feat(streamer): add ffmpeg encoder and mcap recording

include/cvmmap_streamer/encode/encoded_access_unit.hpp

@@ -0,0 +1,18 @@
+#pragma once
+
+#include "cvmmap_streamer/config/runtime_config.hpp"
+
+#include <cstdint>
+#include <vector>
+
+namespace cvmmap_streamer::encode {
+
+struct EncodedAccessUnit {
+	CodecType codec{CodecType::H264};
+	std::uint64_t source_timestamp_ns{0};
+	std::uint64_t stream_pts_ns{0};
+	bool keyframe{false};
+	std::vector<std::uint8_t> annexb_bytes{};
+};
+
+}

include/cvmmap_streamer/encode/encoder_backend.hpp

@@ -0,0 +1,54 @@
+#pragma once
+
+#include "cvmmap_streamer/config/runtime_config.hpp"
+#include "cvmmap_streamer/encode/encoded_access_unit.hpp"
+#include "cvmmap_streamer/ipc/contracts.hpp"
+
+#include <cstdint>
+#include <expected>
+#include <memory>
+#include <span>
+#include <string>
+#include <string_view>
+#include <vector>
+
+namespace cvmmap_streamer::encode {
+
+struct RawVideoFrame {
+	ipc::FrameInfo info{};
+	std::uint64_t source_timestamp_ns{0};
+	std::span<const std::uint8_t> bytes{};
+};
+
+class EncoderBackend {
+public:
+	virtual ~EncoderBackend() = default;
+
+	[[nodiscard]]
+	virtual std::string_view backend_name() const = 0;
+
+	[[nodiscard]]
+	virtual bool using_hardware() const = 0;
+
+	[[nodiscard]]
+	virtual std::expected<void, std::string> init(const RuntimeConfig &config, const ipc::FrameInfo &frame_info) = 0;
+
+	[[nodiscard]]
+	virtual std::expected<void, std::string> poll() = 0;
+
+	[[nodiscard]]
+	virtual std::expected<void, std::string> push_frame(const RawVideoFrame &frame) = 0;
+
+	[[nodiscard]]
+	virtual std::expected<std::vector<EncodedAccessUnit>, std::string> drain() = 0;
+
+	[[nodiscard]]
+	virtual std::expected<std::vector<EncodedAccessUnit>, std::string> flush() = 0;
+
+	virtual void shutdown() = 0;
+};
+
+[[nodiscard]]
+std::expected<std::unique_ptr<EncoderBackend>, std::string> make_encoder_backend(const RuntimeConfig &config);
+
+}