refactor(streamer): adopt proxy backends and typed statuses

include/cvmmap_streamer/config/runtime_config.hpp

@@ -25,6 +25,12 @@ enum class RtmpMode {
 	Domestic,
 };
 
+enum class RtmpTransportType {
+	Libavformat,
+	FfmpegProcess,
+	LegacyCustom,
+};
+
 enum class EncoderBackendType {
 	Auto,
 	FFmpeg,
@@ -58,6 +64,8 @@ struct EncoderConfig {
 struct RtmpOutputConfig {
 	bool enabled{false};
 	std::vector<std::string> urls{};
+	RtmpTransportType transport{RtmpTransportType::Libavformat};
+	std::string ffmpeg_path{"ffmpeg"};
 	RtmpMode mode{RtmpMode::Enhanced};
 };
 
@@ -112,6 +120,7 @@ struct RuntimeConfig {
 std::string_view to_string(CodecType codec);
 std::string_view to_string(RunMode mode);
 std::string_view to_string(RtmpMode mode);
+std::string_view to_string(RtmpTransportType transport);
 std::string_view to_string(EncoderBackendType backend);
 std::string_view to_string(EncoderDeviceType device);
 std::string_view to_string(McapCompression compression);