Two new classes are added to WebRTC from Chrome: ChannelMixer and ChannelMixingMatrix but they are not yet utilized in the audio path for WebRTC. The idea is to utilize these new classes when adding support for multi- channel encoding/decoding in WebRTC/Chrome. Adds support for a new enumerator call webrtc::ChannelLayout and some helper methods which maps between channel layout and number of channels. These parts are also copied from Chrome. Minor (cosmetic) changes are also done on the AudioFrame to prepare for upcoming work. Bug: webrtc:10783 Change-Id: I6cd7a13a3bc1c8bbfa19bc974c7a011d22d19197 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/141674 Commit-Queue: Henrik Andreassson <henrika@webrtc.org> Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org> Cr-Commit-Position: refs/heads/master@{#28482}
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 “.hand.ccfiles come in pairs” rule, so if you declare something inapi/path/to/foo.h, it should be defined inapi/path/to/foo.cc. - Headers in
api/should, if possible, not#includeheaders outsideapi/. It’s not always possible to avoid this, but be aware that it adds to a small mountain of technical debt that we’re trying to shrink. .ccfiles inapi/, on the other hand, are free to#includeheaders outsideapi/.
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 won’t 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.