[FFmpeg-devel] Access RTCP QoS info trought AVFormatContext

[Vitor Vanacor]

I've created a thread in the Libav-user list asking if it was possible for
an application to obtain the info of lost packets sent by RTCP during
streams (http://ffmpeg.org/pipermail/libav-user/2018-June/011193.html).
Carl answered me that this is not exposed by the external API, it is
implemented only for internal use.
I want my app to read this info to show a live status of the quality of the
stream. As my application has access to the AVFormatContext, I figure that
I can add a field to the AVFormatContext to store this data calculated in
ff_rtp_check_and_send_back_rr (
https://www.ffmpeg.org/doxygen/3.0/rtpdec_8c_source.html#l00270).
I would add something like:

s->ic->expected_interval = expected_interval;
s->ic->received_interval = received_interval;
...etc.
(Or maybe an struct instead of several different fields)

I am making this change to myself, but I would like to know:

1. Is there something inherently wrong with my approach? (Instead of using
the AVFormatContext maybe I could use the AVIOContext. I don't know if this
would make any difference)
2. Is there any chance a pull request like this will be accepted? Is there
a change you would suggest to make this acceptable? (Considering all
necessary documentation and such, of course)
3. Do you know any other way to achieve what I am trying to do?

Thank you for your time.
Vitor Vanacor