1<?% config.freshness.owner = 'minyue' %?> 2<?% config.freshness.reviewed = '2021-04-13' %?> 3 4# The WebRTC Audio Coding Module 5 6WebRTC audio coding module can handle both audio sending and receiving. Folder 7[`acm2`][acm2] contains implementations of the APIs. 8 9* Audio Sending Audio frames, each of which should always contain 10 ms worth 10 of data, are provided to the audio coding module through 11 [`Add10MsData()`][Add10MsData]. The audio coding module uses a provided 12 audio encoder to encoded audio frames and deliver the data to a 13 pre-registered audio packetization callback, which is supposed to wrap the 14 encoded audio into RTP packets and send them over a transport. Built-in 15 audio codecs are included the [`codecs`][codecs] folder. The 16 [audio network adaptor][ANA] provides an add-on functionality to an audio 17 encoder (currently limited to Opus) to make the audio encoder adaptive to 18 network conditions (bandwidth, packet loss rate, etc). 19 20* Audio Receiving Audio packets are provided to the audio coding module 21 through [`IncomingPacket()`][IncomingPacket], and are processed by an audio 22 jitter buffer ([NetEq][NetEq]), which includes decoding of the packets. 23 Audio decoders are provided by an audio decoder factory. Decoded audio 24 samples should be queried by calling [`PlayoutData10Ms()`][PlayoutData10Ms]. 25 26[acm2]: https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/modules/audio_coding/acm2/;drc=854d59f7501aac9e9bccfa7b4d1f7f4db7842719 27[Add10MsData]: https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/modules/audio_coding/include/audio_coding_module.h;l=136;drc=d82a02c837d33cdfd75121e40dcccd32515e42d6 28[codecs]: https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/modules/audio_coding/codecs/;drc=883fea1548d58e0080f98d66fab2e0c744dfb556 29[ANA]: https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/modules/audio_coding/audio_network_adaptor/;drc=1f99551775cd876c116d1d90cba94c8a4670d184 30[IncomingPacket]: https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/modules/audio_coding/include/audio_coding_module.h;l=192;drc=d82a02c837d33cdfd75121e40dcccd32515e42d6 31[NetEq]: https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/modules/audio_coding/neteq/;drc=213dc2cfc5f1b360b1c6fc51d393491f5de49d3d 32[PlayoutData10Ms]: https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/modules/audio_coding/include/audio_coding_module.h;l=216;drc=d82a02c837d33cdfd75121e40dcccd32515e42d6 33