Slice video frame buffers before copying data from them into the encoder's input buffer

sdk/android/src/java/org/webrtc/HardwareVideoEncoder.java

 /*
  *  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
  *  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.
  */
 
@@ skipping 524 matching lines @@
     }
   }
 
   /**
    * Enumeration of supported color formats used for MediaCodec's input.
    */
   private static enum ColorFormat {
     I420 {
       @Override
       void fillBufferFromI420(ByteBuffer buffer, VideoFrame.I420Buffer i420) {
-        buffer.put(i420.getDataY());
-        buffer.put(i420.getDataU());
-        buffer.put(i420.getDataV());
+        buffer.put(i420.getDataY().slice());

[sakal, 2017/09/28 07:43:53]

Hmm, I think it is better to fix this at the VideoFrame.I420Buffer level, i.e.
call buffer.slice() before returning from getDataY/U/V(). This makes it clearer
that the state of the buffer object is immutable.

[mellem, 2017/09/28 17:02:39]

Yes, I like that idea even better.  I'll just abandon this cl and send you a
follow-up through gerrit.

+        buffer.put(i420.getDataU().slice());
+        buffer.put(i420.getDataV().slice());
       }
     },
     NV12 {
       @Override
       void fillBufferFromI420(ByteBuffer buffer, VideoFrame.I420Buffer i420) {
-        buffer.put(i420.getDataY());
+        buffer.put(i420.getDataY().slice());
 
         // Interleave the bytes from the U and V portions, starting with U.
-        ByteBuffer u = i420.getDataU();
-        ByteBuffer v = i420.getDataV();
+        ByteBuffer u = i420.getDataU().slice();
+        ByteBuffer v = i420.getDataV().slice();
         int i = 0;
         while (u.hasRemaining() && v.hasRemaining()) {
           buffer.put(u.get());
           buffer.put(v.get());
         }
       }
     };
 
     abstract void fillBufferFromI420(ByteBuffer buffer, VideoFrame.I420Buffer i420);
 
     static ColorFormat valueOf(int colorFormat) {
       switch (colorFormat) {
         case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420Planar:
           return I420;
         case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420SemiPlanar:
         case MediaCodecInfo.CodecCapabilities.COLOR_QCOM_FormatYUV420SemiPlanar:
         case MediaCodecUtils.COLOR_QCOM_FORMATYUV420PackedSemiPlanar32m:
           return NV12;
         default:
           throw new IllegalArgumentException("Unsupported colorFormat: " + colorFormat);
       }
     }
   }
 }