Updated AAC:Parse() to emit better error logs.

media/formats/mp4/aac.cc

Index: media/formats/mp4/aac.cc
diff --git a/media/formats/mp4/aac.cc b/media/formats/mp4/aac.cc
index 9aa749ca310cffe9eb0520c8c2c6395da439c4f0..2f0e91efc2a2226f1166b24c1009db3fb7f0352a 100644
--- a/media/formats/mp4/aac.cc
+++ b/media/formats/mp4/aac.cc
@@ -38,6 +38,11 @@ bool AAC::Parse(const std::vector<uint8>& data,
   frequency_ = 0;
   extension_frequency_ = 0;
 
+  // TODO(msu.koo): Need to update comments after checking which version of
+  // ISO 14496-3 this implementation is according to. Also need to reflect
+  // ISO 14496-3-2009 if ISO 14496-3-2005 was reflected here.
+  // http://crbug.com/532281

[wolenetz, 2015/09/16 19:39:19]

nit: s/http:/https:/

[msu.koo, 2015/09/17 02:49:26]

Done.

+
   // The following code is written according to ISO 14496 Part 3 Table 1.13 -
   // Syntax of AudioSpecificConfig.
 
@@ -58,9 +63,6 @@ bool AAC::Parse(const std::vector<uint8>& data,
     RCHECK(reader.ReadBits(5, &profile_));
   }
 
-  MEDIA_LOG(INFO, media_log) << "Audio codec: mp4a.40." << std::hex
-                             << static_cast<int>(profile_);
-
   RCHECK(SkipDecoderGASpecificConfig(&reader));
   RCHECK(SkipErrorSpecificConfig());
 
@@ -96,12 +98,26 @@ bool AAC::Parse(const std::vector<uint8>& data,
   }
 
   if (frequency_ == 0) {
-    RCHECK(frequency_index_ < kADTSFrequencyTableSize);
+    if (frequency_index_ >= kADTSFrequencyTableSize) {
+      MEDIA_LOG(ERROR, media_log)
+          << "Sampling Frequency Index(0x"
+          << std::hex << static_cast<int>(frequency_index_)
+          << ") is not supported. Please see ISO 14496-3-2005 Table 1.18 "

[wolenetz, 2015/09/16 19:39:19]

nit: in 2005 version, it's not 1.18. similar dittos, below. :)

[msu.koo, 2015/09/17 02:49:26]

Done.

+          << "for supported Sampling Frequencies.";
+      return false;
+    }
     frequency_ = kADTSFrequencyTable[frequency_index_];
   }
 
   if (extension_frequency_ == 0 && extension_frequency_index != 0xff) {
-    RCHECK(extension_frequency_index < kADTSFrequencyTableSize);
+    if (extension_frequency_index >= kADTSFrequencyTableSize) {
+      MEDIA_LOG(ERROR, media_log)
+          << "Extension Sampling Frequency Index(0x"
+          << std::hex << static_cast<int>(extension_frequency_index)
+          << ") is not supported. Please see ISO 14496-3-2005 Table 1.18 "
+          << "for supported Sampling Frequencies.";
+      return false;
+    }
     extension_frequency_ = kADTSFrequencyTable[extension_frequency_index];
   }
 
@@ -109,12 +125,32 @@ bool AAC::Parse(const std::vector<uint8>& data,
   if (ps_present && channel_config_ == 1) {
     channel_layout_ = CHANNEL_LAYOUT_STEREO;
   } else {
-    RCHECK(channel_config_ < kADTSChannelLayoutTableSize);
+    if (channel_config_ >= kADTSChannelLayoutTableSize) {
+      MEDIA_LOG(ERROR, media_log)
+          << "Channel Configuration("
+          << static_cast<int>(channel_config_)
+          << ") is not supported. Please see ISO 14496-3-2005 Table 1.19 "
+          << "for supported Channel Configurations.";
+      return false;
+    }
     channel_layout_ = kADTSChannelLayoutTable[channel_config_];
   }
 
-  return frequency_ != 0 && channel_layout_ != CHANNEL_LAYOUT_NONE &&
-         profile_ >= 1 && profile_ <= 4;
+  if (profile_ < 1 || profile_ > 4) {
+    MEDIA_LOG(ERROR, media_log)
+        << "Audio codec(mp4a.40." << static_cast<int>(profile_)
+        << ") is not supported. Please see ISO 14496-3-2005 Table 1.3 "
+        << "for Audio Profile Definitions.";
+    return false;
+  }
+
+  MEDIA_LOG(INFO, media_log)
+      << "Audio codec: mp4a.40." << static_cast<int>(profile_)
+      << ". Sampling frequency: " << frequency_ << "Hz"
+      << ". Sampling frequency(Extension): " << extension_frequency_ << "Hz"
+      << ". Channel layout: " << channel_layout_ << ".";
+
+  return true;
 }
 
 int AAC::GetOutputSamplesPerSecond(bool sbr_in_mimetype) const {