|
|
|
|
MPEG-1 or MPEG-2 ?
I've noticed many people wondering or complaining about why some people have chosen to forget
about using the MPEG-1 (VCD) Format and instead have chosen to use the newer MPEG-2 (SVCD) Format.
After reading this FAQ, you will understand the differences between these two formats and you will be
able to decide which format will be best for you.
For those of you new to video and even some of you that aren't, you need to know just what MPEG is. MPEG
is a format that was designed to compress video in the AVI format. It tries to maintain quality and at the same
time reduce the file size dramatically. Imagine having to keep a simple 3 minute video clip with audio on your
computer that has a file size of around 2GB! That's right gigabytes, not megabytes. There was obviously a need to
remedy this handicap of AVI files. That's where MPEG comes in. MPEG can compress the previously mentioned AVI to
a 30MB file size, while maintaining an excellent video and sound quality. Just think of how the MP3 format compresses
your WAV files. This is the exact same principle, only with video.
MPEG-1 is the predecessor of MPEG-2 and is a great way to keep those video files small. Uses for MPEG-1 are:
- Making digital libraries of VHS tapes.
- Compressing video captured from your TV.
- Making personal home videos from your camcorder.
- Creating Video-CDs.
MPEG-1 is also the most affordable way to compress your AVIs. Cards that can hardware encode to MPEG-1 are becoming
relatively cheap, and there are many freeware, shareware, and commercial software encoders you can use on your home PC.
It is also fairly easy to edit and manage MPEG-1 video. Many applications are out there for this type of video. MPEG-1 is
meant for low resolution video, usually lower than 352x288. Anything higher results in very noticeable visual artifacts
and perhaps some color bleeding, etc. The bitrate should also be kept under 2000kbps. Anything higher is a waste of HDD space.
If you need higher resolution and bitrates, read on about MPEG-2...
MPEG-2 is a more advanced than MPEG-1 in many aspects. It provides a higher resolution, bitrate, and, in some cases, better audio
quality than MPEG-1. Use this format if you:
- Need to preserve your video in the highest detail/quality possible.
- Plan to make a DVD or SVCD of your video.
- Are capturing from an excellent video source and want to maintain similar quality.
This may make you wonder why MPEG-1 even exists still. There are a few drawbacks to using MPEG-2 over MPEG-1, which are:
- You need a decoder to playback MPEG-2 on a PC.
- Hardware MPEG-2 encoders are very expensive.
- It is difficult to edit MPEG-2 video without the proper tools.
The file size of MPEG-2 video isnt all that different than MPEG-1. An MPEG-2 SVCD stream is only about 12-20MB larger than an MPEG-1 VCD stream.
Bitrates and resolutions for MPEG-2 can be very high, which results in a huge advantage over MPEG-1.
Keep in mind that the uses I have listed for these formats are not limited to such uses. I also use MPEG-2 for digitizing VHS tapes
and sometimes use MPEG-1 even when I have excellent input video. It all depends on what you want to achieve as your results. I myself
have chosen to use MPEG-2 simply because I like the high quality it offers. That is not to say MPEG-1 doesn't offer quality, only that
my needs (or wants) prefer MPEG-2. Whichever format you choose, make sure you read more about them and that you encode them properly
if you are aiming for a certain format, i.e. VCD, SVCD, or DVD. For more info on the technical details of these formats, take a look at my
Video Specs Chart.
Copyright © 1999 - 2001 happyg video
happyg_hgv@hotmail.com
|
|
