On Thu, 22 Oct 2009 21:13:30 +0200, Jean Delvare wrote: > For example, the signal strength. All I know so far is that this is a > 16-bit value. But then what? Do greater values represent stronger > signal or weaker signal? Are 0x0000 and 0xffff special values? Is the > returned value meaningful even when FE_HAS_SIGNAL is 0? When > FE_HAS_LOCK is 0? Is the scale linear, or do some values have > well-defined meanings, or is it arbitrary and each driver can have its > own scale? What are the typical use cases by user-space application for > this value? To close the chapter on signal strength... I understand now that we don't have strict rules about the exact values. But do we have at least a common agreement that greater values mean stronger signal? I am asking because the DVB-T adapter model I have here behaves very strangely in this respect. I get values of: * 0xffff when there's no signal at all * 0x2828 to 0x2e2e when signal is OK * greater values as signal weakens (I have an amplified antenna with manual gain control) up to 0x7272 I would have expected it the other way around: 0x0000 for no signal and greater values as signal strengthens. I think the frontend driver (cx22702) needs to be fixed. -- Jean Delvare -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
