android: Eliminate use of IsZeroSize method

webrtc/api/java/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 805 matching lines @@
     // Return output byte buffer back to codec.
     jni->CallVoidMethod(
         *j_media_codec_video_decoder_,
         j_return_decoded_byte_buffer_method_,
         output_buffer_index);
     if (CheckException(jni)) {
       ALOGE << "returnDecodedOutputBuffer error";
       return false;
     }
   }
-  VideoFrame decoded_frame(frame_buffer, 0, 0, webrtc::kVideoRotation_0);
-  decoded_frame.set_timestamp(output_timestamps_ms);
-  decoded_frame.set_ntp_time_ms(output_ntp_timestamps_ms);
-
   if (frames_decoded_ < frames_decoded_logged_) {
     ALOGD << "Decoder frame out # " << frames_decoded_ <<
         ". " << width << " x " << height <<
         ". " << stride << " x " <<  slice_height <<
         ". Color: " << color_format <<
         ". TS: " << presentation_timestamps_ms <<
         ". DecTime: " << (int)decode_time_ms <<
         ". DelayTime: " << (int)frame_delayed_ms;
   }
 
@@ skipping 15 matching lines @@
         ". DecTime: " << (current_decoding_time_ms_ / current_frames_) <<
         ". DelayTime: " << (current_delay_time_ms_ / current_frames_) <<
         " for last " << statistic_time_ms << " ms.";
     start_time_ms_ = rtc::TimeMillis();
     current_frames_ = 0;
     current_bytes_ = 0;
     current_decoding_time_ms_ = 0;
     current_delay_time_ms_ = 0;
   }
 
-  // |.IsZeroSize())| returns true when a frame has been dropped.
-  if (!decoded_frame.IsZeroSize()) {
-    // Callback - output decoded frame.
+  // If the frame was dropped, frame_buffer is left as nullptr.
+  if (frame_buffer) {
+    VideoFrame decoded_frame(frame_buffer, 0, 0, webrtc::kVideoRotation_0);
+    decoded_frame.set_timestamp(output_timestamps_ms);
+    decoded_frame.set_ntp_time_ms(output_ntp_timestamps_ms);
+
     const int32_t callback_status =
         callback_->Decoded(decoded_frame, decode_time_ms);
     if (callback_status > 0) {
       ALOGE << "callback error";
     }
   }
   return true;
 }
 
 int32_t MediaCodecVideoDecoder::RegisterDecodeCompleteCallback(
@@ skipping 106 matching lines @@
     webrtc::VideoDecoder* decoder) {
   ALOGD << "Destroy video decoder.";
   delete decoder;
 }
 
 const char* MediaCodecVideoDecoder::ImplementationName() const {
   return "MediaCodec";
 }
 
 }  // namespace webrtc_jni