26 May, 2006

Adventures in DVD Authoring

I was thrown into the world of DVD authoring a couple weeks ago when I found myself with a clutch of various television shows and webcasts from the UK that have not been released here in America. While watching them on my computer was not a problem, I much prefer to watch television and movies on my TV. I have a 20" monitor attached to my PC, but my TV has a 52" screen. Plus the couch upstairs is much more comfortable than my chair here. And so it was with these factors in mind that I set out to put my newly-acquired shows on DVD. Unfortunately, each program presented a different technical challenge in addition to the one they all shared – being in PAL format. PAL is an acronym for Phase Alternation Line. It's a method of encoding television images and is used by a large chunk of the world (including Greenland – I didn't know they had broadcast stations there…). Here in the States, we use NTSC or National Television Systems Committee, named after the standards body that chose it. The main differences between PAL and NTSC are the frame rates and the resolution of the picture. And so, in order to create a DVD of these UK TV shows, I had to change the frame rate from 25fps to 29.97fps and bump the resolution down from 720x525 to 720x480.

At my disposal was NeroVision Express and Sony's DVD Architect Studio. Both applications are aimed at the home user and I've had luck with NeroVision. I was directed to a tutorial which required various pieces of software such as DGIndex, DGPulldown, and TMPGEnc. And so I went out and acquired them. The first video I'd tackle would be Richard Dawkins' examination of religion, The Root of All Evil?.

It came to me as a DVD image – an .iso file. There were two options before me: A) rip the video & audio directly from the iso file using a utility such as ISOBuster or B) burn the DVD and then rip it. I chose the latter as it gave me the opportunity to use DVD ripping software and see how it works. The author of the DVD did a neat job. For the menu, he used a picture of flames as the background and set it to the "O Fortuna" section from Carl Orff's Carmina Burana. I ripped the DVD using DVD Decrypter. This left me with some .vob files. Vobs are just mpegs – a term you'll probably recognize. They're files with the audio and video together. Dutifully I followed the tutorial. Using DGIndex, I separated the video and audio from the vobs and was left with an ac3 file which was my audio and a d2v file for the video. I processed the video further with TMPGEnc which changed the resolution of the picture. The last thing was to change the frame rate to 29.97fps and this was done with DGPulldown. If you've never processed video with a computer then understand that all of this re-encoding takes a long time and by "a long time" I mean hours. I'd get the process going before I went to bed and let it run overnight. While I was asleep, my computer's processor was pushed to its limit. Finally I was left with my ac3 audio file and a new m2v file. The m2v is only a video stream – no audio.

One thing about DVD authoring software aimed at home users is that they don't accept m2v files and usually require the purchase of a separate encoder to handle ac3 files. And so I went out and got a high-end bit of DVD authoring software – DVDLab – with its 30-day trial period. DVDLab is much less user-friendly than NeroVision Express or DVD Architect Studio. It's like being used to Microsoft Paint and then having Photoshop thrust upon you. DVDLab has separate windows for everything. One is a flowchart showing your labyrinthine menu system, others have your menus, while there is also a timeline for video & audio. Although I had another handy tutorial at my disposal, it was rough going. I was used to having separate files for each episode but, in this instance, I had to contend with both episodes being run together in one huge video file and one huge audio file. Thusly I had to place a make a couple chapters. And so I placed chapter markers at the very beginning and in the middle of the timeline at the beginning of the second episode. Having some non-linear video editing experience, I didn't find this bit to be very difficult. The concept was easy to understand so it was just a matter of learning DVDLab's interface. The major problem I had was in creating the menu.


(Thanks to the guy at VideoHelp.com.)


Now, this project didn't require a complicated menu and menu construction started off easily enough but digressed into a right royal pain in the ass. I set a frame from the first episode as the background image and used the main theme from The Name of the Rose for music. But I had to get used to dealing with all these separate objects. Each bit of text was a different object but what really threw me off was dealing with the little screenshot – a link - that highlights indicating a chapter. I was used to it and any frame around it being one object. But here, the link was distinct from the frame. Instead of the application placing the frame around the link and resizing automatically, I had to do all that by hand. Uff da! It took some doing but I got it how I wanted and then burned the project.

I didn't find out the results until the next day and was dismayed to find that the menu had no music on it and my highlighting color was a light purple instead of gray. Quite irritated, I went back and did some reading. The lack of music was a dumb mistake on my part which was quickly resolved. But the highlighting color was altogether different. On one tab, there was a trio of color adjusters and one just happened to be the same shade of purple as my menu highlight. There was no text description to be found; #3 was the highlighting color and that was that. After making the adjustments, I burned another copy and it turned out well. My ratio of coasters to watchable DVDs was 1:1. This was soon to change.

Next up was a DVD of the Doctor Who webcast, Shada. It had been made into a bit of Flash animation by the BBC and the folks at Big Finish who make the Doctor Who audio dramas. I got a hold of it on DVD – vob files encoded in PAL. I could skip the DVD ripping bit here and go right to converting the vobs. The time involved aside, it was easy. I took my m2v and ac3 files and put them into DVDLab. Shada consisted of 6 episodes so there was more chapter marking involved and a slightly more busy menu. While there was a bit more work, no new concepts were introduced. I slapped it together and burned. I put the DVD into a case on onto the shelf in the living room preparing to move onto Terry Jones' Medieval Lives. A day later when I actually watched the DVD, I noticed that the chapter markers were off. The first 3 were fine but the last 3 were off a bit so that, when you started one of these chapters, it would actually begin a few seconds into it. While this wasn't a really big deal as all you'd miss was the first few seconds of the opening title sequence, I wasn't prepared to settle for second best. And so it was back to the drawing board. The online help for DVDLab mentioned this problem – "chapter lag" as it was called. This happened, so it was explained, because the user marks chapters via timecode while the program counts mpeg frames. But it had a feature where you could shift a chapter marker a second ahead or behind. The problem was that the last couple chapters were more than a second off and I couldn't find a way to shift things more than 1 second. Frustrated, I applied the fix and burned again. It cleared up the problem with the fourth chapter and made the final two better but it was not perfect. I settled anyway.

Next I took on another Doctor Who webcast - Real Time. I wussed out here and burned it using NeroVision Express. This was partly out of frustration and partly because of the format. Instead of vobs, I had multiple avi files. NeroVision is a nice little program but you trade control for ease-of-use. But Real Time was to be a pretty straight-forward project. The menu was simple and I just wasn't quite ready to deal with converting avi files to some mpeg variation that DVDLab could accommodate. And that whole chapter lag issue loomed in the background.

The last project I attempted last week was Terry Jones' Medieval Lives. Like Real Time, I had multiple PAL avi files. This time I decided to go for it and convert the avis so I could work with them in DVDLab. I found a utility and converted them. But, when I tried to import them into DVDLab, I got an error saying that the ratio was 1:1. WTF? I went back and checked. I had set the program to convert to mpeg2, the DVD format. What happened? While I would eventually go back and find that there's a DVD setting in the program which output vob files, I instead moved on to DVD Architect Studio.

DVD Architect Studio is the little brother of DVD Architect and is meant for home user schmucks like myself. I got it when I bought Vegas Studio and hadn't used it until this point. While it had a slightly longer learning curve than NeroVision, it allowed more control over things. I acclimated to the interface fairly quickly and then decided that I wanted to create custom backgrounds for these DVDs. I went out onto the Net and grabbed some pictures of pages from the Book of Kells, a gorgeously illuminated manuscript from c.800 B.C.E. I decided to create backgrounds which had the illustration at the left-hand side with a big blank space on the right. Cheapie DVD authoring software doesn't allow much manipulation of text and I wanted to make sure that the readability of the text here was hampered by being set on top of some funky multi-colored illumination. That and I wanted the image to be seen in all its glory. In Photoshop, I created a blank image that conformed to the NTSC resolution. I shrunk the images from the Book of Kells so that they took up a bit less than half of the left-hand side. Using the eye dropper tool, I filled in the remaining area with an appropriate shade of brown culled from the illumination. Finally, I used the blur tool to lessen the sharp contrast of the two images at the seam where they met. The result was passable but I wanted more. Again going out onto the Net, I found a little tutorial for making an aged parchment look in Photoshop. I'd never really dealt with layers until this point so the whole exercise was quite a nice learning process. While not perfect, I felt the right side would be hidden enough by text and chapter links to make it decent enough. Here's the result:




I was reluctant to just repeat the process for the second DVD as I wanted some variety. So I found some medieval clip art on the web. I grabbed some heraldry and modified it to fit my image. This involved cropping the clip art and filling in the spaces with the appropriate color one pixel at a time. Here's the result:




Again, not perfect but quite passable with text and links.

I'd be making three DVDs so the question of menu music came up. With the Doctor Who discs, it was simple enough as there was only 1 DVD involved and using the Doctor Who theme for the corresponding Doctor was easy enough. The Root of All Evil? required only 1 song. What to do? My first thought was to use some music from Gryphon's Red Queen to Gryphon Three. Gryphon were a progressive rock band that combined Medieval & Renaissance music with rock. I went up to my room to grab the CD only to recall that I didn't have the album any longer. I used to have it. On vinyl. So I stood there staring at my CD racks with a blank look. Then it occurred to me that I had a wonderful replacement in The Bones of all Men. Medieval & Renaissance music buff Philip Pickett got Richard Thompson and some friends from Fairport Convention and did an album of popular music from the 13th-17th centuries. Just as I had tried to match the illumination with one of the episodes on the DVD, so too with the music. DVD 1 had "The Damsel" so I used the rather stately, yet ethereal "My Lady Careys Dompe" here. For DVD 2, I used the rhythmic and aggressive medley of "Le Forze D'Hercole/Lo Ballo Dell Intoria" as this disc contained "The Knight". The final DVD had "King" so I used "Tutte Venite Armati" which sounded a bit like a fanfare. With everything set to go, I burned the first DVD.

I had burned it overnight and so I watched it the next day. Much to my disappointment, the left and top edges of the menu had been cut off. This flummoxed me as the picture hadn't gone beyond the borders of the menu layout in DVD Architect. However, the music on the menu played fine and the first episode looked to be OK and the program had preserved the aspect ratio just fine. I couldn't find anything in the manual or in the online help to explain why this had happened. So I went back into Photoshop and retooled the background images so that I had more room for the text and linking objects. Rather than trying to fix a problem in a program that Sony no longer updates, I decided to work around the issue. I grouped objects in the menu a bit closer and burned again. I found that I hadn't quite grouped things closely enough together and just the very top of the title text got cut off. I wasn't keen on making any more coasters so I said good enough for government work and added the DVD to my collection. After a couple repetitions, I finally had them all done.

Last weekend The Dulcinea came over and we decided to watch Medieval Lives, DVD 1. The menu worked just fine and the first episode, "Peasant", was a hoot. I eagerly played the second. And then the sound took a digger. For some reason, the sound was out of sync. Not only that, it would stutter and get worse. I checked the other discs and they were the same. The first episode on each was fine but the succeeding chapters had audio that was a complete fucking mess. This irritated the living shit out me.

I went back to NeroVision. While my control over text wasn't as good, at least the sound remained in sync. Another gripe, although much more minor than the aforementioned audio problems, was that I couldn't find a setting for what to do when a chapter ends. I like to have control over this so I can set it to go back to the menu or to play the next chapter.

And so that's where I stand. It's been quite a neat, if periodically very frustrating, learning experience. I've decided that DVD Architect Studio is for shite. Along the way, I learned how Easter eggs are put onto DVDs. What you do is create an object that is a link but you make it invisible. I like DVDLab a lot. I like the control you have over minute details plus its ability to really manipulate text – make it 3D, et al. It's just that the chapter lag thing is a real snag. Next up I need to learn scene selection. With Shada, the chapter lag wasn't a big deal as it would just jump a couple seconds into a title sequence but I want to get more precise if there are none the next time. Another aspect I need to learn more about is the bit rate. Bit rate is, in the simplest terms, the quality of the video. I have a single layer DVD burner so I've got a bit shy of 2 hours to work with on a disc. I have crammed more than 2 hours on a DVD – with Real Time. But it was Flash animation and a series of still images with little movement and what movement there was not smooth by design. Ergo I didn't lose a lot of quality by shrinking it. I will, however, need to figure something else out when it comes to jamming a lengthy live action video onto a single DVD.

The moral here is to practice, practice, practice and not be afraid to make a whole boatload of coasters along the way. NeroVision offers ease of use and reliability. But other DVD authoring programs such as DVDLab gives you more control over everything and allows you to make much snazzier menus. I'm about ready to return to it in order to suss out this whole chapter lag thing.

Lastly, a note about the latest NeroVision. I had absolutely no problems with NeroVision Express 2 which came with Nero 6. I recently upgraded to Nero 7 with its shiny new version of NeroVision and ran into a problem when making the menus for Medieval Lives. The program will put up a menu link for each video file you put into the project. You can then go ahead and use a frame from the video as the picture of the link. With the old version, I had no problems using the slider to find a suitable frame. But with the newest version, it gave me black screens. The very first frame of the file showed up fine, but, if I moved the slider, the picture just turned black. Luckily the program would randomly decided to show the frame you hit on and I was able to fiddle around enough and get things right. Still, it was very frustrating. This problem did not crop up again on the next project, however. Both projects were PAL-encoded but I'm wondering if perhaps NeroVision just doesn't play well with DivX or who.

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