
|
||||
if (ARRAY_IN_BOUNDS(_value, _mapname)) { \
|
||||
_rtn = _mapname[_value]; \
|
||||
} \
|
||||
_rtn; \
|
||||
})
|
||||
|
||||
/*!
|
||||
* \brief Forward declaration for a stream, as it is opaque
|
||||
*/
|
||||
@@ -75,8 +92,273 @@ enum ast_stream_state {
|
||||
* \brief Set when the stream is not sending OR receiving media
|
||||
*/
|
||||
AST_STREAM_STATE_INACTIVE,
|
||||
/*!
|
||||
* \brief Sentinel
|
||||
*/
|
||||
AST_STREAM_STATE_END
|
||||
};
|
||||
|
||||
/*!
|
||||
* \brief Stream state enum to string map
|
||||
* \internal
|
||||
* \since 18
|
||||
*/
|
||||
extern const char *ast_stream_state_map[AST_STREAM_STATE_END];
|
||||
|
||||
/*!
|
||||
* \brief Safely get the name of a stream state
|
||||
* \since 18
|
||||
*
|
||||
* \param stream_state One of enum ast_stream_state
|
||||
* \returns A constant string with the name of the state or an empty string
|
||||
* if an invalid value was passed in.
|
||||
*/
|
||||
#define ast_stream_state_to_str(stream_state) _stream_maps_to_str(ast_stream_state_map, stream_state)
|
||||
|
||||
/*!
|
||||
* \brief Advanced Codec Negotiation Preferences
|
||||
* \since 18
|
||||
*/
|
||||
|
||||
/*!
|
||||
* \brief The preference parameters themselves
|
||||
* \since 18
|
||||
*/
|
||||
enum ast_stream_codec_negotiation_params {
|
||||
CODEC_NEGOTIATION_PARAM_UNSPECIFIED = 0,
|
||||
/*! Which of the lists to "prefer" */
|
||||
CODEC_NEGOTIATION_PARAM_PREFER,
|
||||
/*! "operation" to perform */
|
||||
CODEC_NEGOTIATION_PARAM_OPERATION,
|
||||
/*! "keep" all or only first */
|
||||
CODEC_NEGOTIATION_PARAM_KEEP,
|
||||
/*! Allow or prevent "transcode" */
|
||||
CODEC_NEGOTIATION_PARAM_TRANSCODE,
|
||||
/*! Sentinel */
|
||||
CODEC_NEGOTIATION_PARAM_END,
|
||||
};
|
||||
|
||||
/*!
|
||||
* \brief The "prefer" values
|
||||
* \since 18
|
||||
*/
|
||||
enum ast_stream_codec_negotiation_prefs_prefer_values {
|
||||
CODEC_NEGOTIATION_PREFER_UNSPECIFIED = 0,
|
||||
/*! Prefer the "pending" list */
|
||||
CODEC_NEGOTIATION_PREFER_PENDING,
|
||||
/*! Prefer the "configured" list */
|
||||
CODEC_NEGOTIATION_PREFER_CONFIGURED,
|
||||
/*! Sentinel */
|
||||
CODEC_NEGOTIATION_PREFER_END,
|
||||
};
|
||||
|
||||
/*!
|
||||
* \brief The "operation" values
|
||||
* \since 18
|
||||
*/
|
||||
enum ast_stream_codec_negotiation_prefs_operation_values {
|
||||
CODEC_NEGOTIATION_OPERATION_UNSPECIFIED = 0,
|
||||
/*! "intersect": only those codecs that appear in both lists */
|
||||
CODEC_NEGOTIATION_OPERATION_INTERSECT,
|
||||
/*! "union": all codecs in both lists */
|
||||
CODEC_NEGOTIATION_OPERATION_UNION,
|
||||
/*! "only_preferred": only the codecs in the preferred list */
|
||||
CODEC_NEGOTIATION_OPERATION_ONLY_PREFERRED,
|
||||
/*! "only_nonpreferred": only the codecs in the non-preferred list */
|
||||
CODEC_NEGOTIATION_OPERATION_ONLY_NONPREFERRED,
|
||||
/*! Sentinel */
|
||||
CODEC_NEGOTIATION_OPERATION_END,
|
||||
};
|
||||
|
||||
/*!
|
||||
* \brief The "keep" values
|
||||
* \since 18
|
||||
*/
|
||||
enum ast_stream_codec_negotiation_prefs_keep_values {
|
||||
CODEC_NEGOTIATION_KEEP_UNSPECIFIED = 0,
|
||||
/*! "keep" all codecs after performing the operation */
|
||||
CODEC_NEGOTIATION_KEEP_ALL,
|
||||
/*! "keep" only the first codec after performing the operation */
|
||||
CODEC_NEGOTIATION_KEEP_FIRST,
|
||||
/*! Sentinel */
|
||||
CODEC_NEGOTIATION_KEEP_END,
|
||||
};
|
||||
|
||||
/*!
|
||||
* \brief The "transcode" values
|
||||
* \since 18
|
||||
*/
|
||||
enum ast_stream_codec_negotiation_prefs_transcode_values {
|
||||
CODEC_NEGOTIATION_TRANSCODE_UNSPECIFIED = 0,
|
||||
/*! "allow" transcoding */
|
||||
CODEC_NEGOTIATION_TRANSCODE_ALLOW,
|
||||
/*! "prevent" transcoding */
|
||||
CODEC_NEGOTIATION_TRANSCODE_PREVENT,
|
||||
/*! Sentinel */
|
||||
CODEC_NEGOTIATION_TRANSCODE_END,
|
||||
};
|
||||
|
||||
/*!
|
||||
* \brief Preference enum to string map
|
||||
* \internal
|
||||
* \since 18
|
||||
*/
|
||||
extern const char *ast_stream_codec_negotiation_params_map[CODEC_NEGOTIATION_PARAM_END];
|
||||
|
||||
/*!
|
||||
* \brief "prefer" enum to string map
|
||||
* \internal
|
||||
* \since 18
|
||||
*/
|
||||
extern const char *ast_stream_codec_negotiation_prefer_map[CODEC_NEGOTIATION_PREFER_END];
|
||||
|
||||
/*!
|
||||
* \brief "operation" enum to string map
|
||||
* \internal
|
||||
* \since 18
|
||||
*/
|
||||
extern const char *ast_stream_codec_negotiation_operation_map[CODEC_NEGOTIATION_OPERATION_END];
|
||||
|
||||
/*!
|
||||
* \brief "keep" enum to string map
|
||||
* \internal
|
||||
* \since 18
|
||||
*/
|
||||
extern const char *ast_stream_codec_negotiation_keep_map[CODEC_NEGOTIATION_KEEP_END];
|
||||
|
||||
/*!
|
||||
* \brief "transcode" state enum to string map
|
||||
* \internal
|
||||
* \since 18
|
||||
*/
|
||||
extern const char *ast_stream_codec_negotiation_transcode_map[CODEC_NEGOTIATION_TRANSCODE_END];
|
||||
|
||||
/*!
|
||||
* \brief Safely get the name of a preference parameter
|
||||
* \since 18
|
||||
*
|
||||
* \param value One of enum \ref ast_stream_codec_negotiation_params
|
||||
* \returns A constant string with the name of the preference or an empty string
|
||||
* if an invalid value was passed in.
|
||||
*/
|
||||
#define ast_stream_codec_param_to_str(value) _stream_maps_to_str(ast_stream_codec_negotiation_params_map, value)
|
||||
|
||||
/*!
|
||||
* \brief Safely get the name of a "prefer" parameter value
|
||||
* \since 18
|
||||
*
|
||||
* \param value One of enum \ref ast_stream_codec_negotiation_prefer_values
|
||||
* \returns A constant string with the name of the value or an empty string
|
||||
* if an invalid value was passed in.
|
||||
*/
|
||||
#define ast_stream_codec_prefer_to_str(value) _stream_maps_to_str(ast_stream_codec_negotiation_prefer_map, value)
|
||||
|
||||
/*!
|
||||
* \brief Safely get the name of an "operation" parameter value
|
||||
* \since 18
|
||||
*
|
||||
* \param value One of enum \ref ast_stream_codec_negotiation_operation_values
|
||||
* \returns A constant string with the name of the value or an empty string
|
||||
* if an invalid value was passed in.
|
||||
*/
|
||||
#define ast_stream_codec_operation_to_str(value) _stream_maps_to_str(ast_stream_codec_negotiation_operation_map, value)
|
||||
|
||||
/*!
|
||||
* \brief Safely get the name of a "keep" parameter value
|
||||
* \since 18
|
||||
*
|
||||
* \param value One of enum \ref ast_stream_codec_negotiation_keep_values
|
||||
* \returns A constant string with the name of the value or an empty string
|
||||
* if an invalid value was passed in.
|
||||
*/
|
||||
#define ast_stream_codec_keep_to_str(value) _stream_maps_to_str(ast_stream_codec_negotiation_keep_map, value)
|
||||
|
||||
/*!
|
||||
* \brief Safely get the name of a "transcode" parameter value
|
||||
* \since 18
|
||||
*
|
||||
* \param value One of enum \ref ast_stream_codec_negotiation_transcode_values
|
||||
* \returns A constant string with the name of the value or an empty string
|
||||
* if an invalid value was passed in.
|
||||
*/
|
||||
#define ast_stream_codec_transcode_to_str(value) _stream_maps_to_str(ast_stream_codec_negotiation_transcode_map, value)
|
||||
|
||||
/*!
|
||||
* \brief
|
||||
* \since 18
|
||||
*
|
||||
* The structure that makes up a codec negotiation preference object
|
||||
*/
|
||||
struct ast_stream_codec_negotiation_prefs {
|
||||
/*! Which codec list to prefer */
|
||||
enum ast_stream_codec_negotiation_prefs_prefer_values prefer;
|
||||
/*! The operation to perform on the lists */
|
||||
enum ast_stream_codec_negotiation_prefs_operation_values operation;
|
||||
/*! What to keep after the operation is performed */
|
||||
enum ast_stream_codec_negotiation_prefs_keep_values keep;
|
||||
/*! To allow or prevent transcoding */
|
||||
enum ast_stream_codec_negotiation_prefs_transcode_values transcode;
|
||||
};
|
||||
|
||||
/*!
|
||||
* \brief Define for allocating buffer space for to_str() functions
|
||||
* \since 18
|
||||
*/
|
||||
#define AST_STREAM_MAX_CODEC_PREFS_LENGTH (128)
|
||||
|
||||
/*!
|
||||
* \brief Return a string representing the codec preferences
|
||||
* \since 18
|
||||
*
|
||||
* This function can be used for debugging purposes but is also
|
||||
* used in pjsip_configuration as a sorcery parameter handler
|
||||
*
|
||||
* \param prefs A pointer to a ast_stream_codec_negotiation_prefs structure
|
||||
* \param buf A pointer to an ast_str* used for the output. See note below.
|
||||
*
|
||||
* \returns the contents of the ast_str as a const char *.
|
||||
*
|
||||
* \warning No attempt should ever be made to free the returned
|
||||
* char * and it should be dup'd if needed after the ast_str is freed.
|
||||
*
|
||||
* \note
|
||||
* buf can't be NULL but it CAN contain a NULL value. If so, a new
|
||||
* ast_str will be allocated and the value of buf updated with a pointer
|
||||
* to it. Whether the caller supplies the ast_str or it's allocated by
|
||||
* this function, it's the caller's responsibility to free it.
|
||||
*
|
||||
* Sample output:
|
||||
* "prefer: configured, operation: union, keep:all, transcode:prevent"
|
||||
*/
|
||||
const char *ast_stream_codec_prefs_to_str(const struct ast_stream_codec_negotiation_prefs *prefs,
|
||||
struct ast_str **buf);
|
||||
|
||||
/*!
|
||||
* \brief Parses a string representing the codec prefs into a ast_stream_codec_negotiation_pref structure
|
||||
* \since 18
|
||||
*
|
||||
* This function is mainly used by pjsip_configuration as a sorcery parameter handler.
|
||||
*
|
||||
* \param pref_string A string in the format described by ast_stream_codec_prefs_to_str().
|
||||
* \param prefs Pointer to a ast_stream_codec_negotiation_prefs structure to receive the parsed values.
|
||||
* \param error_message An optional ast_str** into which parsing errors will be placed.
|
||||
*
|
||||
* \retval 0 if success
|
||||
* \retval -1 if failed
|
||||
*
|
||||
* \details
|
||||
* Whitespace around the ':' and ',' separators is ignored and the parameters
|
||||
* can be specified in any order. Parameters missing in the input string
|
||||
* will have their values set to the appropriate *_UNSPECIFIED value and will not
|
||||
* be considered an error. It's up to the caller to decide whether set a default
|
||||
* value, return an error, etc.
|
||||
*
|
||||
* Sample input:
|
||||
* "prefer : configured , operation: union,keep:all, transcode:prevent"
|
||||
*/
|
||||
int ast_stream_codec_prefs_parse(const char *pref_string, struct ast_stream_codec_negotiation_prefs *prefs,
|
||||
struct ast_str **error_message);
|
||||
|
||||
/*!
|
||||
* \brief Create a new media stream representation
|
||||
*
|
||||
@@ -166,6 +448,31 @@ void ast_stream_set_type(struct ast_stream *stream, enum ast_media_type type);
|
||||
*/
|
||||
const struct ast_format_cap *ast_stream_get_formats(const struct ast_stream *stream);
|
||||
|
||||
/*!
|
||||
* \brief Get a string representing the stream for debugging/display purposes
|
||||
* \since 18
|
||||
*
|
||||
* \param stream A stream
|
||||
* \param buf A pointer to an ast_str* used for the output.
|
||||
*
|
||||
* \retval "" (empty string) if either buf or *buf are NULL
|
||||
* \retval "(null stream)" if *stream was NULL
|
||||
* \retval <stream_representation> otherwise
|
||||
*
|
||||
* \warning No attempt should ever be made to free the returned
|
||||
* char * and it should be dup'd if needed after the ast_str is freed.
|
||||
*
|
||||
* \details
|
||||
*
|
||||
* Return format:
|
||||
* <name>:<media_type>:<stream_state> (formats)
|
||||
*
|
||||
* Sample return:
|
||||
* "audio:audio:sendrecv (ulaw,g722)"
|
||||
*
|
||||
*/
|
||||
const char *ast_stream_to_str(const struct ast_stream *stream, struct ast_str **buf);
|
||||
|
||||
/*!
|
||||
* \brief Get the count of the current negotiated formats of a stream
|
||||
*
|
||||
@@ -310,6 +617,33 @@ struct ast_rtp_codecs *ast_stream_get_rtp_codecs(const struct ast_stream *stream
|
||||
*/
|
||||
void ast_stream_set_rtp_codecs(struct ast_stream *stream, struct ast_rtp_codecs *rtp_codecs);
|
||||
|
||||
/*!
|
||||
* \brief Create a resolved stream from 2 streams
|
||||
* \since 18
|
||||
*
|
||||
* \param pending_stream The "live" stream created from an SDP,
|
||||
* passed through the core, or used to create an SDP.
|
||||
* \param configured_stream The static stream used to validate the pending stream.
|
||||
* \param prefs A pointer to an ast_stream_codec_negotiation_prefs structure.
|
||||
* \param error_message If supplied, error messages will be appended.
|
||||
*
|
||||
* \details
|
||||
* The resulting stream will contain all of the attributes and metadata of the
|
||||
* pending stream but will contain only the formats that passed the validation
|
||||
* specified by the ast_stream_codec_negotiation_prefs structure. This may mean
|
||||
* that the stream's format_caps will be empty. It's up to the caller to determine
|
||||
* what to do with the stream in that case. I.E. Free it, set it to the
|
||||
* REMOVED state, etc. A stream will always be returned unless there was
|
||||
* some catastrophic allocation failure.
|
||||
*
|
||||
* \retval NULL if there was some allocation failure.
|
||||
* \retval A new, resolved stream.
|
||||
*
|
||||
*/
|
||||
struct ast_stream *ast_stream_create_resolved(struct ast_stream *pending_stream,
|
||||
struct ast_stream *configured_stream, struct ast_stream_codec_negotiation_prefs *prefs,
|
||||
struct ast_str **error_message);
|
||||
|
||||
/*!
|
||||
* \brief Create a stream topology
|
||||
*
|
||||
@@ -386,6 +720,18 @@ int ast_stream_topology_append_stream(struct ast_stream_topology *topology,
|
||||
*/
|
||||
int ast_stream_topology_get_count(const struct ast_stream_topology *topology);
|
||||
|
||||
/*!
|
||||
* \brief Get the number of active (non-REMOVED) streams in a topology
|
||||
*
|
||||
* \param topology The topology of streams
|
||||
*
|
||||
* \return the number of active streams
|
||||
*
|
||||
* \since 18
|
||||
*/
|
||||
int ast_stream_topology_get_active_count(const struct ast_stream_topology *topology);
|
||||
|
||||
|
||||
/*!
|
||||
* \brief Get a specific stream from the topology
|
||||
*
|
||||
@@ -471,16 +817,60 @@ struct ast_stream_topology *ast_stream_topology_create_from_format_cap(
|
||||
*
|
||||
* \param topology The topology of streams
|
||||
*
|
||||
* \retval non-NULL success
|
||||
* \retval non-NULL success (the resulting format caps must be unreffed by the caller)
|
||||
* \retval NULL failure
|
||||
*
|
||||
* \note The stream topology is NOT altered by this function.
|
||||
*
|
||||
* \since 15
|
||||
*/
|
||||
struct ast_format_cap *ast_format_cap_from_stream_topology(
|
||||
struct ast_format_cap *ast_stream_topology_get_formats(
|
||||
struct ast_stream_topology *topology);
|
||||
|
||||
/*!
|
||||
* \brief Get a string representing the topology for debugging/display purposes
|
||||
* \since 18
|
||||
*
|
||||
* \param topology A stream topology
|
||||
* \param buf A pointer to an ast_str* used for the output.
|
||||
*
|
||||
* \retval "" (empty string) if either buf or *buf are NULL
|
||||
* \retval "(null topology)" if *topology was NULL
|
||||
* \retval <topology_representation> otherwise
|
||||
*
|
||||
* \warning No attempt should ever be made to free the returned
|
||||
* char * and it should be dup'd if needed after the ast_str is freed.
|
||||
*
|
||||
* Return format:
|
||||
* <final>? <stream> ...
|
||||
*
|
||||
* Sample return:
|
||||
* "final <audio:audio:sendrecv (ulaw,g722)> <video:video:sendonly (h264)>"
|
||||
*
|
||||
*/
|
||||
const char *ast_stream_topology_to_str(const struct ast_stream_topology *topology, struct ast_str **buf);
|
||||
|
||||
/*!
|
||||
* \brief Create a format capabilities structure containing all the formats from all the streams
|
||||
* of a particular type in the topology.
|
||||
* \since 18
|
||||
*
|
||||
* \details
|
||||
* A helper function that, given a stream topology and a media type, creates a format
|
||||
* capabilities structure containing all formats from all active streams with the particular type.
|
||||
*
|
||||
* \param topology The topology of streams
|
||||
* \param type The media type
|
||||
*
|
||||
* \retval non-NULL success (the resulting format caps must be unreffed by the caller)
|
||||
* \retval NULL failure
|
||||
*
|
||||
* \note The stream topology is NOT altered by this function.
|
||||
*
|
||||
*/
|
||||
struct ast_format_cap *ast_stream_topology_get_formats_by_type(
|
||||
struct ast_stream_topology *topology, enum ast_media_type type);
|
||||
|
||||
/*!
|
||||
* \brief Gets the first active stream of a specific type from the topology
|
||||
*
|
||||
@@ -534,4 +924,34 @@ int ast_stream_get_group(const struct ast_stream *stream);
|
||||
*/
|
||||
void ast_stream_set_group(struct ast_stream *stream, int group);
|
||||
|
||||
/*!
|
||||
* \brief Create a resolved stream topology from 2 topologies
|
||||
* \since 18
|
||||
*
|
||||
* \param pending_topology The "live" topology created from an SDP,
|
||||
* passed through the core, or used to create an SDP.
|
||||
* \param configured_topology The static topology used to validate the pending topology.
|
||||
* It MUST have only 1 stream per media type.
|
||||
* \param prefs A pointer to an ast_stream_codec_negotiation_prefs structure.
|
||||
* \param error_message If supplied, error messages will be appended.
|
||||
*
|
||||
* \details
|
||||
* The streams in the resolved topology will contain all of the attributes
|
||||
* of the corresponding stream from the pending topology. It's format_caps
|
||||
* however will contain only the formats that passed the validation
|
||||
* specified by the ast_stream_codec_negotiation_prefs structure. This may
|
||||
* mean that some of the streams format_caps will be empty. If that's the case,
|
||||
* the stream will be in a REMOVED state. With those rules in mind,
|
||||
* a resolved topology will always be returned (unless there's some catastrophic
|
||||
* allocation failure) and the resolved topology is guaranteed to have the same
|
||||
* number of streams, in the same order, as the pending topology.
|
||||
*
|
||||
* \retval NULL if there was some allocation failure.
|
||||
* \retval The joint topology.
|
||||
*/
|
||||
struct ast_stream_topology *ast_stream_topology_create_resolved(
|
||||
struct ast_stream_topology *pending_topology, struct ast_stream_topology *validation_topology,
|
||||
struct ast_stream_codec_negotiation_prefs *prefs,
|
||||
struct ast_str **error_message);
|
||||
|
||||
#endif /* _AST_STREAM_H */
|
||||
|
||||
Reference in New Issue
Block a user