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Video always comes in a package. The moving picture file has one format, the sound file has another format, and the container holding them both has yet another format. For example, a camera might capture Motion JPEG video with PCM audio (Pulse Code Modulation, a digital audio format) contained in a WAV file, both of which are carried in an AVI container. The container keeps the sound and image files together and allows compatible software and devices to play them. The video file inside the container is identified by its compression/decompression algorithm, called a codec. The codec specifies the software procedure that makes the video small enough to store and transfer easily, then decompresses it for viewing and editing. Codecs affect video quality, file size, and what you can do with the video once it's been saved.
Take a look at the tables on this page and the next for a quick rundown of the codec and container formats that you'll encounter in digital cameras.
Resolution
| Acronym Usual Pixel Best Displayed |
Usual Pixel Resolution |
Best Displayed on |
| HD (High-Definition) |
1280x720 |
Widescreen HD or TV with 16:9 aspect ratio. |
| WVGA (Wide VGA) |
848x480 or 854x480 |
Widescreen TV or monitor. |
| VGA (Video Graphics Array) |
640x480 |
Standard TV or monitor. |
| QVGA (Quarter VGA) |
320x240 |
Web or portable player. |
| CIF (Common Intermediate Format) or SIF (Source Intermediate Format) |
352×288 or 352x240 |
Web or portable player. |
| QCIF (Quarter CIF) |
176×144 or 176x120 |
Web or e-mail. |
| QSIF (Quarter Source or Intermediate Format) |
180x120 or 160x120 or 160x112 |
Web or e-mail. |
Containers
| Name |
Description |
| AVI (Audio Video Interleave) |
Created by Microsoft, can contain numerous video formats. |
| MOV (a.k.a. Quicktime) |
Created by Apple, can contain numerous video formats. |
| MP4 |
Container for MPEG-4 video. |
| MPG |
Container for MPEG-1 and MPEG VX/EX/HQX video. |
| DivX |
Container for DivX video. |
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