Stop using VoEVideoSync in Call/VideoReceiveStream.

webrtc/call/syncable.h

+/*
+ *  Copyright (c) 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.
+ */
+
+// Syncable is used by RtpStreamsSynchronizer in VideoReceiveStream, and
+// implemented by AudioReceiveStream.
+
+#ifndef WEBRTC_CALL_SYNCABLE_H_
+#define WEBRTC_CALL_SYNCABLE_H_
+
+#include <stdint.h>
+
+#include "webrtc/base/optional.h"
+
+namespace webrtc {
+
+class Syncable {
+ public:
+  struct Info {
+    int64_t latest_receive_time_ms = 0;
+    uint32_t latest_timestamp = 0;

[stefan-webrtc, 2017/01/19 11:59:59]

latest_received_timestamp, I assume?

[stefan-webrtc, 2017/01/26 08:40:50]

I think 'received' is better since this is the capture time (in rtp) of the
frame that we most recently received. It's not the receive timestamp of the
latest frame... Subtle difference, so maybe there's a better name...

latest_received_capture_timestamp?

[the sun, 2017/01/30 15:43:12]

Done.

+    uint32_t ntp_secs = 0;
+    uint32_t ntp_frac = 0;
+    uint32_t rtp_timestamp = 0;

[stefan-webrtc, 2017/01/19 11:59:59]

Would be good to clarify that this is the ntp/rtp timestamp pair in RTCP to be
used to map between rtp and ntp time.

[the sun, 2017/01/30 15:43:12]

I don't really like that we're mixing in RTCP. If we can make the names
transport-agnostic, that'd be preferable.

feedback_ntp_secs
feedback_ntp_frac
feedback_timestamp

?

[stefan-webrtc, 2017/01/30 16:11:11]

Me neither, bad suggestion from my side.

Maybe rtp_timestamp -> capture_time_source_clock and ntp_secs, ntp_frac ->
capture_time_ntp_frac, capture_time_ntp_secs?

Or if we use the NtpTime class, something like this?
std::pair<uint32_t, NtpTime> clock_sync_point_

[the sun, 2017/01/31 10:00:32]

Went with this - I don't like to use pair in this case.

+    int current_delay_ms = 0;
+  };
+
+  virtual ~Syncable();
+
+  virtual int id() const = 0;
+  virtual rtc::Optional<Info> GetInfo() const = 0;
+  virtual uint32_t GetPlayoutTimestamp() const = 0;
+  virtual void SetMinimumPlayoutDelay(int delay_ms) = 0;
+};
+}  // namespace webrtc
+
+#endif  // WEBRTC_CALL_SYNCABLE_H_