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. 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

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. 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

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

i also confirm no time difference with HG20 material

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

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

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

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

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!

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

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

For sure any deinterlacing method that uses blend will "almost" mask the problem, but at a terrible cost to picture quality. As you say though, perhaps people are "used" to the results and don't realise how much better it can be?

I hope they put a fix in soon, because it is a bit of a pain going thru each clip. 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

I understand other issues with avchd are present in PD7, however this thread is about PD7 introducing blocking and compression artifact when rendering AVCHD videos.

More than a month ago some members of this forum were asked to submit clips to resolve this problem, moreover the bad quality of AVCHD files rendered in PD7 was reported more 10 months ago in another extensive thread.

I respectfully request an update to this issue.

THANKS

Yes Juan, the thread has been somewhat highjacked.

I am holding off starting another big project (our last family holiday) because the effort involved to get the output to my satisfaction (albeit with compromises) results in my enthusiasm for editing to wane.
If SVRT worked and the AVCHD render was improved I am sure my drive to get into it would increase again.

Quote: I am holding off starting another big project (our last family holiday) because the effort involved to get the output to my satisfaction (albeit with compromises) results in my enthusiasm for editing to wane.
If SVRT worked and the AVCHD render was improved I am sure my drive to get into it would increase again.

I'm in the same position my friend, videos are piling up on me.

I'm going to act the innocent and wait for a patch. It's been only 10 months.

Seriously, we need an update (any information, please!)

Thanks.

I suspect the render problem is not going to be fixed very quickly. However if the lack of SVRT (which IS A BUG) is fixed then it will be manageable.

I am chasing this issue with CyberLink.

Has everyone read Adrian's postings here:
vn800rider. HD Editing - AVCHD, AVC, HDV and 720p, 1080p, 1080i
Article 1: http://forum.cyberlink.com/forum/posts/list/5924.page
Article 2: http://forum.cyberlink.com/forum/posts/list/5925.page
Article 3: http://forum.cyberlink.com/forum/posts/list/0/5926.page

I found them really interesting.

Dafydd

Yes, have read them thanks. Good info for many.

Not really sure of the relevance to this tread.

pjc - the thread is an "of interest" in relation to what you capture, what you process and how it is presented on ones TV screen. The relevance, darn good articles and has info on what to look for/avoid.

Update information:
For all those who have reported an AVCHD render issue. R&D at CyberLink are currently trying to resolve the problem which entails changing the render algorithms, a lot of work is involved. R&D have indicated they hope to release the fix at the earliest possible time.
Dafydd
[Moderator]

Thanks Dafydd,

This is exactly the news we are waiting for. Gives me some encouragement. I must say I am surprised they are tackling the rendering algorithms. Indeed a big ask ...well done.

Good news, Indeed.

Does this FIX include SVRT for AVCHD?

Thanks