Audio Quality - DV vs. S-Video/RCA

[Bermuda1]

Hi everyone,

so I started capturing analog tapes via my digital camcorder (TRV 230E) using
a) DV/FireWire (via Scenalyzer) and
b) S-Video and RCA (via AmaRecTV)

No discussion on video quality - S-Video is better. However, I feel like the audio is better using DV/FireWire despite only being 32000 Hz. There seems to be less noise in the FireWire capture. Is it only me, or would you agree and what could be the reason for this. Anything I can change? Is it perhaps the RCA cable?

Thanks for your help/feedback!

Best regards,
Bermuda

[The_Doman]

We don't know what your S-Video capture device/setup is?
Possible the camcorder does a better job internally digitizing the sound?

About the audio being 32000 Hz:

Also, why does it capture audio at 32 kHz instead of 48 Khz?

Probably because you have (mis)configured your camera audio setup to use 32kHz audio mode?
Works the same with my D8 camera when capturing using analog-pass through.

Wikipedia: DV (video format)

Audio can be stored in either of two forms: 16-bit Linear PCM stereo at 48 kHz sampling rate (768 kbit/s per channel, 1.5 Mbit/s stereo), or four nonlinear 12-bit PCM channels at 32 kHz sampling rate (384 kbit/s per channel, 1.5 Mbit/s for four channels). In addition, the DV specification also supports 16-bit audio at 44.1 kHz (706 kbit/s per channel, 1.4 Mbit/s stereo), the same sampling rate used for CD audio.[11] In practice, the 48 kHz stereo mode is used almost exclusively.

[dellsam34]

If your camcorder does not have stereo output and you are using a Y splitter to split a mono into 2 channels stereo and no audio gain control that explains why you may have a degraded audio during digitizing, However 32Khz is not promising either, It should be 48Khz 16bit.

[Bermuda1]

We don't know what your S-Video capture device/setup is?
Possible the camcorder does a better job internally digitizing the sound?

About the audio being 32000 Hz:

Also, why does it capture audio at 32 kHz instead of 48 Khz?

Probably because you have (mis)configured your camera audio setup to use 32kHz audio mode?
Works the same with my D8 camera when capturing using analog-pass through.

Wikipedia: DV (video format)

Audio can be stored in either of two forms: 16-bit Linear PCM stereo at 48 kHz sampling rate (768 kbit/s per channel, 1.5 Mbit/s stereo), or four nonlinear 12-bit PCM channels at 32 kHz sampling rate (384 kbit/s per channel, 1.5 Mbit/s for four channels). In addition, the DV specification also supports 16-bit audio at 44.1 kHz (706 kbit/s per channel, 1.4 Mbit/s stereo), the same sampling rate used for CD audio.[11] In practice, the 48 kHz stereo mode is used almost exclusively.

I cannot change settings on my digital camcorder anymore as the wheel is broken (confirm button by clicking on it is faulty and sending me back to display settings).

This is the PCIe TV card I am using:

Hauppauge WIN-TV-HVR-1200 TV Card

Would you agree to my statement on the difference in audio quality though? Or is it perhaps „normal“ for analog capture?

[Alwyn]

Hard to tell because the clips aren't the same. Can you repost with two clips showing exactly the same video, 10sec each?

The analogue capture certainly is "on spec": PCM, 16bit, 48khz, 1536kb/sec (check with Mediainfo).

[Bermuda1]

Hard to tell because the clips aren't the same. Can you repost with two clips showing exactly the same video, 10sec each?

The analogue capture certainly is "on spec": PCM, 16bit, 48khz, 1536kb/sec (check with Mediainfo).

Hi Alwyn, thanks for the help, once again. I reuploaded the videos showing exactly the same video 10 sec each. Any tool that you can use to check if one has "better" audio and/or less "hiss" / background noise / "buzz"ing sound?

Edit: I added a third video, from my previous captchures via VirtualDub. Due to audio/video sync issues, its not 100% exactly the same clip, but I also have the feeling that the audio is better here vs. the S-Video capture via AmarecTV. Or maybe I am just losing it by now

Thanks!

[dellsam34]

They all sound the same with the exact noise floor level expected from an analog tape of a low budget VCR or camcorder using a single analog mono audio track, DV has a slightly higher gain due to the nature of DV flow that uses automatic audio gain, So the winner would be the S-Video because it has the proper properties for audio which is 48Khz/16bit.

[Bermuda1]

They all sound the same with the exact noise floor level expected from an analog tape of a low budget VCR or camcorder using a single analog mono audio track, DV has a slightly higher gain due to the nature of DV flow that uses automatic audio gain, So the winner would be the S-Video because it has the proper properties for audio which is 48Khz/16bit.

Can you recommend a software or method to best reduce this noise level in post-processing?

[dellsam34]

I don't think it's worth the hassle but try the free Audacity.

[The_Doman]

I cannot change settings on my digital camcorder anymore as the wheel is broken (confirm button by clicking on it is faulty and sending me back to display settings).

Ah, understand.
Problems with the menu scroll wheel is a common problem with those Sony camcorders indeed.
Sony camera menu scroll problem
I had fixed my DCR-TRV120E menu wheel, which was jumping uncontrollable all over the place, by blowing it with some canned air.
But as i understand your scroll-wheel confirm button (pushing wheel down) does not work at all and you can not select/confirm anything?
That is annoying indeed.

But then even with 32Khz audio, i doubt you missing/notice much considering the analogue source tapes?
And you can easily convert the audio to the regular 48Khz when encoding.

[timtape]

They all sound the same with the exact noise floor level expected from an analog tape of a low budget VCR or camcorder using a single analog mono audio track, DV has a slightly higher gain due to the nature of DV flow that uses automatic audio gain, So the winner would be the S-Video because it has the proper properties for audio which is 48Khz/16bit.

Can you recommend a software or method to best reduce this noise level in post-processing?

I'm not clear to which noises you are referring. I hear a muffling of the piano sound for short periods, for maybe a second or so at a time. It's evident near the start and then the end of both clips. There's also a click towards the end of the clips.

The muffling sound is quite odd for a Video 8/Hi 8/ Digital 8 camera recording in my experience. More common are clicks, bangs and distortion. Do you know which type of camera initially shot this footage?

[Bermuda1]

They all sound the same with the exact noise floor level expected from an analog tape of a low budget VCR or camcorder using a single analog mono audio track, DV has a slightly higher gain due to the nature of DV flow that uses automatic audio gain, So the winner would be the S-Video because it has the proper properties for audio which is 48Khz/16bit.

Can you recommend a software or method to best reduce this noise level in post-processing?

I'm not clear to which noises you are referring. I hear a muffling of the piano sound for short periods, for maybe a second or so at a time. It's evident near the start and then the end of both clips. There's also a click towards the end of the clips.

The muffling sound is quite odd for a Video 8/Hi 8/ Digital 8 camera recording in my experience. More common are clicks, bangs and distortion. Do you know which type of camera initially shot this footage?

No clue what the original camera was. The „noise“ I am referring to is in the background. I now noticed it especially when there is not much talking or music. Will try to upload another clip. It’s a buzzing sound. Maybe normal for analog tapes though?!

[timtape]

They all sound the same with the exact noise floor level expected from an analog tape of a low budget VCR or camcorder using a single analog mono audio track, DV has a slightly higher gain due to the nature of DV flow that uses automatic audio gain, So the winner would be the S-Video because it has the proper properties for audio which is 48Khz/16bit.

Can you recommend a software or method to best reduce this noise level in post-processing?

I'm not clear to which noises you are referring. I hear a muffling of the piano sound for short periods, for maybe a second or so at a time. It's evident near the start and then the end of both clips. There's also a click towards the end of the clips.

The muffling sound is quite odd for a Video 8/Hi 8/ Digital 8 camera recording in my experience. More common are clicks, bangs and distortion. Do you know which type of camera initially shot this footage?

No clue what the original camera was. The „noise“ I am referring to is in the background. I now noticed it especially when there is not much talking or music. Will try to upload another clip. It’s a buzzing sound. Maybe normal for analog tapes though?!

Then yes we need to hear, obviously, an audio sample where "there is not much talking or music..." and where what you call the buzzing sound is most audible.

[dellsam34]

Only HiFi Stereo has a very low noise floor found in high end camcorders, VHS/VHS-C camcorders recorded linear mono audio like an audio tape recorder on the edge of the tape, Video 8 format recorded one channel mono AFM superior to linear audio but far from being HiFi.
What tapes are you converting? VHS-C or 8mm format?

[Bermuda1]

I reuploaded a passage where you can hear the background noise. Is it as you would expect? The DV seems less "noisy" / buzzing to me. No more difference between VirtualDub and AmarecTV for the S-Video capture though.

[dellsam34]

I don't think so, The DV being very low in specs the low frequency hum has been attenuated, S-Video workflow has captured the full spectrum of audio frequencies, therefore the hum is more audible, Both captured the mid-range frequency hiss equally. Just put into Audacity and low pass filter it or do noise reduction.

[Bermuda1]

I don't think so, The DV being very low in specs the low frequency hum has been attenuated, S-Video workflow has captured the full spectrum of audio frequencies, therefore the hum is more audible, Both captured the mid-range frequency hiss equally. Just put into Audacity and low pass filter it or do noise reduction.

Thanks for the feedback! Will do that!

[timtape]

I reuploaded a passage where you can hear the background noise. Is it as you would expect? The DV seems less "noisy" / buzzing to me. No more difference between VirtualDub and AmarecTV for the S-Video capture though.

Thanks for the quiet uploads. My elderly hearing cant hear it but a younger person might hear the high frequency buzzing/whistle which measures at about 15.5 kHz on the Spectrum Analyzer. The whistle is there on the analog capture but not on the DV capture. There may also be a little more of hum frequencies in the analog capture but most of the hum and random noise seems common to both captures so there's not a lot between them in that respect.

If needed, I would deal with the hum with - unsurprisingly - an audio Dehum tool such as from Izotope RX or Acon, but it may take a little time as there are multiple tones which may need to be filtered separately. The hums may just be from appliances in the room where the footage was shot. They may not be from the camera.

But also the noise is obtrusive here because there is so little going on sound wise in that shot. The baby doesnt speak. The closest thing I hear is a short, audible breath right at the end of the clip. Heavy handed denoising can easily wipe that breath out! So in the end, these sorts of 'cleanups' can be tradeoffs. If we're not careful we can make things worse.

Hope this helps, Tim

[timtape]

I don't think so, The DV being very low in specs the low frequency hum has been attenuated, S-Video workflow has captured the full spectrum of audio frequencies, therefore the hum is more audible, Both captured the mid-range frequency hiss equally. Just put into Audacity and low pass filter it or do noise reduction.

Unlike DV video which is mildly compressed, DV audio is uncompressed. It's most unlikely low frequency audio has been audibly attenuated at the camera's internal analog to digital converter and I see no sign of that on the spectrum analyzer.

As we know, S-video has nothing to do with audio. It deals only with the picture. There is no such thing as 'S-video audio' or 'SVHS audio'. Picture and sound are separate departments within the one overall system.

In any case, the higher the audio sample rate, the higher is the upper high frequency recording limit. The low frequencies remain untouched. As a rough guide, a sample rate of 32 kHz reaps an upper audio frequency limit of a little under 16 kHz, 48 kHz sample rate, a little under 24 kHz. Low frequencies are easy, especially for digital audio. It's the high frequencies which are information hungry.

[Bermuda1]

Got it. thanks. Ill try around a little bit with Audacity or the noise reduction in DaVinci Resolve. If I am not happy with it, I may just leave it as it is.

[dellsam34]

As we know, S-video has nothing to do with audio. It deals only with the picture. There is no such thing as 'S-video audio' or 'SVHS audio'. Picture and sound are separate departments within the one overall system.

I said S-Video workflow, jees do you think that I don't know what S-Video stands for? The DV setting he is using for audio are low 32KHz and probably 12bit, therefore not full spec and as such the camcorder processing of audio could be limiting audio frequencies to the bare minimum to save on bandwidth usually when recording in LP mode.

[timtape]

As we know, S-video has nothing to do with audio. It deals only with the picture. There is no such thing as 'S-video audio' or 'SVHS audio'. Picture and sound are separate departments within the one overall system.

I said S-Video workflow, jees do you think that I don't know what S-Video stands for? The DV setting he is using for audio are low 32KHz and probably 12bit, therefore not full spec and as such the camcorder processing of audio could be limiting audio frequencies to the bare minimum to save on bandwidth usually when recording in LP mode.

I know the OP has problems with a menu select switch but it would still make sense to check the manual of the OP's camcorder to see if there are user options for different internal audio sample and bit conversion rates. The link below worked for me. I only saw options for selecting say stereo, left or right tracks. Didnt see anything about selecting sample or bit AD conversion rates.

That model does play back analog 8mm tapes. My guess is for all 8mm/Hi 8 tapes, it would automatically convert to 48/16 stereo, regardless of whether a stereo or mono analog AFM track. But if a Digital 8 tape it would keep the sample and bit rate of the digital recording. I think it also allowed some choice in the case of choosing one of two stereo files, each at 32/12, but no choice over sample or bit rate. There may be other options I missed.


https://www.sony-asia.com/electronics/support/product/dcr-trv230e/manuals

[The_Doman]

I know the OP has problems with a menu select switch but it would still make sense to check the manual of the OP's camcorder to see if there are user options for different internal audio sample and bit conversion rates. The link below worked for me. I only saw options for selecting say stereo, left or right tracks. Didn't see anything about selecting sample or bit AD conversion rates.
https://www.sony-asia.com/electronics/support/product/dcr-trv230e/manuals

It is mentioned a few pages further in the manual.
Works the same as my DCR-TRV120E.
Annoyingly at the default/factory settings it is set to 32 kHz.
So when your settings/cmos battery is empty, it will always fall back to that settings again.


[Attachment 82266 - Click to enlarge]

[Bermuda1]

I know the OP has problems with a menu select switch but it would still make sense to check the manual of the OP's camcorder to see if there are user options for different internal audio sample and bit conversion rates. The link below worked for me. I only saw options for selecting say stereo, left or right tracks. Didn't see anything about selecting sample or bit AD conversion rates.
https://www.sony-asia.com/electronics/support/product/dcr-trv230e/manuals

It is mentioned a few pages further in the manual.
Works the same as my DCR-TRV120E.
Annoyingly at the default/factory settings it is set to 32 kHz.
So when your settings/cmos battery is empty, it will always fall back to that settings again.


[Attachment 82266 - Click to enlarge]

So do I understand correctly, that without getting the confirmation button fixed, no chance to get my camcorder to play back the tapes in 48khz mode?

[The_Doman]

So do I understand correctly, that without getting the confirmation button fixed, no chance to get my camcorder to play back the tapes in 48khz mode?

Well yes, if the confirmation/selection wheel-button is really doing nothing anymore?
Then the analog tape playback/pass-through is set on 12bit/32kHz audio.
Digital8 tapes of course will be played at original recorded audio mode.