2e540a28c0
As part of go/unblocking-vp9-simulcast (Step 1), EncodedImage is being upgraded to be able to differentiate between what is a simulcast index and what is a spatial index. In order not to break existing code assuming that "if codec != VP9, SpatialIndex() is the simulcast index", SimulcastIndex() has fallback logic to return the value of spatial_index_ in the event that SetSimulcastIndex() has not been called. This allows migrating external code from (Set)SpatialIndex() to (Set)SimulcastIndex(). During this intermediate time, codec gates are still necessary in some places of the code, see TODOs added. In a follow-up CL, after having fixed dependencies, we'll be able to remove the fallback logic and rely on SimulcastIndex() and SpatialIndex() actually being the advertised index and "if codec..." hacks will be a thing of the past! Bug: webrtc:14884 Change-Id: I70095c091d0ce2336640451150888a3c3841df80 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/293343 Commit-Queue: Henrik Boström <hbos@webrtc.org> Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org> Reviewed-by: Erik Språng <sprang@webrtc.org> Reviewed-by: Evan Shrubsole <eshr@webrtc.org> Reviewed-by: Philip Eliasson <philipel@webrtc.org> Cr-Commit-Position: refs/heads/main@{#39318}
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.