Unlike digital photos, there isn't a common standard for videos. If someone sends you a JPG, and all cameras save photos as JPGs, you'll be able to view it on any computer - even smartphones and tablets.
With videos, things get tricky. Different devices shoot in different formats, and playback devices such as smartphones, tablets, games consoles, TVs, and media streamers may not support all formats usually not the one you're trying to play.
Your HD camcorder probably stores footage as AVCHD (.m2ts), while your digital camera could use anything from QuickTime (.MOV), Flash (.FLV) or MPEG-4 (.MP4) to Motion JPEG for videos. Mobile phones also use a range of formats from low-resolution .3GP clips through to 1080p .MP4 files.
Similarly, if you've recorded a video for your website, it would be nice to use the high-quality version from your camcorder. However, the raw files will be too big for people to download, and the video will probably stutter when visitors try to stream it.
This is where video converters come in. These tools allow you to import one or more video clips and convert them to a different format. They support a wide range of formats, so can handle most common formats. Some can cope with multiple audio tracks (for different languages, say) and subtitles.
To keep things simple, most allow you to choose your device, such as a 4th-gen iPod touch, rather than asking you to choose a video format. Some utilities have more presets than others, so your device may or may not be included in the list, depending on its popularity.
There are plenty of free and paid-for versions, and we'll make a few recommendations to help you out. One of our favourite free options is Any Video Converter. It's not amazingly quick, but it does a reliable job and is fairly easy to use.
Freemake is even easier to use, but we've had mixed results - converted videos occasionally that had out-of-synch audio or corruption across the bottom edge. Still, for free, it's hard to complain, and Freemake even supports nVidia Cuda. If you have a compatible graphics card, the conversion process can be hugely speeded up. Both Freemake and Any Video Converter are regularly updated and have a good range of presets.
Another popular free option is Handbrake. This has always been reliable, but lacks presets: the latest version has only 'iPad' and 'iPhone 4'. It's not particularly easy to use, especially if you want to convert several videos at once.
The process with all converters is the same though. You point the program to the video you want to convert, choose a device preset or video format, give it a filename and location for the converted video and press the 'Convert' button.
Depending on the length of the video and your hardware, the conversion could take anything from a few seconds to many hours to complete.
Paid-for converters include CyberLink MediaEspresso. It costs £35, but includes support for Intel Quick Sync, nVidia Cuda and AMD APP to vastly speed up the conversion process. MediaEspresso can also convert photos and music into the bargain.
If you have video editing software, it will be able to export your edited movie in a variety of formats, and may have presets similar to the converters we've already mentioned.
Next page: Understanding video formats