G722 implementation of the AudioEncoderFactoryTemplate API

webrtc/modules/audio_coding/codecs/g722/audio_encoder_g722.cc

Index: webrtc/modules/audio_coding/codecs/g722/audio_encoder_g722.cc
diff --git a/webrtc/modules/audio_coding/codecs/g722/audio_encoder_g722.cc b/webrtc/modules/audio_coding/codecs/g722/audio_encoder_g722.cc
index d5cf6163134fe98dd4b2e218553a15bd6e162317..d3957d8d6f1be7df3b82fde8c8ffd1394e2d82a1 100644
--- a/webrtc/modules/audio_coding/codecs/g722/audio_encoder_g722.cc
+++ b/webrtc/modules/audio_coding/codecs/g722/audio_encoder_g722.cc
@@ -25,19 +25,24 @@ namespace {
 
 const size_t kSampleRateHz = 16000;
 
-AudioEncoderG722::Config CreateConfig(const CodecInst& codec_inst) {
-  AudioEncoderG722::Config config;
-  config.num_channels = codec_inst.channels;
+AudioEncoderG722Config CreateConfig(const CodecInst& codec_inst) {
+  AudioEncoderG722Config config;
+  config.num_channels = rtc::dchecked_cast<int>(codec_inst.channels);
   config.frame_size_ms = codec_inst.pacsize / 16;
-  config.payload_type = codec_inst.pltype;
   return config;
 }
 
-AudioEncoderG722::Config CreateConfig(int payload_type,
-                                      const SdpAudioFormat& format) {
-  AudioEncoderG722::Config config;
-  config.payload_type = payload_type;
-  config.num_channels = format.num_channels;
+}  // namespace
+
+rtc::Optional<AudioEncoderG722Config> AudioEncoderG722::SdpToConfig(
+    const SdpAudioFormat& format) {
+  if (STR_CASE_CMP(format.name.c_str(), "g722") != 0 ||
+      format.clockrate_hz != 8000) {
+    return rtc::Optional<AudioEncoderG722Config>();
+  }
+
+  AudioEncoderG722Config config;
+  config.num_channels = rtc::dchecked_cast<int>(format.num_channels);
   auto ptime_iter = format.parameters.find("ptime");
   if (ptime_iter != format.parameters.end()) {
     auto ptime = rtc::StringToNumber<int>(ptime_iter->second);
@@ -46,19 +51,14 @@ AudioEncoderG722::Config CreateConfig(int payload_type,
       config.frame_size_ms = std::max(10, std::min(whole_packets * 10, 60));
     }
   }
-  return config;
-}
-
-}  // namespace
-
-bool AudioEncoderG722::Config::IsOk() const {
-  return (frame_size_ms > 0) && (frame_size_ms % 10 == 0) &&
-      (num_channels >= 1);
+  return config.IsOk() ? rtc::Optional<AudioEncoderG722Config>(config)
+                       : rtc::Optional<AudioEncoderG722Config>();
 }
 
-AudioEncoderG722::AudioEncoderG722(const Config& config)
+AudioEncoderG722::AudioEncoderG722(const AudioEncoderG722Config& config,
+                                   int payload_type)
     : num_channels_(config.num_channels),
-      payload_type_(config.payload_type),
+      payload_type_(payload_type),
       num_10ms_frames_per_packet_(
           static_cast<size_t>(config.frame_size_ms / 10)),
       num_10ms_frames_buffered_(0),
@@ -76,21 +76,23 @@ AudioEncoderG722::AudioEncoderG722(const Config& config)
 }
 
 AudioEncoderG722::AudioEncoderG722(const CodecInst& codec_inst)
-    : AudioEncoderG722(CreateConfig(codec_inst)) {}
+    : AudioEncoderG722(CreateConfig(codec_inst), codec_inst.pltype) {}
 
 AudioEncoderG722::AudioEncoderG722(int payload_type,
                                    const SdpAudioFormat& format)
-    : AudioEncoderG722(CreateConfig(payload_type, format)) {}
+    : AudioEncoderG722(*SdpToConfig(format), payload_type) {}
 
 AudioEncoderG722::~AudioEncoderG722() = default;
 
 rtc::Optional<AudioCodecInfo> AudioEncoderG722::QueryAudioEncoder(
     const SdpAudioFormat& format) {
   if (STR_CASE_CMP(format.name.c_str(), GetPayloadName()) == 0) {
-    Config config = CreateConfig(0, format);
-    if (format.clockrate_hz == 8000 && config.IsOk()) {
+    const auto config_opt = SdpToConfig(format);
+    if (format.clockrate_hz == 8000 && config_opt) {
+      RTC_DCHECK(config_opt->IsOk());
       return rtc::Optional<AudioCodecInfo>(
-          {rtc::dchecked_cast<int>(kSampleRateHz), config.num_channels, 64000});
+          {rtc::dchecked_cast<int>(kSampleRateHz),
+           rtc::dchecked_cast<size_t>(config_opt->num_channels), 64000});
     }
   }
   return rtc::Optional<AudioCodecInfo>();