Audio de-syncs the longer I record

[ZAV1010]

I have noticed that when I first push the record button the audio is synced, but as time goes on the audio becomes more and more de-synced. I do not know why this is happening. I am using the Stereo Mix to record the sound. Here is an example recording to show how the audio is de-syncing. https://www.youtube.com/watch?v=bSIabBC6xXE

[Squish Gaming]

This is a very common issue with real-time recordings. It's not an hardware problem, it's just the way the sound recording devices work that doesn't go too well in certain situations...

Fortunately, it can be easily fixed (well, for me it works at least). It's even easier if you already know your way in editing softwares. First, make sure that when you record, you start the audio and the video at the same time (if you record them separately of course, if you record them together, ignore this step).

Now, open your video/audio track in any editing software (i personally use Adobe Premiere Pro). Unlink the audio from the video (so the two tracks can be moved and edited separately). If your audio has the same lenght as your video in the editing program, you need to take an extra step.

ONLY if your audio has the same lenght as your video, check the audio wave-lenght. At some point near the end of the video, it should become completely flat until the end. Cut at that exact frame and delete what comes after (there should be no sound after anyway). This step is easier if your video ends with some sound (if your video ends quiet, it can cause accuracy problems).

After that extra step (if you had to do it), place the audio (that should be shorter than the actual video) at the very beginning of your track (so the beginning of the audio track is at the beginning of the video track), then use the option to resize the audio track (in Premiere, you right-click the track, then click size/lenght) so that the audio track have the exact same lenght as the video (that should be exact to the frame, anything less accurate than that and your audio will not feel synced enough).

The result MAY vary between programs, because they probably don't use the same algorithms. But in the case of Premiere, it keeps the audio untouched where the editing cursor line is at, and extrapolates from there, thus cancelling the problem you're experiencing right now.

I don't know if I was clear enough in my explanations (I'm not good to explain things, plus English is not my first language), but the way I tried to explain works all the time and I think it's the most professional and time-efficient way to deal with those awful sync issues. I hope you give it a try and hopefully solve your problem!

Squish Gaming

[Guest]

I have used the video editing software in the past for recordings from my friends' capture cards, but that is very time consuming. A two minute video can take up to 30 minutes of editing to re-sync and render. This is not convenient. I would like to push the record button and then the stop recording button and it be fully synced. My SIIG USB 2.0 capture card has no problem syncing the sound and video correctly so I don't understand why this shouldn't be able to do it either.

[ZAV1010]

I have used the video editing software in the past for recordings from my friends' capture cards, but that is very time consuming. A two minute video can take up to 30 minutes of editing to re-sync and render. This is not convenient. I would like to push the record button and then the stop recording button and it be fully synced. My SIIG USB 2.0 capture card has no problem syncing the sound and video correctly so I don't understand why this shouldn't be able to do it either.

I thought I was logged in when I was making the post, but this was my post. Sorry for any confusion.

[loopy]

No, it should not de-sync more over time. Definitely something I tested while writing the software. Describe how the video is being created, from start to finish.
What software are you recording with? What video codec? (version?) Are you editing the video afterwards? Is the original video also out of sync?

[ZAV1010]

I am using the software 3dscapture 3.2 located here http://3dscapture.com/3ds_capture.3.2.zip. I didn't do any editing. I uploaded the raw file to YouTube. I just rewatched the original file in VLC and it looks like there is no de-sync, but the YouTube version is de-synced on both my laptop in Chrome (runs on Windows 8) and my Android phone in the YouTube app.

In the software I have it set to save the video as Microsoft Video 1, which saves it as an avi file. The capture card hardware and software seems very high quality so I believe you did test and write it to not de-sync. For capturing the audio I use the Stereo-Mix.

Are there any known issues with YouTube and the raw video files?

[Squish Gaming]

I have used the video editing software in the past for recordings from my friends' capture cards, but that is very time consuming. A two minute video can take up to 30 minutes of editing to re-sync and render. This is not convenient. I would like to push the record button and then the stop recording button and it be fully synced. My SIIG USB 2.0 capture card has no problem syncing the sound and video correctly so I don't understand why this shouldn't be able to do it either.

Evn if my explanation was a bit long, doing the entire process takes about 10 minutes once you know what you're doing, and re-encoding a video of 3 hours takes me about 30 minutes (with 3DS screen resolution)... So it's not as time-consuming as you think it is. Like Loopy said, it could be the codec used for the original encoding. And from experimenting a lot in the past on this, I can confirm that it only happens with the avi containers.

My way sure isn't a 1-button click, but it works really well and may be used until you find a better solution.

[Squish Gaming]

Just to add that this is a recurrent problem when working with multimedia tracks.

http://www.afterdawn.com/guides/archive ... oblems.cfm

Your situation is scenario #2. The solution explained is exactly the same as what I'm suggesting you. This is a plague in live recordings, and it happens to everyone, from basic users to audio professionals.

[triple_lei]

I ran into this problem independently today (not with anything 3DS-related but with my Intensity Pro capture card). I searched online and found one solution using AviSynth thanks to the geniuses at SDA:

https://kb.speeddemosarchive.com/AviSyn ... dio_desync

Code: Select all

#Positive value stretches audio, negative value shrinks audio. Value in milliseconds.
stretch=-300
#Do not change the line below.
TimeStretch(tempo=(last.AudioLengthF/(last.AudioLengthF+(stretch*(last.audiorate/1000)))*100))

It's the one thing I always dreaded at the end of long captures. Now I have nothing to worry about! What can I say, it works! For what it's worth my raw capture in this example was nearly two hours with the audio playing later and later and I had to set it to "stretch=-1000".

[Guest]

Yeah, that's not normal bro. I did a 17 hour Pokemon X Marathon Nuzlocke and it was fine. No audio issue's what so ever.
Something is wrong with the capturecard or your setup. Probably setup.