Topic: 129 kbps audio bitrate
Tom4Uhere's photo
Mon 05/17/21 07:54 PM
Recently noticed the lip sync in high def 4k movies slowly gets out of sync as the movie plays. Come to find out the audio bit rate is 129 kbps.
I've never seen a video with an audio bit rate of 129?
I searched for a fix but the internet doesn't even acknowledge 129 kbps as an audio bit rate? Every search result shows conditions related to 128 kbps bit rate but those videos play in sync without issue.

When I contacted the streaming source site about it, they had no idea what I was talking about.
rant
I've found if I run the streams thru my GOM player I can adjust the sync to bring it back into alignment.
Problem is, the stream starts out in sync, then by the halfway point it is out by .5 seconds, if I do nothing, it is out by 1.0 seconds by the end of the movie.
If I ajust the sync at half way back as it should be, but the end of the movie is is off again by .5 seconds. I have to adjust the audio in .1 seconds faster increments and its always the same amount no matter the movie. It only happens on the 4k and higher resolution streams. Only on the streams which have the weird 129 kbps bitrates.

I'm wondering if anyone here has knowledge about audio bit rates of 129 kbps?
I'm wondering if this is an issue with the streaming source or my equipment?
I've no syncing issues with any other bit rate, only the ones at 129.

I'm actually trying to understand the glitch (I have a work-around-GOM).
All my software and hardware is up to date and I'm using hdmi a/v interface between my gaming computer and my TV with my tv audio out to my surround system
I have k-lite codec pack (didn't see anything in that).
I tried different browsers, no change.
I tried different stream sources and when there is a fix it is because the bitrate is different from the 129 weird bitrate and the resolution is 1080 instead of 4k.
I tried ripping the source file but the condition persists.

What is the 129 bitrate?
Is it something which is becoming industry standard on 4k+ video?
I don't own a 'smart TV'.
Is this another way to force people to buy into new technology?
Y'know, like they did when they foced us to buy into digital tvs and antennas?
frustrated

Tom4Uhere's photo
Mon 05/17/21 10:03 PM
I found a stream with 4k and 140 kbps audio bitrate and it plays without a problem.
It seems the only time there is a problem is when its the 129 kbps audio bitrate...

I downloaded Any Video Converter which has the ability to change video resolution and audio bitrates.
I can keep the video resolution and change the audio bit rate.
It offers conversion to the following bitrates:
32
64
96
128
160
192
224
256
320

There is no bitrate for 129 but there is a custom field available.

I'm thinking whoever set the bitrate for the stream source video conversion has it set to a custom value for some reason? All the streams are in mp4 so they were probably converted at some point from disc.
Is there a reason to set the bitrate at 129?
Some sort of anti-piracy, anti-copy measure?

nice1for_u's photo
Tue 05/18/21 07:26 PM
Edited by nice1for_u on Tue 05/18/21 07:28 PM
I wonder if this might be a DRM issue that prevents stealing or using copyrighted material without paying? The first few minutes work fine until the watermark activates the code. Digital is binary so I doubt 129kbs is there at all.

Tom4Uhere's photo
Tue 05/18/21 10:31 PM
I doubt 129kbs is there at all

It is. Its the audio bitrate.
Its also the only factor common to the issue.
All other bitrates play without a hitch.

It may have something to do with DRM, gotta look into that.
Thanx for the suggest.

Güney's photo
Sat 05/22/21 02:42 PM
I guess if it bugs you too much you could try separating the audio, decreasing its bit rate and well you don't even need to put it back together just play it along with the track and it should work.