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1 /*
2  *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 package org.webrtc;
12 
13 import android.graphics.Point;
14 import android.opengl.Matrix;
15 import android.view.View;
16 
17 /**
18  * Static helper functions for renderer implementations.
19  */
20 public class RendererCommon {
21   /** Interface for reporting rendering events. */
22   public static interface RendererEvents {
23     /**
24      * Callback fired once first frame is rendered.
25      */
onFirstFrameRendered()26     public void onFirstFrameRendered();
27 
28     /**
29      * Callback fired when rendered frame resolution or rotation has changed.
30      */
onFrameResolutionChanged(int videoWidth, int videoHeight, int rotation)31     public void onFrameResolutionChanged(int videoWidth, int videoHeight, int rotation);
32   }
33 
34   /**
35    * Interface for rendering frames on an EGLSurface with specified viewport location. Rotation,
36    * mirror, and cropping is specified using a 4x4 texture coordinate transform matrix. The frame
37    * input can either be an OES texture, RGB texture, or YUV textures in I420 format. The function
38    * release() must be called manually to free the resources held by this object.
39    */
40   public static interface GlDrawer {
41     /**
42      * Functions for drawing frames with different sources. The rendering surface target is
43      * implied by the current EGL context of the calling thread and requires no explicit argument.
44      * The coordinates specify the viewport location on the surface target.
45      */
drawOes(int oesTextureId, float[] texMatrix, int frameWidth, int frameHeight, int viewportX, int viewportY, int viewportWidth, int viewportHeight)46     void drawOes(int oesTextureId, float[] texMatrix, int frameWidth, int frameHeight,
47         int viewportX, int viewportY, int viewportWidth, int viewportHeight);
drawRgb(int textureId, float[] texMatrix, int frameWidth, int frameHeight, int viewportX, int viewportY, int viewportWidth, int viewportHeight)48     void drawRgb(int textureId, float[] texMatrix, int frameWidth, int frameHeight, int viewportX,
49         int viewportY, int viewportWidth, int viewportHeight);
drawYuv(int[] yuvTextures, float[] texMatrix, int frameWidth, int frameHeight, int viewportX, int viewportY, int viewportWidth, int viewportHeight)50     void drawYuv(int[] yuvTextures, float[] texMatrix, int frameWidth, int frameHeight,
51         int viewportX, int viewportY, int viewportWidth, int viewportHeight);
52 
53     /**
54      * Release all GL resources. This needs to be done manually, otherwise resources may leak.
55      */
release()56     void release();
57   }
58 
59   /**
60    * Helper class for determining layout size based on layout requirements, scaling type, and video
61    * aspect ratio.
62    */
63   public static class VideoLayoutMeasure {
64     // The scaling type determines how the video will fill the allowed layout area in measure(). It
65     // can be specified separately for the case when video has matched orientation with layout size
66     // and when there is an orientation mismatch.
67     private float visibleFractionMatchOrientation =
68         convertScalingTypeToVisibleFraction(ScalingType.SCALE_ASPECT_BALANCED);
69     private float visibleFractionMismatchOrientation =
70         convertScalingTypeToVisibleFraction(ScalingType.SCALE_ASPECT_BALANCED);
71 
setScalingType(ScalingType scalingType)72     public void setScalingType(ScalingType scalingType) {
73       setScalingType(/* scalingTypeMatchOrientation= */ scalingType,
74           /* scalingTypeMismatchOrientation= */ scalingType);
75     }
76 
setScalingType( ScalingType scalingTypeMatchOrientation, ScalingType scalingTypeMismatchOrientation)77     public void setScalingType(
78         ScalingType scalingTypeMatchOrientation, ScalingType scalingTypeMismatchOrientation) {
79       this.visibleFractionMatchOrientation =
80           convertScalingTypeToVisibleFraction(scalingTypeMatchOrientation);
81       this.visibleFractionMismatchOrientation =
82           convertScalingTypeToVisibleFraction(scalingTypeMismatchOrientation);
83     }
84 
setVisibleFraction( float visibleFractionMatchOrientation, float visibleFractionMismatchOrientation)85     public void setVisibleFraction(
86         float visibleFractionMatchOrientation, float visibleFractionMismatchOrientation) {
87       this.visibleFractionMatchOrientation = visibleFractionMatchOrientation;
88       this.visibleFractionMismatchOrientation = visibleFractionMismatchOrientation;
89     }
90 
measure(int widthSpec, int heightSpec, int frameWidth, int frameHeight)91     public Point measure(int widthSpec, int heightSpec, int frameWidth, int frameHeight) {
92       // Calculate max allowed layout size.
93       final int maxWidth = View.getDefaultSize(Integer.MAX_VALUE, widthSpec);
94       final int maxHeight = View.getDefaultSize(Integer.MAX_VALUE, heightSpec);
95       if (frameWidth == 0 || frameHeight == 0 || maxWidth == 0 || maxHeight == 0) {
96         return new Point(maxWidth, maxHeight);
97       }
98       // Calculate desired display size based on scaling type, video aspect ratio,
99       // and maximum layout size.
100       final float frameAspect = frameWidth / (float) frameHeight;
101       final float displayAspect = maxWidth / (float) maxHeight;
102       final float visibleFraction = (frameAspect > 1.0f) == (displayAspect > 1.0f)
103           ? visibleFractionMatchOrientation
104           : visibleFractionMismatchOrientation;
105       final Point layoutSize = getDisplaySize(visibleFraction, frameAspect, maxWidth, maxHeight);
106 
107       // If the measure specification is forcing a specific size - yield.
108       if (View.MeasureSpec.getMode(widthSpec) == View.MeasureSpec.EXACTLY) {
109         layoutSize.x = maxWidth;
110       }
111       if (View.MeasureSpec.getMode(heightSpec) == View.MeasureSpec.EXACTLY) {
112         layoutSize.y = maxHeight;
113       }
114       return layoutSize;
115     }
116   }
117 
118   // Types of video scaling:
119   // SCALE_ASPECT_FIT - video frame is scaled to fit the size of the view by
120   //    maintaining the aspect ratio (black borders may be displayed).
121   // SCALE_ASPECT_FILL - video frame is scaled to fill the size of the view by
122   //    maintaining the aspect ratio. Some portion of the video frame may be
123   //    clipped.
124   // SCALE_ASPECT_BALANCED - Compromise between FIT and FILL. Video frame will fill as much as
125   // possible of the view while maintaining aspect ratio, under the constraint that at least
126   // |BALANCED_VISIBLE_FRACTION| of the frame content will be shown.
127   public static enum ScalingType { SCALE_ASPECT_FIT, SCALE_ASPECT_FILL, SCALE_ASPECT_BALANCED }
128   // The minimum fraction of the frame content that will be shown for |SCALE_ASPECT_BALANCED|.
129   // This limits excessive cropping when adjusting display size.
130   private static float BALANCED_VISIBLE_FRACTION = 0.5625f;
131 
132   /**
133    * Returns layout transformation matrix that applies an optional mirror effect and compensates
134    * for video vs display aspect ratio.
135    */
getLayoutMatrix( boolean mirror, float videoAspectRatio, float displayAspectRatio)136   public static float[] getLayoutMatrix(
137       boolean mirror, float videoAspectRatio, float displayAspectRatio) {
138     float scaleX = 1;
139     float scaleY = 1;
140     // Scale X or Y dimension so that video and display size have same aspect ratio.
141     if (displayAspectRatio > videoAspectRatio) {
142       scaleY = videoAspectRatio / displayAspectRatio;
143     } else {
144       scaleX = displayAspectRatio / videoAspectRatio;
145     }
146     // Apply optional horizontal flip.
147     if (mirror) {
148       scaleX *= -1;
149     }
150     final float matrix[] = new float[16];
151     Matrix.setIdentityM(matrix, 0);
152     Matrix.scaleM(matrix, 0, scaleX, scaleY, 1);
153     adjustOrigin(matrix);
154     return matrix;
155   }
156 
157   /** Converts a float[16] matrix array to android.graphics.Matrix. */
convertMatrixToAndroidGraphicsMatrix(float[] matrix4x4)158   public static android.graphics.Matrix convertMatrixToAndroidGraphicsMatrix(float[] matrix4x4) {
159     // clang-format off
160     float[] values = {
161         matrix4x4[0 * 4 + 0], matrix4x4[1 * 4 + 0], matrix4x4[3 * 4 + 0],
162         matrix4x4[0 * 4 + 1], matrix4x4[1 * 4 + 1], matrix4x4[3 * 4 + 1],
163         matrix4x4[0 * 4 + 3], matrix4x4[1 * 4 + 3], matrix4x4[3 * 4 + 3],
164     };
165     // clang-format on
166 
167     android.graphics.Matrix matrix = new android.graphics.Matrix();
168     matrix.setValues(values);
169     return matrix;
170   }
171 
172   /** Converts android.graphics.Matrix to a float[16] matrix array. */
convertMatrixFromAndroidGraphicsMatrix(android.graphics.Matrix matrix)173   public static float[] convertMatrixFromAndroidGraphicsMatrix(android.graphics.Matrix matrix) {
174     float[] values = new float[9];
175     matrix.getValues(values);
176 
177     // The android.graphics.Matrix looks like this:
178     // [x1 y1 w1]
179     // [x2 y2 w2]
180     // [x3 y3 w3]
181     // We want to contruct a matrix that looks like this:
182     // [x1 y1  0 w1]
183     // [x2 y2  0 w2]
184     // [ 0  0  1  0]
185     // [x3 y3  0 w3]
186     // Since it is stored in column-major order, it looks like this:
187     // [x1 x2 0 x3
188     //  y1 y2 0 y3
189     //   0  0 1  0
190     //  w1 w2 0 w3]
191     // clang-format off
192     float[] matrix4x4 = {
193         values[0 * 3 + 0],  values[1 * 3 + 0], 0,  values[2 * 3 + 0],
194         values[0 * 3 + 1],  values[1 * 3 + 1], 0,  values[2 * 3 + 1],
195         0,                  0,                 1,  0,
196         values[0 * 3 + 2],  values[1 * 3 + 2], 0,  values[2 * 3 + 2],
197     };
198     // clang-format on
199     return matrix4x4;
200   }
201 
202   /**
203    * Calculate display size based on scaling type, video aspect ratio, and maximum display size.
204    */
getDisplaySize( ScalingType scalingType, float videoAspectRatio, int maxDisplayWidth, int maxDisplayHeight)205   public static Point getDisplaySize(
206       ScalingType scalingType, float videoAspectRatio, int maxDisplayWidth, int maxDisplayHeight) {
207     return getDisplaySize(convertScalingTypeToVisibleFraction(scalingType), videoAspectRatio,
208         maxDisplayWidth, maxDisplayHeight);
209   }
210 
211   /**
212    * Move |matrix| transformation origin to (0.5, 0.5). This is the origin for texture coordinates
213    * that are in the range 0 to 1.
214    */
adjustOrigin(float[] matrix)215   private static void adjustOrigin(float[] matrix) {
216     // Note that OpenGL is using column-major order.
217     // Pre translate with -0.5 to move coordinates to range [-0.5, 0.5].
218     matrix[12] -= 0.5f * (matrix[0] + matrix[4]);
219     matrix[13] -= 0.5f * (matrix[1] + matrix[5]);
220     // Post translate with 0.5 to move coordinates to range [0, 1].
221     matrix[12] += 0.5f;
222     matrix[13] += 0.5f;
223   }
224 
225   /**
226    * Each scaling type has a one-to-one correspondence to a numeric minimum fraction of the video
227    * that must remain visible.
228    */
convertScalingTypeToVisibleFraction(ScalingType scalingType)229   private static float convertScalingTypeToVisibleFraction(ScalingType scalingType) {
230     switch (scalingType) {
231       case SCALE_ASPECT_FIT:
232         return 1.0f;
233       case SCALE_ASPECT_FILL:
234         return 0.0f;
235       case SCALE_ASPECT_BALANCED:
236         return BALANCED_VISIBLE_FRACTION;
237       default:
238         throw new IllegalArgumentException();
239     }
240   }
241 
242   /**
243    * Calculate display size based on minimum fraction of the video that must remain visible,
244    * video aspect ratio, and maximum display size.
245    */
getDisplaySize( float minVisibleFraction, float videoAspectRatio, int maxDisplayWidth, int maxDisplayHeight)246   public static Point getDisplaySize(
247       float minVisibleFraction, float videoAspectRatio, int maxDisplayWidth, int maxDisplayHeight) {
248     // If there is no constraint on the amount of cropping, fill the allowed display area.
249     if (minVisibleFraction == 0 || videoAspectRatio == 0) {
250       return new Point(maxDisplayWidth, maxDisplayHeight);
251     }
252     // Each dimension is constrained on max display size and how much we are allowed to crop.
253     final int width = Math.min(
254         maxDisplayWidth, Math.round(maxDisplayHeight / minVisibleFraction * videoAspectRatio));
255     final int height = Math.min(
256         maxDisplayHeight, Math.round(maxDisplayWidth / minVisibleFraction / videoAspectRatio));
257     return new Point(width, height);
258   }
259 }
260