Add scrcpy window without video playback

Add the possibility to only control the device with any keyboard and
mouse mode without screen mirroring:

    scrcpy -KM --no-video --no-audio

This is different from OTG mode, which does not require USB debugging at
all. Here, the standard mode is used but with the possibility to disable
video playback.

By default, always open a window (even without video playback), and add
an option --no-window.

Fixes #4727 <#4727>
Fixes #4793 <#4793>
PR #4868 <#4868>

app/scrcpy.1

@@ -316,6 +316,10 @@ Disable video forwarding.
 .B \-\-no\-video\-playback
 Disable video playback on the computer.
 
+.TP
+.B \-\-no\-window
+Disable scrcpy window. Implies --no-video-playback and --no-control.
+
 .TP
 .BI "\-\-orientation " value
 Same as --display-orientation=value --record-orientation=value.

app/src/cli.c

@@ -97,6 +97,7 @@ enum {
     OPT_MOUSE,
     OPT_HID_KEYBOARD_DEPRECATED,
     OPT_HID_MOUSE_DEPRECATED,
+    OPT_NO_WINDOW,
 };
 
 struct sc_option {
@@ -566,6 +567,12 @@ static const struct sc_option options[] = {
         .longopt = "no-video-playback",
         .text = "Disable video playback on the computer.",
     },
+    {
+        .longopt_id = OPT_NO_WINDOW,
+        .longopt = "no-window",
+        .text = "Disable scrcpy window. Implies --no-video-playback and "
+                "--no-control.",
+    },
     {
         .longopt_id = OPT_ORIENTATION,
         .longopt = "orientation",
@@ -2486,6 +2493,9 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
             case OPT_CAMERA_HIGH_SPEED:
                 opts->camera_high_speed = true;
                 break;
+            case OPT_NO_WINDOW:
+                opts->window = false;
+                break;
             default:
                 // getopt prints the error message on stderr
                 return false;
@@ -2523,6 +2533,12 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
     v4l2 = !!opts->v4l2_device;
 #endif
 
+    if (!opts->window) {
+        // Without window, there cannot be any video playback or control
+        opts->video_playback = false;
+        opts->control = false;
+    }
+
     if (!opts->video) {
         opts->video_playback = false;
         // Do not power on the device on start if video capture is disabled
@@ -2544,8 +2560,8 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
         opts->audio = false;
     }
 
-    if (!opts->video && !opts->audio && !otg) {
-        LOGE("No video, no audio, no OTG: nothing to do");
+    if (!opts->video && !opts->audio && !opts->control && !otg) {
+        LOGE("No video, no audio, no control, no OTG: nothing to do");
         return false;
     }
 
@@ -2588,13 +2604,26 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
     }
 #endif
 
-    if (opts->keyboard_input_mode == SC_KEYBOARD_INPUT_MODE_AUTO) {
-        opts->keyboard_input_mode = otg ? SC_KEYBOARD_INPUT_MODE_AOA
-                                        : SC_KEYBOARD_INPUT_MODE_SDK;
-    }
-    if (opts->mouse_input_mode == SC_MOUSE_INPUT_MODE_AUTO) {
-        opts->mouse_input_mode = otg ? SC_MOUSE_INPUT_MODE_AOA
-                                     : SC_MOUSE_INPUT_MODE_SDK;
+    if (opts->control) {
+        if (opts->keyboard_input_mode == SC_KEYBOARD_INPUT_MODE_AUTO) {
+            opts->keyboard_input_mode = otg ? SC_KEYBOARD_INPUT_MODE_AOA
+                                            : SC_KEYBOARD_INPUT_MODE_SDK;
+        }
+        if (opts->mouse_input_mode == SC_MOUSE_INPUT_MODE_AUTO) {
+            if (otg) {
+                opts->mouse_input_mode = SC_MOUSE_INPUT_MODE_AOA;
+            } else if (!opts->video_playback) {
+                LOGI("No video mirroring, SDK mouse disabled (you might want "
+                     "--mouse=uhid)");
+                opts->mouse_input_mode = SC_MOUSE_INPUT_MODE_DISABLED;
+            } else {
+                opts->mouse_input_mode = SC_MOUSE_INPUT_MODE_SDK;
+            }
+        } else if (opts->mouse_input_mode == SC_MOUSE_INPUT_MODE_SDK
+                    && !opts->video_playback) {
+            LOGE("SDK mouse mode requires video playback. Try --mouse=uhid.");
+            return false;
+        }
     }
 
     if (otg) {

app/src/display.c

@@ -5,8 +5,36 @@
 
 #include "util/log.h"
 
+static bool
+sc_display_init_novideo_icon(struct sc_display *display,
+                             SDL_Surface *icon_novideo) {
+    assert(icon_novideo);
+
+    if (SDL_RenderSetLogicalSize(display->renderer,
+                                 icon_novideo->w, icon_novideo->h)) {
+        LOGW("Could not set renderer logical size: %s", SDL_GetError());
+        // don't fail
+    }
+
+    display->texture = SDL_CreateTextureFromSurface(display->renderer,
+                                                    icon_novideo);
+    if (!display->texture) {
+        LOGE("Could not create texture: %s", SDL_GetError());
+        return false;
+    }
+
+    SDL_RenderClear(display->renderer);
+    if (display->texture) {
+        SDL_RenderCopy(display->renderer, display->texture, NULL, NULL);
+    }
+    SDL_RenderPresent(display->renderer);
+
+    return true;
+}
+
 bool
-sc_display_init(struct sc_display *display, SDL_Window *window, bool mipmaps) {
+sc_display_init(struct sc_display *display, SDL_Window *window,
+                SDL_Surface *icon_novideo, bool mipmaps) {
     display->renderer =
         SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
     if (!display->renderer) {
@@ -68,6 +96,18 @@ sc_display_init(struct sc_display *display, SDL_Window *window, bool mipmaps) {
     display->pending.frame = NULL;
     display->has_frame = false;
 
+    if (icon_novideo) {
+        // Without video, set a static scrcpy icon as window content
+        bool ok = sc_display_init_novideo_icon(display, icon_novideo);
+        if (!ok) {
+#ifdef SC_DISPLAY_FORCE_OPENGL_CORE_PROFILE
+            SDL_GL_DeleteContext(display->gl_context);
+#endif
+            SDL_DestroyRenderer(display->renderer);
+            return false;
+        }
+    }
+
     return true;
 }
 

app/src/display.h

@@ -44,7 +44,8 @@ enum sc_display_result {
 };
 
 bool
-sc_display_init(struct sc_display *display, SDL_Window *window, bool mipmaps);
+sc_display_init(struct sc_display *display, SDL_Window *window,
+                SDL_Surface *icon_novideo, bool mipmaps);
 
 void
 sc_display_destroy(struct sc_display *display);

app/src/input_manager.c

@@ -403,6 +403,7 @@ sc_input_manager_process_key(struct sc_input_manager *im,
     // controller is NULL if --no-control is requested
     bool control = im->controller;
     bool paused = im->screen->paused;
+    bool video = im->screen->video;
 
     SDL_Keycode keycode = event->keysym.sym;
     uint16_t mod = event->keysym.mod;
@@ -462,13 +463,13 @@ sc_input_manager_process_key(struct sc_input_manager *im,
                 }
                 return;
             case SDLK_z:
-                if (down && !repeat) {
+                if (video && down && !repeat) {
                     sc_screen_set_paused(im->screen, !shift);
                 }
                 return;
             case SDLK_DOWN:
                 if (shift) {
-                    if (!repeat && down) {
+                    if (video && !repeat && down) {
                         apply_orientation_transform(im,
                                                     SC_ORIENTATION_FLIP_180);
                     }
@@ -479,7 +480,7 @@ sc_input_manager_process_key(struct sc_input_manager *im,
                 return;
             case SDLK_UP:
                 if (shift) {
-                    if (!repeat && down) {
+                    if (video && !repeat && down) {
                         apply_orientation_transform(im,
                                                     SC_ORIENTATION_FLIP_180);
                     }
@@ -489,7 +490,7 @@ sc_input_manager_process_key(struct sc_input_manager *im,
                 }
                 return;
             case SDLK_LEFT:
-                if (!repeat && down) {
+                if (video && !repeat && down) {
                     if (shift) {
                         apply_orientation_transform(im,
                                                     SC_ORIENTATION_FLIP_0);
@@ -500,7 +501,7 @@ sc_input_manager_process_key(struct sc_input_manager *im,
                 }
                 return;
             case SDLK_RIGHT:
-                if (!repeat && down) {
+                if (video && !repeat && down) {
                     if (shift) {
                         apply_orientation_transform(im,
                                                     SC_ORIENTATION_FLIP_0);
@@ -533,22 +534,22 @@ sc_input_manager_process_key(struct sc_input_manager *im,
                 }
                 return;
             case SDLK_f:
-                if (!shift && !repeat && down) {
+                if (video && !shift && !repeat && down) {
                     sc_screen_switch_fullscreen(im->screen);
                 }
                 return;
             case SDLK_w:
-                if (!shift && !repeat && down) {
+                if (video && !shift && !repeat && down) {
                     sc_screen_resize_to_fit(im->screen);
                 }
                 return;
             case SDLK_g:
-                if (!shift && !repeat && down) {
+                if (video && !shift && !repeat && down) {
                     sc_screen_resize_to_pixel_perfect(im->screen);
                 }
                 return;
             case SDLK_i:
-                if (!shift && !repeat && down) {
+                if (video && !shift && !repeat && down) {
                     switch_fps_counter_state(im);
                 }
                 return;

app/src/options.c

@@ -89,6 +89,7 @@ const struct scrcpy_options scrcpy_options_default = {
     .kill_adb_on_close = false,
     .camera_high_speed = false,
     .list = 0,
+    .window = true,
 };
 
 enum sc_orientation

app/src/options.h

@@ -279,6 +279,7 @@ struct scrcpy_options {
 #define SC_OPTION_LIST_CAMERAS 0x4
 #define SC_OPTION_LIST_CAMERA_SIZES 0x8
     uint8_t list;
+    bool window;
 };
 
 extern const struct scrcpy_options scrcpy_options_default;

app/src/scrcpy.c

@@ -430,7 +430,7 @@ scrcpy(struct scrcpy_options *options) {
     assert(!options->video_playback || options->video);
     assert(!options->audio_playback || options->audio);
 
-    if (options->video_playback ||
+    if (options->window ||
             (options->control && options->clipboard_autosync)) {
         // Initialize the video subsystem even if --no-video or
         // --no-video-playback is passed so that clipboard synchronization
@@ -684,11 +684,12 @@ scrcpy(struct scrcpy_options *options) {
     // There is a controller if and only if control is enabled
     assert(options->control == !!controller);
 
-    if (options->video_playback) {
+    if (options->window) {
         const char *window_title =
             options->window_title ? options->window_title : info->device_name;
 
         struct sc_screen_params screen_params = {
+            .video = options->video_playback,
             .controller = controller,
             .fp = fp,
             .kp = kp,
@@ -710,20 +711,25 @@ scrcpy(struct scrcpy_options *options) {
             .start_fps_counter = options->start_fps_counter,
         };
 
-        struct sc_frame_source *src = &s->video_decoder.frame_source;
-        if (options->display_buffer) {
-            sc_delay_buffer_init(&s->display_buffer, options->display_buffer,
-                                 true);
-            sc_frame_source_add_sink(src, &s->display_buffer.frame_sink);
-            src = &s->display_buffer.frame_source;
+        struct sc_frame_source *src;
+        if (options->video_playback) {
+            src = &s->video_decoder.frame_source;
+            if (options->display_buffer) {
+                sc_delay_buffer_init(&s->display_buffer,
+                                     options->display_buffer, true);
+                sc_frame_source_add_sink(src, &s->display_buffer.frame_sink);
+                src = &s->display_buffer.frame_source;
+            }
         }
 
         if (!sc_screen_init(&s->screen, &screen_params)) {
             goto end;
         }
         screen_initialized = true;
 
-        sc_frame_source_add_sink(src, &s->screen.frame_sink);
+        if (options->video_playback) {
+            sc_frame_source_add_sink(src, &s->screen.frame_sink);
+        }
     }
 
     if (options->audio_playback) {