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The WebRTC Audio Coding Module

WebRTC audio coding module can handle both audio sending and receiving. Folder [acm2][acm2] contains implementations of the APIs.

• Audio Sending Audio frames, each of which should always contain 10 ms worth

of data, are provided to the audio coding module through [Add10MsData()][Add10MsData]. The audio coding module uses a provided audio encoder to encoded audio frames and deliver the data to a pre-registered audio packetization callback, which is supposed to wrap the encoded audio into RTP packets and send them over a transport. Built-in audio codecs are included the [codecs][codecs] folder. The [audio network adaptor][ANA] provides an add-on functionality to an audio encoder (currently limited to Opus) to make the audio encoder adaptive to network conditions (bandwidth, packet loss rate, etc).

• Audio Receiving Audio packets are provided to the audio coding module

through [IncomingPacket()][IncomingPacket], and are processed by an audio jitter buffer ([NetEq][NetEq]), which includes decoding of the packets. Audio decoders are provided by an audio decoder factory. Decoded audio samples should be queried by calling [PlayoutData10Ms()][PlayoutData10Ms].

[acm2]: https://source.chromium.org/chromium/chromium/src/+/main:thirdparty/webrtc/modules/audiocoding/acm2/;drc=854d59f7501aac9e9bccfa7b4d1f7f4db7842719 [Add10MsData]: https://source.chromium.org/chromium/chromium/src/+/main:thirdparty/webrtc/modules/audiocoding/include/audiocodingmodule.h;l=136;drc=d82a02c837d33cdfd75121e40dcccd32515e42d6 [codecs]: https://source.chromium.org/chromium/chromium/src/+/main:thirdparty/webrtc/modules/audiocoding/codecs/;drc=883fea1548d58e0080f98d66fab2e0c744dfb556 [ANA]: https://source.chromium.org/chromium/chromium/src/+/main:thirdparty/webrtc/modules/audiocoding/audionetworkadaptor/;drc=1f99551775cd876c116d1d90cba94c8a4670d184 [IncomingPacket]: https://source.chromium.org/chromium/chromium/src/+/main:thirdparty/webrtc/modules/audiocoding/include/audiocodingmodule.h;l=192;drc=d82a02c837d33cdfd75121e40dcccd32515e42d6 [NetEq]: https://source.chromium.org/chromium/chromium/src/+/main:thirdparty/webrtc/modules/audiocoding/neteq/;drc=213dc2cfc5f1b360b1c6fc51d393491f5de49d3d [PlayoutData10Ms]: https://source.chromium.org/chromium/chromium/src/+/main:thirdparty/webrtc/modules/audiocoding/include/audiocodingmodule.h;l=216;drc=d82a02c837d33cdfd75121e40dcccd32515e42d6