AVCHD Workflow Question at DVinfo.net

Hugh Walton · October 17th, 2009, 11:50 AM

I found the article below online and I am a little confused. The author suggests that one should transcode AVCHD to ProRes 422, but then edit the clips in a ProRes 422 (HQ) timeline. This seems crazy to me, so I wanted to get some feedback. In my experience there is no reason to capture AVCHD footage in ProRes 422 (HQ), since ProRes 422 is more than adequate to handle the bit rate of AVCHD. Also, Final Cut Pro 6 only lets you "Log and Transfer" to ProRes 422, so why would you want to drop your ProRes 422 clips into a ProRes 422 (HQ) timeline?

Am I missing something or has the article's author made a mistake?

Article: Page #6
http://www.panasonic-broadcast.com/c...ting_FCP_2.pdf

Thanks,
Hugh

Chuck Spaulding · October 17th, 2009, 12:05 PM

I didn't read the article, however for us as a rule of thumb if we have a project that's going to be output to film we'll us ProRes HQ [which is getting to be less often].

If we're finishing in HD [or any video format for that matter] we master in ProRes. We have not upgraded our facility to FCP7 but I suspect that for most broadcast applications the new ProRes 100 Mb/sec will work. This is important for us because we do the equivalent of ten broadcast shows per month so disk space is at a premium.

Nate Morse · October 18th, 2009, 10:28 AM

I've always used ProRess 422 when transcoding from AVCHD. And I think you're right. There is no way to transcode to HQ using Log and Transfer.

Since I can't tell the difference between my original footage and the ProRes 422 version anyway, using ProRess 422 (HQ) seems like a waste of disk space. I don't know why anyone would drop "standard" ProRes into an HQ timeline either.

My guess is it's a mistake.

Chuck Spaulding · October 18th, 2009, 10:35 AM

Actually, if your going to output to film then you do want to make everything ProRes HQ. Film recorders work in 10bit(log)/16bit(linear), when projected you will be able to tell the difference.

Hopefully if your working on a true film project you account for all of the additional bandwidth and budget accordingly.

Nate Morse · October 18th, 2009, 10:52 AM

Makes sense, but wouldn't you generally be working with a different source codec when delivering a film output? Or, are you using AVCHD for this already?

Chuck Spaulding · October 18th, 2009, 10:59 AM

Your right, generally you wouldn't be using a camera that acquired AVCHD. But I still remember the days where some producers were convinced they could upres BetaSP and it looked great on film.

And if you want to be considered for an Academy Award you still need to film it out and project it to an audience in a theater. Just in case.

So basically for most of us there's no real reason to use ProResHQ.

Nate Morse · October 18th, 2009, 11:02 AM

Cool. Thanks for the insight.

Hugh Walton · October 18th, 2009, 11:39 AM

I have a feeling that the author of the article did not mention the use of a Prores (HQ) timeline, because he was expecting to transfer to film. I suspect that if this was his intention he would have mentioned this. Like most people shooting using AVCHD, I have no need to transfer my footage to film, so I will stick with a Prores timeline for my Prores clips.

Thanks a lot guys,
Hugh

October 17th, 2009, 11:50 AM	#1
Hugh Walton Regular Crew Join Date: Aug 2006 Location: New York City Posts: 77	AVCHD Workflow Question I found the article below online and I am a little confused. The author suggests that one should transcode AVCHD to ProRes 422, but then edit the clips in a ProRes 422 (HQ) timeline. This seems crazy to me, so I wanted to get some feedback. In my experience there is no reason to capture AVCHD footage in ProRes 422 (HQ), since ProRes 422 is more than adequate to handle the bit rate of AVCHD. Also, Final Cut Pro 6 only lets you "Log and Transfer" to ProRes 422, so why would you want to drop your ProRes 422 clips into a ProRes 422 (HQ) timeline? Am I missing something or has the article's author made a mistake? Article: Page #6 http://www.panasonic-broadcast.com/c...ting_FCP_2.pdf Thanks, Hugh

October 17th, 2009, 12:05 PM	#2
Chuck Spaulding Trustee Join Date: Nov 2004 Location: Thousand Oaks Posts: 1,104	I didn't read the article, however for us as a rule of thumb if we have a project that's going to be output to film we'll us ProRes HQ [which is getting to be less often]. If we're finishing in HD [or any video format for that matter] we master in ProRes. We have not upgraded our facility to FCP7 but I suspect that for most broadcast applications the new ProRes 100 Mb/sec will work. This is important for us because we do the equivalent of ten broadcast shows per month so disk space is at a premium.

October 18th, 2009, 10:28 AM	#3
Nate Morse Regular Crew Join Date: Sep 2008 Location: Minneapolis, MN Posts: 46	I've always used ProRess 422 when transcoding from AVCHD. And I think you're right. There is no way to transcode to HQ using Log and Transfer. Since I can't tell the difference between my original footage and the ProRes 422 version anyway, using ProRess 422 (HQ) seems like a waste of disk space. I don't know why anyone would drop "standard" ProRes into an HQ timeline either. My guess is it's a mistake.

October 18th, 2009, 10:35 AM	#4
Chuck Spaulding Trustee Join Date: Nov 2004 Location: Thousand Oaks Posts: 1,104	Actually, if your going to output to film then you do want to make everything ProRes HQ. Film recorders work in 10bit(log)/16bit(linear), when projected you will be able to tell the difference. Hopefully if your working on a true film project you account for all of the additional bandwidth and budget accordingly.

October 18th, 2009, 10:52 AM	#5
Nate Morse Regular Crew Join Date: Sep 2008 Location: Minneapolis, MN Posts: 46	Makes sense, but wouldn't you generally be working with a different source codec when delivering a film output? Or, are you using AVCHD for this already?

October 18th, 2009, 10:59 AM	#6
Chuck Spaulding Trustee Join Date: Nov 2004 Location: Thousand Oaks Posts: 1,104	Your right, generally you wouldn't be using a camera that acquired AVCHD. But I still remember the days where some producers were convinced they could upres BetaSP and it looked great on film. And if you want to be considered for an Academy Award you still need to film it out and project it to an audience in a theater. Just in case. So basically for most of us there's no real reason to use ProResHQ.

October 18th, 2009, 11:02 AM	#7
Nate Morse Regular Crew Join Date: Sep 2008 Location: Minneapolis, MN Posts: 46	Cool. Thanks for the insight.

October 18th, 2009, 11:39 AM	#8
Hugh Walton Regular Crew Join Date: Aug 2006 Location: New York City Posts: 77	I have a feeling that the author of the article did not mention the use of a Prores (HQ) timeline, because he was expecting to transfer to film. I suspect that if this was his intention he would have mentioned this. Like most people shooting using AVCHD, I have no need to transfer my footage to film, so I will stick with a Prores timeline for my Prores clips. Thanks a lot guys, Hugh