webrtc/api
Bjorn A Mellem 8e1343aeda Add an alt-protocol to SDP to indicate which m= sections use a plugin transport.
The plugin transport parameters (a=x-opaque: lines) relate to how to create and
set up a plugin transport.  When SDP bundle is used, the x-opaque line needs to
be copied into the bundled m= section.  This means x-opaque can appear on a
section even if the offerer does not intend to use the transport for the media
described by that section.  Consequently, the answerer cannot currently tell
whether the caller is offering an alternate transport for media, data, or both.

This change adds an a=x-alt-protocol: line to SDP.  The value following this
line matches the <protocol> part of the x-opaque:<protocol>:<params> line.
However, alt-protocol is not bundled--it only ever applies to the m= section
that contains the line.  This allows the offerer to express which m= sections
should actually use an alternate transport, even in the case of bundle.

Note that this is still limited by the available configuration options:
datagram transport can be used for media (audio + video) and/or data.  It is
still not possible to use it for audio but not video, or vice versa.

PeerConnection places an alt-protocol line in each media (audio/video) m=
section if it is configured to use a datagram transport for media.  It places
an alt-protocol line in each data m= section if it is configured to use a
datagram transport for data channels.  PeerConnection leaves alt-protocol in
media (audio/video) m= sections of the answer if it is configured to use a
datagram transport for media, and in data m= sections of the answer if it is
configured to use a datagram transport for data channels.

JsepTransport now negotiates use of the datagram transport independently for
media and data channels.  It only uses it for media if the m= sections for
bundled audio/video have an alt-protocol line matching the x-opaque protocol,
and only uses it for data channels if a bundled m= section for data has an
alt-protocol line matching the x-opaque protocol.

Bug: webrtc:9719
Change-Id: I773e4fc10c57d815afcd76a2a74da38dd0c52b3b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/154763
Reviewed-by: Steve Anton <steveanton@webrtc.org>
Reviewed-by: Seth Hampson <shampson@webrtc.org>
Commit-Queue: Bjorn Mellem <mellem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29351}
2019-09-30 23:10:34 +00:00
..
audio Use std::make_unique instead of absl::make_unique. 2019-09-17 15:47:29 +00:00
audio_codecs Delete AudioDecoder method IncomingPacket 2019-09-24 08:30:24 +00:00
call Replacing bandwidth adaptation trial with stable target in Opus encoder. 2019-09-24 16:35:02 +00:00
crypto Introduce api/crypto/BUILD.gn. 2019-09-13 17:21:47 +00:00
rtc_event_log Adds remote estimates to rtc event log. 2019-09-19 09:22:37 +00:00
stats Add qualityLimitationResolutionChanges stat 2019-09-09 15:22:57 +00:00
task_queue Use std::make_unique instead of absl::make_unique. 2019-09-17 15:47:29 +00:00
test Add an alt-protocol to SDP to indicate which m= sections use a plugin transport. 2019-09-30 23:10:34 +00:00
transport Replacing bandwidth adaptation trial with stable target in Opus encoder. 2019-09-24 16:35:02 +00:00
units Format almost everything. 2019-07-08 13:45:15 +00:00
video Fixes for support of disabling lower spatial layers in VP9 2019-09-30 13:20:12 +00:00
video_codecs Revert "Fix minor regression caused by a8336d3" 2019-09-18 14:38:15 +00:00
array_view_unittest.cc Format almost everything. 2019-07-08 13:45:15 +00:00
array_view.h Adding reinterpret to ArrayView to allow data manipulation. 2019-03-22 18:15:22 +00:00
async_resolver_factory.h (4) Rename files to snake_case: update BUILD.gn, include paths, header guards, and DEPS entries 2019-01-11 17:11:39 +00:00
audio_options.cc Remove deprecated code related to AEC2 2019-08-07 10:09:36 +00:00
audio_options.h Remove deprecated code related to AEC2 2019-08-07 10:09:36 +00:00
BUILD.gn Return const char* from ToString(RTCErrorType error). 2019-09-20 08:27:52 +00:00
candidate.cc (4) Rename files to snake_case: update BUILD.gn, include paths, header guards, and DEPS entries 2019-01-11 17:11:39 +00:00
candidate.h (4) Rename files to snake_case: update BUILD.gn, include paths, header guards, and DEPS entries 2019-01-11 17:11:39 +00:00
congestion_control_interface.h Move MediaTransportInterface out of the libjingle_peerconnection_api target 2019-09-13 10:49:56 +00:00
create_peerconnection_factory.cc Use std::make_unique instead of absl::make_unique. 2019-09-17 15:47:29 +00:00
create_peerconnection_factory.h Force DefaultTaskQueueFactory in legacy CreatePeerConnectionFactory 2019-06-19 17:11:04 +00:00
crypto_params.h (4) Rename files to snake_case: update BUILD.gn, include paths, header guards, and DEPS entries 2019-01-11 17:11:39 +00:00
data_channel_interface.cc Datachannel: Use absl::optional for maxRetransmits and maxRetransmitTime. 2019-04-09 08:32:43 +00:00
data_channel_interface.h Format almost everything. 2019-07-08 13:45:15 +00:00
data_channel_transport_interface.h Move MediaTransportInterface out of the libjingle_peerconnection_api target 2019-09-13 10:49:56 +00:00
datagram_transport_interface.h Move MediaTransportInterface out of the libjingle_peerconnection_api target 2019-09-13 10:49:56 +00:00
DEPS Prepare to move packet_socket_factory to api/. 2019-09-06 09:09:02 +00:00
DESIGN.md A threading explanation 2019-06-03 08:15:09 +00:00
dtls_transport_interface.cc Expose SSL ciphersuite on the webrtc::DtlsTransport interface 2019-04-12 08:29:59 +00:00
dtls_transport_interface.h Expose SSL ciphersuite on the webrtc::DtlsTransport interface 2019-04-12 08:29:59 +00:00
dtmf_sender_interface.h (4) Rename files to snake_case: update BUILD.gn, include paths, header guards, and DEPS entries 2019-01-11 17:11:39 +00:00
fec_controller_override.h Define FecControllerOverride and plumb it down to VideoEncoder 2019-06-28 15:57:22 +00:00
fec_controller.h Make VideoFrameType an enum class, and move to separate file and target 2019-03-22 12:44:51 +00:00
function_view_unittest.cc Format almost everything. 2019-07-08 13:45:15 +00:00
function_view.h Move rtc::FunctionView to the public API 2019-03-21 15:23:05 +00:00
ice_transport_factory.cc Use std::make_unique instead of absl::make_unique. 2019-09-17 15:47:29 +00:00
ice_transport_factory.h Add overload to CreateIceTransport that takes additional dependencies 2019-07-01 21:37:54 +00:00
ice_transport_interface.h Add IceTransportInterface object 2019-01-30 16:16:51 +00:00
jsep_ice_candidate.cc Use unique_ptr in JsepCandidateCollection 2019-07-31 01:48:07 +00:00
jsep_ice_candidate.h Use unique_ptr in JsepCandidateCollection 2019-07-31 01:48:07 +00:00
jsep_session_description.h Remove deprecated JsepSession initializer 2019-06-11 17:35:30 +00:00
jsep.cc Move SdpType from/to string definition close to declaration. 2018-10-12 09:59:40 +00:00
jsep.h (4) Rename files to snake_case: update BUILD.gn, include paths, header guards, and DEPS entries 2019-01-11 17:11:39 +00:00
media_stream_interface.cc New target for api/rtp_parameters.h and api/media_types.h. 2019-08-29 09:04:32 +00:00
media_stream_interface.h New build target api:media_interface 2019-09-19 09:32:27 +00:00
media_stream_proxy.h (4) Rename files to snake_case: update BUILD.gn, include paths, header guards, and DEPS entries 2019-01-11 17:11:39 +00:00
media_stream_track_proxy.h (4) Rename files to snake_case: update BUILD.gn, include paths, header guards, and DEPS entries 2019-01-11 17:11:39 +00:00
media_transport_config.h Move MediaTransportInterface out of the libjingle_peerconnection_api target 2019-09-13 10:49:56 +00:00
media_transport_interface.h Move MediaTransportInterface out of the libjingle_peerconnection_api target 2019-09-13 10:49:56 +00:00
media_types.cc New target for api/rtp_parameters.h and api/media_types.h. 2019-08-29 09:04:32 +00:00
media_types.h New target for api/rtp_parameters.h and api/media_types.h. 2019-08-29 09:04:32 +00:00
network_state_predictor.h Add base class NetworkPredictor and NetworkPredictorFactory and wire up. 2019-04-10 12:38:58 +00:00
notifier.h (4) Rename files to snake_case: update BUILD.gn, include paths, header guards, and DEPS entries 2019-01-11 17:11:39 +00:00
OWNERS Remove myself from OWNERS in a few places. 2019-06-10 07:57:46 +00:00
packet_socket_factory.h Prepare to move packet_socket_factory to api/. 2019-09-06 09:09:02 +00:00
peer_connection_factory_proxy.h Delete deprecated version of PeerConnectionFactoryInterface::StartAecDump 2019-06-27 07:33:59 +00:00
peer_connection_interface.cc Delete almost all default methods on PeerConnectionInterface 2019-09-18 16:27:44 +00:00
peer_connection_interface.h Allow receive-only use of datagram transport for data channels. 2019-09-26 20:01:06 +00:00
peer_connection_proxy.h Delete almost all default methods on PeerConnectionInterface 2019-09-18 16:27:44 +00:00
proxy.cc Make member internal::SynchronousMethodCall::e_ a non-pointer. 2018-11-15 10:42:36 +00:00
proxy.h Remove rtc_base/scoped_ref_ptr.h. 2019-01-25 20:29:58 +00:00
README.md Add a small README file for api/ 2019-02-01 13:24:47 +00:00
ref_counted_base.h (4) Rename files to snake_case: update BUILD.gn, include paths, header guards, and DEPS entries 2019-01-11 17:11:39 +00:00
rtc_error_unittest.cc Format almost everything. 2019-07-08 13:45:15 +00:00
rtc_error.cc Return const char* from ToString(RTCErrorType error). 2019-09-20 08:27:52 +00:00
rtc_error.h Return const char* from ToString(RTCErrorType error). 2019-09-20 08:27:52 +00:00
rtc_event_log_output_file_unittest.cc Use std::make_unique instead of absl::make_unique. 2019-09-17 15:47:29 +00:00
rtc_event_log_output_file.cc Format almost everything. 2019-07-08 13:45:15 +00:00
rtc_event_log_output_file.h Format almost everything. 2019-07-08 13:45:15 +00:00
rtc_event_log_output.h Adds functionality to write logs to memory. 2019-01-16 17:36:31 +00:00
rtp_headers.cc Reland "[cleanup] Remove useless includes." 2018-10-08 07:44:19 +00:00
rtp_headers.h Make NetworkStateEstimator injectable in RemoteBitrateEstimator 2019-09-10 18:47:36 +00:00
rtp_packet_info_unittest.cc Add AbsoluteCaptureTime to RtpPacketInfo. 2019-08-07 10:12:56 +00:00
rtp_packet_info.cc Add AbsoluteCaptureTime to RtpPacketInfo. 2019-08-07 10:12:56 +00:00
rtp_packet_info.h Add AbsoluteCaptureTime to RtpPacketInfo. 2019-08-07 10:12:56 +00:00
rtp_packet_infos_unittest.cc Add AbsoluteCaptureTime to RtpPacketInfo. 2019-08-07 10:12:56 +00:00
rtp_packet_infos.h Avoid copying of vectors in RtpPacketInfos. 2019-08-14 15:46:02 +00:00
rtp_parameters_unittest.cc Format almost everything. 2019-07-08 13:45:15 +00:00
rtp_parameters.cc Allow AbsSendTime extension to be used for audio streams. 2019-07-24 10:58:37 +00:00
rtp_parameters.h Format almost everything. 2019-07-08 13:45:15 +00:00
rtp_receiver_interface.cc Split out RtpSource from libjingle_peerconnection_api 2019-09-02 14:04:47 +00:00
rtp_receiver_interface.h Split out RtpSource from libjingle_peerconnection_api 2019-09-02 14:04:47 +00:00
rtp_sender_interface.cc Removing non-const RtpSenderInterface::GetParameters(). 2019-02-23 00:51:30 +00:00
rtp_sender_interface.h Add RtpSenderInterface.SetStreams 2019-05-20 18:38:06 +00:00
rtp_transceiver_interface.cc Implement RTCRtpTransceiver.setCodecPreferences 2019-05-01 20:14:59 +00:00
rtp_transceiver_interface.h Implement RTCRtpTransceiver.setCodecPreferences 2019-05-01 20:14:59 +00:00
scoped_refptr.h Add element_type typedef to rtc::scoped_refptr 2018-12-20 19:11:22 +00:00
sctp_transport_interface.cc Format almost everything. 2019-07-08 13:45:15 +00:00
sctp_transport_interface.h Export symbols needed by the Chromium component build (part 8). 2019-04-02 10:13:36 +00:00
set_remote_description_observer_interface.h (4) Rename files to snake_case: update BUILD.gn, include paths, header guards, and DEPS entries 2019-01-11 17:11:39 +00:00
stats_types.cc Reporting audio device underrun counter 2019-08-16 11:49:55 +00:00
stats_types.h Reporting audio device underrun counter 2019-08-16 11:49:55 +00:00
turn_customizer.h (4) Rename files to snake_case: update BUILD.gn, include paths, header guards, and DEPS entries 2019-01-11 17:11:39 +00:00
uma_metrics.h Remove backwards compatibility names from api/uma_metrics.h. 2019-08-29 13:35:56 +00:00
video_track_source_proxy.h Remove SetLatency/GetLatency from MediaSourceInterface API level 2019-04-18 19:11:31 +00:00

How to write code in the api/ directory

Mostly, just follow the regular style guide, but:

  • Note that api/ code is not exempt from the “.h and .cc files come in pairs” rule, so if you declare something in api/path/to/foo.h, it should be defined in api/path/to/foo.cc.
  • Headers in api/ should, if possible, not #include headers outside api/. Its not always possible to avoid this, but be aware that it adds to a small mountain of technical debt that were trying to shrink.
  • .cc files in api/, on the other hand, are free to #include headers outside api/.

That is, the preferred way for api/ code to access non-api/ code is to call it from a .cc file, so that users of our API headers wont transitively #include non-public headers.

For headers in api/ that need to refer to non-public types, forward declarations are often a lesser evil than including non-public header files. The usual rules still apply, though.

.cc files in api/ should preferably be kept reasonably small. If a substantial implementation is needed, consider putting it with our non-public code, and just call it from the api/ .cc file.