Feeds

Salmon Days: Format Wars

Go DivX!

  • alert
  • submit to reddit

Seven Steps to Software Security

Letters Several viewers complained about format incompatibilities when watching the trailer Salmon Days, our BOFH-inspired comedy epic. Most have been resolved. This correspondent questions the entire basis of our streaming video encoding efforts.



I noticed that your Salmon Days video trailer is trying to feed us, the general public, inferior video formats. Those inferior formats would be WMP, Real Player and Quick time. The superior format would be DivX4.02.

I know David Johns, the tech handling feedback for Salmon Days, thinks that WMP codec for video compression is the cat’s ass, but to be blunt he doesn’t know what he is talking about. Here is his response to my inquiry about why he hasn’t made Salmon Days available in DivX format.

"I don't agree - the codecs in WMP or Real8 actually give better quality for a given bitrate than DivX - it's just that most people don't encode WMP or Real at the kind of bitrates typically used by DivX (eg 1Mbit/sec) hence the widely believed quality difference. Not sure about the codecs used in Movie Maker."

This is just crazy - And shows that either he doesn’t know what he is talking about, or he is a micr$oft b*tch regurgitating their propaganda.

See the article of DivX.com forums "WMP vs DivX4.02 Buddy says WMP is better, is he on crack?"

http://www.divx.com/forums/viewtopic.php?topic=19451&forum=5

I have taken time out of my day to prove him wrong, and here is my response to David Johns.

Hi David,

Sorry I couldn't let this DivX vs WMP comparison go... Instead of debating back and forth I decided to make a DivX clip and send it over to you.

When I made this clip, I wanted to use the harshest possible conditions in order to show the true strength of the codec. This is the opening segment of last night's Enterprise Episode.

First, I captured it off of my TV so it’s an analog signal, and I used UYVY format so I only got 16bit colour. As you should know the source is the most important starting step in compression. I assume you are using a digital camera to capture your episodes so I have handicapped myself right from the start. Had I used a digital signal and MJPEG to do the initial raw capture my final production would be even better than what I am giving you.

Second, the opening scenes are quick and fasted paced with little comparison to each other making compression difficult. This means that the file size will be about twice as big as it normally would.

Third, The sound is not just voice but music as well, to keep the quality and stereo settings I used a much higher settings. Increasing the size of the file.

Fourth, You mentioned your final product was around 300kb/s. A close look shows 312kbs, 16kbs of which is your audio. So you video is in fact almost 300kb/s I decided to make my final production less than half that. My video is 93kb/s <That 1/3 your video size> and my audio is 47kb/s for a total of 140kb/s. I could always use your audio codec and make my total file size 1/3 of yours but as I mentioned before I wanted to keep the sound quality. You can check this by first downloading the file, then right clicking on the file and selecting properties and then summary. You will also notice it was saved at 640x480 a much higher resolution than what you are using. Clicking properties while it is streaming doesn't seem to give the bitrate...

That said the file size of this 2:05 clip is 11 megs. a 3 minute clip of this magnitude and difficulty would be around 15meg. However a clip with standard slow action sceens like the ones you are filming would be about half this size. 7-8megs. And if I used mono sound and further audio compression the file size would be even smaller yet.

I watch these episodes on my 36" TV and they are VHS quality or better. So feel free to watch this clip full screen! 640x480 screen resolution will give you the best results. Also, I did not use any filters on this compression. A smoothing filter would again add a bit to the quality.

You will need the 4.02 codec You can get it from here.
http://www.divx.com/features.php

So install it and see what a 94Kb/s DivX clip looks like on full screen. Humor me and I think you will be impressed.

I placed the clip on some web space I have. I don't know how it will stream because my ISP is fairly slow. So if it’s a bit choppy when it streams don't blame the clip, just down load it and view it off your hard drive.

http://plaza.powersurfr.com/mwilliams/divx402clip.avi

I am just a lowly soldier, if you want further details about DivX contact its designers and creators directly.

http://www.divx.com
http://www.divx.com/contact.php ®

Related Letters and Stories
Salmon Days Makers are Commies
Keepers of The BOFH flame
Salmon Days is Spawned
Salmon Days: Speeds and Feeds
Salmon Days takes shirt off Ted Baker's back

Seven Steps to Software Security

More from The Register

next story
Delaware pair nabbed for getting saucy atop Mexican eatery
Burrito meets soft taco in alleged rooftop romp outrage
Japanese artist cuffed for disseminating 3D ladyparts files
Printable genitalia fall foul of 'obscene material' laws
Brit Rockall adventurer poised to quit islet
Occupation records broken, champagne corks popped
Apple: No, China. iPhone is NOT public enemy number 1
Beijing fears it could beam secrets back to America
Canuck reader threatens suicide over exact dimensions of SPAAAACE!
How many As? Reg hack's writing cops a shoeing
Accused! Yahoo! exec! SUES! her! accuser!, says! sex! harassment! never! happened!
Allegations were for 'financial gain', countersuit claims
Carlos: Slim your working week to just three days of toil
'Midas World' vision suggests you retire later, watch more tellie and buy more stuff
prev story

Whitepapers

Top three mobile application threats
Prevent sensitive data leakage over insecure channels or stolen mobile devices.
The Essential Guide to IT Transformation
ServiceNow discusses three IT transformations that can help CIO's automate IT services to transform IT and the enterprise.
Mobile application security vulnerability report
The alarming realities regarding the sheer number of applications vulnerable to attack, and the most common and easily addressable vulnerability errors.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.