Deliver video frames on Android, on the decode thread.

VideoCoding
* Adding a method for polling for frames on Android only until the capture implementation takes care of this (longer term plan).

CodecDatabase
* Add an accessor for the current decoder
* Use std::unique_ptr<> for ownership.
* Remove "Release()" and "ReleaseDecoder()". Instead just delete.
* Remove |friend| relationship between CodecDatabase and VCMGenericDecoder.

VCMDecodedFrameCallback
* DCHECKs for thread correctness.
* Remove |lock_| now that a threading model has been established and verified.

VCMGenericDecoder
* All methods now have thread checks.
* Variable access associated with thread checkers.

VideoReceiver
* Added two notification methods, DecoderThreadStarting() and DecoderThreadStopped()
  * Allows us to establish a period when the decoder thread is not running and it is safe to modify variables such as callbacks, that are only read when the decoder thread is running.
  * Allows us to DCHECK thread guarantees.
  * Allows synchronizing callbacks from the module process thread and have them only active while the decoder thread is running.
  * The above, allows us to establish two modes for the thread, single-threaded-mutable and multi-threaded-const.
  * Using that knowledge, we can remove |receive_crit_| as well as locking for a number of member variables.

MediaCodecVideoDecoder
* Removed frame polling code from this class, since this is now done from the root thread function in VideoReceiveStream.

VideoReceiveStream
* On Android: Polls for decoded frames every 10ms (same interval as previously in MediaCodecVideoDecoder)
* [Un]Registers the |video_receiver_| with the module thread only around the time the decoder thread is started/stopped.
* Notifies the receiver of start/stop events of the decoder thread.
* Changed the decoder thread to use the new PlatformThread callback type.

BUG=webrtc:7361, 695438

Review-Url: https://codereview.webrtc.org/2764573002
Cr-Commit-Position: refs/heads/master@{#17527}
This commit is contained in:
tommi
2017-04-04 03:53:02 -07:00
committed by Commit bot
parent aa7d935cd5
commit e3aa88bbd5
12 changed files with 511 additions and 321 deletions

View File

@ -35,6 +35,7 @@
namespace webrtc {
class ProcessThread;
class VideoBitrateAllocator;
class VideoBitrateAllocationObserver;
@ -150,7 +151,7 @@ class VideoReceiver : public Module {
VCMTiming* timing,
NackSender* nack_sender = nullptr,
KeyFrameRequestSender* keyframe_request_sender = nullptr);
~VideoReceiver();
~VideoReceiver() override;
int32_t RegisterReceiveCodec(const VideoCodec* receiveCodec,
int32_t numberOfCores,
@ -168,8 +169,10 @@ class VideoReceiver : public Module {
int32_t Decode(const webrtc::VCMEncodedFrame* frame);
// Called on the decoder thread when thread is exiting.
void DecodingStopped();
#if defined(WEBRTC_ANDROID)
// See https://bugs.chromium.org/p/webrtc/issues/detail?id=7361
void PollDecodedFrames();
#endif
int32_t IncomingPacket(const uint8_t* incomingPayload,
size_t payloadLength,
@ -195,39 +198,66 @@ class VideoReceiver : public Module {
int64_t TimeUntilNextProcess() override;
void Process() override;
void ProcessThreadAttached(ProcessThread* process_thread) override;
void TriggerDecoderShutdown();
void DecoderThreadStarting();
void DecoderThreadStopped();
protected:
int32_t Decode(const webrtc::VCMEncodedFrame& frame)
EXCLUSIVE_LOCKS_REQUIRED(receive_crit_);
int32_t Decode(const webrtc::VCMEncodedFrame& frame);
int32_t RequestKeyFrame();
private:
// Used for DCHECKing thread correctness.
// In build where DCHECKs are enabled, will return false before
// DecoderThreadStarting is called, then true until DecoderThreadStopped
// is called.
// In builds where DCHECKs aren't enabled, it will return true.
bool IsDecoderThreadRunning();
rtc::ThreadChecker construction_thread_;
rtc::ThreadChecker decoder_thread_;
rtc::ThreadChecker module_thread_;
Clock* const clock_;
rtc::CriticalSection process_crit_;
rtc::CriticalSection receive_crit_;
VCMTiming* _timing;
VCMReceiver _receiver;
VCMDecodedFrameCallback _decodedFrameCallback;
VCMFrameTypeCallback* _frameTypeCallback GUARDED_BY(process_crit_);
VCMReceiveStatisticsCallback* _receiveStatsCallback GUARDED_BY(process_crit_);
VCMPacketRequestCallback* _packetRequestCallback GUARDED_BY(process_crit_);
VCMFrameBuffer _frameFromFile;
// These callbacks are set on the construction thread before being attached
// to the module thread or decoding started, so a lock is not required.
VCMFrameTypeCallback* _frameTypeCallback;
VCMReceiveStatisticsCallback* _receiveStatsCallback;
VCMPacketRequestCallback* _packetRequestCallback;
// Used on both the module and decoder thread.
bool _scheduleKeyRequest GUARDED_BY(process_crit_);
bool drop_frames_until_keyframe_ GUARDED_BY(process_crit_);
size_t max_nack_list_size_ GUARDED_BY(process_crit_);
VCMCodecDataBase _codecDataBase GUARDED_BY(receive_crit_);
EncodedImageCallback* pre_decode_image_callback_;
// Modified on the construction thread while not attached to the process
// thread. Once attached to the process thread, its value is only read
// so a lock is not required.
size_t max_nack_list_size_;
VCMProcessTimer _receiveStatsTimer;
VCMProcessTimer _retransmissionTimer;
VCMProcessTimer _keyRequestTimer;
QpParser qp_parser_;
ThreadUnsafeOneTimeEvent first_frame_received_;
// Callbacks are set before the decoder thread starts.
// Once the decoder thread has been started, usage of |_codecDataBase| moves
// over to the decoder thread.
VCMCodecDataBase _codecDataBase;
EncodedImageCallback* const pre_decode_image_callback_;
VCMProcessTimer _receiveStatsTimer ACCESS_ON(module_thread_);
VCMProcessTimer _retransmissionTimer ACCESS_ON(module_thread_);
VCMProcessTimer _keyRequestTimer ACCESS_ON(module_thread_);
QpParser qp_parser_ ACCESS_ON(decoder_thread_);
ThreadUnsafeOneTimeEvent first_frame_received_ ACCESS_ON(decoder_thread_);
// Modified on the construction thread. Can be read without a lock and assumed
// to be non-null on the module and decoder threads.
ProcessThread* process_thread_ = nullptr;
bool is_attached_to_process_thread_ ACCESS_ON(construction_thread_) = false;
#if RTC_DCHECK_IS_ON
bool decoder_thread_is_running_ = false;
#endif
};
} // namespace vcm