Android HW decoder: Support odd heights for non-texture output

webrtc/sdk/android/src/jni/androidmediadecoder_jni.cc

 /*
  *  Copyright 2015 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 791 matching lines @@
       return false;
     }
     payload += output_buffer_offset;
 
     // Create yuv420 frame.
     rtc::scoped_refptr<webrtc::I420Buffer> i420_buffer;
 
     i420_buffer = decoded_frame_pool_.CreateBuffer(width, height);
     if (color_format == COLOR_FormatYUV420Planar) {
       RTC_CHECK_EQ(0, stride % 2);
-      RTC_CHECK_EQ(0, slice_height % 2);
       const int uv_stride = stride / 2;
-      const int u_slice_height = slice_height / 2;
       const uint8_t* y_ptr = payload;
       const uint8_t* u_ptr = y_ptr + stride * slice_height;
-      const uint8_t* v_ptr = u_ptr + uv_stride * u_slice_height;
+      // This offset is weird when |slice_height| is not dividable by two, since
+      // the last u row might not be full, but this is what's used in practice.
+      // See http://bugs.webrtc.org/6651 for more info.
+      const int u_offset = (uv_stride * slice_height + 1) / 2;
+      const uint8_t* v_ptr = u_ptr + u_offset;
       libyuv::I420Copy(y_ptr, stride, u_ptr, uv_stride, v_ptr, uv_stride,

[sakal, 2017/02/23 12:59:07]

Hmm, it seems I420Copy is reading uv_stride * ((height + 1) / 2) amount of data
from both U- and V-planes. Is this safe?

[magjed_webrtc, 2017/02/23 14:19:30]

No. I made a new patch set that is more complicated but should be safe.

                        i420_buffer->MutableDataY(), i420_buffer->StrideY(),
                        i420_buffer->MutableDataU(), i420_buffer->StrideU(),
                        i420_buffer->MutableDataV(), i420_buffer->StrideV(),
                        width, height);
     } else {
       // All other supported formats are nv12.
       const uint8_t* y_ptr = payload;
       const uint8_t* uv_ptr = y_ptr + stride * slice_height;
       libyuv::NV12ToI420(y_ptr, stride, uv_ptr, stride,
                          i420_buffer->MutableDataY(), i420_buffer->StrideY(),
@@ skipping 172 matching lines @@
     webrtc::VideoDecoder* decoder) {
   ALOGD << "Destroy video decoder.";
   delete decoder;
 }
 
 const char* MediaCodecVideoDecoder::ImplementationName() const {
   return "MediaCodec";
 }
 
 }  // namespace webrtc_jni