Not detecting no. of channels changing

#1
I'm having a problem with the Quickstream fix and H.264 files which have both 2.0 and 5.1 included.

VR appears to detect a change from 5.1 to 2.0 but is not detecting a switch from 2.0 to 5.1 and encodes the rest of the video as 2.0

So as a simple example; I have recorded a TV programme which has the audio as 2.0 -> 5.1 -. 2.0. I can't cut out the 2.0 segments as there is an error in the video so I need to do a Quickstream fix I do this using the supplied H.264 MP4 profile, the fix works but the whole file is now 2.0.

Any ideas

Thanks
 

jmc

Active member
#2
I'm having a problem with the Quickstream fix and H.264 files which have both 2.0 and 5.1 included.

VR appears to detect a change from 5.1 to 2.0 but is not detecting a switch from 2.0 to 5.1 and encodes the rest of the video as 2.0

So as a simple example; I have recorded a TV programme which has the audio as 2.0 -> 5.1 -. 2.0. I can't cut out the 2.0 segments as there is an error in the video so I need to do a Quickstream fix I do this using the supplied H.264 MP4 profile, the fix works but the whole file is now 2.0.

Any ideas

Thanks
Try setting the QSF setting options to 5.1 audio and force the whole thing to be 5.1.
 
#3
I've tried setting the channels to 5.1 and for most videos, this works but on some, it corrupts the audio stream and I get stuttering so I was looking for an alternative solution.

I'm using a modified copy of the standard h.264 profile with encoding type set to AAC and channels to 5.1 the profile automatically sets bitrate to 128kps
 

Dan203

Senior Developer
Staff member
#4
If you're QSFing why are you recoding the audio at all? Just leave everything alone and it'll be passes through as-is. If the audio is AAC just make sure to save to the TS format and NOT MP4 or MKV. MP4 and MKV strip the individual audio headers and save a single audio header in the container. So they can not handle a switch back and forth between 2.0 and 5.1. TS can just fine though. Once the file is fixed then you can edit and save to whatever format you want. However if you need MP4 or MKV as the final format you'll need to then force a recode of the audio to 5.1 so that it retains the 5.1 portions.
 
#5
But that takes us back to the problem I reported in my first post, the video file starts in 2.0 and then goes to 5.1. VR is not detecting the change so if I just QSF it, the whole audio is turned into 2.0 so I lose the 5.1 from the actual section that I want and whilst I am not 100% certain I think I am also losing some of the audio content as I am not sure that VR is mapping all of the 5.1 channels down on to the 2.0
 

Dan203

Senior Developer
Staff member
#6
Like I said that happens depending on the format you're saving to. If you save to MP4 or MKV then only one format is supported and VideoReDo just uses the first format it finds. So if the first frames are 2.0 the entire output will be 2.0. The only way to fix this would be to QSF to TS instead. Then open the TS and completely remove all 2.0 frames from the start of the file. Save as TS again. Then open that TS and make the rest of your edits and save as MP4 or MKV. That will make it so the first frames in the file are 5.1 and the output will be 5.1.
 
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