I'm grading a project which started with beginner aspirations in my first avid days, using the default setting (115) for dnxhd sample rate for ingesting AVCHD video from a Canon XA1, and I'd now like to substitute the clips on the timeline with dnxhd 175 versions, which I will need to reingest at that setting. Perhaps someone on the forum can say if XA1 HD AVCHD can even benefit from the higher quality. The delivery method is eventually projection.

If it's of value to do this, reingesting will create new master clips, I assume with the same names as the original master clips, and if dynamic relinking is set up as I think I understand it from the manual, I will then have the choice of using either quality versions on the timeline.  I am assuming that subclips will also update to the higher quality versions if settings are right.

This seems like a delicate procedure about which I'd like to be sure before I try. I will be doing some tests on dummy projects.

I would welcome any advice on this, what pitfalls to avoid, and what functions to pay particular attention to.

 

Sheesh. Been so long since I ingested the material for this project that I'd forgotten that I appear to have done so directly from tape -- I'd even forgotten that it wasn't solid state media. There's no way reingested video will resync. 115 will have to do. Still, if anyone has any comments I'll listen. ;-)

djhg:

There's no way reingested video will resync

If the original tape based capture used machine control and TC (or was through Firewire) just duplicate your timeline into a new bin , select it and choose "Batch Capture"

It is mechanical and significantly slower than re-linking but has been a more bullet proof workflow since the very first Avid was sold.

That's impressive...  Thankyou Andrew.  So all I need is do as you say with any tape-based camera.  Can you tell me how changing tapes works?

I'll be in trouble if I didn't prestripe those tapes... It was a while ago and I don't think I did for every tape... But I suppose I can browse to the right shot and tell it to start there...

I take it there would be a noticeable improvement from 115 to 175?

 

What is the format of the tapes?  That may or may not be the most critical issue.  Some formats had timecode, some did not.

Assuming they did have time code, did whoever originally captured them change tape numbers with each tape?  And hopefully the tapes are labeled with those numbers?

Often, new users would not do this critical step and every tape would be called "1" (or such).  And every tape would have the same timecode as well.  If this is the case, then it is eye match time.

Jef

 

Thanks for your thoughts.

They're Canon AVCHD. THere's definitely time code. The tapes are numbered and the 115-ingested master clips are named with that number, but I'm sure I didn't make  time to prestripe them all. I'm sure it was for that reason that some of my audio came in out of sync from one particular tape. (Manually synced that, hoping I can avoid having to relink the audio.)

WHen it comes to non-pre-striped tapes  I suppose AVID will tell me or just start putting the first instance of the time code it can find on the tape.

Luckily, I captured each tape in one go and then broke them all down into subclips. Maybe that makes it easier. I can just ingest each tape and see what happens. If AVID created the subclips the first time and matched them to whatever time code it found on the 115 masters, it should be able to do so with these masters re-ingested at175?

Canon AVCHD isn't a tape format, it's a file based recording format.  Are you talking about the XH A1 HDV camera or the XA1 solid state camera?  Either way, to answer your other question, no, bumping to 175 doesnt get you anything better for picture quality.

 

AVCHD and HDV are both 8 bit, 4:2:0 color space at 24Mbps and 25Mbps respectivley.  Anything above DNX115 is overkill and you won't see a benefit that is worth the increase in storage space.  Also, regarldess of timecode, HDV is notorius for not staying in sync when you re-diidgitize the tapes.

It's with some embarassment that I realize it's been so long that clearly I shouldnt trust myself to be discussing the source! But it's all moot anyway if there's indeed no benefit to 175 and I am now relieved that there's no need to re-ingest. Thanks for the help.