Testing of FileVideoCapturer

webrtc/examples/androidtests/src/org/appspot/apprtc/test/FileVideoCapturerTest.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.appspot.apprtc.test;
+
+import android.test.InstrumentationTestCase;
+import android.test.suitebuilder.annotation.LargeTest;
+import android.test.suitebuilder.annotation.MediumTest;
+import android.test.suitebuilder.annotation.SmallTest;
+
+import org.webrtc.FileVideoCapturer;
+import org.webrtc.VideoCapturer;
+
+import java.io.IOException;
+import java.lang.Thread;
+import java.util.ArrayList;
+import java.util.Random;
+
+public class FileVideoCapturerTest extends InstrumentationTestCase {
+  private static class Frame {
+    public byte[] data;
+    public int width;
+    public int height;
+  }
+
+  public class MockCapturerObserver implements VideoCapturer.CapturerObserver {
+    private ArrayList<Frame> frameDatas = new ArrayList<Frame>();

[magjed_webrtc, 2016/10/20 14:55:33]

Make this variable final.

[mandermo, 2016/10/24 18:08:02]

Done.

+
+    public void onCapturerStarted(boolean success) {

[magjed_webrtc, 2016/10/20 14:55:33]

Annotate every function with @Override.

[mandermo, 2016/10/24 18:08:02]

Done.

+      // Empty on purpose

[magjed_webrtc, 2016/10/20 14:55:33]

assertTrue on success

[mandermo, 2016/10/24 18:08:02]

Done.

+    }
+
+    public void onCapturerStopped() {
+      // Empty on purpose

[magjed_webrtc, 2016/10/20 14:55:33]

Add a dot at the end of every sentence in comments.

[mandermo, 2016/10/24 18:08:02]

Done.

+    }
+
+    public synchronized void onByteBufferFrameCaptured(
+        byte[] data, int width, int height, int rotation, long timeStamp) {
+      Frame frame = new Frame();
+      frame.data = data;
+      frame.width = width;
+      frame.height = height;
+      assertTrue(data.length != 0);
+      frameDatas.add(frame);
+      notify();
+    }
+
+    public void onTextureFrameCaptured(int width, int height, int oesTextureId,
+        float[] transformMatrix, int rotation, long timestamp) {
+      // Empty on purpose
+    }
+
+    public void onOutputFormatRequest(int width, int height, int framerate) {

[magjed_webrtc, 2016/10/20 14:55:33]

This function is no longer part of the interface, so remove it.

+      // Empty on purpose
+    }
+
+    public synchronized ArrayList<Frame> getMinimumFramesBlocking(int minFrames)
+        throws InterruptedException {
+      while (frameDatas.size() < minFrames) {
+        wait();
+      }
+      return new ArrayList<Frame>(frameDatas);
+    }
+  }
+
+  @SmallTest
+  public void testVideoCaptureFromFile() throws InterruptedException, IOException {
+    final int FRAME_WIDTH = 640;
+    final int FRAME_HEIGHT = 360;
+    FileVideoCapturer fileVideoCapturer = new FileVideoCapturer(
+        "/sdcard/chromium_tests_root/resources/reference_video_640x360_30fps_4frames.y4m");
+    MockCapturerObserver capturerObserver = new MockCapturerObserver();
+    fileVideoCapturer.initialize(null, null, capturerObserver);
+    fileVideoCapturer.startCapture(4, 4, 33);
+
+    // The expected data at the pseudo randomly choosen positions
+    String[] expectedFrames = {
+        "7C543C7D7C6C86B31055787FA03F5CE7B0507D5AA42A7B5E867E4462977F99707F95",
+        "CF864F7F7E6C416975871E687673857CA56B88DA7E6F4D991C62A4B7537B7D978E95",
+        "918CA66F877DDE7473A8817E7F7C7E38807D7971E7977F6B877D417B7E7C808E408F",
+        "597D8B4772436380A6388380B6AC7E869E58B46A7B78AB722E6C298B6C66A8678375"};
+
+    ArrayList<Frame> frameDatas;
+    try {
+      frameDatas = capturerObserver.getMinimumFramesBlocking(expectedFrames.length);
+    } catch (InterruptedException e) {
+      throw new RuntimeException(e);
+    }
+    assertTrue(expectedFrames.length == frameDatas.size());
+
+    fileVideoCapturer.stopCapture();
+    fileVideoCapturer.dispose();
+
+    for (int i = 0; i < expectedFrames.length; ++i) {

[magjed_webrtc, 2016/10/20 14:55:33]

Since it's impossible to verify this manually anyway and you don't compare
against the input, just compute a hash with e.g. 
MessageDigest digest = MessageDigest.getInstance("SHA-256");
byte[] hashBytes = digest.digest(frameDatas[i].data);
and compare the hash against a pre-computed expected hash. This will reduce the
code complexity of the test and we won't miss incorrect pixels at e.g. corners
or borders.

BTW, why can't you use a really small file, e.g. 4x4 and do a full equality
test?

[mandermo, 2016/10/24 18:08:02]

Now use hashing approach. Using small file is also a solution. Should I change?

[magjed_webrtc, 2016/10/25 08:02:47]

Yes, a small file would be optimal. Can you do the same as in
VideoFileRendererTest and have:
String inputFile = "YUV4MPEG2 C420 W4 H4 Ip F30:1 A1:1\n"
    + "FRAME\n"
    + "THIS IS JUST SOME TEXT xFRAME\n"
    + "THE SECOND FRAME qwerty.FRAME\n"
    + "HERE IS THE THRID FRAME!";

String[] expectedFrames = {
    "THIS IS JUST SOME TEXT x", "THE SECOND FRAME qwerty.", "HERE IS THE THRID
FRAME!"};
?

+      Frame frame = frameDatas.get(i);
+      // Same seed everytime
+      Random random = new Random(i);
+
+      assertEquals(FRAME_WIDTH, frame.width);
+      assertEquals(FRAME_HEIGHT, frame.height);
+      assertEquals(FRAME_WIDTH * FRAME_HEIGHT * 3 / 2, frame.data.length);
+
+      StringBuilder builder = new StringBuilder();
+      for (int k = 0; k < expectedFrames[i].length() / 2; ++k) {
+        int pos = random.nextInt(frame.data.length);
+        builder.append(String.format("%02X", frame.data[pos]));
+      }
+
+      assertEquals(expectedFrames[i], builder.toString());
+    }
+  }
+}