chore: Fix "potentially uninitialized variable" errors in IAMF (#1445)

These errors were specifically coming up in Windows builds and in Linux release builds.  This initializes those variables.

This also fixes errors in IAMF tests like "offset 2 out of bounds", which some compilers raise when you try to statically initialize a vector, then add to it later.

packager/media/codecs/iamf_audio_util.cc

@@ -151,9 +151,11 @@ bool ParseCodecConfigObu(BitReader& reader, size_t obu_size, Codec& codec) {
 
 bool GetIamfCodecStringInfo(const std::vector<uint8_t>& iacb,
                             uint8_t& codec_string_info) {
-  uint8_t primary_profile;
-  uint8_t additional_profile;
-  Codec iamf_codec;  // codec used to encode IAMF audio substreams
+  uint8_t primary_profile = 0;
+  uint8_t additional_profile = 0;
+  // codec used to encode IAMF audio substreams
+  Codec iamf_codec = Codec::kUnknownCodec;
+
   int obu_type;
   size_t obu_size;
 

packager/media/codecs/iamf_audio_util_unittest.cc

@@ -19,6 +19,11 @@ namespace {
 const int kSimpleProfile = 0;
 const int kBaseProfile = 1;
 
+const std::vector<uint8_t> kIacbBase = {
+    0x01,  // configurationVersion
+    0x20   // configOBUs_size
+};
+
 const std::vector<uint8_t> kSimpleIaSequenceObu = {
     // OBU header
     0xf8,  // obu_type (5 bits), obu_redundant_copy (1 bit),
@@ -60,10 +65,8 @@ const std::vector<uint8_t> kFakeMixPresentationObu = {
 }  // namespace
 
 TEST(IamfAudioUtilTest, GetCodecStringInfoWithSimpleProfiles) {
-  std::vector<uint8_t> iacb = {
-      0x01,  // configurationVersion
-      0x20   // configOBUs_size
-  };
+  std::vector<uint8_t> iacb;
+  iacb.insert(iacb.end(), kIacbBase.begin(), kIacbBase.end());
   iacb.insert(iacb.end(), kSimpleIaSequenceObu.begin(),
               kSimpleIaSequenceObu.end());
   iacb.insert(iacb.end(), kOpusCodecConfigObu.begin(),
@@ -95,10 +98,8 @@ TEST(IamfAudioUtilTest, CodecStringInfoTestWithBaseProfiles) {
       0x01                     // additional_profile = base
   };
 
-  std::vector<uint8_t> iacb = {
-      0x01,  // configurationVersion
-      0x20   // configOBUs_size
-  };
+  std::vector<uint8_t> iacb;
+  iacb.insert(iacb.end(), kIacbBase.begin(), kIacbBase.end());
   iacb.insert(iacb.end(), base_ia_sequence_obu.begin(),
               base_ia_sequence_obu.end());
   iacb.insert(iacb.end(), kOpusCodecConfigObu.begin(),
@@ -130,10 +131,8 @@ TEST(IamfAudioUtilTest, CodecStringInfoWithPcm) {
       0x46, 0x41, 0x4B, 0x45   // 'F''A''K''E' remainder codec config OBU
   };
 
-  std::vector<uint8_t> iacb = {
-      0x01,  // configurationVersion
-      0x20   // configOBUs_size
-  };
+  std::vector<uint8_t> iacb;
+  iacb.insert(iacb.end(), kIacbBase.begin(), kIacbBase.end());
   iacb.insert(iacb.end(), kSimpleIaSequenceObu.begin(),
               kSimpleIaSequenceObu.end());
   iacb.insert(iacb.end(), pcm_codec_config_obu.begin(),
@@ -165,10 +164,8 @@ TEST(IamfAudioUtilTest, CodecStringInfoWithMp4a) {
       0x46, 0x41, 0x4B, 0x45   // 'F''A''K''E' remainder codec config OBU
   };
 
-  std::vector<uint8_t> iacb = {
-      0x01,  // configurationVersion
-      0x20   // configOBUs_size
-  };
+  std::vector<uint8_t> iacb;
+  iacb.insert(iacb.end(), kIacbBase.begin(), kIacbBase.end());
   iacb.insert(iacb.end(), kSimpleIaSequenceObu.begin(),
               kSimpleIaSequenceObu.end());
   iacb.insert(iacb.end(), mp4a_codec_config_obu.begin(),
@@ -200,10 +197,8 @@ TEST(IamfAudioUtilTest, CodecStringInfoWithFlac) {
       0x46, 0x41, 0x4B, 0x45   // 'F''A''K''E' remainder codec config OBU
   };
 
-  std::vector<uint8_t> iacb = {
-      0x01,  // configurationVersion
-      0x20   // configOBUs_size
-  };
+  std::vector<uint8_t> iacb;
+  iacb.insert(iacb.end(), kIacbBase.begin(), kIacbBase.end());
   iacb.insert(iacb.end(), kSimpleIaSequenceObu.begin(),
               kSimpleIaSequenceObu.end());
   iacb.insert(iacb.end(), flac_codec_config_obu.begin(),