"Missing" audio in VPX16

emmrecs wrote on 1/15/2025, 9:50 AM

(The thread title is deliberately cryptic!)

but I wanted to seek the wisdom of fellow-users of this software about a very strange problem!

I recently needed to digitise, for a client, a VHS tape. Following the demise of my computer which included a Canopus ACEDVio PCI card and the fact that the new computer has no PCI slots, I decided to test the Magix, (Black) USB Video Convertor. After several tests using some of the different output options offered by the convertor (initially I tried the .avi user defined option, it produced files recorded at 124mbps(!) but these did not export very well at all to DVD [the intended final output]; I then tried "MPG-DVD" option, c.4kbps, but the quality was rather low, to say the least.) The other options seemed to offer no real "improvement" over this MPG output.

So, being the owner of Topaz Labs Video AI (which I find one of the best softwares for video upscaling) I opened the "MPG-DVD" file in Video AI, chose to have it apply a little enhancement (increasing the bit rate to about 6kbps) and the file successfully exported! The Audio was simply set to "Copy", with no enhancement or changes made to it, officially!

I then opened this "enhanced" version in VPX16, and there was no audio. I opened the same file in my normal "file player", PowerDVD 17, and it played perfectly, video and audio!

I then looked at the Audio data from MediaInfo for both the original and processed files; here is that data:

The "original":

ID : 192 (0xC0)
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 2
Duration : 55 min 36 s
Bit rate mode : Constant
Bit rate : 224 kb/s
Channel(s) : 2 channels
Sampling rate : 48.0 kHz
Frame rate : 41.667 FPS (1152 SPF)
Compression mode : Lossy
Stream size : 89.1 MiB (5%)

The "processed":

ID : 2
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 2
Codec ID : mp4a-6B
Duration : 55 min 36 s
Bit rate mode : Constant
Bit rate : 224 kb/s
Channel(s) : 2 channels
Sampling rate : 48.0 kHz
Compression mode : Lossy
Stream size : 89.1 MiB (4%)
Default : Yes
Alternate group : 1

Obviously, I can see some "different" lines of data; but surely that cannot explain why the file has no audio (and no visible waveform) when opened in VPX16?

I have asked Topaz Labs support about this and they can offer no reason for the behaviour. Before I ask Magix Support I wanted to see whether the collective mind of users in this forum had any ideas to offer?

In the longer term, because I am quite often asked by clients to transcribe VHS video to DVD, I am going to take the plunge and buy an external PCI Expansion Enclosure so I can use my old, but still excellent quality, PCI card for digitising video.

All thoughts very gratefully received!

Jeff

Comments

AAProds wrote on 1/15/2025, 3:20 PM

@emmrecs

Methinks "copy" is not really just that. Topaz could be rewriting the head info that throws Magix.

Magix has done this to me occasionally; seemingly bog-standard audio won't import.

Try another capture process eg the Magix dongle with AmarecTV with an AVI codec.

CubeAce wrote on 1/15/2025, 4:48 PM

@emmrecs

Hi Jeff.

While I'm not sure what is going on, do you have a DAW you could load the video file into and export as a wav file?

Then import that into the project and link it to the video file?

Short of that, play back the video file in VLC or similar and record that into VPX?

At least then you will keep the quality of your video file and not lose the quality of the audio as that should happen within the digital domain.

Ray.

ericlnz wrote on 1/15/2025, 6:00 PM

@emmrecs You could try rewrapping with Shutter Encoder?

johnebaker wrote on 1/16/2025, 3:37 AM

@emmrecs

Hi Jeff

The MediaInfo data looks fine.

In VPX did you try the Restore original sound on the video clip?

A 10 - 20 sec sample of a recording that shows this behaviour may help.

John EB

emmrecs wrote on 1/16/2025, 3:49 AM

@AAProds @ericlnz @CubeAce @johnebaker

Hi Guys,

Many thanks for all these ideas!

I have to go out very soon but will hope to return to this thread later today.

Jeff

emmrecs wrote on 1/16/2025, 8:49 AM

@AAProds @CubeAce @ericlnz @johnebaker

In the end, as a quick workaround, I opened the "silent" file in Handbrake, made as few changes as possible and exported as .mp4. Sound restored and playable in VPX16. But not ideal when the final output is intended for DVD and the file has then gone through at least 3 "processing" stages, even before export to DVD!

I think Al is correct: it seems that Video AI is making some change to the file header, which MediaInfo does not see but which VPX does not like!

Eric, thanks for the suggestion of Shutter Encoder. I will test it out later today, I hope.

Ray, yes I can export a .wav from the original file and then reimport that to the processed copy.

John, where is the "Restore original sound" option to be found? I know I should know, but at the moment I'm stumped! I will endeavour to prepare a very short sample file, demonstrating the original problem, over the next few days.

UPDATE: Shutter Encoder allowed me to very quickly convert the audio of the file to .wav, which, when imported to the VPX timeline, played perfectly. Ideally I would have liked to use the VPX facility to Extract the audio from the processed file to wav but, of course, VPX couldn't "see" that audio!

However, as I suggested in the first post to this thread, because I am not at all happy with the quality of the VHS>Digital transfers I've been able to make with the Magix Convertor (when compared with what I was achieving with the Canopus card) I've bitten the bullet and ordered a powered PCI Expansion Enclosure, which will allow me to use up to 2 PCI and 2PCIe cards connected through one PCIe socket on the Mobo. (The Mobo has 3 but 2 are currently occupied by the NVidia GPU, the third has a FW card. The FW card will be transferred to the Expansion Enclosure, to be joined by the Canopus card and a second PCI which contains several USB 2 ports. I do have several USB2 peripherals.)

All good fun!!!

Jeff

CubeAce wrote on 1/16/2025, 9:10 AM

@emmrecs

Hi Jeff.

I have only ever seen the 'Restore original sound' come up as an option if the sound track to a video clip had previously been cut away from the video portion of the clip first. Found by right clicking on the video portion of a video object.

Whether cutting the audio from the track and then restoring it will make the audio play or not I'm not certain.

Ray.

johnebaker wrote on 1/16/2025, 9:32 AM

@emmrecs

Hi Jeff

. . . . it seems that Video AI is making some change to the file header . . . .

Do you have a sample file available?

. . . . where is the "Restore original sound" option to be found? . . . .

Right click the video clip, Audio functions it should be there if applicable.

John EB

emmrecs wrote on 1/16/2025, 9:45 AM

@johnebaker

Hi John,

Do you have a sample file available?

Hopefully, by the weekend.

Right click the video clip, Audio functions it should be there if applicable.

That's where I assumed it should be, but it isn't so presumably is not applicable.

Jeff

emmrecs wrote on 1/16/2025, 10:01 AM

@johnebaker

Considerably earlier than I first thought, a 30 second sample file can be downloaded from https://we.tl/t-y8CvDb6kb6

Topaz Labs have also suggested I might like to download and test the Beta release of the next version, which I will do, and see if the problem still exists.

Jeff

CubeAce wrote on 1/16/2025, 1:46 PM

@emmrecs

Hi Jeff.

I downloaded your sample video. It will not play in any Windows media player but will in VLC. My DAW has always played any MP4 based video file but opens with 'cannot load audio stream'.

VLC reports the audio is using 32bits per sample when the norm for an mp3 based audio file is either 16 or 24 bits per sample, so I think it is that what is causing the problem.

Ray.

johnebaker wrote on 1/16/2025, 1:59 PM

@emmrecs

Hi Jeff, Ray

. . . . It will not play in any Windows media player but will in VLC . . . .

Confirmed.

Media Info data shows there is a 'non standard' combination of an AVC video stream with a MP2 audio stream, by coincidence I was testing a short while ago with the same combination of codecs.

Options are :-

AVC/h.264 + AAC or AC3 audio.
or
mpeg-2 video with a mp2 audio.

John EB

browj2 wrote on 1/16/2025, 2:18 PM

@emmrecs

Hi Jeff,

For what it's worth, the audio plays and looks fine in SpectraLayers11.

John CB

browj2 wrote on 1/16/2025, 2:49 PM

@emmrecs

Hi Jeff,

...and it also works in Sound Forge Audio Cleaning Lab 4.

John CB

emmrecs wrote on 1/17/2025, 5:20 AM

@CubeAce @johnebaker @browj2

Hi Ray, John and John,

Many thanks for confirming the problem!

I did download and install the Beta version of VideoAI but the problem persists, so I've "thrown it back" to Topaz, and also offered them the same clip as you downloaded.

I will hope to update this thread as more information emerges.

Jeff

Gid wrote on 1/17/2025, 6:13 AM

@emmrecs Hi, I tried your file, VLC & MPC Player play it without problem.

MMS & VP22 don't have audio, the track is there but no sound.

Shutter Encoder plays the file in it's program with sound no problem but exporting (Start Function) as Rewrap doesn't fix it, the exported file still has no audio in MMS. If I change the option in Shutter Encoder from Rewrap to something else fixes it but that's recoding it just as you did in Handbrake.

Reyfox wrote on 1/17/2025, 6:50 AM

I imported the file into Davinci Resolve 19 Studio and there is no audio either. The audio track is there, but it contains no audio/waveforms.

emmrecs wrote on 1/17/2025, 7:59 AM

@Gid @Reyfox

Thanks for your attempts.

All this additional checking points firmly, I think, to a problem being caused by VideoAI. If/when Topaz support reply to my latest email to them I will hope to update this thread.

Jeff

Gid wrote on 1/17/2025, 9:02 AM

@emmrecs 👍

Just out of curiousity, Hitfilm Pro no problemo 😎

Reyfox wrote on 1/17/2025, 9:47 AM

@Gid, I just dragged it into Vegas Effects as a standalone, and it played there also. HFP 2021.3 played it too. Strange....

Gid wrote on 1/17/2025, 9:51 AM

@Reyfox Yep, HFP 2021.3 is the same version I have, I also have VE19 & was going to try it but as it's the same or very similar I just presumed it would work just like HFP 👍

PS. that file won't load into VP18, 19 or 20, video or audio.. I didn't try VP21 because I suspect I'll get the same result as VP22..

Reyfox wrote on 1/17/2025, 3:38 PM

@Gid, yeah... those versions didn't like the file either. I also tried Pinnacle Studio and Videostudio Pro, and no success there either.

CubeAce wrote on 1/17/2025, 5:56 PM

@emmrecs @Gid @johnebaker @ericlnz @AAProds @Reyfox @browj2

So why is VLC showing the file as 32 bit and Hitfilm 24 bit? Both play the file. Surely it can't be both and for some reason the other programs are misreading the audio data including VPX reporting it is 16 bit and not playing it.

Ray.

Gid wrote on 1/17/2025, 6:12 PM

@CubeAce Hitfilm is 16 bit isn't it? & MPC Player