Commit graph

27 commits

Author SHA1 Message Date
Romain Vimont
4c4d02295c Add buffering debugging tools
Output buffering and clock logs by disabling a compilation flag.
2021-07-14 14:54:22 +02:00
Romain Vimont
79278961b9 Implement buffering
To minimize latency (at the cost of jitter), scrcpy always displays a
frame as soon as it available, without waiting.

However, when recording (--record), it still writes the captured
timestamps to the output file, so that the recorded file can be played
correctly without jitter.

Some real-time use cases might benefit from adding a small latency to
compensate for jitter too. For example, few tens of seconds of latency
for live-streaming are not important, but jitter is noticeable.

Therefore, implement a buffering mechanism (disabled by default) to add
a configurable latency delay.

PR #2417 <https://github.com/Genymobile/scrcpy/issues/2417>
2021-07-14 14:27:33 +02:00
Romain Vimont
408a301201 Notify new frames via callbacks
Currently, a frame is available to the consumer as soon as it is pushed
by the producer (which can detect if the previous frame is skipped).

Notify the new frames (and frame skipped) via callbacks instead.

This paves the way to add (optional) buffering, which will introduce a
delay between the time when the frame is produced and the time it is
available to be consumed.
2021-07-14 14:22:32 +02:00
Romain Vimont
4d8bcfc68a Extract current video_buffer to frame_buffer
The current video buffer only stores one pending frame.

In order to add a new buffering feature, move this part to a separate
"frame buffer". Keep the video_buffer, which currently delegates all its
calls to the frame_buffer.
2021-07-14 14:22:32 +02:00
Romain Vimont
336248df08 Rename video_buffer to sc_video_buffer
Add a scrcpy-specific prefix.
2021-07-14 14:22:32 +02:00
Romain Vimont
2a94a2b119 Remove video_buffer callbacks
Now that screen is both the owner and the listener of the video buffer,
execute the code directly without callbacks.
2021-04-25 14:38:42 +02:00
Romain Vimont
2ddf760c09 Make video_buffer more generic
The video buffer took ownership of the producer frame (so that it could
swap frames quickly).

In order to support multiple sinks plugged to the decoder, the decoded
frame must not be consumed by the display video buffer.

Therefore, move the producer and consumer frames out of the video
buffer, and use FFmpeg AVFrame refcounting to share ownership while
avoiding copies.
2021-04-25 14:38:42 +02:00
Romain Vimont
55806e7d31 Remove option --render-expired-frames
This flag forced the decoder to wait for the previous frame to be
consumed by the display.

It was initially implemented as a compilation flag for testing, not
intended to be exposed at runtime. But to remove ifdefs and to allow
users to test this flag easily, it had finally been exposed by commit
ebccb9f6cc.

In practice, it turned out to be useless: it had no practical impact,
and it did not solve or mitigate any performance issues causing frame
skipping.

But that added some complexity to the codebase: it required an
additional condition variable, and made video buffer calls possibly
blocking, which in turn required code to interrupt it on exit.

To prepare support for multiple sinks plugged to the decoder (display
and v4l2 for example), the blocking call used for pacing the decoder
output becomes unacceptable, so just remove this useless "feature".
2021-04-25 14:38:42 +02:00
Romain Vimont
eb7e1070cf Release frame data as soon as possible
During a frame swap, one of the two frames involved can be released.
2021-03-06 22:58:03 +01:00
Romain Vimont
386f017ba9 Factorize frame swap 2021-03-06 22:58:03 +01:00
Romain Vimont
cb9c42bdcb Use a callback to notify frame skip
A skipped frame is detected when the producer offers a frame while the
current pending frame has not been consumed.

However, the producer (in practice the decoder) is not interested in the
fact that a frame has been skipped, only the consumer (the renderer) is.

Therefore, notify frame skip via a consumer callback. This allows to
manage the skipped and rendered frames count at the same place, and
remove fps_counter from decoder.
2021-03-06 22:58:03 +01:00
Romain Vimont
fb9f9848bd Use a callback to notify a new frame
Make the decoder independant of the SDL even mechanism, by making the
consumer register a callback on the video_buffer.
2021-03-06 22:58:03 +01:00
Romain Vimont
441d3fb119 Make video buffer more generic
Video buffer is a tool between a frame producer and a frame consumer.

For now, it is used between a decoder and a renderer, but in the future
another instance might be used to swscale decoded frames.
2021-03-06 22:58:03 +01:00
Romain Vimont
cb197ee3a2 Move fps counter out of video buffer
In order to make video buffer more generic, move out its specific
responsibility to count the fps between the decoder and the renderer.
2021-03-06 22:58:03 +01:00
Romain Vimont
c0c4ba7009 Add intermediate frame in video buffer
There were only two frames simultaneously:
 - one used by the decoder;
 - one used by the renderer.

When the decoder finished decoding a frame, it swapped it with the
rendering frame.

Adding a third frame provides several benefits:
 - the decoder do not have to wait for the renderer to release the
   mutex;
 - it simplifies the video_buffer API;
 - it makes the rendering frame valid until the next call to
   video_buffer_take_rendering_frame(), which will be useful for
   swscaling on window resize.
2021-02-17 09:54:03 +01:00
Romain Vimont
54f5c42d7b Add mutex assertions 2021-02-17 09:54:03 +01:00
Romain Vimont
f6320c7e31 Wrap SDL thread functions into scrcpy-specific API
The goal is to expose a consistent API for system tools, and paves the
way to make the "core" independant of SDL in the future.
2021-02-17 09:54:03 +01:00
Romain Vimont
59feb2a15c Group common includes into common.h
Include config.h and compat.h in common.h, and include common.h from all
source files.
2021-01-08 19:22:10 +01:00
Romain Vimont
510caff0cd Replace SDL_assert() by assert()
SDL_assert() open a dialog on assertion failure.

There is no reason not to use assert() directly.
2019-11-27 21:19:46 +01:00
Romain Vimont
dfd0707a29 Move utilities to util/ 2019-11-24 11:53:23 +01:00
Romain Vimont
e2a272bf99 Improve framerate counting
The FPS counter was called only on new frames, so it could not print
values regularly, especially when there are very few FPS (when the
device surface does not change).

To the extreme, it was never able to display 0 fps.

Add a separate thread to print framerate every second.
2019-06-07 17:16:26 +02:00
Romain Vimont
ebccb9f6cc Add runtime option to render expired frames
Replace the compilation flag SKIP_FRAMES by a runtime flag to force
rendering of expired frames. By default, the expired frames are skipped.
2019-06-05 21:39:42 +02:00
Romain Vimont
8595862005 Use explicit output parameter for skipped frame
The function video_buffer_offer_decoded_frame() returned a bool to
indicate whether the previous frame had been consumed.

This was confusing, because we could expect the returned bool report
whether the action succeeded.

Make the semantic explicit by using an output parameter.

Also revert the flag (report if the frame has been skipped instead of
consumed) to avoid confusion for the first frame (the previous is
neither skipped nor consumed because there is no previous frame).
2019-03-03 00:35:20 +01:00
Romain Vimont
dfed1b250e Replace SDL types by C99 standard types
Scrcpy is a C11 project. Use the C99 standard types instead of the
SDL-specific types:

    SDL_bool -> bool
    SintXX   -> intXX_t
    UintXX   -> uintXX_t
2019-03-02 23:55:23 +01:00
Romain Vimont
aeda583a2c Update code style
Limit source code to 80 chars, and declare functions return type and
modifiers on a separate line.

This allows to avoid very long lines, and all function names are
aligned.

(We do this on VLC, and I like it.)
2019-03-02 20:28:46 +01:00
Romain Vimont
84270e2d18 Rename "stop" to "interrupt"
The purpose of video_buffer_stop() is to interrupt any blocking call, so
rename it to video_buffer_interrupt().
2019-03-02 17:03:15 +01:00
Romain Vimont
fff87095d9 Rename "frames" to "video_buffer"
It better describes the purpose of the structure.
2019-03-02 15:24:33 +01:00