Provide progress status report during authoring

- Track either the number of A/V frames authored, or the time elapsed
- Track the completion of the authoring
- Add multiple camera support for authoring by accepting a camera id parameter
- Set file type based on the OUTPUT_FORMAT requested

Change-Id: I0f9d31b3b7a8fa43eb53f572410fb0ebd4fa0bb7
7 files changed