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..308a12d5255e4078b4681b6704890b22716c86eb 100644
--- a/media/formats/mp4/aac.cc
+++ b/media/formats/mp4/aac.cc
@@ -58,9 +58,6 @@ 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 +93,26 @@ 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 Part 3 Table 1.18 "
+          << "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 Part 3 Table 1.18 "
+          << "for supported Sampling Frequencies.";
+      return false;
+    }
     extension_frequency_ = kADTSFrequencyTable[extension_frequency_index];
   }
 
@@ -109,12 +120,35 @@ 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 Part 3 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;
+  RCHECK_MEDIA_LOGGED(channel_layout_ != CHANNEL_LAYOUT_NONE, media_log,

[wolenetz, 2015/09/15 23:53:17]

nit: it looks like this log is also possible to test.

[msu.koo, 2015/09/16 08:16:23]

This code block is dead. "|channel_config_| == 0" is filtered out during
"RCHECK(SkipDecoderGASpecificConfig(&reader));"(line 61), which tested at line
263.

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

Acknowledged. Since the helper method might change its implementation, let's
protect our borders in debug builds at least and add a DCHECK(channel_layout_ !=
CHANNEL_LAYOUT_NONE) here.

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

Done.

+                      "Undefined Audio Channel layout with value "
+                      "CHANNEL_LAYOUT_NONE.");
+  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 Part 3 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 {