So far I’ve talked about getting 60 fps video, generic deinterlacing, cropping and resizing. This time I’m going to take it in a slightly different direction. This time it’s all about video encoding. There are tons of different encoding formats and in some cases multiple encoders for the same format. I’ll try to use a simile. Encoding formats are like a language you can describe video in, different encoders that have the same target language can still make different translations. I have to admit this text is pretty simple, straight-forward and boring. I suggest you only read it if you're very new to video encoding and video editing. I'll talk about more advanced topics in the next installment. Here are some phases of video production you might find yourself in. I’ll suggest some formats and encoders for each one.
Digitizing
That’s just another word for capturing video from analog sources. At this point in time performance is essential. Usually you have enough processing power to do a reasonable amount of compression and still keep up with the rate of incoming data. Many encoders for a broad range of formats can perform compression at real-time speeds, so you have many options. You want to maintain a high level of quality because you’ll perform many more steps before the end product and every time you recompress (with a lossy encoder) you lose quality. The simplest solution would be to capture using a lossless encoder. The raw RGB24 format produces exceptionally large files, but if you have the disk space and disk-writing speed, it’s a viable option. Huffyuv is also lossless, but does some compression to lighten the bandwidth and storage space load. MJPEG is a lossy format with some very fast encoders available. The highly optimized Windows Media Encoder can get you high quality captures without dropping frames. Your options here are limited by how fast your processor is.
Digital Video
If you’re using video from your camcorder that uses the DV format, your video is already digitized. Bringing it to your computer through firewire or other means is lossless so you won’t need to recompress anything. DV is actually a good format for editing purposes. Some software is optimized for the DV format. There are several DV formats that differ slightly, but there are some tools available for converting between them without having to actually decompress and recompress.
Pre-processing
Once you have your high quality captures you might want to perform some pre-processing steps before you use them for editing. Again, it’s advisable to keep your quality standard very high. Keeping to a lossless format is still viable if you have enough storage space. However, if you need to edit on the go on multiple computers it’s annoying to carry around a whole set of DVD’s that you need to update every time you change something. There are many reasons you might want to use something like a bit-rate Mpeg-4 instead. Xvid is a free encoder that supports Advanced Simple Profile (most widely supported ‘version’ of Mpeg-4). Encoding your video in 7 Kbit/s might be acceptable depending on your standards. The same holds true for Windows Media, h264 and even Mpeg-1.
Final Product – Internet Distribution
At this point you want to make sure you can reach a large audience, so you don’t want some obscure format that people need to download an extra codec for. I was pleasantly surprised to find out that many people were already able to play h264 content when I released my video. WMV is obviously widely supported because of the dominance of the Windows OS. Windows Media Player automatically updates it’s support for newer versions of WMV, so you need not worry. If you intend to YouTube your video, you have to make sure what you upload is the highest quality you could squeeze into 320x240. YouTube does its own (IMO crappy) resizing and then compresses it into the Flash Video format.
Final Product – Digital Media
If you intend on releasing a DVD, SVCD or VCD, there are some very specific rules you must adhere to. Software like Nero’s series of DVD publishing application are an all in one package for encoding. I highly suggest you use that instead of dealing with the directory structure, meta-data files etc. Even if digital media is not your end-goal, encoding with DVD compliant settings gives you the option of doing it later.
Tools
VirtualDub is handy for making AVI files, but nothing else. If your format is Mpeg-1 use the Tsunami encoder. If it's Mpeg-2, ummm... buy an encoder (Tsunami has it if you pay for it). If it's Mpeg-4 or h264, then you can still use VirtualDub, because there are VFW encoders for both of those: Xvid and x264. Remember that using VirtualDub is not easy for beginners and there are more modern simple options to encode into a high quality format. Windows Media Encoder is a good example, though its many buttons and tabs may seem intimidating at first. There is a simple user-friendly solution to Mpeg-4 called Real Anime Encoder. It uses Mp4box as a base, as do many other all-in-one solutions.
