Just a minor fix mostly because I noticed that I kept accidentally
forgetting to add checks to the code properly. This is one of those
cases where macros come in useful, as macros can automate the process
and help prevent these mistakes from happening by accident.
- First, I redid the output interface for libobs. I feel like it's
going in a pretty good direction in terms of design.
Right now, the design is so that outputs and encoders are separate.
One or more outputs can connect to a specific encoder to receive its
data, or the output can connect directly to raw data from libobs
output itself, if the output doesn't want to use a designated encoder.
Data is received via callbacks set when you connect to the encoder or
raw output. Multiple outputs can receive the data from a single
encoder context if need be (such as for streaming to multiple channels
at once, and/or recording with the same data).
When an encoder is first connected to, it will connect to raw output,
and start encoding. Additional connections will receive that same
data being encoded as well after that. When the last encoder has
disconnected, it will stop encoding. If for some reason the encoder
needs to stop, it will use the callback with NULL to signal that
encoding has stopped. Some of these things may be subject to change
in the future, though it feels pretty good with this design so far.
Will have to see how well it works out in practice versus theory.
- Second, Started adding preliminary RTMP/x264 output plugin code.
To speed things up, I might just make a direct raw->FFmpeg output to
create a quick output plugin that we can start using for testing all
the subsystems.
Completely revamped the entire media i/o data and handlers. The
original idea was to have a system that would have connecting media
inputs and outputs, but at a certain point I realized that this was an
unnecessary complexity for what we wanted to do. (Also, it reminded me
of directshow filters, and I HATE directshow with a passion, and
wouldn't wish it upon my greatest enemy)
Now, audio/video outputs are connected to directly, with better callback
handlers, and will eventually have the ability to automatically handle
conversions such as 4:4:4 to 4:2:0 when connecting to an input that uses
them. Doing this will allow the video/audio i/o handlers to also
prevent duplicate conversion, as well as make it easier/simple to use.
My true goal for this is to make output and encoder plugins as simple to
create as possible. I want to be able to be able to create an output
plugin with almost no real hassle of having to worry about image
conversions, media inputs/outputs, etc. A plugin developer shouldn't
have to handle that sort of stuff when he/she doesn't really need to.
Plugins will be able to simply create a callback via obs_video() and/or
obs_audio(), and they will automatically receive the audio/video data in
the formats requested via a simple callback, without needing to do
almost anything else at all.
- Add preliminary (yet to be tested) handling of timestamp invalidation
issues that can happen with specific devices, where timestamps can
reset or go backward/forward in time with no rhyme or reason. Spent
the entire day just trying to figure out the best way to handle this.
If both audio and video are present, it will increment a reference
counter if video timestamps invalidate, and decrement the reference
counter when the audio timestamps invalidate. When the reference
counter is not 0, it will not send audio as the audio will have
invalid timing. What this does is it ensures audio data will never go
out of bounds in relation to the video, and waits for both audio and
video timestamps to "jump" together before resuming audio.
- Moved async video frame timing adjustment code into
obs_source_getframe instead so it's automatically handled whenever
called.
- Removed the 'audio wait buffer' as it was an unnecessary complexity
that could have had problems in the future. Instead, audio will not
be added until video starts for sources that have both async
audio/video. Audio could have buffered for too long of a time anyway,
who knows what devices are going to do.
- Fixed a minor conversion warning in audio-io.c
- Often, timestamps will go "back" in time with certain.. terrible
devices that no one should use. When this occurs, timing is now
reset so that the new audio comes in directly after the old audio
seamlessly.
- Added a volume variable to the obs_source structure and implemented
functions for manipulating source volume.
- Added a volume variable to the audio_data structure so that the
volume will be applied when mixing.
Scenes will now signal via their source when an item has been added
or removed from them.
"add" - Item added to the scene.
Parameters: "scene": Scene that the item was added to.
"item": Item that was added.
"remove" - Item removed from the scene.
Parameters: "scene": Scene that the item was removed from.
"item": Item that was removed.
