Ontopic Random Computer-Electronics Thread

Josh

Biff Clurton
Oct 9, 2006
7,395
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East bumfuck.
Question for someone who is more knowledgeable than me on this subject:

One of my favorite bands had a live streaming concert a few months ago. I paid the "admission" fee and watched the show live. Afterwards, I downloaded the stream (as you were given up to 48 hours to watch or re-watch the concert). After downloading the mp4 (4GB for about 1.75 hours of video), the audio/video is out of sync. I can manually adjust in VLC PLayer, but the problem is it varies from being too fast to being too slow, like almost a second... i.e super noticeable and really annoying. I'm wondering if the server did this on purpose to discourage piracy. Also wondering if there is some way to unfuck the sync issue.
 

wetwillie

Know-It-All Pee-Paw
May 24, 2018
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Mid MIchigan
Question for someone who is more knowledgeable than me on this subject:

One of my favorite bands had a live streaming concert a few months ago. I paid the "admission" fee and watched the show live. Afterwards, I downloaded the stream (as you were given up to 48 hours to watch or re-watch the concert). After downloading the mp4 (4GB for about 1.75 hours of video), the audio/video is out of sync. I can manually adjust in VLC PLayer, but the problem is it varies from being too fast to being too slow, like almost a second... i.e super noticeable and really annoying. I'm wondering if the server did this on purpose to discourage piracy. Also wondering if there is some way to unfuck the sync issue.
Some servers do this intentionally because they know audio will process faster, but that can be a fail too, since hardware latencies vary so much between user systems. Podcasts do it a lot so they won't look stupid due to the lack of sync. Probably not a bad idea for them since they are often starting out with shit hardware. There is software to try and unfuck it . . . .
Sorry man. Curious - who's the band? No judgement :)
 

Josh

Biff Clurton
Oct 9, 2006
7,395
3,734
273
East bumfuck.
Some servers do this intentionally because they know audio will process faster, but that can be a fail too, since hardware latencies vary so much between user systems. Podcasts do it a lot so they won't look stupid due to the lack of sync. Probably not a bad idea for them since they are often starting out with shit hardware. There is software to try and unfuck it . . . .
Sorry man. Curious - who's the band? No judgement :)
Nightwish, 150,000 live streaming views, I guess set some records for streaming shows during quarantine.
 

Jehannum

HO HO HO METH GIANT
Jul 24, 2013
39,578
41,142
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Albuquerque, NM
Question for someone who is more knowledgeable than me on this subject:

One of my favorite bands had a live streaming concert a few months ago. I paid the "admission" fee and watched the show live. Afterwards, I downloaded the stream (as you were given up to 48 hours to watch or re-watch the concert). After downloading the mp4 (4GB for about 1.75 hours of video), the audio/video is out of sync. I can manually adjust in VLC PLayer, but the problem is it varies from being too fast to being too slow, like almost a second... i.e super noticeable and really annoying. I'm wondering if the server did this on purpose to discourage piracy. Also wondering if there is some way to unfuck the sync issue.
huh, I wonder if their SMPTE timecode was wonky. It does sound like some kind of anti-piracy thing, but I've never heard of that scheme in particular.

I don't think @wetwillie knows what he's talking about, as usual.
 

gee

Blame It On The Gassa Nova
Sep 29, 2012
15,553
17,211
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Halifax
Question for someone who is more knowledgeable than me on this subject:

One of my favorite bands had a live streaming concert a few months ago. I paid the "admission" fee and watched the show live. Afterwards, I downloaded the stream (as you were given up to 48 hours to watch or re-watch the concert). After downloading the mp4 (4GB for about 1.75 hours of video), the audio/video is out of sync. I can manually adjust in VLC PLayer, but the problem is it varies from being too fast to being too slow, like almost a second... i.e super noticeable and really annoying. I'm wondering if the server did this on purpose to discourage piracy. Also wondering if there is some way to unfuck the sync issue.
Is it a slow drift over the entire file, or does it "wobble?"

Slow drift could be the audio being at the right sample rate, but the video being encoded at 29.97fps and played at 30fps or something to that effect. If that was the case, it'd give an error of 3.6 seconds over 1 hour if that matches up with what you're seeing.
 
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Jehannum

HO HO HO METH GIANT
Jul 24, 2013
39,578
41,142
723
Albuquerque, NM
Is it a slow drift over the entire file, or does it "wobble?"

Slow drift could be the audio being at the right sample rate, but the video being encoded at 29.97fps and played at 30fps or something to that effect. If that was the case, it'd give an error of 3.6 seconds over 1 hour if that matches up with what you're seeing.
Oh shit, that's probably it - the video is from a bunch of Finnish dorks, so it's probably at 25FPS.
 
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Josh

Biff Clurton
Oct 9, 2006
7,395
3,734
273
East bumfuck.
Is it a slow drift over the entire file, or does it "wobble?"

Slow drift could be the audio being at the right sample rate, but the video being encoded at 29.97fps and played at 30fps or something to that effect. If that was the case, it'd give an error of 3.6 seconds over 1 hour if that matches up with what you're seeing.
It wobbles, goes too fast, then too slow. That's why manual adjustments are annoying.

Capture1.PNGCapture2.PNG
 

gee

Blame It On The Gassa Nova
Sep 29, 2012
15,553
17,211
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Halifax
Not that, then. Not sure what the procedure for fixing that is.

Maybe someone ripped, fixed and threw it up on pirate bay or elsewhere - that'd be my fix.
 
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