Preliminary ALAC support

2 files changed, 92 insertions, 0 deletions

diff --git a/src/codecs/include/alac.hpp b/src/codecs/include/alac.hpp
new file mode 100644
index 00000000..a0dcd1f2
--- /dev/null
+++ b/src/codecs/include/alac.hpp
@@ -0,0 +1,91 @@
+/*
+ * Copyright 2025 ayumi <ayumi@noreply.codeberg.org>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <memory>
+#include <optional>
+#include <string>
+#include <utility>
+#include <variant>
+
+extern "C" {
+  #include "decomp.h"
+}
+#include "sample.hpp"
+
+#include "codec.hpp"
+
+namespace codecs {
+
+class AlacDecoder : public ICodec {
+ public:
+  AlacDecoder();
+  ~AlacDecoder();
+
+  auto OpenStream(std::shared_ptr<IStream> input, uint32_t offset)
+      -> cpp::result<OutputFormat, Error> override;
+  auto DecodeTo(std::span<sample::Sample> destination)
+      -> cpp::result<OutputInfo, Error> override;
+
+  AlacDecoder(const AlacDecoder&) = delete;
+  AlacDecoder& operator=(const AlacDecoder&) = delete;
+
+ private:
+  auto readBoxHeader()
+      -> cpp::result<std::tuple<uint64_t, std::array<std::byte, 4>>, ICodec::Error>;
+  auto readFullBoxHeader() -> std::tuple<uint8_t, uint32_t>;
+  auto readFtyp(uint64_t size) -> cpp::result<void, ICodec::Error>;
+  void readFree(uint64_t size);
+  auto readStsd() -> cpp::result<void, ICodec::Error>;
+  auto readStts() -> cpp::result<void, ICodec::Error>;
+  auto readStsc() -> cpp::result<void, ICodec::Error>;
+  auto readStsz() -> cpp::result<void, ICodec::Error>;
+  auto readStco() -> cpp::result<void, ICodec::Error>;
+  auto readCo64() -> cpp::result<void, ICodec::Error>;
+  auto readBox() -> cpp::result<uint64_t, ICodec::Error>;
+  auto readContainer(uint64_t size) -> cpp::result<uint64_t, ICodec::Error>;
+  auto getFrameDuration(uint32_t frame) -> cpp::result<uint32_t, ICodec::Error>;
+  auto getFrameSize(uint32_t frame) -> uint32_t;
+  auto getTotalSamples() -> uint64_t;
+  auto getTotalFrames() -> uint32_t;
+  auto getTotalFrameSize() -> uint64_t;
+  auto frameToOffset(uint32_t frame)
+      -> cpp::result<std::tuple<uint64_t, uint32_t>, ICodec::Error>;
+  auto getChunkMixMaxFrames(uint32_t chunk)
+      -> cpp::result<std::tuple<uint32_t, uint32_t>, ICodec::Error>;
+  auto sampleToFrame(uint64_t sample)
+      -> cpp::result<std::tuple<uint32_t, uint32_t>, ICodec::Error>;
+  auto UnpackFrame(uint32_t offset) -> cpp::result<void, ICodec::Error>;
+
+  std::shared_ptr<IStream> input_;
+  alac_file alac_;
+  uint8_t bitdepth_;
+  uint8_t channels_;
+  uint16_t sampleRate_;
+  uint16_t index_;
+
+  std::vector<std::tuple<uint32_t, uint32_t>> stts_;
+  std::vector<std::tuple<uint32_t, uint32_t>> stsc_;
+  std::variant<uint32_t, std::vector<uint32_t>> stsz_;
+  std::vector<uint64_t> stco_;
+
+  bool hasStts_ = false;
+  bool hasStsc_ = false;
+  bool hasStsz_ = false;
+  bool hasStco_ = false;
+
+  uint32_t chunk_;
+  uint32_t frame_;
+  std::vector<std::byte> in_;
+  std::vector<std::byte> out_;
+  size_t outSize_;
+  size_t outOff_;
+};
+
+}  // namespace codecs
diff --git a/src/codecs/include/types.hpp b/src/codecs/include/types.hpp
index 493a177a..60a49300 100644
--- a/src/codecs/include/types.hpp
+++ b/src/codecs/include/types.hpp
@@ -18,6 +18,7 @@ enum class StreamType {
   kWav,
   kNative,
   kWavPack,
+  kAlac,
 };
 
 auto StreamTypeToString(StreamType t) -> std::string;