Maximizing HD to SD Quality

Perrone Ford · August 14th, 2009, 12:40 PM

Quote:

Originally Posted by Kenneth Fisher

From my experience in the print and web production world, it is almost always is better to start with higher-resolution source material then "down-res" to a lower resolution.

This does not seem to be the case starting with HD footage then going to SD...or is it? As recently as last night I watch a television program, half on the HD1080P television in my living room, then switch to my old SD television in my bedroom. The program looked great in HD, and it looked great in SD.

I would assume that the show was shot only once in HD, then "down-resed" for SD viewing. Is this technology not available or easily in reach of desktop editors?

I just started mixing HD with SD footage. I thought the big issue was going to be differing aspect ratios, but it seems to be more complex than that.

Ken

Kenneth, as outlined earlier in this thread, the tools to do high quality conversion are available, and in the case of the PC, they are free. They require more effort on the part of the editor, and in many cases, through either inexperience, ignorance, or just unwillingness, these tools are simply not used.

The amount of short-cuts taken and desired by most editors is simply shocking to me for those being paid for their work. I don't mean to be harsh to anyone, but if you are a professional, you are being paid for the quality of your work. If you don't avail yourselves of the (free) tools, then there is no one to blame. Yes, it would be nice if all the NLEs did great down conversions for you at the click of a button. But they do not. So it is incumbent upon us to do what is necessary to create the best product we can.

I'll put the quality of my down conversions against anything on SD broadcast right now. And I didn't pay a dime for the tool to do it. Look at the downconversion quality every time we se a Hollywood film on BluRay, DVD, or TV. That came from FILM scans of 2k or 4k, and through maybe 3-8 different compressions. It CAN be done, and done well.

Kenneth Fisher · August 14th, 2009, 01:09 PM

I understand what you are saying Perrone, and I am actually very familiar with using Virtualdub and its various mods for web video conversion workflows, but I am not yet familiar with the workflows that will give me sterling SD footage from all the various HD sources. I am taking it all in and trying to get it straight.

Do you think the "big boys" are using Virtualdub etc. or are they using a different technology? Obviously a 1-button solution is not realistic even for a big editing house, but I wonder what they generally use for a conversion from HD to SD?

P.S. You can call me Ken - or Kenneth, I don't mind either way. ;-)

Ken

Perrone Ford · August 14th, 2009, 01:19 PM

No, I don't think the big boys are using VirtualDub. They can afford to hire a programmer to write a GUI around a bicubic spline algorithm, or they can pay to buy something that does it for them like this: Multimedia solutions - Custom Technology Corporation

As for the VDub workflow it's simple.

1. Import interlaced high quality .avi file
2. Select "Resize"
3. Input desired size (720x480)
4. Select Lanczos as the rescaler
5. Choose compression type for output
6. Save new .avi file.

Done.

Jim Snow · August 14th, 2009, 01:27 PM

Perrone, what is your opinion of TMPGenc? It uses the Lanczos-3 resizer.

Perrone Ford · August 14th, 2009, 01:38 PM

Quote:

Originally Posted by Jim Snow

Perrone, what is your opinion of TMPGenc? It uses the Lanczos-3 resizer.

Never used it. Couldn't say. I do know that it costs money. And I get Lanczos resizing for free in Virtualdub. Along with a ton of stuff that TMpegenc can't do.

Dennis Murphy · August 14th, 2009, 03:09 PM

Quote:

Originally Posted by Perrone Ford

As for the VDub workflow it's simple.
1. Import interlaced high quality .avi file
2. Select "Resize"
3. Input desired size (720x480)
4. Select Lanczos as the rescaler
5. Choose compression type for output
6. Save new .avi file.
Done.

Perrone, with creating the initial .avi, what sort of hard drive space are we talking about here - what .avi settings are you using?

Perrone Ford · August 14th, 2009, 03:23 PM

Quote:

Originally Posted by Dennis Murphy

Perrone, with creating the initial .avi, what sort of hard drive space are we talking about here - what .avi settings are you using?

I use the Lagarith codec (works in 32 and 64 bit modes and is lossless). For audio I am using PCM 16 or 24bit 48KHz.

It's about 460 Mbps so works out to roughly 3GB/min. Which is about 1/3 what uncompressed 10bit AVI would be or just less than half what uncompressed 8-bit uncompressed would be.

Oren Arieli · August 14th, 2009, 03:51 PM

Just a quick aside. I was invited to Adobe HQ today to give my impressions on improvements that can be made to CS5 (specifically, Encore). The product marketing manager, Sr. product manager and lead engineer from India were eager to get end-user impressions on improvements. I invited two of my colleagues and we chatted for almost 2 hours. I wish I had time to cull from this forum some of your user experience to present...but I did a good job of 'venting my spleen'. Number one on my hit list was Media Concepts atrocious encoder. I hammered that point for all it was worth. Of course, issues such as ease-of-use, glitches, menu transitions, poor quality previews, and much more was covered. If nothing else, I hope that Adobe seriously considers the acquisition or incorporation of Virtual Dub, Procoder, or another high-quality downconversion tool. I tossed out the idea that Premiere is almost useless as an HD cutting tool without aftermarket cards or codecs such as Cineform. I also held out high hopes that they would embrace 64bit Windows 7, GPU processing/encoding, and multithreaded support across their entire line. Don't expect miracles, we're talking Adobe here....but lets hope they take some of our 'mini-panels' suggestions and run with it.

Perrone Ford · August 14th, 2009, 03:58 PM

Good on you for venting end user experiences and frustrations. I am a former Adobe user, and probably still would be had they not fumbled the ball in the end zone years ago and forced me to Vegas.

I wish more Companies would sit up and take note of how their products are ACTUALLY being used (and worked around) rather than just thinking they have a handle on things. I give the Vegas folks credit for reading their forum and being as responsive as possible. They might not get everything right, but they sure do listen.

Kenneth Fisher · August 14th, 2009, 05:44 PM

Quote:

If nothing else, I hope that Adobe seriously considers the acquisition or incorporation of Virtual Dub, Procoder, or another high-quality downconversion tool.

If Adobe (Or anyone) acquired VirtualDub that would be awful. VirtualDub is beautiful in its simplicity and effectiveness, and it is free. I could see Adobe screwing it up. I would hate to see VirtualDub yanked off the freeware scene. It might just be the best free piece of software I own, I'd have to think hard for something better.

Ken

Eugene Kosarovich · August 15th, 2009, 01:01 AM

Quote:

Originally Posted by Jim Snow

Thanks Marc. You may have just given me a practical work flow. I use Cineform. If all I need to do is output my final edit as Cineform and then encode it to MPEG-2 with TMPEG, that's a reasonable work flow.

Actually, you wouldn't need to output your final edit as Cineform to send it to TMPGEnc, you could just use the Frameserver and send it without going back out to Cineform, that would save time and disk space, and the quality should come out the same. Actually, the quality should be better not needing to render out to a lossy codec again.

Oren Arieli · August 15th, 2009, 09:50 AM

Quote:

Originally Posted by Kenneth Fisher

If Adobe (Or anyone) acquired VirtualDub that would be awful. VirtualDub is beautiful in its simplicity and effectiveness, and it is free. I could see Adobe screwing it up. I would hate to see VirtualDub yanked off the freeware scene. It might just be the best free piece of software I own, I'd have to think hard for something better.

Ken

Good point. But I'm still looking forward to the day when I can do all my HD to SD workflow within 1 software piece that will give me the best quality (and hopefully GPU support). I doubt that the good folks making VirtualDub have the time/money/resources/engineering to improve much upon their product for the next version of Windows, 64bit systems, multi-threading improvements and GPU encoding. Adobe has deeper pockets...but let's all hope they don't screw the pooch on this one. Worse case scenario, keep your free copy of VDub handy when Adobe CS5 comes out.

Steve Rusk · August 15th, 2009, 01:19 PM

Thanks for the excellent walk-through, Perrone. I guess I missed the earlier threads on this. I thought going straight from HDV to SD MPEG2 in Vegas was the cleanest route. But a quick test using your method looks very promising.

Richard Hunter · August 15th, 2009, 07:31 PM

Quote:

Originally Posted by Oren Arieli

......If nothing else, I hope that Adobe seriously considers the acquisition or incorporation of Virtual Dub, Procoder, or another high-quality downconversion tool.

Actually, the Procoder downconversion is not considered very high quality. If you go to the Canopus/GV Procoder forum, you will see a similar discussion about using virtualdub to do the resizing, although Procoder is still used for the final compression stage.

Richard

Jim Snow · August 15th, 2009, 08:03 PM

I have spent all day today as well as last evening doing a comparison of various ways to resize and encode. My starting format was Cineform 1440 x 1080i HD clips. As a reference point, I did a MPEG-2 render using CBR with a bit rate of 9,000 kbps using the Main Concepts MPEG encoder in Vegas Pro 8. The result was the loss of resolution that is typical of HD to SD down conversion.

I then loaded CineForm files into TMPGEnc 4.0 and rendered them as MPEG-2 files. TMPGEnc uses the Lanczos resizing filter. The results of this method were clearly much better. The video was noticeably sharper.

I then loaded the CineForm files into VirtualDub and resized them to 720 x 480 and saved them as RAW RGB files. I then encoded the files to MPEG-2 using both the Main Concepts encoder in Vegas as well as TMPGEnc.

My conclusion is that most of the “damage” to resolution is when the files are resized when encoding with Main Concepts. The files that I encoded to MPEG-2 after resizing them in VirtualDub were of apparently equal quality when encoded with either the Main Concepts encoder or TMPGEnc. It appears that the culprit that degrades the files is the resizing operation in Main Concepts.

My question is: If I can do this in a couple of days, why can’t the “Pro” NLE companies do the same thing? I think it isn’t unreasonable for them to incorporate the Lanczos algorithm in their resizing “engine”.

August 14th, 2009, 01:19 PM	#18
Perrone Ford Inner Circle Join Date: Nov 2006 Location: Tallahassee, FL Posts: 4,100	No, I don't think the big boys are using VirtualDub. They can afford to hire a programmer to write a GUI around a bicubic spline algorithm, or they can pay to buy something that does it for them like this: Multimedia solutions - Custom Technology Corporation As for the VDub workflow it's simple. 1. Import interlaced high quality .avi file 2. Select "Resize" 3. Input desired size (720x480) 4. Select Lanczos as the rescaler 5. Choose compression type for output 6. Save new .avi file. Done. __________________ DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.

August 14th, 2009, 03:58 PM	#24
Perrone Ford Inner Circle Join Date: Nov 2006 Location: Tallahassee, FL Posts: 4,100	Good on you for venting end user experiences and frustrations. I am a former Adobe user, and probably still would be had they not fumbled the ball in the end zone years ago and forced me to Vegas. I wish more Companies would sit up and take note of how their products are ACTUALLY being used (and worked around) rather than just thinking they have a handle on things. I give the Vegas folks credit for reading their forum and being as responsive as possible. They might not get everything right, but they sure do listen. __________________ DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.

August 14th, 2009, 01:09 PM	#17
Kenneth Fisher Regular Crew Join Date: Jul 2009 Location: New York City Posts: 47	I understand what you are saying Perrone, and I am actually very familiar with using Virtualdub and its various mods for web video conversion workflows, but I am not yet familiar with the workflows that will give me sterling SD footage from all the various HD sources. I am taking it all in and trying to get it straight. Do you think the "big boys" are using Virtualdub etc. or are they using a different technology? Obviously a 1-button solution is not realistic even for a big editing house, but I wonder what they generally use for a conversion from HD to SD? P.S. You can call me Ken - or Kenneth, I don't mind either way. ;-) Ken

August 14th, 2009, 01:27 PM	#19
Jim Snow Trustee Join Date: Mar 2009 Location: Santa Clara, CA Posts: 1,104	Perrone, what is your opinion of TMPGenc? It uses the Lanczos-3 resizer.

August 14th, 2009, 03:51 PM	#23
Oren Arieli Major Player Join Date: May 2007 Location: San Jose, California Posts: 918	Just a quick aside. I was invited to Adobe HQ today to give my impressions on improvements that can be made to CS5 (specifically, Encore). The product marketing manager, Sr. product manager and lead engineer from India were eager to get end-user impressions on improvements. I invited two of my colleagues and we chatted for almost 2 hours. I wish I had time to cull from this forum some of your user experience to present...but I did a good job of 'venting my spleen'. Number one on my hit list was Media Concepts atrocious encoder. I hammered that point for all it was worth. Of course, issues such as ease-of-use, glitches, menu transitions, poor quality previews, and much more was covered. If nothing else, I hope that Adobe seriously considers the acquisition or incorporation of Virtual Dub, Procoder, or another high-quality downconversion tool. I tossed out the idea that Premiere is almost useless as an HD cutting tool without aftermarket cards or codecs such as Cineform. I also held out high hopes that they would embrace 64bit Windows 7, GPU processing/encoding, and multithreaded support across their entire line. Don't expect miracles, we're talking Adobe here....but lets hope they take some of our 'mini-panels' suggestions and run with it.

August 15th, 2009, 01:19 PM	#28
Steve Rusk Regular Crew Join Date: Jan 2009 Location: Stuttgart Germany Posts: 63	Thanks for the excellent walk-through, Perrone. I guess I missed the earlier threads on this. I thought going straight from HDV to SD MPEG2 in Vegas was the cleanest route. But a quick test using your method looks very promising.

August 15th, 2009, 08:03 PM	#30
Jim Snow Trustee Join Date: Mar 2009 Location: Santa Clara, CA Posts: 1,104	I have spent all day today as well as last evening doing a comparison of various ways to resize and encode. My starting format was Cineform 1440 x 1080i HD clips. As a reference point, I did a MPEG-2 render using CBR with a bit rate of 9,000 kbps using the Main Concepts MPEG encoder in Vegas Pro 8. The result was the loss of resolution that is typical of HD to SD down conversion. I then loaded CineForm files into TMPGEnc 4.0 and rendered them as MPEG-2 files. TMPGEnc uses the Lanczos resizing filter. The results of this method were clearly much better. The video was noticeably sharper. I then loaded the CineForm files into VirtualDub and resized them to 720 x 480 and saved them as RAW RGB files. I then encoded the files to MPEG-2 using both the Main Concepts encoder in Vegas as well as TMPGEnc. My conclusion is that most of the “damage” to resolution is when the files are resized when encoding with Main Concepts. The files that I encoded to MPEG-2 after resizing them in VirtualDub were of apparently equal quality when encoded with either the Main Concepts encoder or TMPGEnc. It appears that the culprit that degrades the files is the resizing operation in Main Concepts. My question is: If I can do this in a couple of days, why can’t the “Pro” NLE companies do the same thing? I think it isn’t unreasonable for them to incorporate the Lanczos algorithm in their resizing “engine”.