Testing of VideoFileRenderer with byte frames

webrtc/examples/androidtests/src/org/appspot/apprtc/test/VideoFileRendererTest.java

+/*
+ *  Copyright 2016 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
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+package org.webrtc;
+
+import android.test.InstrumentationTestCase;
+import android.test.suitebuilder.annotation.SmallTest;
+
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.lang.Thread;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Random;
+
+public class VideoFileRendererTest extends InstrumentationTestCase {
+  @SmallTest
+  public void testYuvRenderingToFile() throws InterruptedException, IOException {
+    EglBase eglBase = EglBase.create();
+    final int outputWidth = 64;
+    final int outputHeight = 64;
+    final String videoOutpath = "/sdcard/chromium_tests_root/testvideoout.y4m";
+    VideoFileRenderer videoFileRenderer =
+        new VideoFileRenderer(videoOutpath, outputWidth, outputHeight, eglBase.getEglBaseContext());
+
+    final int inputWidth = 32;
+    final int inputHeight = 32;
+    for (int frameIdx = 0; frameIdx < 4; frameIdx++) {
+      // Same seed everytime
+      Random random = new Random(frameIdx);

[magjed_webrtc, 2016/10/20 14:21:07]

You only need to seed once. Please declare the Random outside the for-loop and
use a static seed like 'final Random random = new Random(SEED);'.

[mandermo, 2016/10/24 17:37:20]

Done.

+      ByteBuffer[] yuvPlanes = new ByteBuffer[3];
+      int inputFrameSize = inputWidth * inputHeight * 3 / 2;
+      int[] planeSizes = {
+          inputWidth * inputWidth, inputWidth * inputHeight / 4, inputWidth * inputHeight / 4};
+      int[] yuvStrides = {inputWidth, inputWidth / 2, inputWidth / 2};

[magjed_webrtc, 2016/10/20 14:21:07]

Move this variable closer to where you use it.

[mandermo, 2016/10/24 17:37:20]

Done.

+      for (int i = 0; i < 3; i++) {
+        byte[] planeBytes = new byte[planeSizes[i]];

[magjed_webrtc, 2016/10/20 14:21:08]

You can write this whole for loop body simpler with fewer allocations like this:
yuvPlanes[i] = ByteBuffer.allocateDirect(planeSizes[i]);
Random.nextBytes(yuvPlanes[i].array());

[mandermo, 2016/10/24 17:37:20]

Done.

+        random.nextBytes(planeBytes);
+        ByteBuffer buffer = ByteBuffer.allocateDirect(inputFrameSize);

[magjed_webrtc, 2016/10/20 14:21:08]

This should be planeSizes[i] instead of inputFrameSize, but it will go away if
you fix my comment above.

[mandermo, 2016/10/24 17:37:20]

Done.

+        buffer.put(planeBytes);
+        yuvPlanes[i] = buffer;
+      }
+      VideoRenderer.I420Frame frame =
+          new VideoRenderer.I420Frame(inputWidth, inputHeight, 0, yuvStrides, yuvPlanes, 0);
+
+      videoFileRenderer.renderFrame(frame);
+    }
+    videoFileRenderer.release();
+
+    RandomAccessFile writtenFile = new RandomAccessFile(videoOutpath, "r");
+    StringBuilder builder = new StringBuilder();
+    // Same seed everytime
+    Random verificationRandom = new Random(0);
+    // The expected data at the pseudo randomly choosen positions
+    final String expectedData = "275E6B837FB545456E49A397DD139B68B84C9760806D798063";

[magjed_webrtc, 2016/10/20 14:21:07]

What's this? Why isn't the expected data based on the input yuvPlanes? Just loop
over every pixel and compare it against the input. I think the scaling will
cause trouble because of the bilinear filtering. Either use same input and
output size and try to do perfect pixel matching, or make the input image a
smooth gradient and compare +/- a small range when comparing pixels.

[mandermo, 2016/10/24 17:37:20]

Now it is re-designed and compares pixel by pixel.

+    for (int i = 0; i < expectedData.length() / 2; i++) {
+      int pos = verificationRandom.nextInt((int) writtenFile.length());
+      writtenFile.seek(pos);
+      builder.append(String.format("%02X", writtenFile.readByte()));
+    }
+
+    assertEquals(expectedData, builder.toString());
+
+    writtenFile.seek(0);
+    builder = new StringBuilder();
+    for (;;) {

[magjed_webrtc, 2016/10/20 14:41:03]

It looks like you have implemented RandomAccessFile.readLine(), can you use that
function directly instead?

[mandermo, 2016/10/24 17:37:20]

Done.

+      int c = writtenFile.read();
+      if (c == -1) {
+        // End of file reached.
+        throw new RuntimeException("Found end of file before end of header for file");
+      }
+      if (c == '\n') {
+        // End of header found.
+        break;
+      }
+      builder.append((char) c);
+    }
+
+    // Assert that the header is correct
+    assertEquals("YUV4MPEG2 C420 W64 H64 Ip F30:1 A1:1", builder.toString());

[magjed_webrtc, 2016/10/20 14:21:08]

It feels more natural to check the header before checking the pixel data.

[mandermo, 2016/10/24 17:37:20]

Done.

+  }

[magjed_webrtc, 2016/10/20 14:21:08]

You need to clean up after the test and remove
/sdcard/chromium_tests_root/testvideoout.y4m.

[mandermo, 2016/10/24 17:37:20]

Done.

+}