CS5 and AVCHD chroma bug at DVinfo.net

Graham Hickling · June 15th, 2010, 09:37 PM

Someone asked on another forum whether the chroma bug evident in CS3 and CS4 when decoding AVCHD footage has been fixed in CS5. I had a look today and from what I can see the problem remains.

Here's a comparison of the decode produced by CS5 versus Cineform's HDLink. This is 720P24 AVCHD footage from an HMC40, converted to CineformHD avi then framegrabbed using Virtualdub. Final image enlarged 2X using 'nearest neighbour' in Photoshop - click to see it fullsize. An uncompressed bmp of this image is available at http://wildlifehealth.tennessee.edu/video/chroma.bmp (850KB).

Xian Messerschmidt · June 16th, 2010, 08:13 PM

Looks like EDIUS is still the best for native AVCHD editing. Hopefully v6 supports 10-bit color.

Tim Kolb · June 19th, 2010, 01:46 PM

Out of curiosity, what am i looking for in this image?

Xian Messerschmidt · June 19th, 2010, 03:16 PM

You don't see the issues with the first image? The problem is especially evident along the outer edge of the red section in the upper left part of the pic.

David Knarr · June 19th, 2010, 06:18 PM

Tim
Just click on the link or photos themselves. They will enlarge and you can see the difference on the red edge on the left picture.

Mikko Topponen · June 28th, 2010, 06:48 PM

My 7d material doens't seem to have that bug. I haven't seen it in any of my screencaps.

Tim Kolb · June 29th, 2010, 03:18 PM

Quote:

Originally Posted by David Knarr

Tim
Just click on the link or photos themselves. They will enlarge and you can see the difference on the red edge on the left picture.

Oh...there we go.

This web stuff is a bit too complicated for me I guess.... :-)

Thanks David.

Brad Higerd · June 30th, 2010, 07:36 AM

Graham,

The answer is yes, the problem is still present. From what I can tell, Adobe hasn't come up with an answer to this, which is unfortunate given that my camera B records in ACVHD.

Brad

(Not pumping Vegas, as I'm also an Adobe fan, but Vegas handles ACVHD better. I previously asked a question about how MOV files render directly out of Premiere vs using a high-end intermediate like Cineform, ProRes... Didn't get an answer. But I can tell you that while ACVHD converted to Cineform works better in Vegas, ACVHD renders beautifully right off the timeline. May come down to the reality that neither editor can handle ACVHD and MOV files with great ability, and Cineform is the only plausible answer for mixed codec editing. And yes, if ACVHD was all I edited, I'd probably use Edius.)

Brad Higerd · July 2nd, 2010, 07:00 AM

I'll close my time (for now) in the "Adobe Creative Suite" forum with the simple conclusion that the AVCHD chroma bug is so bad that I'm going to wait until it's fixed before I reconsider an Adobe Pr/Ae purchase. Given that I'm getting phenomenal results on Vegas with Cineform right now, I can't stomach Adobe's ridiculous price tag for a product that handles a native format I use so poorly.

I'll check back periodically to see if Adobe addresses this issue...

Matt Lawrence · July 3rd, 2010, 06:35 AM

I posted on this problem a while back but didn't get any responses. I guess since I didn't use the term "Chroma Bug" it didn't register. You can see the effect even more clearly here:

http://www.dvinfo.net/forum/adobe-cr...d-footage.html

I'm surprised to learn this issue has been around for a while and that Adobe didn't fix it for CS5. I use Final Cut Pro so I haven't looked into this too much, but I did run some tests and it only seems to appear with red objects against a dark background, though I wasn't always able to see the affect.

Andrew J Morin · January 26th, 2011, 03:25 PM

I just got a batch of AVCHD MTS files from my director, and noticed the color-fringe artifacts. Thinking quickly, I used the old mini-DV chroma trick in AE of pre-composing a copy of the footage with the blend-mode set to "color" and that layer fast-blurred vertically 2 pixels (4 works as well, not sure which is theoretically correct). IIRC, the theory in mini-DV terms was that a 4:1:1 colorspace (if I'm using the terms and ratios correctly...) spreads a single pixel of chroma info over 4 displayed pixels, and the blur smooths out the artifact.

I was pleased with the result: am I fooling myself, and is there a better fix?

Tim Kolb · January 26th, 2011, 03:53 PM

For DV, that trick was dealing with a horizontal 4 pixel span (4:1:1)...AVCHD is 4:2:0...a two pixel span horizontally and vertically, so I suppose in theory, 2 pixels would be enough.

However, whatever looks best to you is probably the way to go...

Graham Hickling · January 26th, 2011, 04:13 PM

Andrew - thanks for the post. The "better fix" is to apply a different decoder to the AVCHD footage, for example ffdshow through an avisynth script. But life is too short, really, to do that regularly ....

June 15th, 2010, 09:37 PM	#1
Graham Hickling Trustee Join Date: May 2004 Location: Knoxville, Tennessee Posts: 1,669	CS5 and AVCHD chroma bug Someone asked on another forum whether the chroma bug evident in CS3 and CS4 when decoding AVCHD footage has been fixed in CS5. I had a look today and from what I can see the problem remains. Here's a comparison of the decode produced by CS5 versus Cineform's HDLink. This is 720P24 AVCHD footage from an HMC40, converted to CineformHD avi then framegrabbed using Virtualdub. Final image enlarged 2X using 'nearest neighbour' in Photoshop - click to see it fullsize. An uncompressed bmp of this image is available at http://wildlifehealth.tennessee.edu/video/chroma.bmp (850KB). Attached Thumbnails

June 19th, 2010, 01:46 PM	#3
Tim Kolb Major Player Join Date: Mar 2005 Location: Neenah, WI Posts: 547	Out of curiosity, what am i looking for in this image? __________________ TimK Kolb Productions

June 19th, 2010, 03:16 PM	#4
Xian Messerschmidt Regular Crew Join Date: Jul 2009 Location: Sterling Heights, MI Posts: 58	You don't see the issues with the first image? The problem is especially evident along the outer edge of the red section in the upper left part of the pic. Last edited by Xian Messerschmidt; June 20th, 2010 at 09:56 AM.

January 26th, 2011, 03:53 PM	#12
Tim Kolb Major Player Join Date: Mar 2005 Location: Neenah, WI Posts: 547	For DV, that trick was dealing with a horizontal 4 pixel span (4:1:1)...AVCHD is 4:2:0...a two pixel span horizontally and vertically, so I suppose in theory, 2 pixels would be enough. However, whatever looks best to you is probably the way to go... __________________ TimK Kolb Productions

June 16th, 2010, 08:13 PM	#2
Xian Messerschmidt Regular Crew Join Date: Jul 2009 Location: Sterling Heights, MI Posts: 58	Looks like EDIUS is still the best for native AVCHD editing. Hopefully v6 supports 10-bit color.

June 19th, 2010, 06:18 PM	#5
David Knarr Regular Crew Join Date: Nov 2008 Location: Port Orange, FL Posts: 59	Tim Just click on the link or photos themselves. They will enlarge and you can see the difference on the red edge on the left picture.

June 28th, 2010, 06:48 PM	#6
Mikko Topponen Regular Crew Join Date: Oct 2009 Location: helsinki Posts: 104	My 7d material doens't seem to have that bug. I haven't seen it in any of my screencaps.

June 30th, 2010, 07:36 AM	#8
Brad Higerd Regular Crew Join Date: Jan 2003 Location: Orlando, FL Posts: 186	Graham, The answer is yes, the problem is still present. From what I can tell, Adobe hasn't come up with an answer to this, which is unfortunate given that my camera B records in ACVHD. Brad (Not pumping Vegas, as I'm also an Adobe fan, but Vegas handles ACVHD better. I previously asked a question about how MOV files render directly out of Premiere vs using a high-end intermediate like Cineform, ProRes... Didn't get an answer. But I can tell you that while ACVHD converted to Cineform works better in Vegas, ACVHD renders beautifully right off the timeline. May come down to the reality that neither editor can handle ACVHD and MOV files with great ability, and Cineform is the only plausible answer for mixed codec editing. And yes, if ACVHD was all I edited, I'd probably use Edius.)

July 2nd, 2010, 07:00 AM	#9
Brad Higerd Regular Crew Join Date: Jan 2003 Location: Orlando, FL Posts: 186	I'll close my time (for now) in the "Adobe Creative Suite" forum with the simple conclusion that the AVCHD chroma bug is so bad that I'm going to wait until it's fixed before I reconsider an Adobe Pr/Ae purchase. Given that I'm getting phenomenal results on Vegas with Cineform right now, I can't stomach Adobe's ridiculous price tag for a product that handles a native format I use so poorly. I'll check back periodically to see if Adobe addresses this issue...

July 3rd, 2010, 06:35 AM	#10
Matt Lawrence Regular Crew Join Date: Feb 2010 Location: Madison, WI Posts: 69	I posted on this problem a while back but didn't get any responses. I guess since I didn't use the term "Chroma Bug" it didn't register. You can see the effect even more clearly here: http://www.dvinfo.net/forum/adobe-cr...d-footage.html I'm surprised to learn this issue has been around for a while and that Adobe didn't fix it for CS5. I use Final Cut Pro so I haven't looked into this too much, but I did run some tests and it only seems to appear with red objects against a dark background, though I wasn't always able to see the affect.

January 26th, 2011, 03:25 PM	#11
Andrew J Morin Regular Crew Join Date: Dec 2005 Location: Chicago, IL Posts: 140	I just got a batch of AVCHD MTS files from my director, and noticed the color-fringe artifacts. Thinking quickly, I used the old mini-DV chroma trick in AE of pre-composing a copy of the footage with the blend-mode set to "color" and that layer fast-blurred vertically 2 pixels (4 works as well, not sure which is theoretically correct). IIRC, the theory in mini-DV terms was that a 4:1:1 colorspace (if I'm using the terms and ratios correctly...) spreads a single pixel of chroma info over 4 displayed pixels, and the blur smooths out the artifact. I was pleased with the result: am I fooling myself, and is there a better fix?

January 26th, 2011, 04:13 PM	#13
Graham Hickling Trustee Join Date: May 2004 Location: Knoxville, Tennessee Posts: 1,669	Andrew - thanks for the post. The "better fix" is to apply a different decoder to the AVCHD footage, for example ffdshow through an avisynth script. But life is too short, really, to do that regularly ....