VRD audio signal

[Grandpa Broon]

I seem to have an issue with the audio signal displaying wrong info. Just to let you know I use VRD daily and have done so for about 15 years and this has just started occurring. I always display thumbnails and edit in scene mode, usually when audio is blue it's stereo and yellow 5.1. but recently yellow audio that I know is 5.1 when Ctl + L shows it as 2.0 channel. Using media info audio it shows correctly as 5.1. If I save it out using VRD as Match Source it saves as 5.1. So it records correctly but displays as 2.0
Using 6.63.7.836, both input and output files are .TS or M2TS H.264/AVC either Full HD or 1280x720. This has only just started over the past few weeks.
I know there is very little that can be done but I Just wondering if anyone else is experiencing this.

Thanks David

 

[Otter]

I've seen what you are describing in the past. Turned out it was my source (cable tv) changing from 2 ch for adverts to 5.1 ch when the main program started.
VRD seemed to get it's ch info from the first few seconds of the file and stuck with it.
There was a forum thread about it being fixed in a past release, but it was some time ago.
I seldom record 5.1 anymore unless it's something like a music show. The "surround" from my cable provider doesn't sound much different from 2 ch on my 7.1 ch system anyway.

 

[Dan203]

Yep, the info is based entirely on the first frame in the file. So if there is even a single 2ch frame at the start of the source file that’s what the program info will show.

 

[cp2]

On many UK channels I note that the default standard is stereo which switches to 5.1 for some programmes, dipping back to stereo for the adverts. There are one or two channels that are 5.1 throughout including the adverts and this makes me would how accurate the flag is.
I try to trim the start of (allegedly) 5.1 programme to when the 5.1 signal kicks in. This is not always possible. You can use the profile settings to “force“ 5.1 so that programme reflects correctly in MediaInfo.

 

[Dan203]

You can set 2.0 and 5.1 to different colors in the thumbnails so you can see where the switch happens

 

[Infidelus]

Channel 4 HD in the UK most definitely has this issue and I had to make a special output profile to set the recording output to stereo or it would lose sound after an advert break. I'm not sure if that's still an issue but I still use the custom profile if I record on C4 HD.

 

[cp2]

I can’t say that I’ve had a problem with Channel 4 but I have both satellite and terrestrial tuners. (The only thing I don’t like is C4 still using DVB-S rather than S2).
I wonder if instead of forcing stereo you could try using the advance settings to recode the audio stream to/ from AAC with auto channel. Perhaps the audio recoding will sort it out.

 

[Infidelus]

I only have DVB-T2 tuners.

I wonder if instead of forcing stereo you could try using the advance settings to recode the audio stream to/ from AAC with auto channel. Perhaps the audio recoding will sort it out.

Sorry, that's what I meant; I am recoding them all to stereo.

 

[cp2]

OK DVB-T2 tuners which means AAC sound (usually). I don’t have the silence problem that you are experiencing though I have experienced something similar because my tuner card and capture software are not able to handle any change in the audio codec within a recording block. This means that the sound track is “damaged“ before I open it in VRD.
Assuming you edit out the adverts and thus the drop to 2.0 if you use the advanced audio settings in the VRD profile you should be able to ask for the track to be recoded to AC3. There is also an option to change the number of tracks or leave it on auto. I’m wondering whether a request to recode the audio will align either side of the advert break correctly.

 

[Infidelus]

I haven't actually checked if this is still an issue for a while and I know C4 have slightly changed the way they air their programmes as the sound used to fade out in the last second before an advert break, which it no longer does. I might just try changing the stereo to AC3 to see if it still works though it doesn't really make much difference to me as I wouldn't notice change when watching a programme .

 

[Infidelus]

Just following up. I recorded Mission: Impossible last night and, using the default MKV profile, there is no sound on the output folder. Recoding from the AAC stream to either AC3 or Stereo fixes it. Clearly C4 still mess with their streams as none of the other channels have the same issue, but at least a simple audio recode is all that's needed.

 

[Grandpa Broon]

Thanks Guys for your help. I thought I replied to Dan203 last Wednesday but it doesn't seem to have went through. I didn't realise that it reads the first frame to list the audio because invariably the recordings don't necessarily have DD5.1 but 2.0.

 

[cp2]

Thinking about it I realise why I may not have encountered a problem with Channel 4 audio. After editing I save the the output as H264 but only to check for errors. If no errors are reported I immediately save as H265 (space!) which initiates a complete recode, including audio anyway. Just about all of my final output is in H265.
Following up on a previous comment, Alibi channel broadcasts with the 5.1 flag set, rather than switching between stereo and 5.1 as the adverts cut it. As the programme was made in 1990 I doubt that 5.1 is applicable.