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KraftVideoEffectTextureView

KraftVideoEffectTextureView is a specialized view that extends KraftEffectTextureView to provide seamless video playback with shader effects. It handles video rendering, MediaPlayer management, and automatic texture updates for video frames.

Overview​

This view combines video playback capabilities with KraftShade's shader effect system, making it easy to apply real-time effects to video content. It automatically handles:

  • Video texture creation and management
  • MediaPlayer lifecycle
  • Frame synchronization with Choreographer
  • Video rotation and coordinate system transformations
  • Playback controls and state management

Key Features​

  • Automatic video texture management: Handles ExternalOESTexture creation and updates
  • MediaPlayer integration: Built-in MediaPlayer with proper lifecycle management
  • Frame synchronization: Uses Android's Choreographer for smooth frame updates
  • Effect pipeline support: Specialized setEffectWithPipeline method for video processing
  • Playback controls: Play, pause, resume functionality with state tracking
  • Lifecycle awareness: Proper handling of activity pause/resume cycles
  • Auto-rotation handling: Automatically applies correct video transformations

Basic Usage​

Here's a simple example of using KraftVideoEffectTextureView with brightness effect:

class VideoActivity : AppCompatActivity() {
    private lateinit var videoView: KraftVideoEffectTextureView
    
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        
        // Create the view
        videoView = KraftVideoEffectTextureView(this)
        setContentView(videoView)
        
        // Set video source
        val videoUri = Uri.parse("android.resource://$packageName/${R.raw.sample_video}")
        videoView.setVideoUri(videoUri, autoPlay = true)
        
        // Apply brightness effect
        videoView.setEffectWithPipeline { inputTexture, targetBuffer ->
            serialSteps(inputTexture, targetBuffer) {
                step(BrightnessKraftShader(0.2f))
            }
        }
    }
    
    override fun onPause() {
        super.onPause()
        videoView.onPause()
    }
    
    override fun onResume() {
        super.onResume()
        videoView.onResume()
    }
    
    override fun onDestroy() {
        videoView.releaseMediaPlayer()
        super.onDestroy()
    }
}

Video-Specific Effect Pipeline​

setEffectWithPipeline​

The most important method for video effects is setEffectWithPipeline, which handles video-specific operations automatically:

fun setEffectWithPipeline(
    afterSet: suspend GlEnvDslScope.(windowSurface: WindowSurfaceBuffer) -> Unit = { requestRender() },
    effectExecution: suspend GraphPipelineSetupScope.(inputTexture: TextureProvider, targetBuffer: GlBufferProvider) -> Unit
)

This method automatically handles:

  • Video texture updates: Calls SurfaceTexture.updateTexImage() for the latest frame
  • Video rotation: Applies correct rotation transformation from video metadata
  • Vertical flip: Applies necessary coordinate system transformation for video rendering

Complex Effect Pipeline Example​

videoView.setEffectWithPipeline { inputTexture, targetBuffer ->
    serialSteps(inputTexture, targetBuffer) {
        // Apply saturation effect
        step(SaturationKraftShader(1.5f))
        
        // Apply brightness effect
        step(BrightnessKraftShader(0.3f))
        
        // Apply custom shader
        step(MyCustomVideoShader()) { shader ->
            shader.setCustomParameter(someValue)
        }
    }
}

Playback Controls​

Setting Video Source​

// Set video with auto-play
videoView.setVideoUri(uri, autoPlay = true)

// Set video without auto-play (shows first frame)
videoView.setVideoUri(uri, autoPlay = false)

Playback Control Methods​

// Check if video is currently playing
val isPlaying = videoView.isPlaying()

// Pause playback
videoView.pausePlayback()

// Resume playback
videoView.resumePlayback()

// Clean up MediaPlayer resources
videoView.releaseMediaPlayer()

Lifecycle Methods​

// In your Activity/Fragment
override fun onPause() {
    super.onPause()
    videoView.onPause() // Automatically pauses if playing
}

override fun onResume() {
    super.onResume()
    videoView.onResume() // Resumes if was playing before pause
}

Important Considerations​

Memory Management​

  • Always call releaseMediaPlayer() in your activity's onDestroy()
  • The view automatically manages video textures and OpenGL resources
  • MediaPlayer is reused for multiple videos to optimize memory usage

Lifecycle Integration​

  • Use onPause() and onResume() methods to properly handle activity lifecycle
  • The view automatically tracks playback state during pause/resume cycles
  • Choreographer callbacks are properly managed to prevent memory leaks