HD > SD... yes its tired and old

[Jason Selmes]

I just read this post by John rgarding down conversion using avi-synth, virtual dub, HC Encoder and the I-frame Presets and tried this at home last night

My footage is HDV from a Sony Z5P.

Now im planning on making (2) DVD'S with 3 speakers(corporate talk seminar) on each dvd. So each DVD has 3 speakers of 1 hour each.

Now my first HDV profect totalled 2 hours and 45 minutes for 3 speakers. When i exported with adobe media encoder with the i-frame presets at 100 mgbts the total M2V file size was 120 gigabytes????????????? the raw footage is only 30gb.

Am i doing something wrong? It took 25 hours to render the footage and beacuse it was so large virtualdub and HC Encoder couldnt open it and eventually went non reposnsive and crashed....

How can i use the I-Frame presets and keep file size at around 30gb which is what the original RAW footage size is... I wonder why it adds another 100gb onto the file size for no reason???

The write up states encoding is quick and losless..... it sure was not quick i can tell you that.

any help aprreciated

thanks

Jason

[Perrone Ford]

Well first, let's clean up some ideas...

1. HDV is not "Raw". It's simply the native format.

2. HDV is generally either 19 or 25Mbps. It WAS the most highly compressed HD format until AVCHD came along. A full, uncompressed HD signal is ~1.5Gbps. So how much compression do you think is required to get it down to 25Mbps?

3. In order to go from a long-GOP format (HDV) to an intra-frame format the video MUST uncompress a lot. That's perfectly normal.

4. The size of the newly uncompressed file is solely down to bit rate. 100Mbps is a fairly common I-frame bit rate. The Panasonic P2 cameras shoot at this bit rate natively in the camera. Which is why a 64GB P2 card is only an hour for them.

5. It sounds to me, like you are running on an older machine that is not really up to the task of working with less compressed HD formats. HDV was built to give HD-like looks with an SD type workflow. It generally delivers on that. But once you step out of the realm of HDV, you need quite powerful hardware as you are finding.

I am not sure what writeup you are referring to that says "lossless" but any encoding you are likely to be doing is going to be quite lossy. No different for any of us. Lossless compression requires some serious hardware to work with adequately, and few people will spend that kind of money to get it.

So the answer to your question is if you want to get your encodes down to the same size you have now, you need to use a bit rate similar to HDV, which is going to be about 19-25Mbps. Because I-Frame is nowhere NEAR as efficient at compression and storage as HDV, you can rest assured that your quality will suffer tremendously at those kinds of bit rates in an I-Frame codec.

I hope this answers your questions.

-P

Originally Posted by Jason Selmes

I just read this post by John rgarding down conversion using avi-synth, virtual dub, HC Encoder and the I-frame Presets and tried this at home last night

My footage is HDV from a Sony Z5P.

Now im planning on making (2) DVD'S with 3 speakers(corporate talk seminar) on each dvd. So each DVD has 3 speakers of 1 hour each.

Now my first HDV profect totalled 2 hours and 45 minutes for 3 speakers. When i exported with adobe media encoder with the i-frame presets at 100 mgbts the total M2V file size was 120 gigabytes????????????? the raw footage is only 30gb.

Am i doing something wrong? It took 25 hours to render the footage and beacuse it was so large virtualdub and HC Encoder couldnt open it and eventually went non reposnsive and crashed....

How can i use the I-Frame presets and keep file size at around 30gb which is what the original RAW footage size is... I wonder why it adds another 100gb onto the file size for no reason???

The write up states encoding is quick and losless..... it sure was not quick i can tell you that.

any help aprreciated

thanks

Jason

[Jason Selmes]

Hi Perrone thank for the help.

What i meant by RAW was the footage taken off the tapes captured straight to computer.

3 tapes is approx 30gb being 10gb per hour of tape. Ok i feel a bit lost now. What is the best way to get my HDV footage down to a workable DVD size?

I use Premiere Pro CS4, Media Encoder and Encore.....

I am so used to doing Blu-Ray which is simple as shit... render and burn = Done !!!! dam HDV conversions to SD....

any help appreciated

thanks

[Peter D. Parker]

Jason, if I read correctly, you have a 2 hour 45 mins project that you want to put onto DVD from HDV?

I'm afraid that there is no way that you will get the full project on to one DVD without higly compressing it and losing picture quality.

You might be able to use a double layer but I've no experience of these and I've heard they can be a bit of a nightmare when it comes to the layer break.

Can you not split the project in half and use two single layer discs. Find an appropriate spot, about half way and just burn to two disc.

I use CS3 and would imagine the workflow is the same, just export to MPEG2 for DVD, I use CBR at 6mbs and find the results good.

Peter

[Robert M Wright]

I haven't touched Vegas in ages, but I assume an "I frame preset" will result in I-frame only compression. To make a DVD, you don't want I-frame only compression.

[Jason Selmes]

Originally Posted by Peter D. Parker

Jason, if I read correctly, you have a 2 hour 45 mins project that you want to put onto DVD from HDV?

I'm afraid that there is no way that you will get the full project on to one DVD without higly compressing it and losing picture quality.

You might be able to use a double layer but I've no experience of these and I've heard they can be a bit of a nightmare when it comes to the layer break.

Can you not split the project in half and use two single layer discs. Find an appropriate spot, about half way and just burn to two disc.

I use CS3 and would imagine the workflow is the same, just export to MPEG2 for DVD, I use CBR at 6mbs and find the results good.

Peter

hi Pete i think you might be right.

I have a total of 6 speakers that spoke for around 55 minutes each. I was planning on putting 3 speakers on each DVD therefore we have 2 DVD's.

i might just see what 2 speakers per DVD to make 3 dvd's and see what that does for it will do and how much space that will take up...

So yeah 3 DVD'S 2 Speakers per DVD... sounds good to me lets see what type of quality we can get out of that.... Saves all this stupid down converting etc... I loved rendering for Blu Ray So much easier and less hassle...

1. Make Project
2. Render
3. Burn
4. Done!

[Steve Rotter]

Jason, I have used adobe's CS4 suite, premiere pro, export timeline right into encore to make both blu ray and SD DVD with no issues at all. The issues come into play when you use a mac, which I am now using. For you, set your settings for quality and use a dual layer disc. I have had no issues with these whatsoever with break points, etc. No problems. It's great. Where are your issues coming into play? The down convert is easy in CS4. just export timeline right to encore and select DVD or blu ray then set quality.

[Jon Geddes]

Originally Posted by Steve Rotter

Where are your issues coming into play? The down convert is easy in CS4. just export timeline right to encore and select DVD or blu ray then set quality.

The issues come from the downscaling algorithms used by NLE's such as Premiere, Vegas, Final Cut, etc. They are garbage, hence the necessity to use alternate methods such as the one in the article I wrote which the OP is referring to.

The 100 Mbit/s Mpeg2 I-frame export is used as a visually lossless intermediate file, which then gets downscaled and encoded in another application. On most newer systems, mpeg-2 exports are extremely fast, and should not take 25 hours, but in fact should be faster than realtime.

[Steve Rotter]

hmmm, i'm not familiar with all that and i will have to read the article. i have never used anything 3rd party for anything. all i ever did was edit in premiere then go file / export / encore. can't remember the exact terminology but it was file / send to / encore or file / share / encore....whatever it is in CS3 CS4. once that is done, encore will launch and you enter your settings....blu ray disc or image, DVD disc or image. it encodes and actually works pretty fast and does an OUTSTANDING JOB! i couldn't believe the blu ray quality when selecting H.264 codec! that will take a long time...think it took about 14 hours from encoding to burning the blu ray but that's how it is! AND IT'S WORTH IT! i stay away from mpeg2 at all costs! i hate that codec! sure i can get it looking great but an mpeg2 blu ray doesn't come close to an H.264 blu ray! mpeg 2 is fine....but that's just it...it's fine. H.264 slaughters it....but takes 5 times as long to do...fine, get to bed and let it chug.

[Perrone Ford]

Steve,

If you are happy with your results and workflow, no need to change. Others were not pleased with the quality of that workflow and sought other options. There is no doubt that third party tools using Lanczos, Bicubic Spline, or Mitchell rescaling do a better job than the built in tools of the NLEs (apparently doing nearest neighbor or bilinear) but it's more of a hassle and most people just don't care that much.

[Steve Rotter]

Perrone, interesting. thanks for that great info. I will read up on that stuff. If it's a hassle and a lot of $$, and maybe not worth it, I know I won't follow that approach but it's great to learn other ways. Since I'm not using pc anymore, I have been looking around at blu ray on final cut. Exporting right from timeline works great, luckily, as that is the only option for me with mac. I miss encore...it's just not working well in mac...but that's another story.

[Robert M Wright]

Blu-Ray allows for a bitrate as high as 40Mbps. If you go with MPEG-2 at 40Mbps, assuming a quality encoder, H264 isn't likely to give you noticeably better perceived image quality, with typical footage.

[Steve Rotter]

I ran a test via premiere pro CS4 and Encore CS4. same footage, outdoor at the zoo, show with a Canon mark II 1920 HD 30p. exported for blu ray mpeg2 at 35 mb CBR and the same for H.264. H.264 was better. you could see the difference. mpeg2 did look good, but a mini dv type of good. when i saw the lions on the rocks with the H.264 and the wolves in their den with H.264, i said NOW THAT'S WHAT I'M TALKIN' ABOUT. that's another reason to get encore goin' on the mac. i want to be in control.

[Robert M Wright]

I'm kind of curious now. Do you have the option of cranking the MPEG-2 bitrate up a little, to the full 40Mbps that Blu-Ray allows?

[Perrone Ford]

Originally Posted by Steve Rotter

I ran a test via premiere pro CS4 and Encore CS4. same footage, outdoor at the zoo, show with a Canon mark II 1920 HD 30p. exported for blu ray mpeg2 at 35 mb CBR and the same for H.264. H.264 was better. you could see the difference. mpeg2 did look good, but a mini dv type of good. when i saw the lions on the rocks with the H.264 and the wolves in their den with H.264, i said NOW THAT'S WHAT I'M TALKIN' ABOUT. that's another reason to get encore goin' on the mac. i want to be in control.

H.264 at the same bitrate as Mpeg2 is ALWAYS going to be superior. It's a more efficient codec and has less artifacting. So no surprises there.