Add EncodedImageCallback::OnEncodedImage().

webrtc/video_encoder.h

Index: webrtc/video_encoder.h
diff --git a/webrtc/video_encoder.h b/webrtc/video_encoder.h
index 0100239e0a42ab8942de17373cc0bb66a991509f..e0e1f48a2789485bff14fe06837bd7d3ea8a6c8e 100644
--- a/webrtc/video_encoder.h
+++ b/webrtc/video_encoder.h
@@ -30,11 +30,43 @@ class EncodedImageCallback {
  public:
   virtual ~EncodedImageCallback() {}
 
+  struct Result {
+    enum Error {
+      OK,
+
+      // Failed to send the packet.
+      ERROR_SEND_FAILED,
+    };
+
+    Result(Error error) : error(error) {}
+    Result(Error error, uint32_t frame_id) : error(error), frame_id(frame_id) {}
+
+    Error error;
+
+    // Frame ID assigned to the frame. The frame ID should be the same as the ID
+    // seen by the receiver for this frame. RTP timestamp of the frame is used
+    // as frame ID when RTP is used to send video.
+    uint32_t frame_id = 0;

[stefan-webrtc, 2016/07/18 16:51:27]

Default value should probably be -1, or if you prefer to make this an Optional,
since it's not required to pass an ID. Or should the user assume that it's not
set if error != OK? Add that to the comment in that case.

[Sergey Ulanov, 2016/07/21 00:09:40]

it cannot be -1 because it's unsigned, and timestamp in RTP may be any 32-bit
value, so we cannot reserve a special value for null ID. The idea here is that
it's aloways initialized as long as error = OK.

[stefan-webrtc, 2016/07/25 15:17:09]

You could still use an Optional<uint32_t> or an int64_t with -1 representing
uninitialized. But I think the current choice probably is good enough.

+
+    // Tells the encoder that the next frame is going to be dropped.

[stefan-webrtc, 2016/07/18 16:51:27]

Maybe "should be dropped" instead?

[Sergey Ulanov, 2016/07/21 00:09:39]

Done.

+    bool drop_next_frame = false;
+  };
+
   // Callback function which is called when an image has been encoded.
-  // TODO(perkj): Change this to return void.
+  virtual Result OnEncodedImage(
+      const EncodedImage& encoded_image,
+      const CodecSpecificInfo* codec_specific_info,
+      const RTPFragmentationHeader* fragmentation) = 0;
+
+  // DEPRECATED.
+  // TODO(sergeyu): Remove this method.
   virtual int32_t Encoded(const EncodedImage& encoded_image,
                           const CodecSpecificInfo* codec_specific_info,
-                          const RTPFragmentationHeader* fragmentation) = 0;
+                          const RTPFragmentationHeader* fragmentation) {
+    Result result =
+        OnEncodedImage(encoded_image, codec_specific_info, fragmentation);
+    return (result.error != Result::OK) ? -1 : (result.drop_next_frame ? 1 : 0);
+  }
 };
 
 class VideoEncoder {