| Identifying and converting digital video file formats | | | | and is supported by virtually all playback software |
| can be confusing and frustrating because of the | | | | programs. Although the quality is similar to that of |
| large number of file types used in the industry | | | | AVI, the file size is much smaller than an AVI file. |
| and the strange names used to identify them. | | | | Codec problems are must less common in MPEG |
| Here is an easy-to-use guide to help you deal with | | | | files than AVI files. MPEG is the closest thing to a |
| the 40 or so types of formats that today's digital | | | | universal video format on the market today. |
| videos can be saved in. | | | | * ASF (WMV) - ASF files have the.wmv |
| It's not widely known, but digital video files actually | | | | extension, and are more commonly known as |
| have two layers. The outer layer is called the | | | | WMV files, even though WMV is actually a codec |
| container. The container is also called a "wrapper," | | | | name, not a container name. WMV stands for |
| because it wraps together all the different subfiles | | | | Windows Media Video and is a proprietary file |
| that work together as a video. The inner layer of | | | | format owned by Microsoft. This means you will |
| subfiles is called the codec. Codecs usually consist | | | | either need Windows Media Player installed on |
| of a video file plus an audio file. When you play | | | | your computer, or you will need to convert the |
| back the video on your computer, personal music | | | | WMV file into a format that your player |
| player, cell phone, or DVD player, the codec files | | | | recognizes. Windows Media Player is available for |
| work together inside the container to give you a | | | | Windows or Mac free of charge. ASF/WMV files |
| seamless viewing experience. | | | | are suitable for computer playback or for |
| The names of the five most common container | | | | uploading to the internet. |
| formats are probably familiar to you. They are | | | | * Flash - These files have the.flv extension and |
| AVI, MPEG-4, ASF (which is actually WMV), Flash, | | | | are used almost exclusively for uploading to the |
| QuickTime, and 3GPP. There are many more | | | | internet. If you've ever watched a YouTube |
| obscure container types, but most of the time | | | | video, you've seen Flash video in action. The file |
| you'll be dealing with one of the "Big 5." | | | | size is tiny, it streams over the internet into your |
| Usually, you only need to know what type of | | | | browser quickly, and the quality is usually poor. |
| container file your video is stored in to tell you | | | | The playback software for Flash is a proprietary |
| whether you can play it on your playback device. | | | | program by Adobe that comes pre-installed on |
| Occasionally, however, one of the codec files | | | | most browsers like Internet Explorer and Firefox. |
| inside the container will be written in a format that | | | | Codec problems can occur with Flash, but they |
| your player software doesn't recognize. When this | | | | are usually easy to fix by updating your browser |
| happens, your playback device will reject the | | | | to the latest version. |
| video file even though it is supposed to play that | | | | * QuickTime - These files have the.mov |
| type of file. If you run into this problem a lot, | | | | extension. They require the proprietary |
| your best bet is to purchase video converter | | | | QuickTime player software developed by Apple, |
| software that supports the highest number of | | | | which is available for both Mac and Windows free |
| container and codec types you can find, and use | | | | of charge. The MPEG-4 container is a |
| it to convert the files into a format that your | | | | non-proprietary version of the QuickTime |
| player recognizes. | | | | container, so if a codec works in MPEG-4, it |
| Here is a look at the "Big 5" container formats | | | | generally will work in QuickTime too. QuickTime is |
| and their pros and cons: | | | | a virtually trouble-free video format that works |
| * AVI - These files have the.avi extension. AVI is | | | | well for playback on your computer or streaming |
| a very common format in video cameras, | | | | over the internet. |
| particularly inexpensive models such as the Flip. | | | | * 3GPP - These files have the.3gp extension and |
| AVI works acceptably well for playing back on a | | | | are formatted exclusively for playback on a |
| personal computer because it's widely used, so | | | | handheld device like a cell phone, smart phone, or |
| most playback programs support it. AVI's biggest | | | | personal desk assistant. 3GPP works great when |
| problems are needing a large file size to maintain | | | | recorded on a handheld device and then played |
| quality, and wild variations in the codec formats | | | | back. The video quality will vary depending on the |
| inside the AVI container. It's very common for a | | | | quality of the device that recorded it, and can |
| player to reject an AVI file, even though it's | | | | range from poor to excellent, similar to the |
| supposed to play AVI files, because one of the | | | | differences in photos taken with cell phone |
| codec files inside the AVI container is written in a | | | | cameras. QuickTime will play back 3GPP files on a |
| code that the player doesn't recognize. | | | | computer, but very few other player programs |
| * MPEG-4 - These files have the.mpg or.mp4 | | | | will handle 3GPP files. Conversion software is |
| extension. There are many types of MPEG files, | | | | usually needed to transfer videos between a |
| but MPEG-4 is the most common. MPEG-4 is the | | | | computer and a handheld device in a playable |
| best format for playing back files on a personal | | | | format. |
| computer because it's such a common format | | | | |