Effectively reverting parts of d314d47, this commit removes the new
functions that got added to remove the flags parameter. Instead, it just
marks the parameter as unused and documents this. Having what is
effectively an API break just to remove a parameter is a bit overkill.
The other parts of d314d47 which cleaned up the usage of the flags
parameter are untouched here.
This deprecates the following functions, replacing them with new
versions:
- `obs_output_can_begin_data_capture()` - now `*capture2()`
- `obs_output_initialize_encoders()` - now `*encoders2()`
- `obs_output_begin_data_capture()` - now `*capture2()`
The flags parameter was initially designed to support audio-only or
video-only operation of an output which had the `OBS_OUTPUT_AV` flag,
however, full support for that was never implemented, and there are
likely fundamental issues with an implementation, mainly that most
outputs are programmed assuming that there will always be at least one
audio and one video track. This requires new flags specifying support
for optional audio/video, among other things.
An implementation to allow audio/video to be optional is best done
using the flag technique above, with audio/video enablement specified
by whether media (raw, `video_t/audio_t`) or encoder (`obs_encoder_t`)
objects are specified.
Since every implementation I could find always specifies `flags` as 0,
I was able to safely conclude that immediately removing the parameter's
functionality is safe to do.
Since OBS outputs can have any combination of flags for encoded,
video, audio, and service, there are a number of cases where it would
be a good idea to validate that we're not allowing output changes that
risk undefined behavior given the supported flags.
This also does a mild amount of code cleanup, adding inline functions
for checking the flags mentioned above.
Code submissions have continually suffered from formatting
inconsistencies that constantly have to be addressed. Using
clang-format simplifies this by making code formatting more consistent,
and allows automation of the code formatting so that maintainers can
focus more on the code itself instead of code formatting.
(Note: This commit also modifies obs-ffmpeg and obs-outputs)
API Changed:
obs_output_info::void (*stop)(void *data);
To:
obs_output_info::void (*stop)(void *data, uint64_t ts);
This fixes the long-time design flaw where obs_output_stop and the
output 'stop' callback would just shut down the output without
considering the timing of when obs_output_stop was used, discarding any
possible buffering and causing the output to get cut off at an
unexpected timing.
The 'stop' callback of obs_output_info now takes a timestamp with the
expectation that the output will use that timestamp to stop output data
in accordance to that timing. obs_output_stop now records the timestamp
at the time that the function is called and calls the 'stop' callback
with that timestamp. If needed, obs_output_force_stop will still stop
the output immediately without buffering.
This feature allows a user to delay an output (as long as the output
itself supports it). Needless to say this intended for live streams,
where users may want to delay their streams to prevent stream sniping,
cheating, and other such things.
The design this time was a bit more elaborate, but still simple in
design: the user can now schedule stops/starts without having to wait
for the stream itself to stop before being able to take any action.
Optionally, they can also forcibly stop stream (and delay) in case
something happens which they might not want to be streamed.
Additionally, a new option was added to preserve stream cutoff point on
disconnections/reconnections, so that if you get disconnected while
streaming, when it reconnects, it will reconnect right at the point
where it left off. This will probably be quite useful for a number of
applications in addition to regular delay, such as setting the delay to
1 second and then using this feature to minimize, for example, a
critical stream such as a tournament stream from getting any of its
stream data cut off. However, using this feature will of course cause
the stream data to buffer and increase delay (and memory usage) while
it's in the process of reconnecting.
