On initial connection, scrcpy sent some device metadata:
- the device name (to be used as window title)
- the initial video size (before any frame or even SPS/PPS)
But it is better to provide the initial video size as part as the video
stream, so that it can be demuxed and exposed via AVCodecContext to
sinks.
This avoids to pass an explicit "initial frame size" for the screen, the
recorder and the v4l2 sink.
Previously, the packet sink push() implementation just set the codec and
notified a wait condition. Then the recorder thread read the codec and
created the AVStream.
But this was racy: an AVFrame could be pushed before the creation of the
AVStream, causing its video_stream_index or audio_stream_index to be
initialized to -1.
Also, in the future, the AVStream initialization might need data
provided by the packet sink open(), so initialize it there (with a
mutex).
The sc_file_pusher is lazy-initialized, but it was stopped and joined in
all cases (accessing uninitialized values).
Detected by poisoning the struct scrcpy instance with ASAN enabled.
All server logs were printed to stdout, while all client logs were
printed to stderr.
Instead, use stderr for warnings and errors, stdout for the others:
- stdout: verbose, debug, info
- stderr: warn, error
System.out.println() first prints the message, then the new line.
Between these two calls, the client might print a message, breaking
formatting.
Instead, call System.out.print() with '\n' appended to the message.
On the server side, several components are started, stopped and joined.
Extract an interface to handle them generically.
This will help to support both encoded and raw audio stream, because
they will be two different concrete components, but implementing the
same interface.
PR #3757 <https://github.com/Genymobile/scrcpy/pull/3757>
Expose an option to add a buffering delay (in milliseconds) before
playing audio.
This is similar to the options --display-buffer and --v4l2-buffer for
video frames.
PR #3757 <https://github.com/Genymobile/scrcpy/pull/3757>
Play the decoded audio using SDL.
The audio player frame sink receives the audio frames, resample them
and write them to a byte buffer (introduced by this commit).
On SDL audio callback (from an internal SDL thread), copy samples from
this byte buffer to the SDL audio buffer.
The byte buffer is protected by the SDL_AudioDeviceLock(), but it has
been designed so that the producer and the consumer may write and read
in parallel, provided that they don't access the same slices of the
ring-buffer buffer.
PR #3757 <https://github.com/Genymobile/scrcpy/pull/3757>
Co-authored-by: Simon Chan <1330321+yume-chan@users.noreply.github.com>
A delay buffer delayed all the frames except the first one, to open the
scrcpy window immediately and get a picture.
Make this feature optional, so that the delay buffer might also be used
for audio (especially for simulating a high delay for debugging).
PR #3757 <https://github.com/Genymobile/scrcpy/pull/3757>
For clarity, the fields used only when a delay was set were wrapped in
an anonymous structure.
Now that the delay buffer has been extracted to a separate component,
the delay is necessarily set (it may not be 0), so the fields are always
used.
PR #3757 <https://github.com/Genymobile/scrcpy/pull/3757>
The components needing delayed frames (sc_screen and sc_v4l2_sink)
managed a sc_video_buffer instance, which itself embedded a
sc_frame_buffer instance (to keep only the most recent frame).
In theory, these components should not be aware of delaying: they should
just receive AVFrames later, and only handle a sc_frame_buffer.
Therefore, refactor sc_delay_buffer as a frame source (it consumes)
frames) and a frame sink (it produces frames, after some delay), and
plug an instance in the pipeline only when a delay is requested.
This also removes the need for a specific sc_video_buffer.
PR #3757 <https://github.com/Genymobile/scrcpy/pull/3757>
There was a frame sink trait, implemented by components able to receive
AVFrames, but each frame source had to manually send frame to sinks.
In order to mutualise sink management, add a frame sink trait.
There was a packet sink trait, implemented by components able to
receive AVPackets, but each packet source had to manually send packets
to sinks.
In order to mutualise sink management, add a packet source trait.
A video buffer had 2 responsibilities:
- handle the frame delaying mechanism (queuing packets and pushing them
after the expected delay);
- keep only the most recent frame (using a sc_frame_buffer).
In order to be able to reuse only the frame delaying mechanism, extract
it to a separate component, sc_delay_buffer.
The video_buffer thread clears the queue once it is stopped, but new
frames might still be pushed asynchronously.
To avoid the problem, do not push any frame once the video_buffer is
stopped.
The packets queued for buffering were wrapped in a dynamically allocated
structure with a "next" field.
To avoid this additional layer of allocation and indirection, use a
VecDeque.
The packets queued for recording were wrapped in a dynamically allocated
structure with a "next" field.
To avoid this additional layer of allocation and indirection, use a
VecDeque.
Since in scrcpy a video packet passed to avcodec_send_packet() is always
a complete video frame, it is sufficient to call avcodec_receive_frame()
exactly once.
In practice, it also works for audio packets: the decoder produces
exactly 1 frame for 1 input packet.
In theory, it is an implementation detail though, so
avcodec_receive_frame() should be called in a loop.
