Improve FAQ

PR #1202 <https://github.com/Genymobile/scrcpy/pull/1202>

Signed-off-by: Romain Vimont <rom@rom1v.com>

DEVELOP.md

@@ -189,7 +189,7 @@ The client uses 4 threads:
    recording,
  - the **controller** thread, sending _control messages_ to the server,
  - the **receiver** thread (managed by the controller), receiving _device
-   messages_ from the client.
+   messages_ from the server.
 
 In addition, another thread can be started if necessary to handle APK
 installation or file push requests (via drag&drop on the main window) or to
@@ -214,7 +214,7 @@ When a new decoded frame is available, the decoder _swaps_ the decoding and
 rendering frame (with proper synchronization). Thus, it immediatly starts
 to decode a new frame while the main thread renders the last one.
 
-If a [recorder] is present (i.e. `--record` is enabled), then its muxes the raw
+If a [recorder] is present (i.e. `--record` is enabled), then it muxes the raw
 H.264 packet to the output video file.
 
 [stream]: https://github.com/Genymobile/scrcpy/blob/ffe0417228fb78ab45b7ee4e202fc06fc8875bf3/app/src/stream.h

FAQ.md

@@ -3,19 +3,102 @@
 Here are the common reported problems and their status.
 
 
-### On Windows, my device is not detected
+## `adb` issues
 
-The most common is your device not being detected by `adb`, or is unauthorized.
-Check everything is ok by calling:
+`scrcpy` execute `adb` commands to initialize the connection with the device. If
+`adb` fails, then scrcpy will not work.
 
-    adb devices
+In that case, it will print this error:
 
-Windows may need some [drivers] to detect your device.
+>     ERROR: "adb push" returned with value 1
+
+This is typically not a bug in _scrcpy_, but a problem in your environment.
+
+To find out the cause, execute:
+
+```bash
+adb devices
+```
+
+### `adb` not found
+
+You need `adb` accessible from your `PATH`.
+
+On Windows, the current directory is in your `PATH`, and `adb.exe` is included
+in the release, so it should work out-of-the-box.
+
+
+### Device unauthorized
+
+Check [stackoverflow][device-unauthorized].
+
+[device-unauthorized]: https://stackoverflow.com/questions/23081263/adb-android-device-unauthorized
+
+
+### Device not detected
+
+If your device is not detected, you may need some [drivers] (on Windows).
 
 [drivers]: https://developer.android.com/studio/run/oem-usb.html
 
 
-### I can only mirror, I cannot interact with the device
+### Several devices connected
+
+If several devices are connected, you will encounter this error:
+
+>     adb: error: failed to get feature set: more than one device/emulator
+
+the identifier of the device you want to mirror must be provided:
+
+```bash
+scrcpy -s 01234567890abcdef
+```
+
+Note that if your device is connected over TCP/IP, you'll get this message:
+
+>     adb: error: more than one device/emulator
+>     ERROR: "adb reverse" returned with value 1
+>     WARN: 'adb reverse' failed, fallback to 'adb forward'
+
+This is expected (due to a bug on old Android versions, see [#5]), but in that
+case, scrcpy fallbacks to a different method, which should work.
+
+[#5]: https://github.com/Genymobile/scrcpy/issues/5
+
+
+### Conflicts between adb versions
+
+>     adb server version (41) doesn't match this client (39); killing...
+
+This error occurs when you use several `adb` versions simultaneously. You must
+find the program using a different `adb` version, and use the same `adb` version
+everywhere.
+
+You could overwrite the `adb` binary in the other program, or ask _scrcpy_ to
+use a specific `adb` binary, by setting the `ADB` environment variable:
+
+```bash
+set ADB=/path/to/your/adb
+scrcpy
+```
+
+
+### Device disconnected
+
+If _scrcpy_ stops itself with the warning "Device disconnected", then the
+`adb` connection has been closed.
+
+Try with another USB cable or plug it into another USB port. See [#281] and
+[#283].
+
+[#281]: https://github.com/Genymobile/scrcpy/issues/281
+[#283]: https://github.com/Genymobile/scrcpy/issues/283
+
+
+
+## Control issues
+
+### Mouse and keyboard do not work
 
 On some devices, you may need to enable an option to allow [simulating input].
 In developer options, enable:
@@ -29,18 +112,25 @@ In developer options, enable:
 ### Mouse clicks at wrong location
 
 On MacOS, with HiDPI support and multiple screens, input location are wrongly
-scaled. See [issue 15].
+scaled. See [#15].
 
-[issue 15]: https://github.com/Genymobile/scrcpy/issues/15
+[#15]: https://github.com/Genymobile/scrcpy/issues/15
 
-A workaround is to build with HiDPI support disabled:
+Open _scrcpy_ directly on the monitor you use it.
 
-```bash
-meson x --buildtype release -Dhidpi_support=false
-```
 
-However, the video will be displayed at lower resolution.
+### Special characters do not work
 
+Injecting text input is [limited to ASCII characters][text-input]. A trick
+allows to also inject some [accented characters][accented-characters], but
+that's all. See [#37].
+
+[text-input]: https://github.com/Genymobile/scrcpy/issues?q=is%3Aopen+is%3Aissue+label%3Aunicode
+[accented-characters]: https://blog.rom1v.com/2018/03/introducing-scrcpy/#handle-accented-characters
+[#37]: https://github.com/Genymobile/scrcpy/issues/37
+
+
+## Client issues
 
 ### The quality is low on HiDPI display
 
@@ -51,6 +141,11 @@ On Windows, you may need to configure the [scaling behavior].
 
 [scaling behavior]: https://github.com/Genymobile/scrcpy/issues/40#issuecomment-424466723
 
+If your computer definition is far smaller than your screen, then you'll get
+poor quality. See [#40].
+
+[#40]: https://github.com/Genymobile/scrcpy/issues/40
+
 
 ### KWin compositor crashes
 
@@ -61,19 +156,29 @@ As a workaround, [disable "Block compositing"][kwin].
 [kwin]: https://github.com/Genymobile/scrcpy/issues/114#issuecomment-378778613
 
 
-### I get an error "Could not open video stream"
+## Crashes
+
+### Exception
 
 There may be many reasons. One common cause is that the hardware encoder of your
 device is not able to encode at the given definition:
 
-```
-ERROR: Exception on thread Thread[main,5,main]
-android.media.MediaCodec$CodecException: Error 0xfffffc0e
-...
-Exit due to uncaughtException in main thread:
-ERROR: Could not open video stream
-INFO: Initial texture: 1080x2336
-```
+> ```
+> ERROR: Exception on thread Thread[main,5,main]
+> android.media.MediaCodec$CodecException: Error 0xfffffc0e
+> ...
+> Exit due to uncaughtException in main thread:
+> ERROR: Could not open video stream
+> INFO: Initial texture: 1080x2336
+> ```
+
+or
+
+> ```
+> ERROR: Exception on thread Thread[main,5,main]
+> java.lang.IllegalStateException
+>         at android.media.MediaCodec.native_dequeueOutputBuffer(Native Method)
+> ```
 
 Just try with a lower definition:
 

LICENSE

@@ -188,7 +188,7 @@
       identification within third-party archives.
 
    Copyright (C) 2018 Genymobile
-   Copyright (C) 2018-2019 Romain Vimont
+   Copyright (C) 2018-2020 Romain Vimont
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.

README.ko.md

@@ -475,7 +475,7 @@ _²화면이 꺼진 상태에서 우클릭 시 다시 켜지며, 그 외의 상
 ## 라이선스
 
     Copyright (C) 2018 Genymobile
-    Copyright (C) 2018-2019 Romain Vimont
+    Copyright (C) 2018-2020 Romain Vimont
 
     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.

README.md

@@ -37,8 +37,11 @@ control it using keyboard and mouse.
 
 ### Linux
 
-On Linux, you typically need to [build the app manually][BUILD]. Don't worry,
-it's not that hard.
+In Debian (_testing_ and _sid_ for now):
+
+```
+apt install scrcpy
+```
 
 A [Snap] package is available: [`scrcpy`][snap-link].
 
@@ -56,20 +59,39 @@ For Gentoo, an [Ebuild] is available: [`scrcpy/`][ebuild-link].
 [Ebuild]: https://wiki.gentoo.org/wiki/Ebuild
 [ebuild-link]: https://github.com/maggu2810/maggu2810-overlay/tree/master/app-mobilephone/scrcpy
 
+You could also [build the app manually][BUILD] (don't worry, it's not that
+hard).
+
+
 
 ### Windows
 
-For Windows, for simplicity, prebuilt archives with all the dependencies
-(including `adb`) are available:
+For Windows, for simplicity, a prebuilt archive with all the dependencies
+(including `adb`) is available:
 
- - [`scrcpy-win32-v1.12.1.zip`][direct-win32]  
-   _(SHA-256: 0f4b3b063536b50a2df05dc42c760f9cc0093a9a26dbdf02d8232c74dab43480)_
  - [`scrcpy-win64-v1.12.1.zip`][direct-win64]  
    _(SHA-256: 57d34b6d16cfd9fe169bc37c4df58ebd256d05c1ea3febc63d9cb0a027ab47c9)_
 
-[direct-win32]: https://github.com/Genymobile/scrcpy/releases/download/v1.12.1/scrcpy-win32-v1.12.1.zip
 [direct-win64]: https://github.com/Genymobile/scrcpy/releases/download/v1.12.1/scrcpy-win64-v1.12.1.zip
 
+It is also available in [Chocolatey]:
+
+[Chocolatey]: https://chocolatey.org/
+
+```bash
+choco install scrcpy
+choco install adb    # if you don't have it yet
+```
+
+And in [Scoop]:
+
+```bash
+scoop install scrcpy
+scoop install adb    # if you don't have it yet
+```
+
+[Scoop]: https://scoop.sh
+
 You can also [build the app manually][BUILD].
 
 
@@ -214,6 +236,13 @@ scrcpy --serial 0123456789abcdef
 scrcpy -s 0123456789abcdef  # short version
 ```
 
+If the device is connected over TCP/IP:
+
+```bash
+scrcpy --serial 192.168.0.1:5555
+scrcpy -s 192.168.0.1:5555  # short version
+```
+
 You can start several instances of _scrcpy_ for several devices.
 
 #### SSH tunnel
@@ -489,7 +518,7 @@ Read the [developers page].
 ## Licence
 
     Copyright (C) 2018 Genymobile
-    Copyright (C) 2018-2019 Romain Vimont
+    Copyright (C) 2018-2020 Romain Vimont
 
     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.

app/scrcpy.1

@@ -261,7 +261,7 @@ Copyright \(co 2018 Genymobile
 Genymobile
 .UE
 
-Copyright \(co 2018\-2019
+Copyright \(co 2018\-2020
 .MT rom@rom1v.com
 Romain Vimont
 .ME

app/src/command.c

@@ -4,6 +4,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
 
 #include "config.h"
 #include "common.h"
@@ -202,3 +205,14 @@ process_check_success(process_t proc, const char *name) {
     }
     return true;
 }
+
+bool
+is_regular_file(const char *path) {
+    struct stat path_stat;
+    int r = stat(path, &path_stat);
+    if (r) {
+        perror("stat");
+        return false;
+    }
+    return S_ISREG(path_stat.st_mode);
+}

app/src/server.c

@@ -6,13 +6,11 @@
 #include <libgen.h>
 #include <stdio.h>
 #include <SDL2/SDL_timer.h>
-#include <SDL2/SDL_platform.h>
 
 #include "config.h"
 #include "command.h"
 #include "util/log.h"
 #include "util/net.h"
-#include "util/str_util.h"
 
 #define SOCKET_NAME "scrcpy"
 #define SERVER_FILENAME "scrcpy-server"
@@ -20,39 +18,20 @@
 #define DEFAULT_SERVER_PATH PREFIX "/share/scrcpy/" SERVER_FILENAME
 #define DEVICE_SERVER_PATH "/data/local/tmp/scrcpy-server.jar"
 
-static char *
+static const char *
 get_server_path(void) {
-#ifdef __WINDOWS__
-    const wchar_t *server_path_env = _wgetenv(L"SCRCPY_SERVER_PATH");
-#else
     const char *server_path_env = getenv("SCRCPY_SERVER_PATH");
-#endif
     if (server_path_env) {
+        LOGD("Using SCRCPY_SERVER_PATH: %s", server_path_env);
         // if the envvar is set, use it
-#ifdef __WINDOWS__
-        char *server_path = utf8_from_wide_char(server_path_env);
-#else
-        char *server_path = SDL_strdup(server_path_env);
-#endif
-        if (!server_path) {
-            LOGE("Could not allocate memory");
-            return NULL;
-        }
-        LOGD("Using SCRCPY_SERVER_PATH: %s", server_path);
-        return server_path;
+        return server_path_env;
     }
 
 #ifndef PORTABLE
     LOGD("Using server: " DEFAULT_SERVER_PATH);
-    char *server_path = SDL_strdup(DEFAULT_SERVER_PATH);
-    if (!server_path) {
-        LOGE("Could not allocate memory");
-        return NULL;
-    }
     // the absolute path is hardcoded
-    return server_path;
+    return DEFAULT_SERVER_PATH;
 #else
-
     // use scrcpy-server in the same directory as the executable
     char *executable_path = get_executable_path();
     if (!executable_path) {
@@ -88,17 +67,12 @@ get_server_path(void) {
 
 static bool
 push_server(const char *serial) {
-    char *server_path = get_server_path();
-    if (!server_path) {
-        return false;
-    }
+    const char *server_path = get_server_path();
     if (!is_regular_file(server_path)) {
         LOGE("'%s' does not exist or is not a regular file\n", server_path);
-        SDL_free(server_path);
         return false;
     }
     process_t process = adb_push(serial, server_path, DEVICE_SERVER_PATH);
-    SDL_free(server_path);
     return process_check_success(process, "adb push");
 }
 

app/src/sys/unix/command.c

@@ -15,7 +15,6 @@
 #include <signal.h>
 #include <stdlib.h>
 #include <sys/types.h>
-#include <sys/stat.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
@@ -128,14 +127,3 @@ get_executable_path(void) {
     return NULL;
 #endif
 }
-
-bool
-is_regular_file(const char *path) {
-    struct stat path_stat;
-
-    if (stat(path, &path_stat)) {
-        perror("stat");
-        return false;
-    }
-    return S_ISREG(path_stat.st_mode);
-}

app/src/sys/win/command.c

@@ -4,8 +4,6 @@
 #include "util/log.h"
 #include "util/str_util.h"
 
-#include <sys/stat.h>
-
 static int
 build_cmd(char *cmd, size_t len, const char *const argv[]) {
     // Windows command-line parsing is WTF:
@@ -92,22 +90,3 @@ get_executable_path(void) {
     buf[len] = '\0';
     return utf8_from_wide_char(buf);
 }
-
-bool
-is_regular_file(const char *path) {
-    wchar_t *wide_path = utf8_to_wide_char(path);
-    if (!wide_path) {
-        LOGC("Could not allocate wide char string");
-        return false;
-    }
-
-    struct _stat path_stat;
-    int r = _wstat(wide_path, &path_stat);
-    SDL_free(wide_path);
-
-    if (r) {
-        perror("stat");
-        return false;
-    }
-    return S_ISREG(path_stat.st_mode);
-}