UTmvMediaTranscodeJob

The transcode job implements a staged transcoding pipeline.

API > API/Plugins > API/Plugins/TmvMedia

The transcode job implements a staged transcoding pipeline.

The stages are pre-determined and described as follows (in that order):

  • FrameProducer: media source, produces the frames that are pushed to the frame converter.
  • FrameConverter: Bridges the producer and encoder. It will inspect the needed format for encoder and produce the appropriate conversion.
  • FrameEncoder: Receives frames ready (in the right format) to be encoded by a tmv encoder. It will query the muxer stage to get an access unit.
  • FrameMuxer: Final stage of the pipeline that will typically write to file or media container.

There can only be one stage of each class per pipeline and the order is fixed as listed above.

Todo - Audio and other streams: The current implementation only deals with a single video stream. For audio streams, we will need to make the pipeline more complex and deal with different streams into a common muxer stage.

   
Name UTmvMediaTranscodeJob
Type class
Header File /Engine/Plugins/Media/TmvMedia/Source/TmvMedia/Public/Transcoder/TmvMediaTranscodeJob.h
Include Path #include "Transcoder/TmvMediaTranscodeJob.h"

Syntax

UCLASS (MinimalAPI)  
class UTmvMediaTranscodeJob : public UObject

Inheritance Hierarchy

Constructors

Name Remarks Include Path Unreal Specifiers

UTmvMediaTranscodeJob()

   Transcoder/TmvMediaTranscodeJob.h  

Variables

Public

Name Type Remarks Include Path Unreal Specifiers
bIsError std::atomic< bool > Indicate a stage had an error somewhere that requires the job to stop. Transcoder/TmvMediaTranscodeJob.h  
JobName FString Original Job Item Name. Transcoder/TmvMediaTranscodeJob.h  
JobStatus std::atomic< ETmvMediaTranscodeJobStatus > Overall job state. Transcoder/TmvMediaTranscodeJob.h  
Settings FTmvMediaTranscodeJobSettings Common job settings. Transcoder/TmvMediaTranscodeJob.h  
Stages TArray< TObjectPtr< UTmvMediaTranscodeStage > > Stages in this pipeline. Transcoder/TmvMediaTranscodeJob.h  
StopReason ETmvMediaTranscodeJobStopReason Keep track of the stopping reason. This is mostly used for UI and logging. Transcoder/TmvMediaTranscodeJob.h  

Protected

Name Type Remarks Include Path Unreal Specifiers
Id FGuid Unique Id of this job item (from a corresponding job list). Transcoder/TmvMediaTranscodeJob.h  

Functions

Public

Name Remarks Include Path Unreal Specifiers

bool AddStage ( UTmvMediaTranscodeStage* InStage
)

 Add the specified stage to the pipeline. Transcoder/TmvMediaTranscodeJob.h  

bool AreStagesStopped()

 Returns true if all the stages are stopped. Transcoder/TmvMediaTranscodeJob.h  

DECLARE_TS_MULTICAST_DELEGATE_OneParam ( FOnTranscodeJobFinished
)

 Job Finished Delegate. Transcoder/TmvMediaTranscodeJob.h  

DECLARE_TS_MULTICAST_DELEGATE_ThreeParams ( FOnTranscodeJobEvent
)

 Job Event Delegate. Transcoder/TmvMediaTranscodeJob.h  

void Discard ( double InCurrentTime
)

 When the job is done and will not be used anymore, explicitly discarding it to remove it from the job manager. Transcoder/TmvMediaTranscodeJob.h  

const FGuid & GetId()

 Returns Job Id. Transcoder/TmvMediaTranscodeJob.h  
Returns a copy of job stats (thread safe). Transcoder/TmvMediaTranscodeJob.h  

TStageClass * GetStage()

 Get the specified stage from the stage class. There is only one stage of each type in the pipeline. Transcoder/TmvMediaTranscodeJob.h  

bool IsCompleted()

 Determine the global status of the jobs to see if it is completed or not. Transcoder/TmvMediaTranscodeJob.h  

bool IsRunning()

 Returns true if overall job status is running. Transcoder/TmvMediaTranscodeJob.h  

void RequestStop ( double InCurrentTime,
ETmvMediaTranscodeJobStopReason InReason
)

 Request Stop (cancel) the job. Transcoder/TmvMediaTranscodeJob.h  

void SetId ( const FGuid& InId
)

 Update the id of a job. Transcoder/TmvMediaTranscodeJob.h  

void SetNotificationHandler ( const TSharedPtr< ITmvMediaTranscodeNotification >& InNotification
)

 (Optional) Set a notification handler that will be used for progress update display. Transcoder/TmvMediaTranscodeJob.h  

bool Start ( double InCurrentTime
)

 Start the job. Transcoder/TmvMediaTranscodeJob.h  

void Tick ( const FTmvMediaTranscodeJobTime& InTime
)

 Tick called in the main thread. Performs sync tasks. Transcoder/TmvMediaTranscodeJob.h  

void UpdateProgress ( int32 InCurrentFrame,
int32 InTotalFrames
)

 Update job progress stats. Transcoder/TmvMediaTranscodeJob.h  

Public Virtual

Overridden from UObject

Name Remarks Include Path Unreal Specifiers

virtual void BeginDestroy()

   Transcoder/TmvMediaTranscodeJob.h  

Static

Name Remarks Include Path Unreal Specifiers

static void SafeBroadcastJobEvent ( UTmvMediaTranscodeJob* InJob,
ETmvMediaTranscodeJobEvent InEvent,
UTmvMediaTranscodeStage* InStage
)

 Helper function to broadcast a job event. Transcoder/TmvMediaTranscodeJob.h  

static void SafeBroadcastJobFinished ( UTmvMediaTranscodeJob* InJob
)

 Helper function to broadcast job finished event. Transcoder/TmvMediaTranscodeJob.h  

static void SafeReportError ( UTmvMediaTranscodeJob* InJob,
const FText& InErrorMessage
)

 Called by the processing stages in case a fatal error requires the job to stop. Transcoder/TmvMediaTranscodeJob.h  

static void SafeUpdateProgress ( UTmvMediaTranscodeJob* InJob,
int32 InCurrentFrame,
int32 InTotalFrames
)

 Helper function to update the job progress stats. Transcoder/TmvMediaTranscodeJob.h  

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