I’ve had satellite radio in all my cars and trucks for almost 2 decades and I’ve never had this experience.
We were on a vacation and had a rental car (Nissan Rogue) which was ok except it had no digital speedometer which was odd as it was otherwise loaded to the gills.
The XM radio did something weird. Say a song started on the 80’s station. If I flipped over to the 70’s station, even for just one second, and flipped back, the song on the 80’s station was half way over already. WTH? And if I did it again, for even a second, the 80’s station would be on another song. I could fast forward through a song just by flipping back and forth a couple of times.
It did this with every station, not just the 80’s station.
Did this radio have some kind of digital recirder or something? I have never had this happen before.
I don’t know for sure, but I think that your radio is ‘buffering’ the song data. Such that if you lost signal, the song would continue to play for another 30 seconds or minute, and if you only lost it for several seconds, the song would continue to play without being interrupted.
If this is the case, by flipping stations, you may be clearing the ‘cache’ of the stored song data, where it starts again.
I have a fully loaded 2021 Nissan Rogue and I have seen an option on the SXM menu to repeat a song, so there must be some recording buffer in there. Going to have to play with this feature now.
You can also set the display to not show a digital readout. My Rogue has a heads up display that shows the speed on the windshield so I have it turned off on my main display.
In my wife’s car you can set a station (just one I think) to start songs at the beginning (So that station is always “recording” like a DVR or something) . When you switch away and go back, it doesn’t start at the beginning again, but switches to “live.”
Seeing it was a rental car I didn’t futs to much with it. It was kind of neat how I could zip past a bad song just by by changing station a couple of times.
Well my digital TV has a hard drive recorder, so that if at any time I want to press pause or rewind,
I can do so … as long as I haven’t yet changed channel. But of course I can’t get to the future…
I think you must have pressed pause (mute, silence, or answer phone call,or maybe “off” ? ) or rewind along the way… so as to get some time ahead…
Remember that old spec on portable CD players like ‘5 seconds anti skip’? It’s a similar thing, the device holds some future audio in reserve in case the source is interrupted.
With any form of streamed data, including XM, that raises an issue.
Unless they are transmitting frames redundantly and faster than real time, the only way to build up, e.g. 30 seconds of buffered content is to have the receiver blank when first tuned to a new station for the same 30 seconds to fill the buffer.
I know I don’t know anything about how XM or any other streamer actually formats and sends data. But the only way to have buffered data in the receiver is to get it faster, or sooner, than the receiver needs to play it to the user.
I also don’t know anything about how XM radio streams its data, but there are other ways to fill the buffer. You start off with a delay of zero then slowly work your way up to a delay of 30 seconds, so there’s no blank. In a video image you just repeat one frame every now and then. For audio you can do something similar except that audio doesn’t neatly have “frames”, but you can repeat small bits of audio without it being noticeable to your ear.
This is commonly done in live broadcasts. That way if someone says a naughty word, they just hit a button and dump 15 seconds or so of the buffer. Now their buffer went from 30 seconds to 15. They can hit the button again, but then they are out of buffer, and hitting it again will cause a noticeable pause in the audio/video stream. Once you hit the button, the buffer will again slowly refill. It doesn’t fill instantly, so there’s no blank. But if you hit the button and it dumps 15 seconds, your 15 second buffer will slowly refill to 30 seconds and you’ll be back where you started.
(Note - 15 and 30 seconds are just to illustrate the point - I don’t know what actual delay and buffer values are used)
Good point. I hadn’t considered fakery, IOW replaying actual “frames” or artificially created interpolated frames as a technique to “buy time” and build a buffer.
As Confucius almost said: “Very clever these modern engineers” (comp_geeks).
Another variation, my 2013 Focus ST with SYNC 2 has DVR-like capabilities for SiriusXM. I can toggle Replay on and then use the left and right arrow controls to skip to previous/next song. It only starts buffering when you switch to a channel, so if you’ve just switched to a channel you can only go back a few seconds. And switching to a new channel empties the buffer. But if you’ve been listening to one channel a long time you can skip to each song in that timeframe. I think it buffers up to an hour or so.
