Re-enable PCAP reading in neteq_rtpplay

webrtc/modules/audio_coding/neteq/tools/rtp_file_source.cc

 /*
  *  Copyright (c) 2014 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 14 matching lines @@
 
 namespace webrtc {
 namespace test {
 
 RtpFileSource* RtpFileSource::Create(const std::string& file_name) {
   RtpFileSource* source = new RtpFileSource();
   RTC_CHECK(source->OpenFile(file_name));
   return source;
 }
 
+bool RtpFileSource::ValidRtpDump(const std::string& file_name) {
+  rtc::scoped_ptr<RtpFileReader> temp_file(
+      RtpFileReader::Create(RtpFileReader::kRtpDump, file_name));
+  return !!temp_file;

[ivoc, 2015/11/02 15:27:09]

I have a hard time understanding the !!, is there some alternative that might be
easier to understand for mere mortals like myself? :-)

[hlundin-webrtc, 2015/11/02 15:41:21]

I blame kwiberg for recruiting me to the dark side. I'll let him be the arbiter.

[kwiberg-webrtc, 2015/11/02 19:24:59]

!x is true if x is false, false if x is true. So !!x is false if x is false,
true if x is true. Basically, it's a shorter way to write static_cast<bool>(x).

If you feel that it's too short, note that any even number of exclamation marks
will do.

[hlundin-webrtc, 2015/11/03 06:44:41]

Thanks for providing that invaluable truth table.

I feel that !!temp_file is more attractable than static_cast<bool>(temp_file).

+}
+
+bool RtpFileSource::ValidPcap(const std::string& file_name) {
+  rtc::scoped_ptr<RtpFileReader> temp_file(
+      RtpFileReader::Create(RtpFileReader::kPcap, file_name));
+  return !!temp_file;
+}
+
 RtpFileSource::~RtpFileSource() {
 }
 
 bool RtpFileSource::RegisterRtpHeaderExtension(RTPExtensionType type,
                                                uint8_t id) {
   assert(parser_.get());
   return parser_->RegisterRtpHeaderExtension(type, id);
 }
 
 Packet* RtpFileSource::NextPacket() {
@@ skipping 36 matching lines @@
   rtp_reader_.reset(RtpFileReader::Create(RtpFileReader::kPcap, file_name));
   if (!rtp_reader_) {
     FATAL() << "Couldn't open input file as either a rtpdump or .pcap. Note "
                "that .pcapng is not supported.";
   }
   return true;
 }
 
 }  // namespace test
 }  // namespace webrtc