SSTV 解码与保存

sequenceDiagram
actor U as 用户
participant UI
participant R as Runtime
participant D as Decoder
participant S as Store
U->>UI: Start RX
UI->>R: start
R->>D: audio
D-->>UI: mode/level/progress
D-->>R: frame
R->>S: save
S-->>UI: path/error