Configuring the Video Recorder

This tutorial describes how to configure the video recorder.

Purpose

The purpose of this tutorial is to show you how to make configuration adjustments to video recording parameters.

Required Background

The Video Client Overview introduces the video client utilities.

Introduction

The video recorder utility is used to record video clips to files, descriptors or URLs and manipulate embedded meta data. This functionality is implemented by the CVideoRecorderUtility class.

Using Video Recording Parameters

The following tasks will be covered in this tutorial:

Configure the Priority
Enable Audio Playback
Configure Video Frame Size
Configure MIME Type and Codecs
Configure Bit and Frame Rates
Configure Gain

Configuring the Priority

The high level steps to configure the priority are shown here:

To set the priority of the video/audio device, which is used to arbitrate between multiple objects trying to access a controller, use the CVideoRecorderUtility::SetPriorityL() function.
```
void CRecordVideo::SetPriorityL(TInt aPriority, TMdaPriorityPreference aPref)
    {
    iVideoRecordUtility->SetPriorityL(aPriority, aPref);
    }
```

To retrieve the priority setting of the video/audio device, use the CVideoRecorderUtility::GetPriorityL() function.

void CRecordVideo::GetPriorityL(TInt &aPriority, TMdaPriorityPreference &aPref)
    {
    iVideoRecordUtility->GetPriorityL(aPriority, aPref);
    }

Enabling Audio Playback

The high level steps to enable audio playback are shown here:

To determine whether an audio track is associated with a video clip, use the CVideoRecorderUtility::AudioEnabledL(). This function returns the status of audio support for the video clip currently being recorded.
```
 TBool CRecordVideo::AudioEnabledL()
    {
    return iVideoRecordUtility->AudioEnabledL();
    }
    
```
To set whether the current video clip has an audio track associated with it, use clipCVideoRecorderUtility::SetAudioEnabledL() function.
```
 void CRecordVideo::SetAudioEnabledL(TBool aEnabled)
    {
    iVideoRecordUtility->SetAudioEnabledL(aEnabled);
    }
```
Note: The above listed APIs are relevant only if the video clip is associated with an audio stream.

Configuring Video Frame Size

The high level steps to configure video frame size are shown here:

To retrieve the current frame size of the video clip, use the CVideoRecorderUtility::GetVideoFrameSizeL(). This function returns the video frame size in pixels.
```
 void CRecordVideo::GetVideoFrameSizeL(TSize &aSize)
    {
    iVideoRecordUtility->GetVideoFrameSizeL(aSize);
    }
```
To set the video frame to the desired size, use CVideoRecorderUtility::SetVideoFrameSizeL() function. This functions sets the video frame size in pixels.
```
 void CRecordVideo::SetVideoFrameSizeL(const TSize &aSize)
    {
    iVideoRecordUtility->SetVideoFrameSizeL(aSize);
    }
```

To set the video frame size to 176x144, use the CVideoRecorderUtility::SetVideoFrameSizeL() function.

 TSize frameSize;
    frameSize.iWidth = 176;
    frameSize.iHeight = 144;
    TRAP(err, iVideoRecorderUtility->SetVideoFrameSizeL(frameSize));

Configuring MIME Type and Codecs

The high level steps to configure MIME type and codecs are shown here:

To retrieve a list of video codecs supported by the currently open video clip, use CVideoRecorderUtility::GetSupportedVideoTypesL() function. This function returns an array of Four Character Codes representing the video types supported.
To retrieve a list of audio codecs supported by the current video clip, use CVideoRecorderUtility::GetSupportedAudioTypesL() function. This function returns an array of Four Character Codes representing the audio types supported.
To retrieve an audio codec currently in use by the video clip, use the and CVideoRecorderUtility::AudioTypeL() function. This function returns the audio type of the clip.
```
TFourCC CRecordVideo::AudioTypeL()
    {
    return iVideoRecordUtility->AudioTypeL();
    }
```

To set new video and audio codecs to use when recording data to the video clip, use the CVideoRecorderUtility::SetVideoTypeL() and CVideoRecorderUtility::SetAudioTypeL() functions.

void CRecordVideo::SetVideoTypeL(const TDesC8 &aType)
    {
    iVideoRecordUtility->SetVideoTypeL(aType);
    }

 void CRecordVideo::SetAudioTypeL(TFourCC aType)
    {
    iVideoRecordUtility->SetAudioTypeL(aType);
    }

Configuring Bit and Frame Rates

The high level steps to configure bit and frame rates are shown here:

To retrieve or set the video bit rates, use the CVideoRecorderUtility::VideoBitRateL() and CVideoRecorderUtility::SetVideoBitRateL() functions.

TInt CRecordVideo::VideoBitRateL()
    {
    return iVideoRecordUtility->VideoBitRateL();
    }

 void CRecordVideo::SetVideoBitRateL(TInt aBitRate)
    {
    iVideoRecordUtility->SetVideoBitRateL(aBitRate);
    }

To retrieve or set the audio bit rates, use the CVideoRecorderUtility::AudioBitRateL() and CVideoRecorderUtility::SetAudioBitRateL() functions.

TInt CRecordVideo::AudioBitRateL()
    {
    return iVideoRecordUtility->AudioBitRateL();
    }

 void CRecordVideo::SetAudioBitRateL(TInt aBitRate)
    {
    iVideoRecordUtility->SetAudioBitRateL(aBitRate);
    }

To retrieve or set the current frame rate of the video, use the CVideoRecorderUtility::VideoFrameRateL() and CVideoRecorderUtility::SetVideoFrameRateL() functions.

 TReal32 CRecordVideo::VideoFrameRateL()
    {
    return iVideoRecordUtility->VideoFrameRateL();
    }

void CRecordVideo::SetVideoFrameRateL(TReal32 aFrameRate)
    {
    iVideoRecordUtility->SetVideoFrameRateL(aFrameRate);
    }

Configuring Gain

The high level steps to configure recording gain are shown here:

To return the current recording gain use GainL().

 TInt CRecordVideo::GainL() 
    {
    return iVideoRecordUtility->GainL();
    }

To set the audio recording gain use SetGainL().

void CRecordVideo::SetGainL(TInt aGain)
    {
    iVideoRecordUtility->SetGainL(aGain);
    }

To return the maximum possible setting for the recording gain use MaxGain().

TInt CRecordVideo::MaxGainL() 
    {
    return iVideoRecordUtility->MaxGainL();
    }

Configuring the Video Recorder

Purpose

Using Video Recording Parameters

See Also