Is it true that if I capture on low volume then the Audio will be better?

[gil900]

Hello.

i have the easycap device and i capture a VHS video with it.

there is a problam that i get a noise in my Audio when i capture the video with easyca.
i know haw to make it better by Audacity but there is Something I do not understand ..

im trying some small settings in my device and i can Lower the capture volume Through the normal settings of Windows.
I have a feeling (I'm not sure about this.'s Why I'm asking here) that if Lower the capture volume so i get lees noise.

i can't be Sure about this.. i want to ask here if someone with More experience can give me an answer about this.

Anyway, if I lower the capture volume then i have a low volume Audio.
How do I change the volume to the correct volume standard?
i even don't know what is the "standard"


thanks for the helpers!

[jagabo]

Low capture volume won't reduce noise (relative to the signal) unless the sound is overmodulated. Then you will get less noise from the distortion.

[gil900]

i found that on 100% capture volume i get some other problem when someone Scream or there is a huge Sound.
i can't describe this phenomenon but the closest Description is that part of the high sound(like someone screaming) is "Breaking".

i found that if i capture on a last 20% volume than this phenomenon not happening.
there is no way to solve this Specific problem by filtering or Processing. this is like burned image but not image.. sound.

i still don't know what is the standard volume. after i capture the audio on low volume, i need to change the volume to standard volume.
or i don't need to do this?

[jagabo]

i found that on 100% capture volume i get some other problem when someone Scream or there is a huge Sound.
i can't describe this phenomenon but the closest Description is that part of the high sound(like someone screaming) is "Breaking".

Yes, that is over modulation. You need to avoid that at all costs as there is no way to fix it later.

i still don't know what is the standard volume. after i capture the audio on low volume, i need to change the volume to standard volume.
or i don't need to do this?

Generally, you want to capture so that the loudest sounds don't over modulate. Sometimes you'll want to compromise and let the loud parts over modulate a little. Or you can "ride the pot" -- adjust the volume manually while recording, setting it louder when sounds are soft, lower when sounds are loud.

[gil900]

OK thanks.. this started to happen because i replaced my old Video Machine with new one that support Stereo.

do you Recommend to Stay with the same settings on all other tapes because it is the video Machine?

[jagabo]

do you Recommend to Stay with the same settings on all other tapes because it is the video Machine?

No, there may be differences in the volume level on different tapes, depending on what they are records of and what deck was used to record them. So you should adjust the recording level for each tape.

[gil900]

do you Recommend to Stay with the same settings on all other tapes because it is the video Machine?

No, there may be differences in the volume level on different tapes, depending on what they are records of and what deck was used to record them. So you should adjust the recording level for each tape.

Thank you!
It really helped me ..
I did not expect such an answer.

But I'm afraid it will not be easy to decide again and again about the volume on each tape ..
Do you have some tips for how to decide about the volume on each tape to make the process faster ?

[jagabo]

Do you have some tips for how to decide about the volume on each tape to make the process faster ?

Does the software you use have VU meters to monitor the volume level? If not, all I can suggest is go by ear -- just listen for distortion while you capture. Of course, if the distortion is on the tape you won't be able to work around it by adjusting the volume level. You can also load the audio into an audio editor and check the wave forms.

Too low:


Good:


Too high:

[gil900]

Do you have some tips for how to decide about the volume on each tape to make the process faster ?

Does the software you use have VU meters to monitor the volume level? If not, all I can suggest is go by ear -- just listen for distortion while you capture. Of course, if the distortion is on the tape you won't be able to work around it by adjusting the volume level. You can also load the audio into an audio editor and check the wave forms.

Too low:

[Attachment 16279 - Click to enlarge]

Good:

[Attachment 16280 - Click to enlarge]

Too high:

[Attachment 16281 - Click to enlarge]

i have this software. but to get the closet to "good", i need to set the volume level to 100%.
and this settings was not good. so it can't be Sign for adjusting the volume.

but Anyway that gave me the answer About what should be the standard volume.

[Cornucopia]

A simple analog meter in line between the "video machine" deck and the capture box (easycap - uugghh!! why am I not surprised?) will go a long way to maintaining the correct gain structure. Something like this (which would also allow adjustment of the gain: http://www.fullcompass.com/product/388885.html?utm_source=googleps&utm_medium=shopping...FSNqMgodoC4AaA

And NO, you should NOT be riding the levels at this stage in the game (that's appropriate for original studio recording or for mixdown, or for live sound, not for "transfers" - you would be destroying the intended artistic style of the program, like putting an AGC/Auto-iris on a finished movie!). Go to the loudest point in the program, set the level for just below clipping, and leave it there for the length of the program.

Scott

[gil900]

Cornucopia, what do you meen by "you should NOT be riding the levels at this stage in the game"?

and i trying now my sound card laptop divice for the Audio capture Instead of the easycap.
the easycap will be only for the image capturing..
if you say that it is "simple analog meter" so this is the Cheapest Idea and analog meter.
i hate to pay 120$ just for this analog meter.
(120$ is not really simple as you say)

i will update if it is better

[hello_hello]

In theory, the graphs jagabo posted are perfectly correct, so if a waveform similar to the middle one causes the loudest parts to distort, you'll probably need to set the volume by ear. There may be some sort of level mismatch happening, which in theory you'd probably fix by adjusting the output level from the video machine (I'd assume lowering it in your case) while also adjusting (increasing) the input level on the PC until you can get close to the "middle" waveform without hearing distortion. If you can't adjust the output level from the video machine then you'll just need to lower the input level on the PC to get it as close as you can.
An obvious type of level mismatch might be outputting a "line level" audio signal to the PC while the PC's input is set to expect a "mic level" signal or it's connected to a microphone input in the PC. If that was the case the loud parts may continue to distort a little no matter how much you lower the input volume on the PC. Simply put, I guess you could say a level mismatch might overload the hardware on the input side long before the audio reaches the theoretical maximum level (jagabo's middle graph). If there's no level mismatch anywhere in the chain, then the middle graph is exactly what you should be able to achieve. I guess in theory the same thing can happen the other way around too... the output device's hardware may distort the audio because it can't deliver enough level for the input device. A little like increasing the volume of an amplifier until it begins to distort the signal. Hopefully that makes sense....
It seems Cornucopia's already suggested a device to put between the output and input to keep both sides of the audio chain happy if need be.

Without knowing what sort of video you're capturing, I'd tend to agree with not riding the levels while capturing as obviously you're changing the volume as you do.
I assume the noise you refer to is included in the audio you're trying to capture, so by turning it up and down as you go it'll also turn the noise up and down at the same time, so the audio/noise ratio wouldn't really change. If the noise was being introduced some other way (it doesn't seem likely unless there is quite an output/input mismatch) adjusting the volume as you capture might be worth it, as then you'd be more likely to be increasing the audio you want relative to the noise you don't during the quieter sections.
It'd probably be best to find the loudest section of audio, set the level so it doesn't distort due to being too loud, and then capture it all at that level. After it's captured you can load the audio into some sort of editor (ie Audacity) in order to remove some of the noise, and even compress it, but at least you're working with the original audio rather than a version which has been manually turned up or down while hoping to get it right.

I don't do much video capturing but I have captured the odd VHS tape now and then by connecting the old VHS player to the WinFast capture card. I think with a halfway decent capture card you'd be far less likely to have this sort of problem.

[Cornucopia]

Cornucopia, what do you meen by "you should NOT be riding the levels at this stage in the game"?

and i trying now my sound card laptop divice for the Audio capture Instead of the easycap.
the easycap will be only for the image capturing..
if you say that it is "simple analog meter" so this is the Cheapest Idea and analog meter.
i hate to pay 120$ just for this analog meter.
(120$ is not really simple as you say)

i will update if it is better

I mean just what I said:

Go to the loudest point in the program, set the level for just below clipping, and leave it there for the length of the program.

That means, once you know where the max should be (which you do by going to that max and testing out which is the top level that DOESN'T clip), that setting should be left during the course of the whole capture of that program. Reset & redo for EACH program.

If the easycap is anywhere near decent, it should be using consumer line level on the RCA inputs, just like the consumer line level being output from your "video machine" (Model#??? btw).

That "analog meter" is more than that: it's a little mini mixer as well. This would give you the chance of boosting or dimming the audio separately from the capabilities of your "video machine". That's why it costs a little more. I'm sure you can find other less expensive models, including some that JUST have the metering, but I don't need to be doing the looking for you. That was just ONE EXAMPLE.

@hello_hello, I would have agreed with the assessment of the possible gain mismatch if one were using a stock soundcard input, but from the OP's words it was clear that the original attempt used the easycap device, which, like I just said, should have been expecting standard Consumer Line Level (just exactly what OUGHT to have been coming out the the OP's "video machine").

There are lots of variables here which won't get ironed out until the OP starts using Troubleshooting101 and clarifying/referencing each isolated piece in the chain.

This is one of those areas where an educated understanding of "optimal gain structure" separates the men from the boys, audio-wise.

Scott

[gil900]

OK.. I tried to record with the PC card device and with the easycap device.

this is the Results:


is that tell you Something?

what is Better?

i think i hearer the same noise but in the laptop it may higher


EDIT:

by what hello_hello wrote, i understand that the laptop card is better.
I correct?

[hello_hello]

In theory the laptop card waveform is closer to optimal.

Assuming the "noise" you refer to wasn't there, then ideally the closer the audio peaks are to maximum without being "clipped" the better, because that'd give you the best signal to noise ratio (noise being any introduced by the hardware itself, which should be so low it's not really a factor).

However if you're simply recording noise that's already on the tape then it's effectively part of the signal you're recording so the audio/noise level won't really change according to the volume at which you record.

The perceived relative level can change quite a bit according to the listening volume, so in order to compare the two more effectively I'd use Audacity's normalising function to raise the peaks of both to maximum level (or adjust the volume of one until they both sound like their volumes are the same) and then listen for differences. That way the PC/sound card is also amplifying both by the same amount so any noise added while amplifying the recorded audio stays constant each time.

It's even possible one method may record a wider range of frequencies, or have a flatter frequency response than the other, and sound nosier as a result because it's recorded a noisy signal more accurately, although hopefully that's not the case. The visual stuff can help to work out why you hear what you do, but ultimately I'd go with my ears, given I don't listen to audio with my eyes all that often.

[gil900]

yes, the noise is in the tape.. I checked it.
so i will use the laptop card for capture.

i found this guide with your words("normalising function"):


it may halp me

[jagabo]

Using a separate audio capture device along with a video capture card is a recipe for sync problems. Using the video capture card's own audio ports is usually safer.

[gil900]

Using a separate audio capture device along with a video capture card is a recipe for sync problems. Using the video capture card's own audio ports is usually safer.

but i have no problem to do this on Debut Video Capture Software


If you thought that i Recording the audio on other software and the video on this software so it may right but this is not the case
I checked it and everything is fine

[jagabo]

When both the audio and video are captured by the same device they use a common clock for timing so they can get precise results. Different devices will be using different clocks for their timing. That can lead to the audio and video drifting out of sync over time. All you can do is try capturing some long videos and see what happens.

[gil900]

OK i will test it and see if it.. thanks for the warning

Do you have some tips for how to decide about the volume on each tape to make the process faster ?

Does the software you use have VU meters to monitor the volume level? If not, all I can suggest is go by ear -- just listen for distortion while you capture. Of course, if the distortion is on the tape you won't be able to work around it by adjusting the volume level. You can also load the audio into an audio editor and check the wave forms.

Too low:

[Attachment 16279 - Click to enlarge]

Good:

[Attachment 16280 - Click to enlarge]

Too high:

[Attachment 16281 - Click to enlarge]

if i change the Audio to the "good" then i have a problem in VLC Media Player when i change in this player the Volume to the max ( 200%) but up to 100% the sound is OK.

if i make audio in Audacity that his volume level is up to 0.5#? so the problem Does not occur even on the Max volume on VLC Media Player.

when i say "problem" i mean to the problem that i Described in #3 and you call it "over modulation".
i found that the "over modulation" was Occurs in the player and not really happen in the file.

But i have a question -
this does not happen when the volume is up to 0.5#? in Audacity.
it happen only if the sound on Audacity is up to 1.0#? (what you called as "good" in the image)

So what do you say?
do i need to set it to up to 1.0#? in Audacity although this problem?
i just need to be sure...

[jagabo]

if i change the Audio to the "good" then i have a problem in VLC Media Player when i change in this player the Volume to the max ( 200%) but up to 100% the sound is OK.

Of course. VLC at 200 percent plays the audio back twice as loud as intended. The result is the same as if you recorded the sound twice as loud and play back at 100 percent. As you've seen, if the peak volume of the audio is over 50 percent, doubling it at playback will cause peaks to be clipped.

Here's an example of three channels from a commercial DVD with 5.1 audio:



As you can see, it has peaks all the way up to the max. But some may not have such high peaks. TV shows tend to have a smaller dynamic range.

[gil900]

the reason way i am asking about it is because this is the first time that i get this problem in VLC on 200% sound.
so i think that something is not ok..

this is how the audio look in my case:


i make it by the "Amplify..." in Audacity.
i hope that i did ok

so is that ok? or i did wrong?

[jagabo]

Anywhere in that range is fine.