How do I extract the watermark from the ts file?

when i run this:
```bash
audiowmark hls-add vs0prep/out1.ts send1.ts 0123456789abcdef0011223344556677
```
How do I know it works correctly?
How do I extract the watermark from send1.ts ?

And , What should I do to get the watermark added every second?
Please help me.