[FFmpeg-cvslog] lavd/avfoundation: Add basic transport control observation for capable devices.
Thilo Borgmann
git at videolan.org
Mon Mar 16 11:28:16 EET 2020
ffmpeg | branch: master | Thilo Borgmann <thilo.borgmann at mail.de> | Thu Mar 5 12:32:49 2020 +0100| [39fbd0631407f6ce7575699248cb05057203af58] | committer: Thilo Borgmann
lavd/avfoundation: Add basic transport control observation for capable devices.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=39fbd0631407f6ce7575699248cb05057203af58
---
libavdevice/avfoundation.m | 67 ++++++++++++++++++++++++++++++++++++++++------
1 file changed, 59 insertions(+), 8 deletions(-)
diff --git a/libavdevice/avfoundation.m b/libavdevice/avfoundation.m
index 0d854a18a3..43b2edb44d 100644
--- a/libavdevice/avfoundation.m
+++ b/libavdevice/avfoundation.m
@@ -88,7 +88,6 @@ typedef struct
int64_t first_pts;
int64_t first_audio_pts;
pthread_mutex_t frame_lock;
- pthread_cond_t frame_wait_cond;
id avf_delegate;
id avf_audio_delegate;
@@ -130,6 +129,10 @@ typedef struct
AVCaptureAudioDataOutput *audio_output;
CMSampleBufferRef current_frame;
CMSampleBufferRef current_audio_frame;
+
+ AVCaptureDevice *observed_device;
+ AVCaptureDeviceTransportControlsPlaybackMode observed_mode;
+ int observed_quit;
} AVFContext;
static void lock_frames(AVFContext* ctx)
@@ -163,10 +166,50 @@ static void unlock_frames(AVFContext* ctx)
{
if (self = [super init]) {
_context = context;
+
+ // start observing if a device is set for it
+ if (_context->observed_device) {
+ NSString *keyPath = NSStringFromSelector(@selector(transportControlsPlaybackMode));
+ NSKeyValueObservingOptions options = NSKeyValueObservingOptionNew;
+
+ [_context->observed_device addObserver: self
+ forKeyPath: keyPath
+ options: options
+ context: _context];
+ }
}
return self;
}
+- (void)dealloc {
+ // stop observing if a device is set for it
+ NSString *keyPath = NSStringFromSelector(@selector(transportControlsPlaybackMode));
+ [_context->observed_device removeObserver: self forKeyPath: keyPath];
+ [super dealloc];
+}
+
+- (void)observeValueForKeyPath:(NSString *)keyPath
+ ofObject:(id)object
+ change:(NSDictionary *)change
+ context:(void *)context {
+ if (context == _context) {
+ AVCaptureDeviceTransportControlsPlaybackMode mode =
+ [change[NSKeyValueChangeNewKey] integerValue];
+
+ if (mode != _context->observed_mode) {
+ if (mode == AVCaptureDeviceTransportControlsNotPlayingMode) {
+ _context->observed_quit = 1;
+ }
+ _context->observed_mode = mode;
+ }
+ } else {
+ [super observeValueForKeyPath: keyPath
+ ofObject: object
+ change: change
+ context: context];
+ }
+}
+
- (void) captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)videoFrame
fromConnection:(AVCaptureConnection *)connection
@@ -179,8 +222,6 @@ static void unlock_frames(AVFContext* ctx)
_context->current_frame = (CMSampleBufferRef)CFRetain(videoFrame);
- pthread_cond_signal(&_context->frame_wait_cond);
-
unlock_frames(_context);
++_context->frames_captured;
@@ -225,8 +266,6 @@ static void unlock_frames(AVFContext* ctx)
_context->current_audio_frame = (CMSampleBufferRef)CFRetain(audioFrame);
- pthread_cond_signal(&_context->frame_wait_cond);
-
unlock_frames(_context);
++_context->audio_frames_captured;
@@ -253,7 +292,6 @@ static void destroy_context(AVFContext* ctx)
av_freep(&ctx->audio_buffer);
pthread_mutex_destroy(&ctx->frame_lock);
- pthread_cond_destroy(&ctx->frame_wait_cond);
if (ctx->current_frame) {
CFRelease(ctx->current_frame);
@@ -499,6 +537,15 @@ static int add_video_device(AVFormatContext *s, AVCaptureDevice *video_device)
}
[ctx->video_output setAlwaysDiscardsLateVideoFrames:ctx->drop_late_frames];
+ // check for transport control support and set observer device if supported
+ 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;
+ }
+
ctx->avf_delegate = [[AVFFrameReceiver alloc] initWithContext:ctx];
queue = dispatch_queue_create("avf_queue", NULL);
@@ -709,7 +756,6 @@ static int avf_read_header(AVFormatContext *s)
ctx->first_audio_pts = av_gettime();
pthread_mutex_init(&ctx->frame_lock, NULL);
- pthread_cond_init(&ctx->frame_wait_cond, NULL);
#if !TARGET_OS_IPHONE && __MAC_OS_X_VERSION_MIN_REQUIRED >= 1070
CGGetActiveDisplayList(0, NULL, &num_screens);
@@ -1110,7 +1156,12 @@ static int avf_read_packet(AVFormatContext *s, AVPacket *pkt)
ctx->current_audio_frame = nil;
} else {
pkt->data = NULL;
- pthread_cond_wait(&ctx->frame_wait_cond, &ctx->frame_lock);
+ unlock_frames(ctx);
+ if (ctx->observed_quit) {
+ return AVERROR_EOF;
+ } else {
+ return AVERROR(EAGAIN);
+ }
}
unlock_frames(ctx);
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