Drift off of Canon XH-A1S at DVinfo.net

Benjamin Maas · December 1st, 2010, 11:28 AM

I posted this above in the canon sticky section, but i figured this might be more likely to be answered here:

I'm using PP CS5 to capture video from a borrowed XH-A1S. The tapes were recorded HDV (1080i) but I'm having a heck of a time getting them to capture properly.

The capture seemingly went without a hitch- no reported dropped frames or anything. However, once I placed the files into the Sequence, I had major drift issues compared to the 2 other cameras I was using (both Sony- NX5U and an MC50U) The two sonys were a frame or two off over 20 min- not horrible, but not great but somethng that is easily compensated for. However, the Canon was off by at least a second over 10 min or so.

Any idea what is causing this? Am I missing a setting somewhere?

This is really far out obviously and I need things in sync for 20 min or so at a time (I'm working with classical music so the pieces can be long). I know my NX5U can maintain sync over an hour or more compared to the audio I record at the same time.

Thanks for any help you can provide.

--Ben

Jay West · December 1st, 2010, 12:36 PM

I use a similar multi-cam set-up which includes an an XHA1, and NX5 and CX550 (the plain-Jane version of your M50).

I'll can offer a couple of suggestions for things to check or do, but it would help if you could be more specific about the problem.

First, are you using PPro CS5 to capture tape from your XHA1s or are you using a tapeless recording unit?

Are you having a problem with (a) losing synch between the multi-cam tracks or (b) losing synch between the XH audio and its video?

If you are experiencing problem (a), is the XH footage falling behind or running longer than the other cams?

I've run into both problems (a) and (b) and the solutions to each are different.

If you've got problem (a), and you are capturing to tape, and the captured XH footage is running shorter than the file footage from the NX and MC cams, then you've probably got some drop outs on the XH tape. My experience is that drop-outs in shooting will not be registered as "dropped frames" when using PPro to capture from tape. (PPro only registers the drop-outs that it creates in capturing.) Before I added an MRC unit to my XH, I often ran into this kind of problem with my concert and dance recital shoots. The good news is that having the XH track only a second out of synch means you've only got one or two drop-outs. You have to find the drop-outs, make cuts there and slide the XH back in synch. The best way I found to work with this kind of problem in PPro is to create a sequence, put a known good track (say from your NX) on track 1 and put your XH footage on track 2. If you've got good audio from both cams, you can scan the audio tracks to identify places where the XH seems to get ahead of the NX audio. Otherwise, you scroll through the video to try to locate the drop-outs. When you find them, make a cut and slide the remaining XH footage to the right until it is back in synch. That will probably be 15 or 16 frames. I have seen a couple of 45 frame dropouts, though. When you have everything in synch, you can drop the XH footage from track 2 to overwrite track 1 (which avoids gaps) or simply delete track 1. Nest that sequence in place of the XH track for your mutli-cam set-up sequence.

If you have got problem (b) --- that is, losing audio synch --- and you are capturing from HDV tape from your XH, my work around was to use another application for capturing. I had audio synch problems when capturing from HDV tape through CS3. I used HDVSplit and Cineform to avoid that problem. HDVSplit is a free utility for the PC if that is what you are editing on. Google it and you'll find some free download sites.

I got rid of both problems (a) and (b) when I got a tapeless recording unit for my XH.

If your XH tape footage is running longer than your NX and MC footage or if you are already running your XH into a tapeless unit, I haven't got a clue.

Bill Engeler · December 1st, 2010, 01:17 PM

I second the dropout theory. It happens with my XHA1 about once every other tape. As I recall, CS4 would put in some red frames when it detected a dropout - you couldn't miss that! CS5 seems to handle it differently, but the dropout remains, and sync with other cameras is messed up.

Benjamin Maas · December 1st, 2010, 02:34 PM

I should have been more clear...

Canon camera is going to tape, not a nonlinear format. The sync issue is between the canon and the Sony cameras. Basically, over the first piece on the program, the Canon's footage was over a second shorter than the Sony cameras (which are both flash- AVCHD cameras)

If Premiere isn't going to tell me where these possible dropouts are, how do I find them? On a quick look at the video, it seems pretty smooth- certainly nothing huge that would cause a solid second or so of difference between the cameras.

--Ben

Bill Engeler · December 1st, 2010, 04:15 PM

I would put the two shots together on a timeline and sync the start. Scrub forward until sync is lost. I suspect it will be sudden. Move back to where it is ok, then forward until you find the spot where the sound changes. It should take about 2 minutes.

Jay West · December 1st, 2010, 10:57 PM

To add to what Bill said and repeat a bit of my earlier post, the easiest way I've found for locating a drop out point is to: (a) make a sequence; (b) synch a good track (NX5, say) with the XH track and (c) look at the audio tracks. If you've got good audio from both cams, you should be able to scroll along and spot the point where they diverge, and that will be your drop out. Otherwise, scroll to a point ¼ of the way in your 20 minute segment. Check the video. Are they still in synch? If not, your first drop out is back closer to the beginning. If they are in synch, your drop out will be further on. Go to the half-way point (half-way back if it is towards the beginning, halfway to the end if it is beyond your first check point). Keep checking like that and you'll find it.

Your drop out is going to be a 15 frame (½ second) skip. Might be larger, like a full second. The reason is that HDV uses 15 frame GOPs. Where a drop out with SD would give you a one frame (1/30th second) glitch, you lose a whole GOP with an HDV drop out. It may be 2 GOPs, which would account for the whole second.

Benjamin Maas · December 2nd, 2010, 11:08 AM

Thanks so much for your info. I'll give it a try and see what happens. I may also try another load- I remember from my days with DAT tapes that a playback may have an issue, but redoing it ends up fixing it. Don't know if DV tapes are the same way.

I also appreciate the description of how HDV works on these cameras- I am still quite new to video so I have a lot to learn about the tech side of things. If dropouts are going to be an issue, I may encourage the owner of the camera to go with a disc-based system for future shows. I think in the long run, it will make everybody's life easier.

--Ben

Benjamin Maas · December 2nd, 2010, 01:29 PM

Turns out that is exactly what happened- and I was wrong- it was closer to a second and a half. Guess there was just a bad spot in the tape. Took me a couple minutes to find it, but once I did I was able to get everything back in sync without issue.

thanks for your help everybody.

--Ben

December 1st, 2010, 11:28 AM	#1
Benjamin Maas Regular Crew Join Date: Jul 2010 Location: Long Beach, CA Posts: 150	Drift off of Canon XH-A1S I posted this above in the canon sticky section, but i figured this might be more likely to be answered here: I'm using PP CS5 to capture video from a borrowed XH-A1S. The tapes were recorded HDV (1080i) but I'm having a heck of a time getting them to capture properly. The capture seemingly went without a hitch- no reported dropped frames or anything. However, once I placed the files into the Sequence, I had major drift issues compared to the 2 other cameras I was using (both Sony- NX5U and an MC50U) The two sonys were a frame or two off over 20 min- not horrible, but not great but somethng that is easily compensated for. However, the Canon was off by at least a second over 10 min or so. Any idea what is causing this? Am I missing a setting somewhere? This is really far out obviously and I need things in sync for 20 min or so at a time (I'm working with classical music so the pieces can be long). I know my NX5U can maintain sync over an hour or more compared to the audio I record at the same time. Thanks for any help you can provide. --Ben __________________ Benjamin Maas • Fifth Circle Audio • Signal Hill, CA http://www.fifthcircle.com

December 1st, 2010, 02:34 PM	#4
Benjamin Maas Regular Crew Join Date: Jul 2010 Location: Long Beach, CA Posts: 150	I should have been more clear... Canon camera is going to tape, not a nonlinear format. The sync issue is between the canon and the Sony cameras. Basically, over the first piece on the program, the Canon's footage was over a second shorter than the Sony cameras (which are both flash- AVCHD cameras) If Premiere isn't going to tell me where these possible dropouts are, how do I find them? On a quick look at the video, it seems pretty smooth- certainly nothing huge that would cause a solid second or so of difference between the cameras. --Ben __________________ Benjamin Maas • Fifth Circle Audio • Signal Hill, CA http://www.fifthcircle.com

December 2nd, 2010, 11:08 AM	#7
Benjamin Maas Regular Crew Join Date: Jul 2010 Location: Long Beach, CA Posts: 150	Thanks so much for your info. I'll give it a try and see what happens. I may also try another load- I remember from my days with DAT tapes that a playback may have an issue, but redoing it ends up fixing it. Don't know if DV tapes are the same way. I also appreciate the description of how HDV works on these cameras- I am still quite new to video so I have a lot to learn about the tech side of things. If dropouts are going to be an issue, I may encourage the owner of the camera to go with a disc-based system for future shows. I think in the long run, it will make everybody's life easier. --Ben __________________ Benjamin Maas • Fifth Circle Audio • Signal Hill, CA http://www.fifthcircle.com

December 2nd, 2010, 01:29 PM	#8
Benjamin Maas Regular Crew Join Date: Jul 2010 Location: Long Beach, CA Posts: 150	Turns out that is exactly what happened- and I was wrong- it was closer to a second and a half. Guess there was just a bad spot in the tape. Took me a couple minutes to find it, but once I did I was able to get everything back in sync without issue. thanks for your help everybody. --Ben __________________ Benjamin Maas • Fifth Circle Audio • Signal Hill, CA http://www.fifthcircle.com

December 1st, 2010, 12:36 PM	#2
Jay West Major Player Join Date: Mar 2010 Location: Red Lodge, Montana Posts: 889	I use a similar multi-cam set-up which includes an an XHA1, and NX5 and CX550 (the plain-Jane version of your M50). I'll can offer a couple of suggestions for things to check or do, but it would help if you could be more specific about the problem. First, are you using PPro CS5 to capture tape from your XHA1s or are you using a tapeless recording unit? Are you having a problem with (a) losing synch between the multi-cam tracks or (b) losing synch between the XH audio and its video? If you are experiencing problem (a), is the XH footage falling behind or running longer than the other cams? I've run into both problems (a) and (b) and the solutions to each are different. If you've got problem (a), and you are capturing to tape, and the captured XH footage is running shorter than the file footage from the NX and MC cams, then you've probably got some drop outs on the XH tape. My experience is that drop-outs in shooting will not be registered as "dropped frames" when using PPro to capture from tape. (PPro only registers the drop-outs that it creates in capturing.) Before I added an MRC unit to my XH, I often ran into this kind of problem with my concert and dance recital shoots. The good news is that having the XH track only a second out of synch means you've only got one or two drop-outs. You have to find the drop-outs, make cuts there and slide the XH back in synch. The best way I found to work with this kind of problem in PPro is to create a sequence, put a known good track (say from your NX) on track 1 and put your XH footage on track 2. If you've got good audio from both cams, you can scan the audio tracks to identify places where the XH seems to get ahead of the NX audio. Otherwise, you scroll through the video to try to locate the drop-outs. When you find them, make a cut and slide the remaining XH footage to the right until it is back in synch. That will probably be 15 or 16 frames. I have seen a couple of 45 frame dropouts, though. When you have everything in synch, you can drop the XH footage from track 2 to overwrite track 1 (which avoids gaps) or simply delete track 1. Nest that sequence in place of the XH track for your mutli-cam set-up sequence. If you have got problem (b) --- that is, losing audio synch --- and you are capturing from HDV tape from your XH, my work around was to use another application for capturing. I had audio synch problems when capturing from HDV tape through CS3. I used HDVSplit and Cineform to avoid that problem. HDVSplit is a free utility for the PC if that is what you are editing on. Google it and you'll find some free download sites. I got rid of both problems (a) and (b) when I got a tapeless recording unit for my XH. If your XH tape footage is running longer than your NX and MC footage or if you are already running your XH into a tapeless unit, I haven't got a clue.

December 1st, 2010, 01:17 PM	#3
Bill Engeler Regular Crew Join Date: Aug 2006 Location: Brussels, Belgium Posts: 162	I second the dropout theory. It happens with my XHA1 about once every other tape. As I recall, CS4 would put in some red frames when it detected a dropout - you couldn't miss that! CS5 seems to handle it differently, but the dropout remains, and sync with other cameras is messed up.

December 1st, 2010, 04:15 PM	#5
Bill Engeler Regular Crew Join Date: Aug 2006 Location: Brussels, Belgium Posts: 162	I would put the two shots together on a timeline and sync the start. Scrub forward until sync is lost. I suspect it will be sudden. Move back to where it is ok, then forward until you find the spot where the sound changes. It should take about 2 minutes.

December 1st, 2010, 10:57 PM	#6
Jay West Major Player Join Date: Mar 2010 Location: Red Lodge, Montana Posts: 889	To add to what Bill said and repeat a bit of my earlier post, the easiest way I've found for locating a drop out point is to: (a) make a sequence; (b) synch a good track (NX5, say) with the XH track and (c) look at the audio tracks. If you've got good audio from both cams, you should be able to scroll along and spot the point where they diverge, and that will be your drop out. Otherwise, scroll to a point ¼ of the way in your 20 minute segment. Check the video. Are they still in synch? If not, your first drop out is back closer to the beginning. If they are in synch, your drop out will be further on. Go to the half-way point (half-way back if it is towards the beginning, halfway to the end if it is beyond your first check point). Keep checking like that and you'll find it. Your drop out is going to be a 15 frame (½ second) skip. Might be larger, like a full second. The reason is that HDV uses 15 frame GOPs. Where a drop out with SD would give you a one frame (1/30th second) glitch, you lose a whole GOP with an HDV drop out. It may be 2 GOPs, which would account for the whole second.