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AVCHD Final Render Quality
Dafydd B [Avatar]
Senior Contributor Joined: Aug 26, 2006 08:20 Messages: 11973 Offline
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Quote: Dafydd,

I have an AVCHD camera so I can send clips as well. Just let me know exactly what you want and what settings to take the video at.

Jim


Thanks Jim, details have been sent to you.

Dafydd
arise [Avatar]
Newbie Joined: Jan 10, 2009 15:24 Messages: 30 Offline
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Dafydd, count me in also if you need more clips.
FYI, I have a HG20.
Benny [Avatar]
Newbie Location: New York Joined: May 14, 2008 22:11 Messages: 10 Offline
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Why would the Moderator ask to start a new topic instead of continuing the "SVRT for AVCHD" thread that I started on 5/14/2008? (http://forum.cyberlink.com/forum/posts/list/2993.page)

Is it because my last comment was "9 months later and yet another patch but this issue is still not resolved" ?

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Quote:
Is it because my last comment was "9 months later and yet another patch but this issue is still not resolved" ?



I wouldn't have thought so
Davec_Surrey_UK
Newbie Location: Surrey Joined: Feb 07, 2009 05:37 Messages: 33 Offline
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Quote: The issue I raised, may have a bearing/be related to on the quality issues. Obviously with an advanced filter on the PC media player I can remove these occasional artifacts and watch "normal" looking playback. Also, as you would expect playback of the AVCDH DVD on a blue ray player, also shows no "combing" artifacts.

However, the actual rendered, interlaced output at these specific areas is slightly degraded, hence the need for a more advanced deinterlacer to view the output with no obvious combing on the PC. When viewing on the blu ray player, I can see the slight degradations at these spots.


I quote the above as a reminder of the specific problem I had and how I believe it might be related to the general rendering issues. I have been doing some experiments and can now reproduce the effect, or at least predict when it is going to happen.

Look at the image below and the durations indicated in the arrows for a clip that has NOT been trimmed.



Interestingly when I get the render problems, it always seems to happen in the same places and is probably stored as a parameter in the .pds project files. Even if I make a new project and simply copy the previous projects clips, but highlighting them and copy on the timeline and then past into the new project it still happens.

It appears that if the duration of the image and the duration in the timeline differ (for NON trimmed,split images), I get the degraded outputs.
I can only presume due to some problem to do with the timings and incorrect data being sent to the render engine!

.01 difference seems to happen on some clips simply as a result of saving and reopening the project. This does not appear to be enough to cause a significant problem, but of course I don't know if the effect is cumulative.

Would be interested to know if other people have a correlation between the durations being reported as different and degraded output? Intel Quad Core, NV 8800GT, Vista (32bit), Canon Powershot TX1. Editing 1280x720 (p) NTSC 30 fps motion jpeg in .avi container....to AVCHD DVDs for Blu Ray playback
WilliamI [Avatar]
Newbie Joined: Oct 22, 2008 01:05 Messages: 23 Offline
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David,

I would love to see one of your rendered output files that exhibit this combing effect or even a screen capture of a frame showing it. I think you are describing the same issue that I've been trying to nail down for months. This post http://forum.cyberlink.com/forum/posts/list/4218.page#16115 has rendered examples that can be downloaded although I'm working on a more evident example now. Intel Core 2 Quad, 4 GB DDR2 RAM, Vista 64 bit, ATI Radeon HD 3850, Canon HF100
Davec_Surrey_UK
Newbie Location: Surrey Joined: Feb 07, 2009 05:37 Messages: 33 Offline
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Check out my posting on page 1 of this thread, I have done exactly that with 2 screen captures. Intel Quad Core, NV 8800GT, Vista (32bit), Canon Powershot TX1. Editing 1280x720 (p) NTSC 30 fps motion jpeg in .avi container....to AVCHD DVDs for Blu Ray playback
Dafydd B [Avatar]
Senior Contributor Joined: Aug 26, 2006 08:20 Messages: 11973 Offline
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Quote: Dafydd, count me in also if you need more clips.
FYI, I have a HG20.

Thank you.
I'm holding back from recruiting more clips etc because I think there are enough examples. However PM me your email contact details and I'll ask you immediately if CyberLink need more.

The render issue is being investigated by CyberLink R & D.

I've set up a different FTP location for the AVCHD Trim issue which WilliamI has mentioned to me as this will likely involve whole project uploading.

Thank you to all those who have provided valuable information and continue to do so.

Dafydd

This message was edited 1 time. Last update was at Feb 13. 2009 06:52

WilliamI [Avatar]
Newbie Joined: Oct 22, 2008 01:05 Messages: 23 Offline
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Quote: Check out my posting on page 1 of this thread, I have done exactly that with 2 screen captures.


Yes David, the result is the same as what I have experienced with trimming clips. Although it's a different function creating the problem (clip vs anti-shake) the result is the exact same. When it occurs after performing a trim, it can be corrected by adjusting the trim points in the clip until the problem goes away, but you have to go through a render / preview cycle with each trim adjustment keeping a watchful eye out for the interlacing effect. So to be fair, there is a work around, just a really time consuming work around.

David, if possible I think it would be beneficial for you to get a sample project and files to Cyberlink. PM Dafydd for the details on adding a report to the TRIM issue that he is pulling together. Intel Core 2 Quad, 4 GB DDR2 RAM, Vista 64 bit, ATI Radeon HD 3850, Canon HF100
Dafydd B [Avatar]
Senior Contributor Joined: Aug 26, 2006 08:20 Messages: 11973 Offline
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Bill, I've emailed the Trim FTP data to Dave - 5 minutes ago.

Dafydd
Davec_Surrey_UK
Newbie Location: Surrey Joined: Feb 07, 2009 05:37 Messages: 33 Offline
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I should make it clear that I don't actually have to do anything for this to happen. Now when I produce output for later editing I try NOT to save the project before outputiing AVCHD files for later editing! As this effect can even happen after a save. However it certainly happends most of the time with larger projects and lots of clips, even more so when there are effects.

I am not sure really what to post back up as I don't want to be uploading 500 mb at 256kb per sec. I have also just deleted a little set of trest clips I had and the project file which could have replicated this.

I will see if I can manufacture something small that can replicate the errors. I am keen to see it solved because my workaround is not reliable in terms of producing the initial known good file for editing.

This message was edited 1 time. Last update was at Feb 13. 2009 16:18

Intel Quad Core, NV 8800GT, Vista (32bit), Canon Powershot TX1. Editing 1280x720 (p) NTSC 30 fps motion jpeg in .avi container....to AVCHD DVDs for Blu Ray playback
Davec_Surrey_UK
Newbie Location: Surrey Joined: Feb 07, 2009 05:37 Messages: 33 Offline
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I believe I have found the cause of the problem of the interlace combing effect that affects many of us, this problem on playback of AVCHD in a Blu Ray player leads to degraded Video quality. I would love it if some of you can confirm back whether this fix/recreation of the problem works on your systems?

I am pretty sure this is the same problem we all have whether we are editing AVCHD or as in my case mjpeg and rendering to AVCHD (it may well even affect render quality into other interlaced formats!). I have been able to reliably reproduce the problem with both mjpeg and AVCHD starting files >> rendered to AVCHD.

The problem is caused because either trim or edit effects in some way change the speed of the Video. This results in the Video on the timeline being shown with a duration longer than the original clip, see images:

You get to the speed function by highlighting the video clip on the timeline, or in storyboard view.



Then once in, you press the reset button if the times shown in the two areas ringed are different.



Resetting the clip to it's original duration fixes the problem with my mjpeg starting files/or AVCHD starting files, and renders perfectly with no interlacing problems. I purposely used fast motion to make the effect more apparent...see before and after in Windows Media Player:



You to can create the interlace artifacts, simply take a small clip, select it on the timeline, click the speed button, click in the timecode box in the 10th and 100ths of a second, make the new video length 2 100ths of a second longer and you too can have your own interlacing artifacts when you render to AVCHD 1920x1080.

As to why PD7 does this unwanted stretching of the clips and subsequent poor rendering? I have no idea, it seems to happen randomly in the longer projects when effects, trims etc are performed. Although the fix to prevent it happening is easy, it's a real PITA, simply because you have to go through each clip! You cannot unfortunately select all and then select speed and then reset all the clips to their original speed (unfortunately).

It's even better that even if you have trimmed clips, you can still go to the speed button and hit reset, this does not affect the trimming in the clip, but does prevent any interlacing artifacts on rendered output.

I ought to add that there is a particularily irritating feature of this error. You cannot reload the project (or shutdown and restart PD), if you do, these random errors in timing will return, so once you have changed the timings produce your output file straight away and hope it doesn't crash!

So Cyberlink....could we get a quick and dirty fix to this problem (until you find out why it's happening)? Perhaps a patch that allows the "Normalisation" of times for all clips on the timeline simultaneously. This should obviously be done prior to rendering or at users request (each and every time you render, just in case). and without me needing to upload 100s of mb of files.

P.S. This extra unwanted duration will of course always cause the complete re-rendering of an existing AVCHD clip (previously produced by powerdirector), remove it and the clip should SRVT fine.

To Moderator, I have removed thumbnails, because I am unhappy about the advertising being used by the image hosting servce, but I love the image hosting service because it's so fast (compared to others). So I have resized and resampled to much smaller (filesize) images and linked directly.

This message was edited 6 times. Last update was at Feb 14. 2009 06:19

Intel Quad Core, NV 8800GT, Vista (32bit), Canon Powershot TX1. Editing 1280x720 (p) NTSC 30 fps motion jpeg in .avi container....to AVCHD DVDs for Blu Ray playback
James W
Senior Contributor Location: Lakeland, FL USA Joined: Aug 18, 2008 10:36 Messages: 911 Offline
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David,

I tried to recreate your problem but had no luck. To took a file recorded with my Cannon HG20 at 17 Mb/s 24p and dragged it from the media library to the timeline. I trimmed about 3 seconds from the clip and check the speed. Both the original and new times matched as they should. Q9300 2.5 GHz
4 GB Ram
Nvidia 9800 GT
arise [Avatar]
Newbie Joined: Jan 10, 2009 15:24 Messages: 30 Offline
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i also confirm no time difference with HG20 material
Davec_Surrey_UK
Newbie Location: Surrey Joined: Feb 07, 2009 05:37 Messages: 33 Offline
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The problem does not seem to happen with 1 clip or even 2 it usually takes a bigger project for it to start happening. Also on my system trimming a clip does not seem to cause it, it can be a combination of things and lastly, it may need the project saving closing then reopening.

Try using the speed tab and add time to the clip and see if you get the effect? select speed, highlight the new Video length and use the arrow key to make it 2 100ths of a second longer. All AVCHD (PD produced) and mjpeg clips I have both show combing when re-rendered to SVCHD after this is done.

Certainly it's a fix to the combing artifacts for my scenario and I would be surprised if it also does not fix this for others whether they use AVCHD, MJPEG etc. starting files.

Lastly you don't say if you have had a project with degraded output and combing artifacts, if you have actually re-open that project, go to the clip where there is degraded source material and check it's new and original duration in the speed tab to see if it differs.

P.S there was only 1 clip on the timeline, simply because it was taken from a 30 minute edit, where other material had been removed to leave the "bad" clip (because it was small and rendered fast). Intel Quad Core, NV 8800GT, Vista (32bit), Canon Powershot TX1. Editing 1280x720 (p) NTSC 30 fps motion jpeg in .avi container....to AVCHD DVDs for Blu Ray playback
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I would like to add my latest results which again surprised me. I updated my NVIDIA drivers to 181.22 which has now enabled GPU rendering.

I would have thought that the quality of rendering was dependent on the rendering engine (powerdirector) not the processor used but this is not the case with my setup. I get different files if I have GPU rendering enabled compared with GPU disabled. The quality of the final product is dependent on the type of processing used.

Firstly I did multiple renders with GPU rendering disabled. Each time the file size was slightly different (only 40 KB or so) and the macroblocking effect was slightly different in the specific frame I am examining for comparison.

When GPU is enabled the file size is significantly larger (12%) and the file size is constant for multiple renders of the same clip.

Also when examining the resultant clip the field order is different with No GPU rendering file being flagged as MBAFF and the GPU rendered file being flagged as progressive. This is from an interlaced source file.

All a bit strange.

The end effect is that the GPU rendering gives a result much closer to the original in terms of definition. Attached is a jpeg with a cropped section of a frame for comparison.

http://www.4shared.com/file/87734087/c4c265da/Comparison.html
Juan [Avatar]
Newbie Location: Canada Joined: Dec 01, 2008 23:35 Messages: 33 Offline
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pjc,

That's a great picture, it shows clearly the difference in quality between the original and the AVCHD file rendered by PD7. The guys at Cyberlink should have a copy.

Unfortunately, I don't have a NVidia card to test the GPU rendering. Anyway, that's an unexpected result!

Juan
Dafydd B [Avatar]
Senior Contributor Joined: Aug 26, 2006 08:20 Messages: 11973 Offline
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Update info:

WilliamI, has reported an issue with avchd Trim.

It's a "BUG" and the matter has gone to R&D for further testing.

Dafydd
batwings [Avatar]
Newbie Joined: Jan 01, 2009 11:37 Messages: 6 Offline
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David,

Thank you!!!

Your fix works for me. It's an extra step but I now am able to render and export to Blu-Ray without the video being degraded. Video playback on my set top Blu-Rayer player is now fantastic.

Thank you again!

Davec_Surrey_UK
Newbie Location: Surrey Joined: Feb 07, 2009 05:37 Messages: 33 Offline
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Batwings, thank goodness someone else also has the same problem. I cannot believe you are the only one. There seems to be a basic flaw in how it deinterlaces some Video for HD rendering. I am still waiting to hear from Cyberlink on this issue....even to hear they have replicated the problem with the files I sent would be something.

Just a small tip, what I do now is "normalise" or "reset" every clip whether time affected or not, because I suppose it's possible for the difference to be .00n of a second (which might not show) and if so, perhaps there is still degradation?

To make it much easier the keyboard shortcut "cntrl"+"right arrow" is a pain, because you can make the necessary mouse click (only 2 hands). I mapped the shortcut to a single key on my keyboard. This allows me to put the PD into storyboard view then quickly press the mapped key and then the mouse click. These strokes are saved, so it can be done quite quickly as you wait for PD to catch up. The only area where you need to wait and do something to bypass are still images or colour-boards. Intel Quad Core, NV 8800GT, Vista (32bit), Canon Powershot TX1. Editing 1280x720 (p) NTSC 30 fps motion jpeg in .avi container....to AVCHD DVDs for Blu Ray playback
WilliamI [Avatar]
Newbie Joined: Oct 22, 2008 01:05 Messages: 23 Offline
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David,

I'm sure the few users who have posted on this are not the only ones experiencing the problem. Although you and I represented the steps to reproduce the combing effect differently the net result appears to be identical. Cyberlink has accepted the steps and samples that I provided as a bug. My hope is that it also corrects the way you are reproducing the issue.

Personally I think a great deal of people don't even notice the issue or just think something weird happened in the video and go on. Hardware can also mask the problem so that might play into it as well. For example my video card has a deinterlacing mode that when enabled "almost" totally masks the problem. Intel Core 2 Quad, 4 GB DDR2 RAM, Vista 64 bit, ATI Radeon HD 3850, Canon HF100
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