Ref: <https://github.com/Genymobile/scrcpy/issues/829>
Suggested-by: NLouis Kruger <louisk@gmail.com>

To packetize the H.264 raw stream, av_parser_parse2() (called by
av_read_frame()) knows that it has received a full frame only after it
has received some data for the next frame. As a consequence, the client
always waited until the next frame before sending the current frame to
the decoder!

On the device side, we know packets boundaries. To reduce latency,
make the device always transmit the "frame meta" to packetize the stream
manually (it was already implemented to send PTS, but only enabled on
recording).

On the client side, replace av_read_frame() by manual packetizing and
parsing.

<https://stackoverflow.com/questions/50682518/replacing-av-read-frame-to-reduce-delay>
<https://trac.ffmpeg.org/ticket/3354>

A drag & drop always pushed the file to /sdcard/.

Add an option to customize the target directory.

Fixes <https://github.com/Genymobile/scrcpy/issues/659>

Add an option to set a custom window title.
Signed-off-by: NRomain Vimont <rom@rom1v.com>

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.

After commit bfb86ca2, the controller
was not stopped and destroyed on quit.

Replace the compilation flag SKIP_FRAMES by a runtime flag to force
rendering of expired frames. By default, the expired frames are skipped.

In addition to the shortcut (Ctrl+o) to turn the device screen off, add
a command-line argument to turn it off on start.

If --no-control is disabled, there is no need for a controller.

It also avoids to power on the device on start if control is disabled.

Starting the server requires more and more parameters. For clarity,
group them in a struct.

For clarity, store the flag resulting of the command-line options
--no-control and --no-display into "control" and "display".

The default behavior seems annoying.

Fixes <https://github.com/Genymobile/scrcpy/issues/554>

handle_event return the type enum event_result not bool
Signed-off-by: NYu-Chen Lin <npes87184@gmail.com>

The socket used the device-to-computer direction to stream the video and
the computer-to-device direction to send control events.

Some features, like copy-paste from device to computer, require to send
non-video data from the device to the computer.

To make them possible, use two sockets:
 - one for streaming the video from the device to the client;
 - one for control/events in both directions.

The cleanup is not linear: for example, the server must be stopped and
its sockets must be shutdown after the stream and controller are stopped
(so that they don't continue processing garbage), but before they are
joined, to avoid a deadlock if they are blocked on a socket read.

Simplify the spaghetti-cleanup by keeping trace of initialization at
runtime.

The resulting socket is accessible from the server instance, there is no
need to return it.

This paves the way to use several sockets in parallel.

Previous refactorings broke indentation.

Compositor bypass is meant for fullscreen games consuming lots of GPU
resources. For a light app that will usually be windowed, this only
causes unnecessary compositor suspends, especially visible (and
annoying) with complying window manager like KWin.
Signed-off-by: NRomain Vimont <rom@rom1v.com>

Mouse focus clickthrough didn't work due to compat.h header not being
included in scrcpy.c.
Signed-off-by: NRomain Vimont <rom@rom1v.com>

Replace the "global" control flag in the input_manager by a function
parameter to make explicit that the behavior depends whether
--no-control has been set.

The SDL video subsystem is not necessary if we don't display the video.

Move the sdl_init_and_configure() function from screen.c to scrcpy.c,
because it is not only related to the screen display.

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

Add an option to disable device control: -n/--no-control.

The description of scrcpy is "Display and control your Android device".
We want an option to disable display, another one to disable control.

For naming consistency, name it --no-display.

Also change the shortname to -N, so that we can use -n for --no-control
later.

If --no-window is passed, there is no need to register an event watcher.

To avoid too many levels of nested blocks, move the event handling logic
in a separate function.

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.)

Disable decoder, screen (display), file_handler and controller when
--no-window is requested.

<https://github.com/Genymobile/scrcpy/pull/418>

The decoder initially read from the socket, decoded the video and sent
the decoded frames to the screen:

              +---------+      +----------+
  socket ---> | decoder | ---> |  screen  |
              +---------+      +----------+

The design was simple, but the decoder had several responsabilities.

Then we added the recording feature, so we added a recorder, which
reused the packets received from the socket managed by the decoder:

                                    +----------+
                               ---> |  screen  |
              +---------+     /     +----------+
  socket ---> | decoder | ----
              +---------+     \     +----------+
                               ---> | recorder |
                                    +----------+

This lack of separation of concerns now have concrete implications: we
could not (properly) disable the decoder/display to only record the
video.

Therefore, split the decoder to extract the stream:

                                    +----------+      +----------+
                               ---> | decoder  | ---> |  screen  |
              +---------+     /     +----------+      +----------+
  socket ---> | stream  | ----
              +---------+     \     +----------+
                               ---> | recorder |
                                    +----------+

This will allow to record the stream without decoding the video.

This avoids to test explicitly whether options->record_filename is NULL.

The order of cleanup was not the reverse as the initialization order. As
a consequence, recorder_destroy() could theoretically be called even if
recorder_init() failed.

It better describes the purpose of the structure.

Implement recording to Matroska files.

The format to use is determined by the option -F/--record-format if set,
or by the file extension (".mp4" or ".mkv").

FFmpeg logs can be useful to understand the cause of issues.

It is very convenient when I play mobile game and watch video at the
same time.

Tested on Linux mint Cinnamon as well as Windows 10.
Signed-off-by: NYu-Chen Lin <npes87184@gmail.com>

The client needs the PTS for each frame only if recording is enabled.
Otherwise, the PTS are not necessary, and the protocol is more
straighforward.

To record the screen to a local file:

    scrcpy --record file.mp4

This partially reverts commit f00c6c5b.

On Ctrl+C, we need to execute cleanup code. For instance, if recording
is enabled, we need to write MP4 file trailer on exit.

Custom SDL signal handlers were disabled because it leaded to process
hanging on Ctrl+C during network calls on initialization, but now it
seems to work correctly, the network calls return immediately on signal.

Implement recording in a separate "class".