06.26.09
Pink and Green Dots
Stare at the black ‘+’ in the center and you will see a moving green dot but try to follow the green dot with your eyes and it will disappear.
06.09.09
No, that’s not me
http://www.mininggazette.com/page/content.detail/id/504993.html?nav=5006
A different fellow named “William Frantz” was sentenced for negligent homicide following a DUI accident. We both happen to be from Michigan but the defendant is a 19 year old Michigan Tech student who just happens to share my name. I sympathize for the kid but the moral is clear. Drunk driving can be deadly.
12.09.08
Difference between DivX and Xvid?
First, an example, what do these things have in common?
- Microsoft in Seattle, WA
- Apple in Cupertino, CA
- LAME, the open source project on SourceForge
Answer: all of them offer a MP3 audio encoder.
Likewise…
- DivX Inc. in San Diego, CA
- Xvid Solutions in Hof, Germany
- XviD, the open source project on SourceForge
All of them offer an MPEG4 Advanced Simple Profile (ASP) video encoder. The Xvid Solutions encoder is the same as the XviD open-source encoder and often appears in free software. The DivX encoder is propriety and only appears in DivX Certified software such as the free DivX Converter.
What’s missing in this comparison with MP3 is a colloquial name for a video file. Some people call them MPEG4 files but that’s not descriptive enough. MPEG4 ASP is a broad standard that includes many esoteric features that are not in common use. Even devices which claim to play “MPEG4 ASP” files probably do not actually support all MPEG4 ASP features.
Some people talk of “DivX” files or “Xvid” files. Usually they mean “MPEG4 ASP files created by the DivX (or Xvid) encoder”. However, there are many software programs that use neither the DivX encoder or the Xvid encoder yet still claim to create “DivX” files and/or “Xvid” files.
DivX Inc. and Xvid Solutions offer a certification program for consumer electronics to guarantee compatibility among devices by precisely defining a DivX file and an Xvid file. However, there are many devices which claim “DivX” and/or “Xvid” playback even though the device is not certified by either company.
It’s no surprise then that consumers are often confused. Terms appear thrown together and comparisons are made in non-sensible ways.
In fact, since DivX and Xvid are two different encoders that both produce MPEG4 ASP video in an AVI file container, you can’t tell the difference between a DivX encoded video and an Xvid encoded video if you were just looking at the video data in the file. However, the encoders leave tell-tale indicators embedded in the file that usually clearly indicate which encoder was used.
It might seem then, that it doesn’t matter which encoder is used. That is true, however, DivX Inc. and Xvid.org have defined slightly different “profiles” for encoding. For example, the DivX Home Theater profile does not allow multiple warp point Global Motion Compensation or Quarter Pixel Estimation even though these features are allowed under the MPEG4 ASP standard and part of the Xvid “home” profile. The DivX encoder can make use GMC and QPel but by default, it does not.
For most people, the best advice is to only buy DivX Home Theater certified products and only use DivX Home Theater certified software. That way, video compatibility is guaranteed. Furthermore, DivX Home Theater files may contain features such as sub-titles or multiple audio tracks. These features are only supported by DivX Certified players. Non-certified devices that claim “DivX” compatibility will not do anything other than basic video playback. Non-certified encoders that claim to create “DivX” files cannot create DivX sub-titles or multiple audio tracks. For example, if you are careful with how you configure the Xvid encoder, you can create videos that play on most DivX devices but you’d be limited to making basic video files without advanced features.
Over 100 Million DivX Certified devices have been sold. Xvid Solutions offers a similar certification program but there are very few Xvid certified devices despite numerous claims of “Xvid” compatibility. Manufacturers get away with these claims because in practice nearly all “Xvid” files are actually videos created to the DivX standard using Xvid software. Few people actually make videos to any Xvid profile because they would be incompatible with the millions of DivX players. Whether they are using DivX software or Xvid software, people are almost always making DivX videos.
05.19.08
Convert Phone Video using FFMPEG
I recently shot some video using the camera on my HTC Touch Cruise. I was easily able to send it as an e-mail attachment using Pocket Outlook and my GMail account. However, when the video arrived it was in an unusable format so I had to do some FFMPEG processing on it. Read the rest of this entry »
01.24.08
DivX Noobs
I saw this question today so I’m posting my response here for everyone.
I am seeking a way to covert my dvd’s to a video file format. I am looking to use mp4 or divx…
In the USA it is illegal to circumvent the copy protection found on most commercial DVDs. However, if you have an unprotected DVD, you can use DivX Converter to convert the DVD to a DivX file.
For example, I have a DVD from my wedding. I paid the videographer for the footage and he gave me an unencrypted DVD. I put that DVD into my computer and can see the contents of the disc. In one of the sub-directories there is a set of large files with names ending in VOB.
Drag and drop the VOB files into DivX Converter, select the “Home Theater” profile, wait a while, and you’ll get a file out with a name ending in divx that is about one quarter the size of the original VOB files. Converter automatically stitches the VOBs together into one file. Take that divx file, burn it on to a CD-ROM and you can watch it on any DivX Certified DVD player. There are many models to choose from starting from as little as $40.
Go to www.divx.com for the software. The DivX Converter software is free, but you’ll need the optional ($10) MPEG2 plug-in to read VOB files. If you are converting lots of videos, consider upgrading to DivX Pro ($20) that will convert files faster and/or provide better quality.
Beware of software that says it creates “DivX” files but is not actually certified by DivX or does not use the DivX encoder. There are lots of free converters out there, many based on FFMPEG, MENCODER, and/or XVID that do not use the fast, high-quality DivX encoder. I only use DivX Converter, Dr. DivX, StreamClip or VirtualDub. I avoid ffmpegx, handbrake, etc.
Advanced Encoding
So you’ve tried DivX Converter but you’ve found you want more control over the encoding process. I’d suggest using software that gives you direct access to the DivX encoder options.
For Mobile, I always crop to 4:3 aspect ratio then scale to 320×240 (qVGA) and keep the video bitrate around 300 kbps. Lanczos is the best resize filter. Always crop off any black borders that may appear around the original video. You waste lots of bitrate trying to encode a sharp black frame around your video. Get rid of them.
For all encodings, I take advantage of the optional enhancements offered by DivX Pro. That means, Multipass (fast first pass), Insane Quality, Experimental SSE4 Search, Enhanced Multithreading, Bidirectional coding, Auto Noise Reduction, Optimized Quantization, Shaping Psychovisual Enhancements and Enhanced I-Blocks. For grainy video, I use Masking Psychovisual Enhancements.
Multi-pass provides better quality and better control of the bitrate. For example, if you try 300 kbps with 1 pass, you might get 275 kbps or 325 kbps. With fast first pass, you will usually get within 2 kbps of your target rate. If you really want exactly the target rate, make a slow first pass.
If you don’t care about rate, use the “1-pass quality based” setting. It’s really the best and fastest method. You let the encoder choose the optimal bit-rate based on the content. I typically use a Quality setting between 3.5 and 5.0 depending on the content. Unfortunately, with this setting, you don’t know what bitrate you’ll end up with and you could easily get something your phone can’t handle, so I don’t use this setting for Mobile sized videos.
I never mess with the max key frames and keyframe threshold. Theoretically you could optimize those settings based on your content. For example, if you have lots of video of a talking head, use a very high max key frame. If you have lots of panning or short, similar scenes, lower the max or the keyframe threshold. By default, you’ll get a key frame at least every 3 seconds and I rarely try to tweak it.
For more detail about what all these settings mean, see the Dr. DivX user guide.
Don’t forget about the audio. Many DivX videos have 128 kbps MP3 stereo audio. That’s usually what you want for Mobile clips and a converter like VirtualDub will copy the audio stream as-is without re-encoding it. Unfortunately Dr. DivX will always re-encode the audio stream whether you need to or not. Sometimes I will use DivXMux to use the original audio stream and the converted video stream.
If you never use stereo headphones, you can save a few bytes by converting the audio to mono and drop the bitrate to 96 kbps.
12.26.07
William Frantz Elementary School Address
William Frantz Elementary School is located at 3811 North Galvez Street, New Orleans, LA 70117. While we share the same name, I’m not related to the school.
Lee Harvey Oswald was born October 18, 1939. He lived on Alvar Street, across from William Frantz Elementary which he attended with his brother.
Decades later, 6 year old Ruby Bridges also attended William Frantz Elementary marking the end of segregation on November 14, 1960.
3 years later, on November 22, 1963, Lee assassinated one of the biggest proponents of civil rights, President John F. Kennedy.
12.21.07
Apple Teaches People
By now there are a few million iPhone users compared to hundreds of million Windows Mobile phone users. Yet, in The Seven Biggest Mobile Content Stories of 2007, Fierce Mobile reported that iPhone Safari browser usage has dramatically exceeded Windows Mobile Pocket Internet Explorer.
I find this astonishing. Apple overcame a 100:1 disadvantage and a several year head start. Then again, I’m often taken aback when “average users” believe some feature is revolutionary when in fact it has been available for years. Now I realize that Apple’s skill is not simply making good products but actually promoting their use. There are no commercials on TV that show happy Windows Mobile users scrolling around web pages on a phone, so I guess nobody realizes its possible until Apple runs an iPhone ad. Suddenly everyone thinks only an iPhone can do this, that or the other thing.
For example, in Year of the iPhone Sue Marek says, Apple’s iPhone transformed wireless handsets with its innovative design and touch screen. I disagree. Hold an iPhone next to an iPaq from 1999. The design is sleeker and smaller but it doesn’t seem innovative considering 8 years have past.
Sue continues, the device finally showed consumers that mobile computing was not only possible but actually fun to do. Here I agree and this is where Apple made a difference. They showed consumers.
Consider iTunes and CD burners. Nobody realized they could make their own CD’s until the “Rip, Mix, Burn” commercials ran?
Go back to the first iPod. Handheld, digital music players had been around for a long time but people didn’t know they existed or didn’t understand what they did. Apple entered the market and taught everybody.
Go back to the first Mac. Other computers had mice and GUIs (including Apple’s own Lisa) but Apple had to show people that computers could be easy to use. I honestly don’t think Apple computers are any easier or harder to use than other computers but Apple does the best job at teaching people.
I’m not an Apple basher. To the contrary, I have an iPod, iMac and a Macbook. I love the products, however I didn’t pay retail for any of them and they don’t offer any feature I can’t replicate for less money. It seems, the “average user” doesn’t share my aptitude for cobbling together solutions or hunting down alternative products.
10.24.07
Fire Map
The KPBS Fire Map has been a great source of information during the San Diego fire. It’s a Google Map with icons and boundries drawn by a local San Diego PBS station.
There’s also a good KBSP News Feed on Twitter that gets updated regularly.
Here’s another Map at Live.com