Tried Downconverting from HDV to SD...Found No Difference In Quality at DVinfo.net

Akbar Ukani · July 13th, 2008, 06:14 PM

Hi Guys...I need some information on how to possibly achieve the highest quality when downconverting from HD to SD.......Here is my equipment information:

- JVC Gy-hd200 (720p60)
- DR-hd100 Recorder
- Final Cut Pro 6.0.4

Here is what I did:
1. Recorded a few HD clips
2. Transferred them into a FCP timeline (preset used: 720p60)
3. Edited it
4. Did a quicktime conversion (setting used was ApplePro Res HQ)
5. Once the conversion completed, I took the file and made a .m2v file for DVD Studio PRO using compressor
6. Burned the content on a SD DVD

I compared that with with the same clips which I recorded in SD format...but I found no visible change or difference between the two after viewing them on the DVD

Any suggestions....Its kind of hard to explain....but I am trying to achieve the cleanest possible look....something like you would see in a short and small documentary about a movie on a SD DVD before the actual movie starts or what you would see in a movie theatre before the actual movie starts.....please any suggestions would help tremendously

Rick L. Allen · July 13th, 2008, 07:30 PM

Akbar, the SD DVD is going to be an mpeg.4 regardless of what you put into it. The HD version you made is a downconvert to SD DVD. The SD version is a transcode to SD DVD. Your playback compression is the same regardless of the input since everything must fit into 4 GB of space. You essentially did the same thing 2 different ways.

Akbar Ukani · July 13th, 2008, 07:52 PM

Hey Rick....It makes perfect sense now since you put it that way....Well now that you put it like that, is it even possible to achieve a higher quality video from the HDV footage on a 4.7Gb DVD so that it can played back on a regular DVD Player....If not then why do people shoot in HDV and then down convert to SD....Pardon my lack of knowledge...I sincerely do appreciate your input regarding this dilemma

Craig Parkes · July 13th, 2008, 08:37 PM

HDV gives you more latitude in terms of resolution - so if you need to pan and scan, crop etc then it's genuinely more flexible if your final output is lower res.

Also in some situations noise from a dark scene etc might be easier to deal with in post if the source is HD resolution (De-noising the footage BEFORE down rezzing the footage in this case would be better than de noising the footage after down rezzing) and other post FX work.

Alternatively they may just want an HD master to future proof themselves if someone ever needs and HD master.

At the end of the day before you pick up your camera you ideally should know as much about the format you will end up exporting to as the format you are shooting on.

Bill Davis · July 13th, 2008, 11:24 PM

One thing to think about is that any storage medium like a DVD is just a container for a certain number of digital bits.

A "bit bucket" if you will.

The disc doesn't actually care what KIND of bits, nor how they're created, encoded, or arranged. It just stores the bits.

So you have to divorce yourself from thinking about a DVD as just one thing.

For example, an array of bits arranged into DVD format where there's been MPEG compression and a VOB file structure (DVD-VIDEO) so that any DVD player can play the content is just ONE way to store the bits on the disc. It's probably the MOST compatible way to format them, cuz if it's done properly, you can expect the disc to play in most standalone players and on most computers that have DVD movie playback capability.

But of course, the DVD itself is perfectly capable of storing some OTHER kind of video file. Like as a raw Quicktime file, or a DIVX file, or an H-264 file, or even a totally uncompressed clip shot on a RED camera.

Yes, when your source is a BIG data stream like a RAW SDI signal, you won't get very much content on a single layer, single sided DVD. But again, the disc doesn't care what it stores.

So if you want to burn true High-def content to a DVD - there's nothing really to stop you except the gross amount of data the disc can hold.

Storing video as DATA rather than as an authored DVD means the system that attempts to PLAY IT BACK will need to understand how to decode the data and display it. But there are lots of ways to do that.

I just wanted to bring this up, because a lot of people when they think about DVDs think that the format MUST be DVD-VIDEO - and that's just ONE of the things you can store on a DVD.

Noah Kadner · July 15th, 2008, 05:31 AM

Quote:

Originally Posted by Akbar Ukani

Hi Guys...I need some information on how to possibly achieve the highest quality when downconverting from HD to SD.......Here is my equipment information:

- JVC Gy-hd200 (720p60)
- DR-hd100 Recorder
- Final Cut Pro 6.0.4

Here is what I did:
1. Recorded a few HD clips
2. Transferred them into a FCP timeline (preset used: 720p60)
3. Edited it
4. Did a quicktime conversion (setting used was ApplePro Res HQ)
5. Once the conversion completed, I took the file and made a .m2v file for DVD Studio PRO using compressor
6. Burned the content on a SD DVD

I compared that with with the same clips which I recorded in SD format...but I found no visible change or difference between the two after viewing them on the DVD

Any suggestions....Its kind of hard to explain....but I am trying to achieve the cleanest possible look....something like you would see in a short and small documentary about a movie on a SD DVD before the actual movie starts or what you would see in a movie theatre before the actual movie starts.....please any suggestions would help tremendously

In order to achieve a better looking SD DVD you'll want to invest in a higher end encoder to use with DVD Studio Pro. The encoding that comes standard with Compressor is nice but there is better. Two encoders that come to mind are:

http://www.innobits.com/

and

http://www.omni-cinemacraft.com/prod...ncodermp.shtml

-Noah

Robert Lane · July 15th, 2008, 09:02 AM

Akbar,

Based on my own experience of making high-quality SD-DVD encodes I'd say that it's most likely that your settings in Compressor were not optimized for the task. Compressor can absolutely pull-off amazing MPEG-2 encodes but you've got to tweak the built-in settings a bit, which will require taking longer to create the encode, but the results are absolutely stunning.

BitVice, Episode Pro and and even Sorenson's Squeeze are very capable encoders but so far I've not seen another software-based encoder that can output better quality than Compressor. Some of the others listed above are *faster*, but not better.

The Omni CinemaCraft encoder Noah mentioned is a brand-new plug-in encoding engine for Compressor; it has great promise but we have not tested it (yet); there are a few DVinfo members who do have it and I'm waiting to see if they share results. It's also worth noting that the CCE plug-in is *only* for SD encodes or down-converting from HD, they have not released any HD encoding software engines (yet); for that you'd still need their hardware only-option - which is totally amazing.

July 13th, 2008, 06:14 PM	#1
Akbar Ukani Regular Crew Join Date: Aug 2007 Location: Lawrenceville, GA Posts: 69	Tried Downconverting from HDV to SD...Found No Difference In Quality Hi Guys...I need some information on how to possibly achieve the highest quality when downconverting from HD to SD.......Here is my equipment information: - JVC Gy-hd200 (720p60) - DR-hd100 Recorder - Final Cut Pro 6.0.4 Here is what I did: 1. Recorded a few HD clips 2. Transferred them into a FCP timeline (preset used: 720p60) 3. Edited it 4. Did a quicktime conversion (setting used was ApplePro Res HQ) 5. Once the conversion completed, I took the file and made a .m2v file for DVD Studio PRO using compressor 6. Burned the content on a SD DVD I compared that with with the same clips which I recorded in SD format...but I found no visible change or difference between the two after viewing them on the DVD Any suggestions....Its kind of hard to explain....but I am trying to achieve the cleanest possible look....something like you would see in a short and small documentary about a movie on a SD DVD before the actual movie starts or what you would see in a movie theatre before the actual movie starts.....please any suggestions would help tremendously

July 13th, 2008, 07:30 PM	#2
Rick L. Allen Major Player Join Date: Dec 2007 Location: Fayetteville, NC Posts: 535	Akbar, the SD DVD is going to be an mpeg.4 regardless of what you put into it. The HD version you made is a downconvert to SD DVD. The SD version is a transcode to SD DVD. Your playback compression is the same regardless of the input since everything must fit into 4 GB of space. You essentially did the same thing 2 different ways. __________________ "The good thing about science is that it's true whether you believe it or not." Neil deGrasse Tyson https://www.nautilusproductions.com/

July 13th, 2008, 07:52 PM	#3
Akbar Ukani Regular Crew Join Date: Aug 2007 Location: Lawrenceville, GA Posts: 69	Hey Rick....It makes perfect sense now since you put it that way....Well now that you put it like that, is it even possible to achieve a higher quality video from the HDV footage on a 4.7Gb DVD so that it can played back on a regular DVD Player....If not then why do people shoot in HDV and then down convert to SD....Pardon my lack of knowledge...I sincerely do appreciate your input regarding this dilemma

July 13th, 2008, 08:37 PM	#4
Craig Parkes Major Player Join Date: Dec 2006 Location: Auckland, New Zealand Posts: 444	HDV gives you more latitude in terms of resolution - so if you need to pan and scan, crop etc then it's genuinely more flexible if your final output is lower res. Also in some situations noise from a dark scene etc might be easier to deal with in post if the source is HD resolution (De-noising the footage BEFORE down rezzing the footage in this case would be better than de noising the footage after down rezzing) and other post FX work. Alternatively they may just want an HD master to future proof themselves if someone ever needs and HD master. At the end of the day before you pick up your camera you ideally should know as much about the format you will end up exporting to as the format you are shooting on.

July 13th, 2008, 11:24 PM	#5
Bill Davis Trustee Join Date: Jan 2004 Location: Scottsdale, AZ 85260 Posts: 1,538	One thing to think about is that any storage medium like a DVD is just a container for a certain number of digital bits. A "bit bucket" if you will. The disc doesn't actually care what KIND of bits, nor how they're created, encoded, or arranged. It just stores the bits. So you have to divorce yourself from thinking about a DVD as just one thing. For example, an array of bits arranged into DVD format where there's been MPEG compression and a VOB file structure (DVD-VIDEO) so that any DVD player can play the content is just ONE way to store the bits on the disc. It's probably the MOST compatible way to format them, cuz if it's done properly, you can expect the disc to play in most standalone players and on most computers that have DVD movie playback capability. But of course, the DVD itself is perfectly capable of storing some OTHER kind of video file. Like as a raw Quicktime file, or a DIVX file, or an H-264 file, or even a totally uncompressed clip shot on a RED camera. Yes, when your source is a BIG data stream like a RAW SDI signal, you won't get very much content on a single layer, single sided DVD. But again, the disc doesn't care what it stores. So if you want to burn true High-def content to a DVD - there's nothing really to stop you except the gross amount of data the disc can hold. Storing video as DATA rather than as an authored DVD means the system that attempts to PLAY IT BACK will need to understand how to decode the data and display it. But there are lots of ways to do that. I just wanted to bring this up, because a lot of people when they think about DVDs think that the format MUST be DVD-VIDEO - and that's just ONE of the things you can store on a DVD.

July 15th, 2008, 09:02 AM	#7
Robert Lane Go Go Godzilla Join Date: Nov 2004 Location: Scottsdale, AZ USA Posts: 2,788 Images: 15	Akbar, Based on my own experience of making high-quality SD-DVD encodes I'd say that it's most likely that your settings in Compressor were not optimized for the task. Compressor can absolutely pull-off amazing MPEG-2 encodes but you've got to tweak the built-in settings a bit, which will require taking longer to create the encode, but the results are absolutely stunning. BitVice, Episode Pro and and even Sorenson's Squeeze are very capable encoders but so far I've not seen another software-based encoder that can output better quality than Compressor. Some of the others listed above are faster, but not better. The Omni CinemaCraft encoder Noah mentioned is a brand-new plug-in encoding engine for Compressor; it has great promise but we have not tested it (yet); there are a few DVinfo members who do have it and I'm waiting to see if they share results. It's also worth noting that the CCE plug-in is only for SD encodes or down-converting from HD, they have not released any HD encoding software engines (yet); for that you'd still need their hardware only-option - which is totally amazing.