Sclive Writes 48Khz Files No Matter What

[dellsam34]

I'm transferring some miniDV NTSC tapes with audio 32Khz 12bit on them and instructed Sclive to keep the same sampling frequency as the tape but it's producing files with 48Khz no matter what? resulting in a chipmunks audio playback for half of the video and no sound for the rest of it, even the Sclive app itself plays the files that way, Haven't tried WinDV yet. What am I missing?
The player is the Sony HVR-M15AU connected to the laptop's onboard iLink port with the original Win7 drivers.

[_Al_]

what kind of version is it? I used to use perhaps different, it says v 4.0

[_Al_]

image

[Cornucopia]

What happens when you FORCE it to 32kHz/16bit?


Scott

[dellsam34]

what kind of version is it? I used to use perhaps different, it says v 4.0

It's the latest found on their website after they pulled out the plug. I will check when I get home.

[DB83]

Not wishing to dis-believe what you write, how can you be certain that these tapes have 32 kHz 12 bit audio on them ?


What I find odd about that audio option within SC is that AFAIK 32 kHz 16 bit is not part of the DV spec (44.1 kHz 16 bit is) and I would have thought that to keep in spec and ensure proper playback only supported specs would be selectable - although I do believe that SC can transcode but I also guess you are not doing that.


But also did you record them or are merely transferring for a third party and the tapes have mixed audio which might explain the whole issue.

[aedipuss]

32khtz 16 bit was used on DVCAM tape, never saw a miniDV cam that used it though.

audio type mismatches are very common on reused tapes. there can be a frame or two of one type of audio, and then the real video starts and it's the other type of audio but the capture program has already locked into the wrong type and can't change. a way to get around it is to start the tape playing and not hit the start recording button until you're sure it's playing the right video/audio. that way the capture program locks on the first audio type it finds and it's the correct one. at any stops/breaks in the tape the audio could change again and you have to go through the same process for each mismatch.

[aedipuss]

put a checkmark in the scene detection box and have it start a new file for any audio/video changes. otherwise the capture will not play properly as once a file is started it's properties can't be changed by the capturing program.

[Cornucopia]

All the specs I've ever seen show (for both DV, DVCam, DVCPro): Audio can be 48kHz/16bit/2ch (preferred standard), 32kHz/12bit/4ch, or 44.1kHz/16bits/2ch. No 16bit for 32kHz. And it was always a bear trying to be able to choose WHICH 2 channels of the 4 it would capture (because I know of NO apps that can get all 4 channels). To get all 4 you almost always have to cap twice and then sync back up in post.
The thing about 16bit is very likely padding to full word length, which is where issues can happen if it isn't padded (with 0s last 4 LSBs) correctly.

Man I hate 32k audio!

Scott

[johnmeyer]

I may have an answer (see below), but to get to that answer, let me address the issue of 12-bit audio on MiniDV tapes

DV cameras can very definitely capture 12-bit. Here is a copy/paste from my Sony TRV-11 MiniDV camcorder User Manual:

Audio mode

12-bit mode: The original sound can be recorded in stereo 1, and the new sound in stereo 2 in 32 kHz. The balance between stereo 1 and stereo 2 can be adjusted by selection AUDIO MIX in the menu settings during playback. Both sounds can be played back.

16-bit mode; A new sound cannot be recorded but the original sound can be recorded in high quality. Moreover, it can also play back sound recorded in 32 kHz, 44.1 kHz or 48 kHz. When playing back a tape recorded in the 16-bit mode, 16BIT appears on the LCD screen or in the viewfinder.

In reading this, a light bulb went off: I'll bet the 32-bit audio is recorded on the second channel. Therefore, you need to click on, and put a check in, the "write other audio channel to separate WAV file" option (I see from your screen grab that it is not checked). Once you check that, re-capture and see if you don't get the 32-bit channel saved as a WAV file.

Years ago, just for grins, I did record a second channel and then captured both of them in SCLive. It worked.

[aedipuss]

agreed, it's not in any dv spec. but dvcam isn't really either. it runs at 2x tape speed and i've run into some pro dvcam decks that do 32khtz 16bit stereo.

[aedipuss]

I may have an answer (see below), but to get to that answer, let me address the issue of 12-bit audio on MiniDV tapes

DV cameras can very definitely capture 12-bit. Here is a copy/paste from my Sony TRV-11 MiniDV camcorder User Manual:

Audio mode

12-bit mode: The original sound can be recorded in stereo 1, and the new sound in stereo 2 in 32 kHz. The balance between stereo 1 and stereo 2 can be adjusted by selection AUDIO MIX in the menu settings during playback. Both sounds can be played back.

16-bit mode; A new sound cannot be recorded but the original sound can be recorded in high quality. Moreover, it can also play back sound recorded in 32 kHz, 44.1 kHz or 48 kHz. When playing back a tape recorded in the 16-bit mode, 16BIT appears on the LCD screen or in the viewfinder.

In reading this, a light bulb went off: I'll bet the 32-bit audio is recorded on the second channel. Therefore, you need to click on, and put a check in, the "write other audio channel to separate WAV file" option (I see from your screen grab that it is not checked). Once you check that, re-capture and see if you don't get the 32-bit channel saved as a WAV file.

Years ago, just for grins, I did record a second channel and then captured both of them in SCLive. It worked.

yes DV can have 4 channels. but they have to all be 12 bit 32 khtz.

[dellsam34]

not wishing to dis-believe what you write, how can you be certain that these tapes have 32 khz 12 bit audio on them ?

vvvvvvvvvv

[dellsam34]

Some of you guessed that the tape may have different audio sample rates. Yes, that's exactly what it is, The last recording on the tape is 16/48 and the beginning is 12/32 and who knows what is in the middle I didn't check the entire tape so I guess Sclive will read the entire transfer as 16/48 which makes the the 12/32 portion playback faster, I'm pretty sure there is a simple tool to re-sync audio but I will just go ahead and re-transfer the tape with the option convert all to 16/48, it is a voice audio so conversion will not do much harm. So I will report back after the transfer is done.

[johnmeyer]

I think aedipuss' idea in Post #8 will probably fix the problem: enable scene detection, which will create a new file each time the camera starts and stops. I strongly suspect that SCLive will be smart enough to change the audio when the next scene changes to a different audio sampling rate and bandwidth. If you eventually want a single file, it is trivial to combine them together, without any loss or re-encoding (one great thing about DV). You can either do this in your NLE (most support "smart rendering" for DV files) or I think you can use a DOS copy operation. There are lots of posts here about how to do that.

[Cornucopia]

Don't use DOS/binary copy for video files. Not a good idea, even if sometimes you can get away with it.

Also, not a good idea to combine diff samplerate audio into a larger file. That's kinda what got him in the first place. SRC to a common rate, then append with a proper muxing/editing tool.


Scott

[dellsam34]

Thank you guys, I just want to be able to capture one file, I don't mind converting sample rate on the fly, like I said it's voice so not worth the effort, From there I can encode to H.264 to match the other files from 8mm/Hi8.
I just checked the transfer and using the option to convert everything to 16/48 on the fly did the trick, Sweet.

[johnmeyer]

I just checked the transfer and using the option to convert everything to 16/48 on the fly did the trick, Sweet.

Andi, the SCLive author, did a great job on that utility. I still enjoy using it, on the rare occasion where I need to transfer DV tapes.