Post
by Willen » Sun Jul 26, 2009 10:25 pm
Here goes my Zero1 Longpost™...
As a codec, there is nothing wrong with MPEG-2. All the video quality demo Blu-ray Discs I get from TV manufacturers use it, the in-store video generators all run MPEG-2 encoded video (albeit 1080i), and the HD over-the-air broadcasts all use it (although some stations don't seem to give a shit about video quality, but that's the fault of the person in charge, not the codec).
That being said, MPEG-2's biggest failing is that it's inefficient compared to the newer codecs like H.264, VC-1/WMV9, and even MPEG-4 SP/ASP (DivX/XviD). If filesize isn't important, but computing power is limited, then MPEG-2 is the champ. It's a lot simpler to encode and decode. The biggest rap it gets is due to it being hamstrung in the DVD format implementation. To get a decent amount of content on a 4.7GB or 8.5GB DVD and due to data throughput limitations on single speed playback devices, the MPEG-2 video bitrate is capped. Unfortunately, it's capped just about where it would make standard definition 480i content look decent. Since MPEG-2 hardware (including standalone DVD players) usually use or at least implement DVD compliant chipsets, the best standardized playback environment is limited to DVD-level standard def quality. It's interesting that the most recommended MPEG-2 encoder, TMPGEnc, allows you to go above the DVD video bitrate when encoding. And some of the AMV encoding guides suggest using this higher, non-standard profile for con submissions. Which may require contest coordinators to have to re-encode those video to a lower bitrate that is compatible with their hardware. (I'm sorry, Buma!)
Now if filesize is important, like when transmitting them over the internet efficiently (FTP), or to file sharing sites that have limits on the size of a file, then high quality MPEG-2 falls flat on it's face. This is where newer codecs (and containers) shine. The quality can be the same (or better), but the file sizes of H.264 and VC-1 videos are much smaller compared to MPEG-2. Even good old MPEG-4 SP/ASP implementations like DivX can be leaps and bounds more efficient. Look at the file sizes of your videos you've uploaded to a-m-v.org. My "And So It Begins" video if encoded at 640x480 (and with the inefficient masked edges), at 29.97fps comes in at about a 4 minute 37 second runtime including bumper and credits. Encoded at the highest quality XviD settings with 190kbps MP3 audio, I get a file about 96MB in size. The same video in MPEG-2, albeit with a 720x480 frame size and MPEG audio at 384kbps, encoded as for a con submission via TMPGEnc rings up at a whopping 273MB! XviD bitrate is at 2694kbps. MPEG-2 video bitrate is at 8000kbps. And these were encoded with circa 2006 versions of their respective encoders. I'm not sure if there are significant gains, if any, in efficiency with newer versions.
But ultimately, crap is crap. I can give you a beautiful MPEG-2 encode that is too huge to send practically over internet methods, or I can give you a crappy H.264 encode that looks like it went through You-Tube first but can be sent in less than a minute. And in the end, it comes down to lack of knowledge and experience of how to properly encode video and differences in people's level of standards. Some people don't realize that what may be passable for quality internet streaming in a little window on a 17" monitor may not be good for viewing full screen on a 70+" projection system, not to mention a 40+" HDTV.
Having trouble playing back videos? I recommend:
