DVD Mastering Using QDVDAuthor
If you're working from footage taken on a miniDV camera, outputting a DVD-ready video from Kino is relatively simple. If you haven't used it before, Kino's interface is comfortable and easy to navigate. Good user guides are available at several places on the Web, most obviously at Kino's home page (kinodv.org/article/archive/13). It's not a multitrack editor, more's the pity, but for quick-and-dirty edit work with basic transitions and soundtrack mixing, it works encouragingly well. When outputting video from Kino, I've found that I get the best results (for both video quality and a minimum of sound sync slippage) with the dual-pass encoding in the DV Pipe screen.
On the off chance that you're wanting to burn DVDs from your PVR, you still need to get the files into the right format. Mencoder is great for this, though it has a confusing array of options. Here's a sample command argument for moving from xvid to DVD-compatible MPEG-2:
mencoder -ovc lavc -lavcopts vcodec=mpeg2video -oac lavc -lavcopts \ acodec=mp2:abitrate=512 foo.avi -o foo.mpg
An important caveat about encoding to DVD-format MPEGs: every Linux video encoder I have ever run into uses FFmpeg or MJPEGTools as a back end, and they both have the same problem—a big one. They both seem to have a bug that causes a slip of sound sync progressively throughout the file, becoming noticeable after about the first two minutes of footage. It's a problem in the library that I've not found a way around, though it is markedly less pronounced using FFmpeg than MJPEGTools. This is the biggest and most troublesome hurdle still facing Linux DVD authors. The only solution I've found to this deeply irritating problem is to slice your video into two- to five-minute tracks and use each of these tracks as separate titles on your DVD. It's an ugly solution, and not the kind of thing you want to talk about at parties, but for the moment it's the best we can do. In an ideal world, the good folks who maintain these projects would fix the issue, but as this is a common problem for many commercial MPEG encoders, I'm not holding my breath. (I should add, dear reader, on the off chance that this is a user-brain-dead error and I'm missing something obvious, I look forward to your hate mail with cheerful enthusiasm.)
In case you want to strike out on your own with the available command-line tools (mencoder, FFmpeg and mjpegtools), here are the vital stats you'll need to encode a serviceable DVD video file (all numbers are for NTSC):
720x480 with 4:3 (standard) or 16:9 (anamorphic) aspect ratio.
MPEG-2 @ up to 98,00kbps
48khz @ 32–1,536kbps
PCM, AC3, MPEG-1 Layer2
Up to eight audio tracks encoded
DVD File Structure
The difference between a data DVD and a video DVD is essentially the file structure and video format. The proper encoding of the file structure is handled by DVDAuthor, the back end on which all Linux DVD programs depend. It takes an XML file and builds the DVD image from it. Here is the DVDAuthor output from the project I built for this article:
<dvdauthor dest="/home/user/dvddirectory/" jumppad="yes" > <vmgm> <menus> <video format="ntsc" resolution="720x480" /> <pgc entry="title" > <vob file="/tmp/HK Promo disc/Main Menu VMGM_menu.mpg" pause="inf" /> <button name="1" >jump title2; </button> <post> jump vmgm menu 1; </post> </pgc> </menus> </vmgm> <titleset> <menus> <pgc> <post> jump vmgm menu 1; </post> </pgc> </menus> <titles> <pgc> <vob file="/home/user/dvdmenu1.mpeg.vob" /> <vob file="/home/user/trailerdvd.mpeg.vob" /> <vob file="/home/user/video/cinereel1.mpg" /> <vob file="/home/user/video/cinereel2.mpg" /> <post> call vmgm menu 1; </post> </pgc> </titles> </titleset> </dvdauthor>
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
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- Doing for User Space What We Did for Kernel Space
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide