Chen Xing cd8a6e2f38 Add writing and parsing of the abs-capture-time RTP header extension.
This change adds the writing and parsing of the `abs-capture-time` RTP header extension defined at:

  http://www.webrtc.org/experiments/rtp-hdrext/abs-capture-time

We are still missing the code to:

- Negotiate the header extension.
- Collect capture time for audio and video and have the info sent with the header extension.
- Receive the header extension and use its info.

Bug: webrtc:10739
Change-Id: I75af492e994367f45a5bdc110af199900327b126
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/144221
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Chen Xing <chxg@google.com>
Cr-Commit-Position: refs/heads/master@{#28468}
2019-07-03 14:07:36 +00:00
..
2019-06-03 08:15:09 +00:00
2019-01-25 20:29:58 +00:00
2019-02-01 13:24:47 +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.