Cast: Increase max outstanding frames to 120

media/cast/cast_defines.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_CAST_CAST_DEFINES_H_
 #define MEDIA_CAST_CAST_DEFINES_H_
 
 #include <stdint.h>
 
 #include <map>
 #include <set>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/time/time.h"
 #include "media/cast/net/cast_transport_config.h"
 
 namespace media {
 namespace cast {
 
 const int64 kDontShowTimeoutMs = 33;
 const float kDefaultCongestionControlBackOff = 0.875f;
 const uint32 kVideoFrequency = 90000;
 const uint32 kStartFrameId = UINT32_C(0xffffffff);
 
 // This is an important system-wide constant.  This limits how much history the
 // implementation must retain in order to process the acknowledgements of past
 // frames.
-const int kMaxUnackedFrames = 60;
+// This value is carefully choosen such that it fits in the 8-bits range for
+// frame IDs. It is also less than half of the full 8-bits range such that we
+// can handle wrap around and compare two frame IDs.
+const int kMaxUnackedFrames = 120;
 
 const int kStartRttMs = 20;
 const int64 kCastMessageUpdateIntervalMs = 33;
 const int64 kNackRepeatIntervalMs = 30;
 
 enum CastInitializationStatus {
   STATUS_AUDIO_UNINITIALIZED,
   STATUS_VIDEO_UNINITIALIZED,
   STATUS_AUDIO_INITIALIZED,
   STATUS_VIDEO_INITIALIZED,
@@ skipping 148 matching lines @@
 
 inline base::TimeDelta RtpDeltaToTimeDelta(int64 rtp_delta, int rtp_timebase) {
   DCHECK_GT(rtp_timebase, 0);
   return rtp_delta * base::TimeDelta::FromSeconds(1) / rtp_timebase;
 }
 
 }  // namespace cast
 }  // namespace media
 
 #endif  // MEDIA_CAST_CAST_DEFINES_H_