The SDL clean up does not crash anymore on exit, probably since the
memory corruption caused by calling SDLNet_TCP_Close() too early has
been resolved.
On startup, the client has to:
1. listen on a port
2. push and start the server to the device
3. wait for the server to connect (accept)
4. read device name and size
5. initialize SDL
6. initialize the window and renderer
7. show the window
From the execution of the app_process command to start the server on the
device, to the execution of the java main method, it takes ~800ms. As a
consequence, step 3 also takes ~800ms on the client.
Once complete, the client initializes SDL, which takes ~500ms.
These two expensive actions are executed sequentially:
HOST DEVICE
listen on port | |
push/start the server |----------------->|| app_process loads the jar
accept the connection . ^ ||
. | ||
. | WASTE ||
. | OF ||
. | TIME ||
. | ||
. | ||
. v X execution of our java main
connection accepted |<-----------------| connect to the host
init SDL || |
|| ,----------------| send frames
|| |,---------------|
|| ||,--------------|
|| |||,-------------|
|| ||||,------------|
init window/renderer | |||||,-----------|
display frames |<++++++-----------|
(many frames skipped)
The rationale for step 3 occuring before step 5 is that initializing
SDL replaces the SIGTERM handler to receive the event in the event loop,
so pressing Ctrl+C during step 5 would not work (since it blocks the
event loop).
But this is not so important; let's parallelize the SDL initialization
with the app_process execution (we'll just add a timeout to the
connection):
HOST DEVICE
listen on port | |
push/start the server |----------------->||app_process loads the jar
init SDL || ||
|| ||
|| ||
|| ||
|| ||
|| ||
accept the connection . ||
. X execution of our java main
connection accepted |<-----------------| connect to the host
init window/renderer | |
display frames |<-----------------| send frames
|<-----------------|
In addition, show the window only once the first frame is available to
avoid flickering (opening a black window for 100~200ms).
Note: the window and renderer are initialized after the connection is
accepted because they use the device information received from the
device.
SDLNet_TCP_Close() not only closes, but also release the resources.
Therefore, we must not close the socket if another thread attempts to
read it.
For that purpose, move socket closing from server_stop() to
server_destroy().
Replace screen_update() by a higher-level screen_update_frame() handling
the whole frame updating, so that scrcpy.c just call it without managing
implementation details.
Do not wait 100ms anymore to let the server print any exception: we
justly want to ignore them.
Moreover, there is no nanosleep() on Windows, so this solve another
problem.
When the video stream socket is closed and read_packey() returns -1,
av_read_frame() still returns 0.
To detect EOF, check the flag eof_reached in the AVIOContext.
This avoids garbage errors on closing.
Expose frames_offer_decoded_frame() and frames_consume_rendered_frame()
so that callers are not exposed to frame swapping (between the decoding
and rendering frames) details.
The skip_frames flag was a non-configurable runtime flag. Since it is
not exposed to the user, there is no need for a (possible) runtime cost.
For testing purpose, we still want it to be configurable, so make it a
compilation flag.
We encounter some problems with SDL2_image on MSYS2 (Windows), so
implement our own XPM parsing which does not depend on SDL_image.
The input XPM is considered safe (it's in our source repo), so do not
check XPM format errors. This implies that read_xpm() is not safe to
call on any unsafe input.
Although less straightforward, use SDL_CreateRGBSurfaceFrom() instead of
SDL_CreateRGBSurfaceWithFormatFrom() because it is available with SDL
versions older than 2.0.5.
The purpose of handle_shortcut() was to group all actions together,
whether they are initiated from a text input event or a keycode event.
However, it did not handle the case where it was initiated from a mouse
event (a right-click must turn the screen on), since the action was
identified by the shortcut char.
Instead, expose one function per action, to be called directly from
where the event is handled.
The right-click is almost useless on Android, so use it to turn the
screen on.
Add a new control event type (command) to request the server to turn the
screen on.
The server is built as an APK to simplify the build, but in fact this is
a simple jar (it is not even signed).
In order to avoid confusion, rename it to .jar, so that users do not try
to "adb install" it.
Also rename it from "scrcpy" to "scrcpy-server" to distinguish from the
client-side.
The server path may be customized using SCRCPY_APK. If its basename is
different from "scrcpy.apk", it will be pushed with a different name,
so the execution would fail.
Therefore, force the push target filename.
Romain Vimont