[media] Create IamfMimeUtil

starboard/common/BUILD.gn

@@ -110,6 +110,7 @@ target(gtest_target_type, "common_test") {
     "memory_test.cc",
     "player_test.cc",
     "socket_test.cc",
+    "string_test.cc",
     "test_main.cc",
   ]
   deps = [

starboard/common/string.h

@@ -101,6 +101,33 @@ static SB_C_FORCE_INLINE int strlcat(CHAR* dst, const CHAR* src, int dst_size) {
          dst_length;
 }
 
+// Splits a string on a char delimiter.
+inline std::vector<std::string> SplitString(const std::string& input,
+                                            char delimiter) {
+  std::vector<std::string> output;
+  if (input.empty()) {
+    return output;
+  }
+
+  size_t start = 0;
+  while (start != std::string::npos) {
+    size_t end = input.find_first_of(delimiter, start);
+    std::string piece;
+
+    if (end == std::string::npos) {
+      piece = input.substr(start);
+      start = std::string::npos;
+    } else {
+      piece = input.substr(start, end - start);
+      start = end + 1;
+    }
+
+    output.emplace_back(piece);
+  }
+
+  return output;
+}
+
 }  // namespace starboard
 
 #endif  // STARBOARD_COMMON_STRING_H_

starboard/common/string_test.cc

@@ -0,0 +1,62 @@
+// Copyright 2024 The Cobalt Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <string>
+#include <vector>
+
+#include "starboard/common/string.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace starboard {
+namespace {
+
+TEST(StringTest, SplitString) {
+  std::string str = "The quick brown fox jumps over the lazy dog";
+  std::vector<std::string> output = SplitString(str, '.');
+  ASSERT_EQ(output.size(), 1);
+  ASSERT_EQ(output[0], str);
+
+  std::vector<std::string> vec = {"The",  "quick", "brown", "fox", "jumps",
+                                  "over", "the",   "lazy",  "dog"};
+  output = SplitString(str, ' ');
+  ASSERT_EQ(output.size(), vec.size());
+  for (int i = 0; i < vec.size(); ++i) {
+    ASSERT_EQ(output[i], vec[i]);
+  }
+
+  str = "iamf.001.001.Opus";
+  output = SplitString(str, '.');
+  vec = {"iamf", "001", "001", "Opus"};
+  ASSERT_EQ(output.size(), vec.size());
+  for (int i = 0; i < vec.size(); ++i) {
+    ASSERT_EQ(output[i], vec[i]);
+  }
+}
+
+TEST(StringTest, SplitStringEmptyInput) {
+  std::string str;
+  std::vector<std::string> output = SplitString(str, '.');
+  ASSERT_TRUE(output.empty());
+}
+
+TEST(StringTest, SplitStringNullDelimiter) {
+  std::string str = "The quick brown fox jumps over the lazy dog";
+  std::vector<std::string> output = SplitString(str, '\0');
+  ASSERT_EQ(output.size(), 1);
+  ASSERT_EQ(output[0], str);
+}
+
+}  // namespace
+}  // namespace starboard

starboard/shared/starboard/media/BUILD.gn

@@ -19,6 +19,8 @@ static_library("media_util") {
     "//starboard/shared/starboard/media/avc_util.h",
     "//starboard/shared/starboard/media/codec_util.cc",
     "//starboard/shared/starboard/media/codec_util.h",
+    "//starboard/shared/starboard/media/iamf_util.cc",
+    "//starboard/shared/starboard/media/iamf_util.h",
     "//starboard/shared/starboard/media/key_system_supportability_cache.cc",
     "//starboard/shared/starboard/media/key_system_supportability_cache.h",
     "//starboard/shared/starboard/media/media_support_internal.h",

starboard/shared/starboard/media/iamf_util.cc

@@ -0,0 +1,112 @@
+// Copyright 2024 The Cobalt Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "starboard/shared/starboard/media/iamf_util.h"
+
+#include <sstream>
+#include <string>
+#include <vector>
+
+#include "starboard/common/string.h"
+
+namespace starboard {
+namespace shared {
+namespace starboard {
+namespace media {
+
+IamfMimeUtil::IamfMimeUtil(const std::string& mime_type) {
+  // Reference: Immersive Audio Model and Formats;
+  //            v1.0.0
+  //            6.3. Codecs Parameter String
+  // (https://aomediacodec.github.io/iamf/v1.0.0-errata.html#codecsparameter)
+  if (mime_type.find("iamf") != 0) {
+    return;
+  }
+
+  // 4   FOURCC string "iamf".
+  // +1  delimiting period.
+  // +3  primary_profile as 3 digit string.
+  // +1  delimiting period.
+  // +3  additional_profile as 3 digit string.
+  // +1  delimiting period.
+  // +9  The remaining string is one of "Opus", "mp4a.40.2", "fLaC", or "ipcm".
+  constexpr int kMaxIamfCodecIdLength = 22;
+  if (mime_type.size() > kMaxIamfCodecIdLength) {
+    return;
+  }
+
+  const std::vector<std::string> vec = SplitString(mime_type, '.');
+  // The mime type must be in 4 parts for all substreams other than AAC, which
+  // is 6 parts.
+  if (vec.size() != 4 && vec.size() != 6) {
+    return;
+  }
+
+  // The primary profile string should be three digits, and should be between 0
+  // and 255 inclusive.
+  int primary_profile;
+  std::stringstream stream(vec[1]);
+  stream >> primary_profile;
+  if (stream.fail() || vec[1].size() != 3 || primary_profile > 255) {
+    return;
+  }
+
+  // The additional profile string should be three digits, and should be between
+  // 0 and 255 inclusive.
+  stream = std::stringstream(vec[2]);
+  int additional_profile;
+  stream >> additional_profile;
+  if (stream.fail() || vec[2].size() != 3 || additional_profile > 255) {
+    return;
+  }
+
+  // The codec string should be one of "Opus", "mp4a", "fLaC", or "ipcm".
+  std::string codec = vec[3];
+  if ((codec != "Opus") && (codec != "mp4a") && (codec != "fLaC") &&
+      (codec != "ipcm")) {
+    return;
+  }
+
+  // Only IAMF codec parameter strings with "mp4a" should be greater than 4
+  // elements.
+  if (codec == "mp4a") {
+    if (vec.size() != 6) {
+      return;
+    }
+
+    // The fields following "mp4a" should be "40" and "2" to signal AAC-LC.
+    if (vec[4] != "40" || vec[5] != "2") {
+      return;
+    }
+    substream_codec_ = kIamfSubstreamCodecMp4a;
+  } else {
+    if (vec.size() > 4) {
+      return;
+    }
+    if (codec == "Opus") {
+      substream_codec_ = kIamfSubstreamCodecOpus;
+    } else if (codec == "fLaC") {
+      substream_codec_ = kIamfSubstreamCodecFlac;
+    } else {
+      substream_codec_ = kIamfSubstreamCodecIpcm;
+    }
+  }
+
+  profile_ = primary_profile;
+}
+
+}  // namespace media
+}  // namespace starboard
+}  // namespace shared
+}  // namespace starboard

starboard/shared/starboard/media/iamf_util.h

@@ -0,0 +1,72 @@
+// Copyright 2024 The Cobalt Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef STARBOARD_SHARED_STARBOARD_MEDIA_IAMF_UTIL_H_
+#define STARBOARD_SHARED_STARBOARD_MEDIA_IAMF_UTIL_H_
+
+#include <limits>
+#include <string>
+
+#include "starboard/common/log.h"
+
+namespace starboard {
+namespace shared {
+namespace starboard {
+namespace media {
+
+enum IamfSubstreamCodec {
+  kIamfSubstreamCodecUnknown,
+  kIamfSubstreamCodecOpus,
+  kIamfSubstreamCodecMp4a,
+  kIamfSubstreamCodecFlac,
+  kIamfSubstreamCodecIpcm
+};
+
+// These values must match the profile values defined in
+// https://aomediacodec.github.io/iamf/v1.0.0-errata.html#profiles
+inline constexpr int kIamfProfileSimple = 0;
+inline constexpr int kIamfProfileBase = 1;
+inline constexpr int kIamfProfileMax = 255;
+
+// Parses an IAMF codecs parameter string following the convention defined in
+// https://aomediacodec.github.io/iamf/v1.0.0-errata.html#codecsparameter.
+// Always check is_valid() before calling the getter functions.
+class IamfMimeUtil {
+ public:
+  explicit IamfMimeUtil(const std::string& mime_type);
+
+  bool is_valid() const {
+    return profile_ <= kIamfProfileMax &&
+           substream_codec_ != kIamfSubstreamCodecUnknown;
+  }
+  int profile() const {
+    SB_DCHECK(is_valid());
+    return profile_;
+  }
+  IamfSubstreamCodec substream_codec() const {
+    SB_DCHECK(is_valid());
+    return substream_codec_;
+  }
+
+ private:
+  int profile_ = std::numeric_limits<int>::max();
+  IamfSubstreamCodec substream_codec_ = kIamfSubstreamCodecUnknown;
+};
+
+}  // namespace media
+}  // namespace starboard
+}  // namespace shared
+}  // namespace starboard
+
+#endif  // STARBOARD_SHARED_STARBOARD_MEDIA_IAMF_UTIL_H_