New interface (AudioDecoderFactory), with an implementation

webrtc/modules/audio_coding/codecs/audio_format.cc

+/*
+ *  Copyright (c) 2016 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.
+ */
+
+#include "webrtc/modules/audio_coding/codecs/audio_format.h"
+
+namespace webrtc {
+
+SdpAudioFormat::SdpAudioFormat() = default;
+SdpAudioFormat::SdpAudioFormat(const SdpAudioFormat&) = default;
+SdpAudioFormat::SdpAudioFormat(SdpAudioFormat&&) = default;
+
+SdpAudioFormat::SdpAudioFormat(const char* name,
+                               int clockrate_hz,
+                               int num_channels)
+    : name(name), clockrate_hz(clockrate_hz), num_channels(num_channels) {}
+
+SdpAudioFormat::~SdpAudioFormat() = default;
+SdpAudioFormat& SdpAudioFormat::operator=(const SdpAudioFormat&) = default;
+SdpAudioFormat& SdpAudioFormat::operator=(SdpAudioFormat&&) = default;
+
+void swap(SdpAudioFormat& a, SdpAudioFormat& b) {
+  using std::swap;
+  swap(a.name, b.name);
+  swap(a.clockrate_hz, b.clockrate_hz);
+  swap(a.num_channels, b.num_channels);
+  swap(a.parameters, b.parameters);
+}
+
+std::ostream& operator<<(std::ostream& os, const SdpAudioFormat& saf) {
+  os << "{name: " << saf.name;
+  os << ", clockrate_hz: " << saf.clockrate_hz;
+  os << ", num_channels: " << saf.num_channels;
+  os << ", parameters: {";
+  const char* sep = "";

[hlundin-webrtc, 2016/04/27 14:35:56]

I think the const qualifier is confusing here, since you are in fact changing
the separator string further down. (I realize that you are not violating the
constness, since you are setting a new value for the (non-const) pointer, not
modifying the (const) pointed data.)

[ossu, 2016/04/28 08:35:53]

Well, it's still correct - the char * can't point to "" without being const,
since "" is const. (I mean, it probably can but it's wrong).

[hlundin-webrtc, 2016/04/28 09:04:18]

Oh. Yes. Well... eeh... [voice tapering off as Shame Cube is lowered over me]

+  for (const auto& kv : saf.parameters) {
+    os << sep << kv.first << ": " << kv.second;
+    sep = ", ";
+  }
+  os << "}}";
+  return os;
+}
+
+}  // namespace webrtc