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Post by EnMar on Dec 16, 2020 16:51:45 GMT
We are starting an ensemble project today and already I have students having sync issues. My first student to record said that he was so out of sync that even with the nudge slider all the way over he was still two full seconds behind. Is there a way to get the nudge slider to move the video more than it does now? I've had several instances where it doesn't adjust the video enough. Now that we are doing longer pieces, I'm really worried that the students will get frustrated when they get a good recording only to find that it is so out of sync that they can't use it. I've asked them to re start their computer before using CL, and to make sure it is the only program running while they use it. Anything else that can be done?
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Post by lizrad on Dec 16, 2020 17:00:53 GMT
Hello, 2 full seconds, or 200 milliseconds? 2 full seconds is incredible and if this is within the realm of possibility of an error experienced while operating within reasonable parameters of using the program, then we will need to think about a fix. As far as what can be done right now: - it's possible that calibration is done with too much background noise present; students should silence background noise as best they can; spikes in ambient noise will cause miscalculations;
- it's possible that the plugged-in headphones are being held up to the wrong microphone; if students are not positive where their microphone is, they can unplug their headphones and calibrate with unplugged headphones.
As the troubleshooting page states, microphones calculating more than a 50 millisecond variation between calibrations are calculating "unreliably". "Unreliably" means that calculations that fall outside 50 milliseconds of your average latency measurement may not accurately represent the latency that your device will actually produce at the time of recording. Students who are experiencing extreme syncing issues should try to get a sense of what their average calculated latency is. To do this, they should calculate multiple times while on the 'Setup' page, and get a sense of what the average final calculation is. Once they know what the average is, they can choose to re-calculate if the first calculation is more than 50 (.050) milliseconds off from their normal average range. For example, I always end up needing to calibrate my microphone twice. The first time it calibrates, it always calculates a latency of 400-500 (0.400-0.500) milliseconds. I know for my computer this is not accurate, because I have a sense of what a 'normal' latency calculation is for my device. The second/third/fourth/etc time I calibrate, it always calculates between 220-240 (0.220-0.240) milliseconds. |
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Post by EnMar on Dec 16, 2020 19:36:22 GMT
The student told me that he refreshed the page, left the nudge slider at 0 and then suddenly it was in sync. Not sure what happened but just glad it worked out. Hopefully it stays that way! Appreciate the quick replies.
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Post by lizrad on Dec 16, 2020 20:17:11 GMT
Ok.
It sounds like this was a refresh (or in the future) a restart issue. In other words, this sounds like the issue was not troubleshooting a syncing problem, it was troubleshooting a tired browser/computer problem.
In addition to what is listed on the troubleshooting page, and my post above, please consider the refresh/restart option as part of your toolbox for addressing this and similar issues.
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Post by EnMar on Dec 17, 2020 16:10:56 GMT
I misunderstood the student - the recording did not fix itself, he just had to try over and over again until one finally worked, which is what I'm trying to avoid because I know students will get frustrated. Today he restarted his Chromebook, calibrated twice and said the second reading was .23649... I'm not sure what that really means or what a good range is but it sounds like he's still having issues. I check one of his off recordings and he was indeed about 1.5 second early in terms of syncing. Too much for the nudge slider to be able to correct the video. It sounds like more of my students are having issues than not.
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Post by lizrad on Dec 17, 2020 16:47:45 GMT
Please confirm the student has done the below. I do not know what a normal calibration is for your student. As the post says below, the student should calibrate several times in a row to determine a normal range for themselves. Every device will be different. It doesn't matter what the number is, as long as it is consistent.
As far as what can be done right now:
it's possible that calibration is done with too much background noise present; students should silence background noise as best they can; spikes in ambient noise will cause miscalculations;
it's possible that the plugged-in headphones are being held up to the wrong microphone; if students are not positive where their microphone is, they can unplug their headphones and calibrate with unplugged headphones.
As the troubleshooting page states, microphones calculating more than a 50 millisecond variation between calibrations are calculating "unreliably". "Unreliably" means that calculations that fall outside 50 milliseconds of your average latency measurement may not accurately represent the latency that your device will actually produce at the time of recording.
Students who are experiencing extreme syncing issues should try to get a sense of what their average calculated latency is. To do this, they should calculate multiple times while on the 'Setup' page, and get a sense of what the average final calculation is. Once they know what the average is, they can choose to re-calculate if the first calculation is more than 50 (.050) milliseconds off from their normal average range.
For example, I always end up needing to calibrate my microphone twice. The first time it calibrates, it always calculates a latency of 400-500 (0.400-0.500) milliseconds. I know for my computer this is not accurate, because I have a sense of what a 'normal' latency calculation is for my device. The second/third/fourth/etc time I calibrate, it always calculates between 220-240 (0.220-0.240) milliseconds.
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Post by afdoni on Dec 17, 2020 20:08:34 GMT
Hi sorry to jump in, I just wanted to add that I found that the wired headphones can make a huge difference. My students really wanted to wear their wireless airpods, but we found that using wireless can cause extreme syncing issues. Just wanted to offer that in case it's as easy a solution as it was for my group, sorry to jump in
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Post by lizrad on Dec 18, 2020 2:28:13 GMT
Yes, thanks for bringing that up - wireless anything will be unreliable. Wearing wireless headphones could also produce the kind of extreme syncing errors described
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