Neo Scene- Sound out of Synch
 

Okay, I've heard others complain randomly about it, but today I got a taste of it for myself. It is really not creating acceptable results. I did about a 4 minute straight capture, and a quarter of the way through the converted .avi clip, things have gotten out of line. By the end of the clip things are badly out. This is footage from my Canon 5DMarkII. I edit with Vegas and I have to try to jocky the sound clip to match.

Have I missed something, in terms of uploading some sort of encoder? My understanding was that this version of NeoScene was self contained. By the way, the .mov clip is in solid synch, so I do not think it is anything other than the transcoding process that is causing the problem.

Chris, *usually* this is a problem with performance on your machine. It could be CPU or a fragmented drive. The quickest test is to select the "Desktop Playback - Fast" option in the Cineform --> Tools directory under Start Menu.

This tells the CineForm decoder to play back the file using 1/2 horizontal and 1/2 vertical resolution, a very cool Wavelet trick. It also minimizes CPU usage.

Give this a try and report back.

Hey David. I selected the Fast Playback option, and the system confirmed I had invoked it. Playback using Media Player Classic still showed the synch issue without change. I also played in Media Player same issue.

The reason this does not seem like a playback issue is because I actually have to dissect voice track to synch up on the Vegas time line. I did wonder if it was due to converting to High Quality, but same occurred in low quality setting.

The two files are a 1.5g .mov file and a 3.5 g .avi. I guess I could try to upload somewhere so you guys could see difference between two... I don't have a server to do that with.

I guess I should submit a ticket ??

Is it possible this has something to do with different frame rate 30 FPS v. 29.97 or some issue like that ?

Unless Canon doesn't know their own hardware, the 5D2 shoots video at 29.97 fps. The MOV file incorrectly has the frame rate in the metadata at 30.00 fps. If an NLE uses this information, things could be goofy. Some do and some don't. See part of the discussion in this recent thread:

http://www.dvinfo.net/conf/canon-eos...2-minutes.html

Yeah, but my .mov file is in synch. Int plays in synch in QT. Its the transcoded Cineform file that is out of synch. That seems to be a trancoding issue, doesn't it ?

One would think so. Unfortunately, I have NEO HD, so I can't help. I installed the demo of NEO Scene on of one my other computers, just to play around with it, but unfortunately, now the demo has expired.

Although all files except the 5D2 MOV files convert to CFHD files of the same duration, I did notice (since you asked) that a 5D2 MOV file is slightly longer in duration than the transcoded CFHD AVI file. Here's some examples of track durations on an Premiere CS3 29.97 timeline:

x.MOV (original 5D2 file) - 11.24 sec.
x.MOV (edited 5D2 file, so the metadata frame rate is 29.97) - 11.24 sec.
x.AVI (original 5D2 MOV transcoded to CFHD) - 11.22 sec
x.AVI (metadata edited MOV transcoded to CFHD) - 11.22 sec.

The ratios of the durations are suspiciously close to the ratio of 29.97 to 30.00 (1000:1001), but that may be a coincidence.

Try lining up the MOV and transcoded AVI files in your NLE and see what you come up with.

I have observed this too but I haven't had time to fully analyze what I've seen yet, so I haven't posted my findings here. I'm in the middle of building a new system and have temporarily borrowed a few components from my video editing system so I won't be able to look back into it for a few days. But on several of my longer clips I have seen a very noticeable loss in synch on the transcoded files. I haven't decided on a methodology to use to experiment and determine what the problem is.


Chris, have you filed a troubleticket with cineform yet?

Keith, if you check out the posts here:

http://www.dvinfo.net/conf/canon-eos...editing-7.html

I've dones some experimenting with the suggestions made by Yang Wen, and it is clear that the Cineform video portion of the transcode file goes out of synch with the original 5D generated .mov- at least in my file example. Sound generated for the .avi file does synch up with the original, but in my 5 minute clip, at least, there is a "rogue" clip of sound/noise insterted at the end for about 8 frames to make the length of the sound track match up with the video.

In Vegas, I was able to synch the sound by adjusting length of video track- but that demands another whole reincode and does who know what to the whole 30p thing...

Waiting for some word from Cineform.

I did not file a ticket, because this does not appear to be problem on my end, but in the reencoding process itself.

My guess is that there are a few dodgy problems with the 5D2 MOV files. They may be 30.00 fps or they may be 29.97 fps. They have a kind of QT audio track that is also somewhat unusual for Windows-based systems. They have a very high video bit rate. Canon certainly didn't do all their homework, when they decided on the 5D2 file format.

If Canon Support thinks the 5D2 files have a frame rate of 29.97 fps, but the general video community isn't sure, no wonder 3rd party software developers can't figure out how to work with the files.

Jay:

My testing shows it should be obvious to the third party. The Canon QT .mov file before encoding has equal length video and sound files. Every thing is in synch. The third party need only assure its file does the same. Problem with Cineform process is it ends up with a temporally longer Video file. My testing shows about 1/4 of second difference over a five minute file. And for some reason, since their audio track encodes or is ripped and copied at the same length as the QT file, Cineform adds a rogue noise audio track at the end.

More experimenting
 

Chris,

In NEO HD, you can convert to Cineform in a MOV wrapper. I just tested this out and the durations of the original 5D2 MOV file & the converted CFHD MOV file are identical. Whatever is going wrong, has to do with rewrapping the file as AVI. I'd probably file a support ticket with Cineform on your NEO Scene "sync"problem, if I were you. As I said before, I have never seen this issue with any other file conversion done by any Cineform software. It seems to be isolated to the 5D2 MOV file being converted to a Cineform AVI.

Jay

David Taylor said to report back here, and thats what I have done. There is a short term work around-- you stretch the audio, or shrink the video track in Vegas (I would probably choose audio because of the render issues. In meantime, I suspect, because of the utter silence, they are looking into the issue. If I don't hear back in a day or two, I will go ahead and file a ticket.

Fix is here
 

David Newman posted a new beta addressing this issue. I have checked it out, and it appears that they have resolved the synch issue. Thanks Cineform crew for addressing that !