diff options
author | Yoann Lopes <yoann.lopes@qt.io> | 2016-08-01 11:52:05 +0200 |
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committer | Yoann Lopes <yoann.lopes@qt.io> | 2016-08-01 11:52:05 +0200 |
commit | 339944b284e9dd11302dd013f9d9a10ad0d9055a (patch) | |
tree | c2952d186b1dbc6f2380448fa2cfd9ec55043da6 /src/plugins/avfoundation/camera | |
parent | 53d0a1e5454f4e5beecdea19acb9df11c87cc375 (diff) | |
parent | d7d31d63db5f0029a4a5e24d998601baee8bade0 (diff) | |
download | qtmultimedia-339944b284e9dd11302dd013f9d9a10ad0d9055a.tar.gz |
Merge remote-tracking branch 'origin/5.6' into 5.7
Change-Id: Ic29cb09048003f18ff86d4546cd547be715eaec8
Diffstat (limited to 'src/plugins/avfoundation/camera')
4 files changed, 84 insertions, 77 deletions
diff --git a/src/plugins/avfoundation/camera/avfmediaassetwriter.h b/src/plugins/avfoundation/camera/avfmediaassetwriter.h index fa1ec46a2..624906c85 100644 --- a/src/plugins/avfoundation/camera/avfmediaassetwriter.h +++ b/src/plugins/avfoundation/camera/avfmediaassetwriter.h @@ -44,7 +44,6 @@ #include <QtCore/qglobal.h> #include <QtCore/qatomic.h> -#include <QtCore/qmutex.h> #include <AVFoundation/AVFoundation.h> @@ -53,13 +52,10 @@ QT_BEGIN_NAMESPACE class AVFMediaRecorderControlIOS; class AVFCameraService; -typedef QAtomicInteger<bool> AVFAtomicBool; typedef QAtomicInteger<qint64> AVFAtomicInt64; QT_END_NAMESPACE -// TODO: any reasonable error handling requires smart pointers, otherwise it's getting crappy immediately. - @interface QT_MANGLE_NAMESPACE(AVFMediaAssetWriter) : NSObject<AVCaptureVideoDataOutputSampleBufferDelegate, AVCaptureAudioDataOutputSampleBufferDelegate> { @@ -72,22 +68,20 @@ QT_END_NAMESPACE QT_PREPEND_NAMESPACE(AVFScopedPointer)<AVAssetWriterInput> m_audioWriterInput; AVCaptureDevice *m_audioCaptureDevice; + // Queue to write sample buffers: + QT_PREPEND_NAMESPACE(AVFScopedPointer)<dispatch_queue_t> m_writerQueue; // High priority serial queue for video output: QT_PREPEND_NAMESPACE(AVFScopedPointer)<dispatch_queue_t> m_videoQueue; // Serial queue for audio output: QT_PREPEND_NAMESPACE(AVFScopedPointer)<dispatch_queue_t> m_audioQueue; - // Queue to write sample buffers: - QT_PREPEND_NAMESPACE(AVFScopedPointer)<dispatch_queue_t> m_writerQueue; QT_PREPEND_NAMESPACE(AVFScopedPointer)<AVAssetWriter> m_assetWriter; QT_PREPEND_NAMESPACE(AVFMediaRecorderControlIOS) *m_delegate; bool m_setStartTime; - QT_PREPEND_NAMESPACE(AVFAtomicBool) m_stopped; - QT_PREPEND_NAMESPACE(AVFAtomicBool) m_aborted; - QT_PREPEND_NAMESPACE(QMutex) m_writerMutex; + QT_PREPEND_NAMESPACE(QAtomicInt) m_state; @public QT_PREPEND_NAMESPACE(AVFAtomicInt64) m_durationInMs; @private @@ -98,8 +92,7 @@ QT_END_NAMESPACE NSDictionary *m_videoSettings; } -- (id)initWithQueue:(dispatch_queue_t)writerQueue - delegate:(QT_PREPEND_NAMESPACE(AVFMediaRecorderControlIOS) *)delegate; +- (id)initWithDelegate:(QT_PREPEND_NAMESPACE(AVFMediaRecorderControlIOS) *)delegate; - (bool)setupWithFileURL:(NSURL *)fileURL cameraService:(QT_PREPEND_NAMESPACE(AVFCameraService) *)service @@ -107,10 +100,10 @@ QT_END_NAMESPACE videoSettings:(NSDictionary *)videoSettings transform:(CGAffineTransform)transform; +// This to be called from the recorder control's thread: - (void)start; - (void)stop; -// This to be called if control's dtor gets called, -// on the control's thread. +// This to be called from the recorder control's dtor: - (void)abort; @end diff --git a/src/plugins/avfoundation/camera/avfmediaassetwriter.mm b/src/plugins/avfoundation/camera/avfmediaassetwriter.mm index 98c8f99ff..28735bc6a 100644 --- a/src/plugins/avfoundation/camera/avfmediaassetwriter.mm +++ b/src/plugins/avfoundation/camera/avfmediaassetwriter.mm @@ -46,7 +46,6 @@ #include "avfcameradebug.h" #include "avfmediacontainercontrol.h" -//#include <QtCore/qmutexlocker.h> #include <QtCore/qmetaobject.h> #include <QtCore/qsysinfo.h> @@ -74,6 +73,13 @@ bool qt_camera_service_isValid(AVFCameraService *service) return true; } +enum WriterState +{ + WriterStateIdle, + WriterStateActive, + WriterStateAborted +}; + } // unnamed namespace @interface QT_MANGLE_NAMESPACE(AVFMediaAssetWriter) (PrivateAPI) @@ -85,21 +91,14 @@ bool qt_camera_service_isValid(AVFCameraService *service) @implementation QT_MANGLE_NAMESPACE(AVFMediaAssetWriter) -- (id)initWithQueue:(dispatch_queue_t)writerQueue - delegate:(AVFMediaRecorderControlIOS *)delegate +- (id)initWithDelegate:(AVFMediaRecorderControlIOS *)delegate { - Q_ASSERT(writerQueue); Q_ASSERT(delegate); if (self = [super init]) { - // "Shared" queue: - dispatch_retain(writerQueue); - m_writerQueue.reset(writerQueue); - m_delegate = delegate; m_setStartTime = true; - m_stopped.store(true); - m_aborted.store(false); + m_state.store(WriterStateIdle); m_startTime = kCMTimeInvalid; m_lastTimeStamp = kCMTimeInvalid; m_durationInMs.store(0); @@ -127,6 +126,12 @@ bool qt_camera_service_isValid(AVFCameraService *service) m_audioSettings = audioSettings; m_videoSettings = videoSettings; + m_writerQueue.reset(dispatch_queue_create("asset-writer-queue", DISPATCH_QUEUE_SERIAL)); + if (!m_writerQueue) { + qDebugCamera() << Q_FUNC_INFO << "failed to create an asset writer's queue"; + return false; + } + m_videoQueue.reset(dispatch_queue_create("video-output-queue", DISPATCH_QUEUE_SERIAL)); if (!m_videoQueue) { qDebugCamera() << Q_FUNC_INFO << "failed to create video queue"; @@ -173,15 +178,12 @@ bool qt_camera_service_isValid(AVFCameraService *service) - (void)start { - // To be executed on a writer's queue. - const QMutexLocker lock(&m_writerMutex); - if (m_aborted.load()) - return; - [self setQueues]; m_setStartTime = true; - m_stopped.store(false); + + m_state.storeRelease(WriterStateActive); + [m_assetWriter startWriting]; AVCaptureSession *session = m_service->session()->captureSession(); if (!session.running) @@ -190,27 +192,36 @@ bool qt_camera_service_isValid(AVFCameraService *service) - (void)stop { - // To be executed on a writer's queue. - { - const QMutexLocker lock(&m_writerMutex); - if (m_aborted.load()) + if (m_state.loadAcquire() != WriterStateActive) return; - if (m_stopped.load()) + if ([m_assetWriter status] != AVAssetWriterStatusWriting) return; - m_stopped.store(true); - } - + // Do this here so that - + // 1. '-abort' should not try calling finishWriting again and + // 2. async block (see below) will know if recorder control was deleted + // before the block's execution: + m_state.storeRelease(WriterStateIdle); + // Now, since we have to ensure no sample buffers are + // appended after a call to finishWriting, we must + // ensure writer's queue sees this change in m_state + // _before_ we call finishWriting: + dispatch_sync(m_writerQueue, ^{}); + // Done, but now we also want to prevent video queue + // from updating our viewfinder: + dispatch_sync(m_videoQueue, ^{}); + + // Now we're safe to stop: [m_assetWriter finishWritingWithCompletionHandler:^{ // This block is async, so by the time it's executed, // it's possible that render control was deleted already ... - const QMutexLocker lock(&m_writerMutex); - if (m_aborted.load()) + if (m_state.loadAcquire() == WriterStateAborted) return; AVCaptureSession *session = m_service->session()->captureSession(); - [session stopRunning]; + if (session.running) + [session stopRunning]; [session removeOutput:m_audioOutput]; [session removeInput:m_audioInput]; QMetaObject::invokeMethod(m_delegate, "assetWriterFinished", Qt::QueuedConnection); @@ -219,12 +230,26 @@ bool qt_camera_service_isValid(AVFCameraService *service) - (void)abort { - // To be executed on any thread (presumably, it's the main thread), - // prevents writer from accessing any shared object. - const QMutexLocker lock(&m_writerMutex); - m_aborted.store(true); - if (m_stopped.load()) + // -abort is to be called from recorder control's dtor. + + if (m_state.fetchAndStoreRelease(WriterStateAborted) != WriterStateActive) { + // Not recording, nothing to stop. return; + } + + // From Apple's docs: + // "To guarantee that all sample buffers are successfully written, + // you must ensure that all calls to appendSampleBuffer: and + // appendPixelBuffer:withPresentationTime: have returned before + // invoking this method." + // + // The only way we can ensure this is: + dispatch_sync(m_writerQueue, ^{}); + // At this point next block (if any) on the writer's queue + // will see m_state preventing it from any further processing. + dispatch_sync(m_videoQueue, ^{}); + // After this point video queue will not try to modify our + // viewfider, so we're safe to delete now. [m_assetWriter finishWritingWithCompletionHandler:^{ }]; @@ -236,13 +261,12 @@ bool qt_camera_service_isValid(AVFCameraService *service) Q_ASSERT(m_setStartTime); Q_ASSERT(sampleBuffer); - const QMutexLocker lock(&m_writerMutex); - if (m_aborted.load() || m_stopped.load()) + if (m_state.loadAcquire() != WriterStateActive) return; QMetaObject::invokeMethod(m_delegate, "assetWriterStarted", Qt::QueuedConnection); - m_durationInMs.store(0); + m_durationInMs.storeRelease(0); m_startTime = CMSampleBufferGetPresentationTimeStamp(sampleBuffer); m_lastTimeStamp = m_startTime; [m_assetWriter startSessionAtSourceTime:m_startTime]; @@ -251,10 +275,10 @@ bool qt_camera_service_isValid(AVFCameraService *service) - (void)writeVideoSampleBuffer:(CMSampleBufferRef)sampleBuffer { + // This code is executed only on a writer's queue. Q_ASSERT(sampleBuffer); - // This code is executed only on a writer's queue. - if (!m_aborted.load() && !m_stopped.load()) { + if (m_state.loadAcquire() == WriterStateActive) { if (m_setStartTime) [self setStartTimeFrom:sampleBuffer]; @@ -264,17 +288,15 @@ bool qt_camera_service_isValid(AVFCameraService *service) } } - CFRelease(sampleBuffer); } - (void)writeAudioSampleBuffer:(CMSampleBufferRef)sampleBuffer { - // This code is executed only on a writer's queue. - // it does not touch any shared/external data. Q_ASSERT(sampleBuffer); - if (!m_aborted.load() && !m_stopped.load()) { + // This code is executed only on a writer's queue. + if (m_state.loadAcquire() == WriterStateActive) { if (m_setStartTime) [self setStartTimeFrom:sampleBuffer]; @@ -293,10 +315,7 @@ bool qt_camera_service_isValid(AVFCameraService *service) { Q_UNUSED(connection) - // This method can be called on either video or audio queue, - // never on a writer's queue, it needs access to a shared data, so - // lock is required. - if (m_stopped.load()) + if (m_state.loadAcquire() != WriterStateActive) return; if (!CMSampleBufferDataIsReady(sampleBuffer)) { @@ -307,8 +326,7 @@ bool qt_camera_service_isValid(AVFCameraService *service) CFRetain(sampleBuffer); if (captureOutput != m_audioOutput.data()) { - const QMutexLocker lock(&m_writerMutex); - if (m_aborted.load() || m_stopped.load()) { + if (m_state.load() != WriterStateActive) { CFRelease(sampleBuffer); return; } @@ -447,7 +465,7 @@ bool qt_camera_service_isValid(AVFCameraService *service) if (!CMTimeCompare(duration, kCMTimeInvalid)) return; - m_durationInMs.store(CMTimeGetSeconds(duration) * 1000); + m_durationInMs.storeRelease(CMTimeGetSeconds(duration) * 1000); m_lastTimeStamp = newTimeStamp; } } diff --git a/src/plugins/avfoundation/camera/avfmediarecordercontrol_ios.h b/src/plugins/avfoundation/camera/avfmediarecordercontrol_ios.h index 6736f4639..a0967efa3 100644 --- a/src/plugins/avfoundation/camera/avfmediarecordercontrol_ios.h +++ b/src/plugins/avfoundation/camera/avfmediarecordercontrol_ios.h @@ -97,8 +97,6 @@ private: void stopWriter(); AVFCameraService *m_service; - - AVFScopedPointer<dispatch_queue_t> m_writerQueue; AVFScopedPointer<QT_MANGLE_NAMESPACE(AVFMediaAssetWriter)> m_writer; QUrl m_outputLocation; diff --git a/src/plugins/avfoundation/camera/avfmediarecordercontrol_ios.mm b/src/plugins/avfoundation/camera/avfmediarecordercontrol_ios.mm index 7c8725260..5f604e9a0 100644 --- a/src/plugins/avfoundation/camera/avfmediarecordercontrol_ios.mm +++ b/src/plugins/avfoundation/camera/avfmediarecordercontrol_ios.mm @@ -92,13 +92,7 @@ AVFMediaRecorderControlIOS::AVFMediaRecorderControlIOS(AVFCameraService *service { Q_ASSERT(service); - m_writerQueue.reset(dispatch_queue_create("asset-writer-queue", DISPATCH_QUEUE_SERIAL)); - if (!m_writerQueue) { - qDebugCamera() << Q_FUNC_INFO << "failed to create an asset writer's queue"; - return; - } - - m_writer.reset([[QT_MANGLE_NAMESPACE(AVFMediaAssetWriter) alloc] initWithQueue:m_writerQueue delegate:this]); + m_writer.reset([[QT_MANGLE_NAMESPACE(AVFMediaAssetWriter) alloc] initWithDelegate:this]); if (!m_writer) { qDebugCamera() << Q_FUNC_INFO << "failed to create an asset writer"; return; @@ -295,9 +289,15 @@ void AVFMediaRecorderControlIOS::setState(QMediaRecorder::State state) Q_EMIT stateChanged(m_state); Q_EMIT statusChanged(m_lastStatus); - dispatch_async(m_writerQueue, ^{ - [m_writer start]; - }); + // Apple recommends to call startRunning and do all + // setup on a special queue, and that's what we had + // initially (dispatch_async to writerQueue). Unfortunately, + // writer's queue is not the only queue/thread that can + // access/modify the session, and as a result we have + // all possible data/race-conditions with Obj-C exceptions + // at best and something worse in general. + // Now we try to only modify session on the same thread. + [m_writer start]; } else { [session startRunning]; Q_EMIT error(QMediaRecorder::FormatError, tr("Failed to start recording")); @@ -324,7 +324,7 @@ void AVFMediaRecorderControlIOS::setMuted(bool muted) void AVFMediaRecorderControlIOS::setVolume(qreal volume) { - Q_UNUSED(volume); + Q_UNUSED(volume) qDebugCamera() << Q_FUNC_INFO << "not implemented"; } @@ -409,9 +409,7 @@ void AVFMediaRecorderControlIOS::stopWriter() Q_EMIT stateChanged(m_state); Q_EMIT statusChanged(m_lastStatus); - dispatch_async(m_writerQueue, ^{ - [m_writer stop]; - }); + [m_writer stop]; } } |