Generalize FEC unit tests and rename GenerateFec. (pt. 3)

webrtc/modules/rtp_rtcp/source/forward_error_correction.cc

 /*
  *  Copyright (c) 2012 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 76 matching lines @@
 // Output packet
 //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 //   |                    FEC Header (10 octets)                     |
 //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 //   |                      FEC Level 0 Header                       |
 //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 //   |                     FEC Level 0 Payload                       |
 //   |                                                               |
 //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 //
-// Note that any potential RED headers are added/removed before calling
-// GenerateFec() or DecodeFec().
-int ForwardErrorCorrection::GenerateFec(const PacketList& media_packets,
-                                        uint8_t protection_factor,
-                                        int num_important_packets,
-                                        bool use_unequal_protection,
-                                        FecMaskType fec_mask_type,
-                                        std::list<Packet*>* fec_packets) {
-  const uint16_t num_media_packets = media_packets.size();
+int ForwardErrorCorrection::EncodeFec(const PacketList& media_packets,
+                                      uint8_t protection_factor,
+                                      int num_important_packets,
+                                      bool use_unequal_protection,
+                                      FecMaskType fec_mask_type,
+                                      std::list<Packet*>* fec_packets) {
+  const size_t num_media_packets = media_packets.size();
+
   // Sanity check arguments.
-  RTC_DCHECK_GT(num_media_packets, 0);
+  RTC_DCHECK_GT(num_media_packets, 0u);
   RTC_DCHECK_GE(num_important_packets, 0);
-  RTC_DCHECK_LE(num_important_packets, num_media_packets);
+  RTC_DCHECK_LE(static_cast<size_t>(num_important_packets), num_media_packets);

[danilchap, 2016/08/23 13:08:50]

may be instead change num_important_packets type to size_t?
It doesn's seem to propagate too much (just into 
ProducerFec::num_important_packets_ and ProducerFec::SetFecParams)

[brandtr, 2016/08/23 14:05:07]

I would like to, but it also propagates into internal::GeneratePacketMasks.

In the internal:: functions, all parameters are currently int, even though they
probably should be size_t. I'm afraid of "search and replace" changing it
though, since it may affect the choice of the packet masks. It is on my to do
list to look into though.

   RTC_DCHECK(fec_packets->empty());
 
   if (num_media_packets > kMaxMediaPackets) {
     LOG(LS_WARNING) << "Can't protect " << num_media_packets
                     << " media packets per frame. Max is " << kMaxMediaPackets
                     << ".";
     return -1;
   }
 
   bool l_bit = (num_media_packets > 8 * kMaskSizeLBitClear);
@@ skipping 650 matching lines @@
   }
   InsertPackets(received_packets, recovered_packets);
   AttemptRecover(recovered_packets);
   return 0;
 }
 
 size_t ForwardErrorCorrection::MaxPacketOverhead() const {
   return kFecHeaderSize + kUlpHeaderSizeLBitSet;
 }
 }  // namespace webrtc