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Recording through the Datastead Encoder

The installation and functions overview are described in the Datastead Encoder chapter.

It is possible:

  1. either to record through the Datastead recording functions, allowing to use TVideoGrabber's OnRecording... events, in this case TVideoGrabber is started by invoking StartRecording()

  2. either to record through an external Encoder instance (not managed by TVideoGrabber), in this case TVideoGrabber is started by invoking StartPreview(), that will send the audio/video samples to all the active Encoder instances.

SAMPLE CODE

  1. sample code for a recording using the TVideoGrabber recording functions:

managed by TVideoGrabber, that controls it and raises the corresponding recording events

IMPORTANT NOTE:

The TVideoGrabber recording features (RecordingFileName / CompressionMode / StartRecording / PauseRecording / ResumeRecording / RecordToNewFileNow, etc...) invoke the internal Encoder instance with ID 0.

In this case, do not invoke Encoders_CreateInstanceForRecording to pass the recording file name instead of setting RecordingFileName, this is already controlled internally by TVideoGrabber.

Only Encoder_SetInt and Encoder_SetStr should be invoked with ID 0 to configure the parameters, as shown in the MainDemo project -> "multipurpose" tab.

If preferring to configure and control the recording by configuring a recorder instance with Encoders_CreateInstanceForRecording, run TVideoGrabber in preview mode only (by invoking StartPreview), it will pass the audio/video samples to the instance having created, as described in the paragraph 2. below.

A) STARTING THE RECORDING

#define ENCODER_RECORDING_ID 0 // the encoder with ID 0 is the TVideoGrabber's embedded encoder, this will never change

  • // in the MainDemo project, "video source" tab*

VideoGrabber.VideoDevice = VideoGrabber.VideoDeviceIndex ("c922 Pro Stream Webcam");

VideoGrabber.AudioDevice = VideoGrabber.AudioDeviceindex ("Microphone (C922 Pro Stream Webcam)");

VideoGrabber.VideoCompressor = VideoCompressorIndex ("Datastead Multipurpose Encoder");

VideoGrabber.AudioCompressor = AudioCompressorIndex ("Datastead Multipurpose Encoder");

  • // in the MainDemo project, "multipurpose" tab*

VideoGrabber.Encoder_SetInt (ENCODER_RECORDING_ID, Enc_Video_Bitrate_kb, 2000);

VideoGrabber.Encoder_SetStr (ENCODER_RECORDING_ID, Enc_Video_Codec, "hevc");

VideoGrabber.Encoder_SetInt (ENCODER_RECORDING_ID, Enc_Video_Thread_Count, 4); // default 1

// VideoGrabber.Encoder_SetInt (ENCODER_RECORDING_ID, Enc_Video_GPU_Encoder, integer (Enc_GPU_NVidia_NVENC)); to enable the GPU encoding through NVidia (to select any GPU available set Enc_GPU_Auto)

VideoGrabber.Encoder_SetStr (ENCODER_RECORDING_ID, Enc_Audio_Codec, "aac");

  • // in the MainDemo project, "recording" tab*

VideoGrabber.RecordingMethod = rm_MP4; // to generate the file name automatically,

// VideoGrabber.RecordingFileName = "VideoClip.mp4"; // if the file name is specified, it determines the recording method, no need to set RecordingMethod above

VideoGrabber.AudioRecording = true;

VideoGrabber.CompressionMode = cm_CompressOnTheFly;

VideoGrabber.StartRecording();

B) PAUSING THE RECORDING

VideoGrabber.PauseRecording();

C) RESUMING THE RECORDING

VideoGrabber.ResumeRecording();

D) RECORDING TO A NEW FILE

VideoGrabber.RecordToNewFileNow ("c:/folder/newvideoclip.mp4");

E) STOPPING THE RECORDING

VideoGrabber.Stop();

  1. same sample code to recording using an external encoder instance

not managed by TVideoGrabber, that just sends the audio/video samples to the encoder(s)

A) STARTING THE RECORDING

int m_EncoderInstanceID = -1;

  • // in the MainDemo project, "video source" tab*

VideoGrabber.VideoDevice = VideoGrabber.VideoDeviceIndex ("c922 Pro Stream Webcam");

VideoGrabber.AudioDevice = VideoGrabber.AudioDeviceindex ("Microphone (C922 Pro Stream Webcam)");

m_EncoderInstanceID = VideoGrabber.Encoders_CreateInstanceForRecording ("VideoClip.mp4");

if (m_EncoderInstanceID > -1)

{

VideoGrabber.Encoder_SetInt (m_EncoderInstanceID, Enc_Video_Enabled_bool, 1);

VideoGrabber.Encoder_SetInt (m_EncoderInstanceID, Enc_Video_Bitrate_kb, 2000);

VideoGrabber.Encoder_SetStr (m_EncoderInstanceID, Enc_Video_Codec, "hevc");

VideoGrabber.Encoder_SetInt (m_EncoderInstanceID, Enc_Video_Thread_Count, 4); // default 1

// VideoGrabber.Encoder_SetInt (m_EncoderInstanceID, Enc_Video_GPU_Encoder, integer (Enc_GPU_NVidia_NVENC)); to enable the GPU encoding through NVidia (to select any GPU available set Enc_GPU_Auto)

VideoGrabber.Encoder_SetInt (m_EncoderInstanceID, Enc_Audio_Enabled_bool, 1);

VideoGrabber.Encoder_SetStr (m_EncoderInstanceID, Enc_Audio_Codec, "aac");

VideoGrabber.Encoder_SetInt (m_EncoderInstanceID, Enc_Audio_Bitrate_kb, 64);

VideoGrabber.AudioDeviceRendering = true;

VideoGrabber.StartPreview();

}

B) PAUSING THE RECORDING

VideoGrabber.Encoder_Pause (m_EncoderInstanceID);

C) RESUMING THE RECORDING

VideoGrabber.Encoder_Resume (m_EncoderInstanceID);

D) RECORDING TO A NEW FILE

bool OpenInPausedState = false; // to record to the new file immediately, otherwise the current file is closed and the recording to the next file will start when invoking Encoder_Resume

VideoGrabber.Encoder_NewOutputFile(m_EncoderInstanceID, "c:/folder/newvideoclip.mp4", OpenInPausedState);

D) STOPPING THE RECORDING ONLY

VideoGrabber.Encoder_NewOutputFile(m_EncoderInstanceID, "c:/folder/AnyNewFileName.mp4", true); // this closes the current file and prepare for the next file. If Encoder_Resume is never invoked, the next file will

E) STOPPING THE PREVIEW AND RECORDING

VideoGrabber.Stop();

F) SETTING A NEW FILE NAME BEFORE RESTARTING THE VIDEO

bool OpenInPausedState = false; // to record to the new file immediately, otherwise the current file is closed and the recording to the next file will start when invoking Encoder_Resume

VideoGrabber.Encoder_NewOutputFile(m_EncoderInstanceID, "c:/folder/anothervideoclip.mp4", OpenInPausedState);

VideoGrabber.StartPreview();