This fixes a bug where the RTMP send thread can deadlock upon the
underlying TCP connection being broken. By introducing a send timeout,
this allows the thread to unblock and give up, triggering a reconnect
as normal. The correct solution to this problem would be to rewrite
librtmp with asynchronous IO, but that seems like something unlikely
to happen.
**Before**:
- Start stream in OBS
- Use tool (pfSense) to invalidate connection state
- OBS bitrate drops to 0
- Output does not respond to stop signals, and hangs for an undefined
amount of time (usually multiple minutes) before finally giving up
**After**:
- Start stream in OBS
- Use tool (pfSense) to invalidate connection state
- OBS bitrate drops to 0
- Output sits in blocked state for maximum of 8 seconds, then cleans
up and triggers the reconnect logic
Bug is caused by the internal connection variables not being reset on
reconnect, leading OBS to both be unable to parse valid packets from and
send valid packets to the remote end. This commit splits RTMP_Init off
into a new RTMP_Reset function, which resets these internal variables
without re-initing the rest of the library. The original RTMP_Init
calls the new function, perfectly preserving the old behaviour while
adding a new reset function to address the issue with.
Fixesobsproject/obs-studio#2865
This code is very old and seems to be non-functional in its current
state. The TLS support is also complicated to maintain across multiple
deprecated mbedtls functions.
Per mbedtls documentation, "If you share a context between threads, you
need to call these functions only from the main thread, at the beginning
and end of the context's lifetime.". OBS violated this since librtmp
uses a global context and it was allocated and freed in different
threads such as the auto config test.
This commit attaches the mbedtls context to an RTMP structure so there
is no more global state. It also fixes a rare double-free crash that
could occur if RTMP_TLS_Free was called twice (this happened in rare
situations such as the auto config running followed by a mode change
from Advanced to Simple).
Certain RTMP services will support multi audio tracks via RTMP. This
updates librtmp with custom code that enables multiple streams per
connection to be used; each subsequent stream typically containing extra
audio tracks. The audio encoder names are used to indicate the names of
tracks, and the name of the tracks are used for the stream keys for
those subsequent tracks.
Note that this is a somewhat heavily modified custom version of librtmp.
I modified all the platform specific code that we were using for the
OBS1 to make it platform-independent.
I don't really like the code in this library, but it works well enough,
so I can't really fault anyone for it. It's just very.. unclean. Even
for a C library, quite unclean. Some parts are also a little less safe
than I'd prefer as well.
