[PROBLEM] Latency reduction when using audio/video player as input

[jiemdev]

Rectification after more tries:

- with no buffer and period specific params, latency is about 1.2s (2s was exagerated, I now use a specific video for sync test)
- with buffer and period specific params, latency is about 1s
- with configure>Audio>Output mode>Direct (hw) instead of Default (plughw), no buffer and period specific params, latency is about 1s
- with output mode set to direct (hw), plus buffer and period specific params, latency is about 1s also