feat: add tactile codec

components/ffmsep/cpdecoder.hh

@@ -0,0 +1,133 @@
+//
+// Simple FFmpeg-inspired serial decoding toolkit.
+//
+
+#pragma once
+
+#include <cstdint>
+#include <cstddef>
+#include <mutex>
+#include <optional>
+#include <string>
+#include <string_view>
+#include <vector>
+#include <initializer_list>
+
+namespace ffmsep {
+
+// Error codes loosely mirroring FFmpeg semantics.
+inline constexpr int CP_SUCCESS = 0;
+inline constexpr int CP_ERROR_EOF = -1;
+inline constexpr int CP_ERROR_EAGAIN = -2;
+inline constexpr int CP_ERROR_NOT_OPEN = -3;
+inline constexpr int CP_ERROR_INVALID_STATE = -4;
+inline constexpr int CP_ERROR_INVALID_ARGUMENT = -5;
+
+enum class CPMediaType : std::uint8_t {
+    Unknown = 0,
+    Data,
+    Audio,
+    Video
+};
+
+enum class CPCodecID : std::uint32_t {
+    Unknown = 0,
+    Tactile = 0x54514354u // 'T','Q','C','T' marker for tactile quick codec.
+};
+
+struct CPPacket {
+    std::vector<std::uint8_t> payload;
+    std::int64_t pts = 0;
+    std::int64_t dts = 0;
+    bool end_of_stream = false;
+    bool flush = false;
+
+    CPPacket() = default;
+    CPPacket(std::vector<std::uint8_t> data, std::int64_t pts_value = 0, std::int64_t dts_value = 0) noexcept
+        : payload(std::move(data)), pts(pts_value), dts(dts_value) {}
+
+    [[nodiscard]] bool empty() const noexcept { return payload.empty(); }
+};
+
+struct CPFrame {
+    std::vector<std::uint8_t> data;
+    std::int64_t pts = 0;
+    bool key_frame = false;
+    bool valid = false;
+
+    void reset() noexcept {
+        data.clear();
+        pts = 0;
+        key_frame = false;
+        valid = false;
+    }
+};
+
+struct CPCodecContext;
+
+struct CPCodec {
+    using InitFn = int (*)(CPCodecContext*);
+    using CloseFn = void (*)(CPCodecContext*);
+    using SendPacketFn = int (*)(CPCodecContext*, const CPPacket&);
+    using ReceiveFrameFn = int (*)(CPCodecContext*, CPFrame&);
+
+    const char* name = nullptr;
+    const char* long_name = nullptr;
+    CPMediaType type = CPMediaType::Unknown;
+    CPCodecID id = CPCodecID::Unknown;
+    std::size_t priv_data_size = 0;
+    InitFn init = nullptr;
+    CloseFn close = nullptr;
+    SendPacketFn send_packet = nullptr;
+    ReceiveFrameFn receive_frame = nullptr;
+};
+
+struct CPCodecContext {
+    const CPCodec* codec = nullptr;
+    void* priv_data = nullptr;
+    CPMediaType codec_type = CPMediaType::Unknown;
+    bool is_open = false;
+
+    void clear() noexcept {
+        codec = nullptr;
+        priv_data = nullptr;
+        codec_type = CPMediaType::Unknown;
+        is_open = false;
+        priv_storage.clear();
+    }
+
+    void* ensure_priv_storage(std::size_t size);
+    void release_priv_storage() noexcept;
+
+    template <typename T>
+    [[nodiscard]] T* priv_as() noexcept {
+        return static_cast<T*>(priv_data);
+    }
+
+    template <typename T>
+    [[nodiscard]] const T* priv_as() const noexcept {
+        return static_cast<const T*>(priv_data);
+    }
+
+private:
+    std::vector<std::uint8_t> priv_storage;
+
+    friend CPCodecContext* cpcodec_alloc_context3(const CPCodec*);
+    friend int cpcodec_open2(CPCodecContext*, const CPCodec*);
+    friend int cpcodec_close(CPCodecContext*);
+};
+
+void cpcodec_register(const CPCodec* codec);
+void cpcodec_register_many(std::initializer_list<const CPCodec*> codecs);
+const CPCodec* cpcodec_find_decoder(CPCodecID id);
+const CPCodec* cpcodec_find_decoder_by_name(std::string_view name);
+std::vector<const CPCodec*> cpcodec_list_codecs();
+
+CPCodecContext* cpcodec_alloc_context3(const CPCodec* codec);
+int cpcodec_open2(CPCodecContext* ctx, const CPCodec* codec = nullptr);
+int cpcodec_close(CPCodecContext* ctx);
+void cpcodec_free_context(CPCodecContext** ctx);
+int cpcodec_send_packet(CPCodecContext* ctx, const CPPacket* packet);
+int cpcodec_receive_frame(CPCodecContext* ctx, CPFrame* frame);
+
+} // namespace ffmsep