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

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

Index: sdk/android/src/java/org/webrtc/HardwareVideoEncoder.java
diff --git a/sdk/android/src/java/org/webrtc/HardwareVideoEncoder.java b/sdk/android/src/java/org/webrtc/HardwareVideoEncoder.java
index f3be4cbc694ebeac96d04b07b0fdfce35dfabf05..4a0a4d993d147a7e0c5e2dc8afb0f0ca5014792a 100644
--- a/sdk/android/src/java/org/webrtc/HardwareVideoEncoder.java
+++ b/sdk/android/src/java/org/webrtc/HardwareVideoEncoder.java
@@ -542,19 +542,19 @@ class HardwareVideoEncoder implements VideoEncoder {
     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());