lavd/avfoundation.m: Do not use transport controls for screen capture devices.

libavdevice/avfoundation.m

@@ -99,6 +99,7 @@ typedef struct
     int             capture_raw_data;
     int             drop_late_frames;
     int             video_is_muxed;
+    int             video_is_screen;
 
     int             list_devices;
     int             video_device_index;
@@ -545,12 +546,14 @@ static int add_video_device(AVFormatContext *s, AVCaptureDevice *video_device)
 
 #if !TARGET_OS_IPHONE && __MAC_OS_X_VERSION_MIN_REQUIRED >= 1070
     // check for transport control support and set observer device if supported
-    int trans_ctrl = [video_device transportControlsSupported];
-    AVCaptureDeviceTransportControlsPlaybackMode trans_mode = [video_device transportControlsPlaybackMode];
+    if (!ctx->video_is_screen) {
+        int trans_ctrl = [video_device transportControlsSupported];
+        AVCaptureDeviceTransportControlsPlaybackMode trans_mode = [video_device transportControlsPlaybackMode];
 
-    if (trans_ctrl) {
-        ctx->observed_mode   = trans_mode;
-        ctx->observed_device = video_device;
+        if (trans_ctrl) {
+            ctx->observed_mode   = trans_mode;
+            ctx->observed_device = video_device;
+        }
     }
 #endif
 
@@ -750,7 +753,6 @@ static int get_audio_config(AVFormatContext *s)
 static int avf_read_header(AVFormatContext *s)
 {
     NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
-    int capture_screen      = 0;
     uint32_t num_screens    = 0;
     AVFContext *ctx         = (AVFContext*)s->priv_data;
     AVCaptureDevice *video_device = nil;
@@ -847,7 +849,7 @@ static int avf_read_header(AVFormatContext *s)
             }
 
             video_device = (AVCaptureDevice*) capture_screen_input;
-            capture_screen = 1;
+            ctx->video_is_screen = 1;
 #endif
          } else {
             av_log(ctx, AV_LOG_ERROR, "Invalid device index\n");
@@ -884,7 +886,7 @@ static int avf_read_header(AVFormatContext *s)
                 AVCaptureScreenInput* capture_screen_input = [[[AVCaptureScreenInput alloc] initWithDisplayID:screens[idx]] autorelease];
                 video_device = (AVCaptureDevice*) capture_screen_input;
                 ctx->video_device_index = ctx->num_video_devices + idx;
-                capture_screen = 1;
+                ctx->video_is_screen = 1;
 
                 if (ctx->framerate.num > 0) {
                     capture_screen_input.minFrameDuration = CMTimeMake(ctx->framerate.den, ctx->framerate.num);
@@ -975,7 +977,7 @@ static int avf_read_header(AVFormatContext *s)
 
     /* Unlock device configuration only after the session is started so it
      * does not reset the capture formats */
-    if (!capture_screen) {
+    if (!ctx->video_is_screen) {
         [video_device unlockForConfiguration];
     }