Sync problems converting videogame footage

[tokumaru]

Hi guys
I was experimenting the other day with my new DV camcorder and it's analog to digital feature, and decided to capture some clips of me playing one of my famiclones (clones of the japanese Nintendo Entertainment System, the FAMICOM). The video quality was very good and all, but the audio got out of sync after a while, it was going faster than the video. None of my other tests had this effect, only this one.

Then I remembered reading somewhere that the NES framerate wasn't the actual 29.97 fps of the NTSC standard. And the cause for this might be the 262 lines per field it outputs, instead of the 262.5 of standard NTSC. In theory, that would make the video run faster... But I have the audio going faster... Could this be the cause of the bad sync? Has anyone experienced anything like this?

[MpegEncoder]

Hi guys
I was experimenting the other day with my new DV camcorder and it's analog to digital feature, and decided to capture some clips of me playing one of my famiclones (clones of the japanese Nintendo Entertainment System, the FAMICOM). The video quality was very good and all, but the audio got out of sync after a while, it was going faster than the video. None of my other tests had this effect, only this one.

Then I remembered reading somewhere that the NES framerate wasn't the actual 29.97 fps of the NTSC standard. And the cause for this might be the 262 lines per field it outputs, instead of the 262.5 of standard NTSC. In theory, that would make the video run faster... But I have the audio going faster... Could this be the cause of the bad sync? Has anyone experienced anything like this?

This is a CLASSIC analog->digital passthrough problem. There is NO synchronization of the audio and video in the passthrough. So any time you capture this way, you will have to deal with it after the fact.

Personally, I just just VirtualDub to resync the video/audio and frame serve to TMPGEnc.

There is NO way around this with consumer DV camcorders.

[tokumaru]

Yeah, I used VirtualDub... I changed the framerate to 30.051 and it all got nicely sync'ed up. I just never heard of it before, and when I saw it got a little scared! =)

I got a little upset about having to drop frames in order to make compliant NTSC movies out of my game systems, but I got a nice suggestion in a NES forum: resample the audio to match the video. I think this is a better way out, as it is harder to screw up audio than video.

Thanks for the reply, I didn't know it was a CLASSIC issue! =)

[greymalkin]

i know some NES emulators have an option to record your game as a movie file..it might record at the same frame rate however..

[tokumaru]

i know some NES emulators have an option to record your game as a movie file..it might record at the same frame rate however..

Yeah, it is possible in many ways... but emulators are just not the way! In emulators, the sound is different, the colors are different... The real console outputs video as it was meant to in the first place.