avoiding motion artefacts at DVinfo.net

Martin Sercombe · November 5th, 2005, 10:13 AM

When using Windows Media 9 1080i 50i or 25p anamorphic codecs, exported via Adobe Media encoder, I get highly visible interlace artefacts on all movements (hens teeth). The same happens when I export Cineform HDV avis. None of these show on the preview monitor prior to encoding. Is this due to watching interlaced footage on a progressive monitor (hp 2335)? If so, how does the Cineform intermediate codec manage to avoid displaying hens teeth, when displaying rapid movemements on the same monitor? Playback from the timeline gives a nice even blur on moving objects.

Is there a 1080i PAL codec available that will allow me to view my edit in Media Player, at near HDV quality, without motion artefacts, on any fast PC (2 Ghz plus)?

Thanks

David Newman · November 5th, 2005, 12:34 PM

Yes, interlaced playback on a progressive computer monitor will show interlacing artifacts. In you intend to output for progressive displays you should select de-interlace in the export options. Aspect HD avoids this interlacing issue on the timeline by de-interlacing as part of the preview playback. In the playback options, turn off "de-interlace" will scrubbing and you will see that the interlace information is in the file(s).

Martin Sercombe · November 5th, 2005, 01:08 PM

Thanks David, that has clarified things for me! I have deinterlaced an exported file without problems using the export movie dialogue. I can't find a deinterlace command for any of the Windows Media 9 codec presets, when using Adobe Media encoder. Is there another route via Windows Media Encoder, for example? I have had a quick look at it, and none of the presets it offers fit the bill.

David Newman · November 5th, 2005, 03:44 PM

When using the AME, select the "Pre Encoding Tasks" check box in the Summary section, that will allow you to add a de-interlacer.

Martin Sercombe · November 7th, 2005, 11:21 AM

thanks again. I have tried none (progressive mode), upper field first and lower field first options. Only the last of these produces clean results, the other two still show hens teeth, though their impact is now less noticeable. Why is this?

David Newman · November 7th, 2005, 01:12 PM

De-interlacing with a "Field Order" of progressive doesn't really make much sense (i.e. it doesn't de-interlace.) However Upper or Lower choice should work equally well, that control just determines which field will be used of the frame reconstruction. I don't know way you see a significant difference between upper and lower options.

Martin Sercombe · November 8th, 2005, 10:22 AM

yes, now I have looked more closely at my test files, I see that both options give similar results. I rendered out a 5 min file in Windows Media 9 1080i, and it looks quite horrible in places, with pixellation and unreal skin tones, where it has too many changes to contend with.

I tried your tip, and used 1280x720p24 instead. It seems a better compromise for overall pic quality, and more clients will be able to watch it smoothly.

Steve Crisdale · November 8th, 2005, 04:22 PM

Quote:

Originally Posted by Martin Sercombe

yes, now I have looked more closely at my test files, I see that both options give similar results. I rendered out a 5 min file in Windows Media 9 1080i, and it looks quite horrible in places, with pixellation and unreal skin tones, where it has too many changes to contend with.

I tried your tip, and used 1280x720p24 instead. It seems a better compromise for overall pic quality, and more clients will be able to watch it smoothly.

Have you looked at the bitrate options when encoding your WMV9 file?

The WMV9 encode template options (can't remember the Premiere one's cause I've been using Vegas instead...) are based around far lower bitrates than will give good (not so artifacted) results - and employ variable bitrates; that at their minimum, are just way too low.

With WMV9 HD - as with MPEG2 for DVD - you should keep bitrates up and use two pass encoding for the best results.

Martin Sercombe · November 9th, 2005, 03:49 AM

I guessed this is the problem, as the max variable bit rate I am getting from the presets offered by Media Encoder hover around 1.7 meg/sec. I can't see a way, within adobe media encoder to manually select my bit rate. Am I missing something, or should I be using Windows Media Encoder or another software package, and import a hires avi to it for recompressing? Thanks.

Steve Crisdale · November 9th, 2005, 05:43 AM

Quote:

Originally Posted by Martin Sercombe

I guessed this is the problem, as the max variable bit rate I am getting from the presets offered by Media Encoder hover around 1.7 meg/sec. I can't see a way, within adobe media encoder to manually select my bit rate. Am I missing something, or should I be using Windows Media Encoder or another software package, and import a hires avi to it for recompressing? Thanks.

1.7?... Yikes!! and that's the max? DVD works out at around the 9.8Mbit mark, and that's for 720x480 for NTSC and 720x576 for PAL: i.e. if you're creating a 1280x720 WMV, you'll need at least around the same.

As the resolution of the video goes up - so too should the bitrate if you wish to retain as close to the originals quality.

If you want to make WMV9 HD clips to write to DVD for use in a media player like the Avel Linkplayer 2, you'll want to get as close to the native HD/HDV originals' bitrate as you can. The proviso is - of course; trying to keep file size down!

Anyway; 1.7 is very low bitrate for retaining any quality in a WMV9 that you intend to show the advantage of shooting as HD!

If you can't find the options to adjust within Media Encoder, it may be worth your while to download WMV9 encoder from the dreaded Microsloth... Come to think of it... I seem to recall that without downloading the WMV9 encoder from Big M, Premiere didn't have the same WMV9 encoding options. Once installed - WMV encode options in all my video editing appz got access to the WMV9 HD options. Wouldn't hurt to get it and load it anyway - it does have a 'stand-alone' version of the encoder for encoding from AVI.

Hope you get it sorted - WMV9 HD files seem to be a good option for distribution - and with the impending X-Box 360, PS3, Zensonic Z5000, HD media players portals or whatever you want to call them... with drives that'll play WMV9 DVDs; it may become even more popular.

Martin Sercombe · November 9th, 2005, 09:36 AM

I already have WME installed, and I have played with all the codec options which then appear in Adobe ME, but still don't get the choice to increase bit rates. I have also tried exporting Cineform HDV and HD Export avis. (What is the difference between these codecs btw?). Both the Cineform codecs give a very clean pic, but the sound is out of sync and drops out about 5 secs before the end of the clip. Both Cineform avis play smoothly in Media Player 9 on my 3GHz machine (apart from the sound issue). When I try to import either of these clips to WME to recompress them, the software crashes.

So I still havn't figured how to get a good quality HDV demo avi off the system, which will be playable on a laptop or desktop with a 2 GHz + processor. Can anyone give me a step by step proven production route? Many thanks!

David Newman · November 9th, 2005, 11:19 AM

Martin,
playback of HD is tricker on slower systems (3GHz put you on the edge.) We have a little tool that speeds playback of CineForm AVIs on these systems. Your audio is going out of sync due to system load.

http://www.cineform.com/downloads/PlaybackControls.zip

Unzip and double click on "AcceratedPlay.reg".

Tim Kolb · November 12th, 2005, 08:45 AM

Also, Martin...you may want to try Windows Media Encoder (Free Download from Microsoft). The settings are incredibly flexible and I've had great results encoding with it.

The drawback is that you have to export a clip of the entire show. Potentially big file.

November 5th, 2005, 10:13 AM	#1
Martin Sercombe New Boot Join Date: Oct 2005 Posts: 11	avoiding motion artefacts When using Windows Media 9 1080i 50i or 25p anamorphic codecs, exported via Adobe Media encoder, I get highly visible interlace artefacts on all movements (hens teeth). The same happens when I export Cineform HDV avis. None of these show on the preview monitor prior to encoding. Is this due to watching interlaced footage on a progressive monitor (hp 2335)? If so, how does the Cineform intermediate codec manage to avoid displaying hens teeth, when displaying rapid movemements on the same monitor? Playback from the timeline gives a nice even blur on moving objects. Is there a 1080i PAL codec available that will allow me to view my edit in Media Player, at near HDV quality, without motion artefacts, on any fast PC (2 Ghz plus)? Thanks

November 5th, 2005, 12:34 PM	#2
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	Yes, interlaced playback on a progressive computer monitor will show interlacing artifacts. In you intend to output for progressive displays you should select de-interlace in the export options. Aspect HD avoids this interlacing issue on the timeline by de-interlacing as part of the preview playback. In the playback options, turn off "de-interlace" will scrubbing and you will see that the interlace information is in the file(s). __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

November 5th, 2005, 01:08 PM	#3
Martin Sercombe New Boot Join Date: Oct 2005 Posts: 11	deinterlacing Thanks David, that has clarified things for me! I have deinterlaced an exported file without problems using the export movie dialogue. I can't find a deinterlace command for any of the Windows Media 9 codec presets, when using Adobe Media encoder. Is there another route via Windows Media Encoder, for example? I have had a quick look at it, and none of the presets it offers fit the bill.

November 5th, 2005, 03:44 PM	#4
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	When using the AME, select the "Pre Encoding Tasks" check box in the Summary section, that will allow you to add a de-interlacer. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

November 7th, 2005, 11:21 AM	#5
Martin Sercombe New Boot Join Date: Oct 2005 Posts: 11	deinterlacing options thanks again. I have tried none (progressive mode), upper field first and lower field first options. Only the last of these produces clean results, the other two still show hens teeth, though their impact is now less noticeable. Why is this?

November 7th, 2005, 01:12 PM	#6
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	De-interlacing with a "Field Order" of progressive doesn't really make much sense (i.e. it doesn't de-interlace.) However Upper or Lower choice should work equally well, that control just determines which field will be used of the frame reconstruction. I don't know way you see a significant difference between upper and lower options. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

November 8th, 2005, 10:22 AM	#7
Martin Sercombe New Boot Join Date: Oct 2005 Posts: 11	deinterlacing yes, now I have looked more closely at my test files, I see that both options give similar results. I rendered out a 5 min file in Windows Media 9 1080i, and it looks quite horrible in places, with pixellation and unreal skin tones, where it has too many changes to contend with. I tried your tip, and used 1280x720p24 instead. It seems a better compromise for overall pic quality, and more clients will be able to watch it smoothly.

November 9th, 2005, 03:49 AM	#9
Martin Sercombe New Boot Join Date: Oct 2005 Posts: 11	I guessed this is the problem, as the max variable bit rate I am getting from the presets offered by Media Encoder hover around 1.7 meg/sec. I can't see a way, within adobe media encoder to manually select my bit rate. Am I missing something, or should I be using Windows Media Encoder or another software package, and import a hires avi to it for recompressing? Thanks.

November 9th, 2005, 09:36 AM	#11
Martin Sercombe New Boot Join Date: Oct 2005 Posts: 11	I already have WME installed, and I have played with all the codec options which then appear in Adobe ME, but still don't get the choice to increase bit rates. I have also tried exporting Cineform HDV and HD Export avis. (What is the difference between these codecs btw?). Both the Cineform codecs give a very clean pic, but the sound is out of sync and drops out about 5 secs before the end of the clip. Both Cineform avis play smoothly in Media Player 9 on my 3GHz machine (apart from the sound issue). When I try to import either of these clips to WME to recompress them, the software crashes. So I still havn't figured how to get a good quality HDV demo avi off the system, which will be playable on a laptop or desktop with a 2 GHz + processor. Can anyone give me a step by step proven production route? Many thanks!

November 9th, 2005, 11:19 AM	#12
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	Martin, playback of HD is tricker on slower systems (3GHz put you on the edge.) We have a little tool that speeds playback of CineForm AVIs on these systems. Your audio is going out of sync due to system load. http://www.cineform.com/downloads/PlaybackControls.zip Unzip and double click on "AcceratedPlay.reg". __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

November 12th, 2005, 08:45 AM	#13
Tim Kolb Major Player Join Date: Mar 2005 Location: Neenah, WI Posts: 547	Also, Martin...you may want to try Windows Media Encoder (Free Download from Microsoft). The settings are incredibly flexible and I've had great results encoding with it. The drawback is that you have to export a clip of the entire show. Potentially big file.