Add feature: select display to mirror

[peanutwolf]

This is rebased version of #1177 PR

@rom1v I was in the middle of rebasing #1177 and accidentally deleted remote branch from my fork repository but pushed it back again. Unfortunately github doesn't allow to reopen my previous PR(button is disabled). Is it possible for you as a maintained to reopen #1177 and close this one to preserve the conversation history?

[rom1v]

Thank you 👍

I squashed the commits, and applied several changes locally. The result is on branch pr1238.

In particular, setDisplayId() is not called if displayId is 0 (the method might not exist).

Could you please review the changes, and test?

I don't understand what FLAG_SUPPORTS_PROTECTED_BUFFERS does? Is it important to check it (just to print a warning)?

[rom1v]

When the display does not exist, the server terminates before connecting to the client.

In that case, the client awaited on accept() indefinitely (and we had to Ctrl+C).

It's a problem I have known for a long time, but I never took the time to fix it. I just did it (but I tested only on Linux).

Could you please test (+review) the branch threadwait (it includes your PR) on Windows or Mac? Attempt to execute scrcpy --display 1234 (an invalid display id). It should terminate properly immediately.

Thank you :)

[rom1v]

Arf, on threadwait, it does not start on Windows 😞

(select() does not work for pipes on Windows)

[rom1v]

I fixed the problem a bit differently. Could you test threadwait.2 please?

[peanutwolf]

I've test changes on threadwait.2 and it works fine for display_id and server termination features. But the thing is I have Linux machine too and can't test it on Mac or Windows, sorry.

I don't know how exactly MediaCodec works under the hood but what I have noticed is that if display doesn't have FLAG_SUPPORTS_PROTECTED_BUFFERS then android.media.MediaCodec#dequeueOutputBuffer is never called. Android doc says that absence of this flag means that display is unable to form secure buffers. So maybe it is worth terminating mirroring if display does not have this flag. I couldn't find clear connection, so that is why I used warning instead.

[rom1v]

Android doc says that absence of this flag means that display is unable to form secure buffers.

Oh, what if you pass false here:

scrcpy/server/src/main/java/com/genymobile/scrcpy/ScreenEncoder.java

Line 163 in 7bb9163

return SurfaceControl.createDisplay("scrcpy", true);

?

[peanutwolf]

I tested it but it has the same behavior even if i pass 'false' argument.

[rom1v]

Merged on dev branch: 4150eed

Thanks 👍