Android: Add helper class VideoFrameDrawer that can render VideoFrames

webrtc/sdk/android/api/org/webrtc/VideoFrameDrawer.java

Index: webrtc/sdk/android/api/org/webrtc/VideoFrameDrawer.java
diff --git a/webrtc/sdk/android/api/org/webrtc/RendererCommon.java b/webrtc/sdk/android/api/org/webrtc/VideoFrameDrawer.java
similarity index 29%
copy from webrtc/sdk/android/api/org/webrtc/RendererCommon.java
copy to webrtc/sdk/android/api/org/webrtc/VideoFrameDrawer.java
index 18d96c22e57fdc25ee9ae2f589b6500683a9d327..491fd054c26c5894c580c8252e72cd186898515b 100644
--- a/webrtc/sdk/android/api/org/webrtc/RendererCommon.java
+++ b/webrtc/sdk/android/api/org/webrtc/VideoFrameDrawer.java
@@ -1,5 +1,5 @@
 /*
- *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
+ *  Copyright 2017 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
@@ -10,61 +10,29 @@
 
 package org.webrtc;
 
+import android.graphics.Matrix;
 import android.graphics.Point;
 import android.opengl.GLES20;
-import android.opengl.Matrix;
-import android.view.View;
 import java.nio.ByteBuffer;
 
 /**
- * Static helper functions for renderer implementations.
+ * Helper class to draw VideoFrames. Calls either drawer.drawOes, drawer.drawRgb, or
+ * drawer.drawYuv depending on the type of the buffer. The frame will be rendered with rotation
+ * taken into account. You can supply an additional render matrix for custom transformations.
  */
-public class RendererCommon {
-  /** Interface for reporting rendering events. */
-  public static interface RendererEvents {
-    /**
-     * Callback fired once first frame is rendered.
-     */
-    public void onFirstFrameRendered();
-
-    /**
-     * Callback fired when rendered frame resolution or rotation has changed.
-     */
-    public void onFrameResolutionChanged(int videoWidth, int videoHeight, int rotation);
-  }
-
-  /** Interface for rendering frames on an EGLSurface. */
-  public static interface GlDrawer {
-    /**
-     * Functions for drawing frames with different sources. The rendering surface target is
-     * implied by the current EGL context of the calling thread and requires no explicit argument.
-     * The coordinates specify the viewport location on the surface target.
-     */
-    void drawOes(int oesTextureId, float[] texMatrix, int frameWidth, int frameHeight,
-        int viewportX, int viewportY, int viewportWidth, int viewportHeight);
-    void drawRgb(int textureId, float[] texMatrix, int frameWidth, int frameHeight, int viewportX,
-        int viewportY, int viewportWidth, int viewportHeight);
-    void drawYuv(int[] yuvTextures, float[] texMatrix, int frameWidth, int frameHeight,
-        int viewportX, int viewportY, int viewportWidth, int viewportHeight);
-
-    /**
-     * Release all GL resources. This needs to be done manually, otherwise resources may leak.
-     */
-    void release();
-  }
-
+public class VideoFrameDrawer {
   /**
    * Draws a VideoFrame.TextureBuffer. Calls either drawer.drawOes or drawer.drawRgb
    * depending on the type of the buffer. You can supply an additional render matrix. This is
    * used multiplied together with the transformation matrix of the frame. (M = renderMatrix *
    * transformationMatrix)
    */
-  static void drawTexture(GlDrawer drawer, VideoFrame.TextureBuffer buffer,
-      android.graphics.Matrix renderMatrix, int frameWidth, int frameHeight, int viewportX,
-      int viewportY, int viewportWidth, int viewportHeight) {
-    android.graphics.Matrix finalMatrix = new android.graphics.Matrix(buffer.getTransformMatrix());
+  static void drawTexture(RendererCommon.GlDrawer drawer, VideoFrame.TextureBuffer buffer,
+      Matrix renderMatrix, int frameWidth, int frameHeight, int viewportX, int viewportY,
+      int viewportWidth, int viewportHeight) {
+    Matrix finalMatrix = new Matrix(buffer.getTransformMatrix());
     finalMatrix.preConcat(renderMatrix);
-    float[] finalGlMatrix = convertMatrixFromAndroidGraphicsMatrix(finalMatrix);
+    float[] finalGlMatrix = RendererCommon.convertMatrixFromAndroidGraphicsMatrix(finalMatrix);
     switch (buffer.getType()) {
       case OES:
         drawer.drawOes(buffer.getTextureId(), finalGlMatrix, frameWidth, frameHeight, viewportX,
@@ -83,7 +51,7 @@ public class RendererCommon {
    * Helper class for uploading YUV bytebuffer frames to textures that handles stride > width. This
    * class keeps an internal ByteBuffer to avoid unnecessary allocations for intermediate copies.
    */
-  public static class YuvUploader {
+  private static class YuvUploader {
     // Intermediate copy buffer for uploading yuv frames that are not packed, i.e. stride > width.
     // TODO(magjed): Investigate when GL_UNPACK_ROW_LENGTH is available, or make a custom shader
     // that handles stride and compare performance with intermediate copy.
@@ -143,6 +111,10 @@ public class RendererCommon {
       return uploadYuvData(buffer.getWidth(), buffer.getHeight(), strides, planes);
     }
 
+    public int[] getYuvTextures() {
+      return yuvTextures;
+    }
+
     /**
      * Releases cached resources. Uploader can still be used and the resources will be reallocated
      * on first use.
@@ -156,240 +128,100 @@ public class RendererCommon {
     }
   }
 
-  /**
-   * Helper class for determining layout size based on layout requirements, scaling type, and video
-   * aspect ratio.
-   */
-  public static class VideoLayoutMeasure {
-    // The scaling type determines how the video will fill the allowed layout area in measure(). It
-    // can be specified separately for the case when video has matched orientation with layout size
-    // and when there is an orientation mismatch.
-    private ScalingType scalingTypeMatchOrientation = ScalingType.SCALE_ASPECT_BALANCED;
-    private ScalingType scalingTypeMismatchOrientation = ScalingType.SCALE_ASPECT_BALANCED;
+  private static int distance(float x0, float y0, float x1, float y1) {
+    return (int) Math.round(Math.hypot(x1 - x0, y1 - y0));
+  }
 
-    public void setScalingType(ScalingType scalingType) {
-      this.scalingTypeMatchOrientation = scalingType;
-      this.scalingTypeMismatchOrientation = scalingType;
-    }
+  // These points are used to calculate the size of the part of the frame we are rendering.
+  final static float[] srcPoints =
+      new float[] {0f /* x0 */, 0f /* y0 */, 1f /* x1 */, 0f /* y1 */, 0f /* x2 */, 1f /* y2 */};
+  private final float[] dstPoints = new float[6];
+  private final Point renderSize = new Point();
+  private int renderWidth;
+  private int renderHeight;
 
-    public void setScalingType(
-        ScalingType scalingTypeMatchOrientation, ScalingType scalingTypeMismatchOrientation) {
-      this.scalingTypeMatchOrientation = scalingTypeMatchOrientation;
-      this.scalingTypeMismatchOrientation = scalingTypeMismatchOrientation;
+  // Calculate the frame size after |renderMatrix| is applied. Stores the output in member variables
+  // |renderWidth| and |renderHeight| to avoid allocations since this function is called for every
+  // frame.
+  private void calculateTransformedRenderSize(
+      int frameWidth, int frameHeight, Matrix renderMatrix) {
+    if (renderMatrix == null) {
+      renderWidth = frameWidth;
+      renderHeight = frameHeight;
+      return;
     }
+    // Transform the texture coordinates (in the range [0, 1]) according to |renderMatrix|.
+    renderMatrix.mapPoints(dstPoints, srcPoints);
 
-    public Point measure(int widthSpec, int heightSpec, int frameWidth, int frameHeight) {
-      // Calculate max allowed layout size.
-      final int maxWidth = View.getDefaultSize(Integer.MAX_VALUE, widthSpec);
-      final int maxHeight = View.getDefaultSize(Integer.MAX_VALUE, heightSpec);
-      if (frameWidth == 0 || frameHeight == 0 || maxWidth == 0 || maxHeight == 0) {
-        return new Point(maxWidth, maxHeight);
-      }
-      // Calculate desired display size based on scaling type, video aspect ratio,
-      // and maximum layout size.
-      final float frameAspect = frameWidth / (float) frameHeight;
-      final float displayAspect = maxWidth / (float) maxHeight;
-      final ScalingType scalingType = (frameAspect > 1.0f) == (displayAspect > 1.0f)
-          ? scalingTypeMatchOrientation
-          : scalingTypeMismatchOrientation;
-      final Point layoutSize = getDisplaySize(scalingType, frameAspect, maxWidth, maxHeight);
-
-      // If the measure specification is forcing a specific size - yield.
-      if (View.MeasureSpec.getMode(widthSpec) == View.MeasureSpec.EXACTLY) {
-        layoutSize.x = maxWidth;
-      }
-      if (View.MeasureSpec.getMode(heightSpec) == View.MeasureSpec.EXACTLY) {
-        layoutSize.y = maxHeight;
-      }
-      return layoutSize;
+    // Multiply with the width and height to get the positions in terms of pixels.
+    for (int i = 0; i < 3; ++i) {
+      dstPoints[i * 2 + 0] *= frameWidth;
+      dstPoints[i * 2 + 1] *= frameHeight;
     }
-  }
 
-  // Types of video scaling:
-  // SCALE_ASPECT_FIT - video frame is scaled to fit the size of the view by
-  //    maintaining the aspect ratio (black borders may be displayed).
-  // SCALE_ASPECT_FILL - video frame is scaled to fill the size of the view by
-  //    maintaining the aspect ratio. Some portion of the video frame may be
-  //    clipped.
-  // SCALE_ASPECT_BALANCED - Compromise between FIT and FILL. Video frame will fill as much as
-  // possible of the view while maintaining aspect ratio, under the constraint that at least
-  // |BALANCED_VISIBLE_FRACTION| of the frame content will be shown.
-  public static enum ScalingType { SCALE_ASPECT_FIT, SCALE_ASPECT_FILL, SCALE_ASPECT_BALANCED }
-  // The minimum fraction of the frame content that will be shown for |SCALE_ASPECT_BALANCED|.
-  // This limits excessive cropping when adjusting display size.
-  private static float BALANCED_VISIBLE_FRACTION = 0.5625f;
-  // clang-format off
-  public static final float[] identityMatrix() {
-    return new float[] {
-        1, 0, 0, 0,
-        0, 1, 0, 0,
-        0, 0, 1, 0,
-        0, 0, 0, 1};
-  }
-  // Matrix with transform y' = 1 - y.
-  public static final float[] verticalFlipMatrix() {
-    return new float[] {
-        1,  0, 0, 0,
-        0, -1, 0, 0,
-        0,  0, 1, 0,
-        0,  1, 0, 1};
+    // Get the length of the sides of the transformed rectangle in terms of pixels.
+    renderWidth = distance(dstPoints[0], dstPoints[1], dstPoints[2], dstPoints[3]);
+    renderHeight = distance(dstPoints[0], dstPoints[1], dstPoints[4], dstPoints[5]);
   }
 
-  // Matrix with transform x' = 1 - x.
-  public static final float[] horizontalFlipMatrix() {
-    return new float[] {
-        -1, 0, 0, 0,
-         0, 1, 0, 0,
-         0, 0, 1, 0,
-         1, 0, 0, 1};
-  }
-  // clang-format on
+  private final YuvUploader yuvUploader = new YuvUploader();
+  // This variable will only be used for checking reference equality and is used for caching I420
+  // textures.
+  private VideoFrame lastI420Frame;
+  private final Matrix renderMatrix = new Matrix();
 
-  /**
-   * Returns texture matrix that will have the effect of rotating the frame |rotationDegree|
-   * clockwise when rendered.
-   */
-  public static float[] rotateTextureMatrix(float[] textureMatrix, float rotationDegree) {
-    final float[] rotationMatrix = new float[16];
-    Matrix.setRotateM(rotationMatrix, 0, rotationDegree, 0, 0, 1);
-    adjustOrigin(rotationMatrix);
-    return multiplyMatrices(textureMatrix, rotationMatrix);
+  public void drawFrame(VideoFrame frame, RendererCommon.GlDrawer drawer) {
+    drawFrame(frame, drawer, null /* additionalRenderMatrix */);
   }
 
-  /**
-   * Returns new matrix with the result of a * b.
-   */
-  public static float[] multiplyMatrices(float[] a, float[] b) {
-    final float[] resultMatrix = new float[16];
-    Matrix.multiplyMM(resultMatrix, 0, a, 0, b, 0);
-    return resultMatrix;
+  public void drawFrame(
+      VideoFrame frame, RendererCommon.GlDrawer drawer, Matrix additionalRenderMatrix) {
+    drawFrame(frame, drawer, additionalRenderMatrix, 0 /* viewportX */, 0 /* viewportY */,
+        frame.getRotatedWidth(), frame.getRotatedHeight());
   }
 
-  /**
-   * Returns layout transformation matrix that applies an optional mirror effect and compensates
-   * for video vs display aspect ratio.
-   */
-  public static float[] getLayoutMatrix(
-      boolean mirror, float videoAspectRatio, float displayAspectRatio) {
-    float scaleX = 1;
-    float scaleY = 1;
-    // Scale X or Y dimension so that video and display size have same aspect ratio.
-    if (displayAspectRatio > videoAspectRatio) {
-      scaleY = videoAspectRatio / displayAspectRatio;
-    } else {
-      scaleX = displayAspectRatio / videoAspectRatio;
-    }
-    // Apply optional horizontal flip.
-    if (mirror) {
-      scaleX *= -1;
-    }
-    final float matrix[] = new float[16];
-    Matrix.setIdentityM(matrix, 0);
-    Matrix.scaleM(matrix, 0, scaleX, scaleY, 1);
-    adjustOrigin(matrix);
-    return matrix;
-  }
+  public void drawFrame(VideoFrame frame, RendererCommon.GlDrawer drawer,
+      Matrix additionalRenderMatrix, int viewportX, int viewportY, int viewportWidth,
+      int viewportHeight) {
+    final int width = frame.getRotatedWidth();
+    final int height = frame.getRotatedHeight();
 
-  /** Converts a float[16] matrix array to android.graphics.Matrix. */
-  public static android.graphics.Matrix convertMatrixToAndroidGraphicsMatrix(float[] matrix4x4) {
-    // clang-format off
-    float[] values = {
-        matrix4x4[0 * 4 + 0], matrix4x4[1 * 4 + 0], matrix4x4[3 * 4 + 0],
-        matrix4x4[0 * 4 + 1], matrix4x4[1 * 4 + 1], matrix4x4[3 * 4 + 1],
-        matrix4x4[0 * 4 + 3], matrix4x4[1 * 4 + 3], matrix4x4[3 * 4 + 3],
-    };
-    // clang-format on
+    calculateTransformedRenderSize(width, height, additionalRenderMatrix);
 
-    android.graphics.Matrix matrix = new android.graphics.Matrix();
-    matrix.setValues(values);
-    return matrix;
-  }
-
-  /** Converts android.graphics.Matrix to a float[16] matrix array. */
-  public static float[] convertMatrixFromAndroidGraphicsMatrix(android.graphics.Matrix matrix) {
-    float[] values = new float[9];
-    matrix.getValues(values);
-
-    // The android.graphics.Matrix looks like this:
-    // [x1 y1 w1]
-    // [x2 y2 w2]
-    // [x3 y3 w3]
-    // We want to contruct a matrix that looks like this:
-    // [x1 y1  0 w1]
-    // [x2 y2  0 w2]
-    // [ 0  0  1  0]
-    // [x3 y3  0 w3]
-    // Since it is stored in column-major order, it looks like this:
-    // [x1 x2 0 x3
-    //  y1 y2 0 y3
-    //   0  0 1  0
-    //  w1 w2 0 w3]
-    // clang-format off
-    float[] matrix4x4 = {
-        values[0 * 3 + 0],  values[1 * 3 + 0], 0,  values[2 * 3 + 0],
-        values[0 * 3 + 1],  values[1 * 3 + 1], 0,  values[2 * 3 + 1],
-        0,                  0,                 1,  0,
-        values[0 * 3 + 2],  values[1 * 3 + 2], 0,  values[2 * 3 + 2],
-    };
-    // clang-format on
-    return matrix4x4;
-  }
-
-  /**
-   * Calculate display size based on scaling type, video aspect ratio, and maximum display size.
-   */
-  public static Point getDisplaySize(
-      ScalingType scalingType, float videoAspectRatio, int maxDisplayWidth, int maxDisplayHeight) {
-    return getDisplaySize(convertScalingTypeToVisibleFraction(scalingType), videoAspectRatio,
-        maxDisplayWidth, maxDisplayHeight);
-  }
+    final boolean isTextureFrame = frame.getBuffer() instanceof VideoFrame.TextureBuffer;
+    renderMatrix.reset();
+    renderMatrix.preTranslate(0.5f, 0.5f);
+    if (!isTextureFrame) {
+      renderMatrix.preScale(1f, -1f); // I420-frames are upside down
+    }
+    renderMatrix.preRotate(frame.getRotation());
+    renderMatrix.preTranslate(-0.5f, -0.5f);
+    if (additionalRenderMatrix != null) {
+      renderMatrix.preConcat(additionalRenderMatrix);
+    }
 
-  /**
-   * Move |matrix| transformation origin to (0.5, 0.5). This is the origin for texture coordinates
-   * that are in the range 0 to 1.
-   */
-  private static void adjustOrigin(float[] matrix) {
-    // Note that OpenGL is using column-major order.
-    // Pre translate with -0.5 to move coordinates to range [-0.5, 0.5].
-    matrix[12] -= 0.5f * (matrix[0] + matrix[4]);
-    matrix[13] -= 0.5f * (matrix[1] + matrix[5]);
-    // Post translate with 0.5 to move coordinates to range [0, 1].
-    matrix[12] += 0.5f;
-    matrix[13] += 0.5f;
-  }
+    if (isTextureFrame) {
+      lastI420Frame = null;
+      drawTexture(drawer, (VideoFrame.TextureBuffer) frame.getBuffer(), renderMatrix, renderWidth,
+          renderHeight, viewportX, viewportY, viewportWidth, viewportHeight);
+    } else {
+      // Only upload the I420 data to textures once per frame, if we are called multiple times
+      // with the same frame.
+      if (frame != lastI420Frame) {
+        lastI420Frame = frame;
+        final VideoFrame.I420Buffer i420Buffer = frame.getBuffer().toI420();
+        yuvUploader.uploadFromBuffer(i420Buffer);
+        i420Buffer.release();
+      }
 
-  /**
-   * Each scaling type has a one-to-one correspondence to a numeric minimum fraction of the video
-   * that must remain visible.
-   */
-  private static float convertScalingTypeToVisibleFraction(ScalingType scalingType) {
-    switch (scalingType) {
-      case SCALE_ASPECT_FIT:
-        return 1.0f;
-      case SCALE_ASPECT_FILL:
-        return 0.0f;
-      case SCALE_ASPECT_BALANCED:
-        return BALANCED_VISIBLE_FRACTION;
-      default:
-        throw new IllegalArgumentException();
+      drawer.drawYuv(yuvUploader.getYuvTextures(),
+          RendererCommon.convertMatrixFromAndroidGraphicsMatrix(renderMatrix), renderWidth,
+          renderHeight, viewportX, viewportY, viewportWidth, viewportHeight);
     }
   }
 
-  /**
-   * Calculate display size based on minimum fraction of the video that must remain visible,
-   * video aspect ratio, and maximum display size.
-   */
-  private static Point getDisplaySize(
-      float minVisibleFraction, float videoAspectRatio, int maxDisplayWidth, int maxDisplayHeight) {
-    // If there is no constraint on the amount of cropping, fill the allowed display area.
-    if (minVisibleFraction == 0 || videoAspectRatio == 0) {
-      return new Point(maxDisplayWidth, maxDisplayHeight);
-    }
-    // Each dimension is constrained on max display size and how much we are allowed to crop.
-    final int width = Math.min(
-        maxDisplayWidth, Math.round(maxDisplayHeight / minVisibleFraction * videoAspectRatio));
-    final int height = Math.min(
-        maxDisplayHeight, Math.round(maxDisplayWidth / minVisibleFraction / videoAspectRatio));
-    return new Point(width, height);
+  public void release() {
+    yuvUploader.release();
+    lastI420Frame = null;
   }
 }