Cliff Notes:
- Download and Install ffmpegX
- Choose h.264 mencoder
- Set video resolution to 640x480 and bitrate to 1185 kbit/s
- Set audio to AAC
- 192 kbit/s bitrate, 48000 khz sampling, Stereo channels, VBR mode,
- Deinterlace if interlaced source
- Use CABAC, b-frames, two-pass encoding, and UNCHECK Constant bitrate
- Scaling method: bicubic spline, ME function: Exhaustive.
- Press "Encode" and come back in an hour.
First thing's first, you need to download ffmpegX. This is a freeware program. You can use it as long as you want without a fee, and you can also choose to register it for a small fee. You don't lose any functionality if you don't register it though.
I'll assume you're new with Mac and give you a couple steps on installing. First download the DMG file. DMG files are Mac's way of creating virtual drives and most, if not all, Mac programs that are downloaded come in DMG form. By double clicking on the file a new drive will appear on your desktop and open up in a window. Here's where it gets a bit different from Windows users. There's no complex install wizard or setup or guide. Installing a program on a Mac is as simple as dragging the icon into your Applications folder. Some programs (Skype comes to mind) even include a link to your Applications folder in the DMG file to make it even simpler. The program will copy itself over and once it's done you've installed ffmpegX. I'm not clear on whether or not Mac maintains a registry of all installed software and such, but from a consumer's point of view, it's all self contained in the APP file.
Drag and drop your original file into the top text box. This will fill in the file name as well as the information on your file in the left boxes under "Source format." My preferred target format is h.264 in an MP4 file. I choose "h.264 mencoder" under the drop down menu. Now it's time for the different settings.
Click to the "Video" tab. Typically I need to reset the resolution back to the original size, in my case 640x480. Under the bitrate calculator are 6 buttons. Rate, Time, Best, Auto, Size, and Img. If you hover your mouse over the button there'll be a short tool tip explaining what each does. The only two I really use are "Best" and "Size." First I'll press "Best" to see what the suggested bitrate is for optimal quality. Now that I have an accurate bitrate I'll press "Size" just to see for my own information approximately how large the file size will be. The bitrate box is probably pretty accurate to set values, but I think the MB box is only used to display values. The Video Bitrate box will display red text if the bitrate level is too low for the resolution, green if it's an ideal value, or blue if it's too high and you've passed the point where you'll gain quality by having a larger file. My "Auto" button usually sets a Video Bitrate of 1078 kbit/s. From testing, I usually find a value of 1185 kbit/s to be the highest setting while still remaining in this ideal portion. Feel free to play around with the numbers to see what works best for you. ffmpegX's help page on the Video tab here.
Audio can be just as important as video in a project. To get highest quality at the best compression I use the AAC setting, with the parameters or 192 kbit/s bitrate, 48000 khz sampling, Stereo channels, and VBR (Variable Bit Rate) mode. By using VBR areas with more complex sound are given higher bitrate and room to squeeze in all those sounds, while quiet or empty areas are given less bitrate because it doesn't need it. The actual bitrate will be jumping all over the place during playback, but I feel that this is a more efficient (albeit slower) way to get better quality audio and reduce file size. More info on ffmpegX's page on the Audio tab here.
The only thing you'll need to do on the "Filters" tab is deinterlace if your source video is from an interlaced format such as a DV camcorder. Personally I prefer to deinterlace in the video editor, such as Final Cut. You can pick if the odd or even lines go first and see how it looks afterwards. There's mixed responses about using the deinterlace option with ffmpegX. If your format is interlaced and you're only going to be encoding with it, then you should definitely check this box. More info here.
The most confusing tab is most likely the "Options" tab. Everything I choose here results in higher quality/longer encoding times/smaller files. Any and all of the above. I haven't actually spent time encoding it in fast and easy method and compared quality and file size to comprehensive approach I take. It's not like I can't do other things while I encode (as long as they don't take up too much CPU! You don't want to mess things up while encoding), such as chat or surf the web, so I choose the most exhaustive approach for that bit of extra quality. It's worth it to me. I check the options Use CABAC, Use b-frames, and Two-pass encoding. Also to note I UNcheck Constant bitrate, for the same reason I use variable bitrate in audio. CABAC allows improved encoding and small file sizes at a price of time. B-frames reduce the file size. Two-pass encoding allows it to encode once to first calculate the bitrate statistics, then use that information for optimal settings during the second and final pass. For scaling method I choose "bicubic spline." I'm fuzzy on what these exactly do, but this is what the website says:
Selects the algorithm used to resize the image. Choose the default "fast-bilinear" when speed is important. For better image quality but slower encoding, you can choose either Bicubic (best for upscaling, ie scaling to a larger size), Bilinear (best for downscaling, ie scaling to a smaller size than source), Lanczos, or Bicubic spline (sharp picture).
I usually just set it to Bicubic spline because I'm encoding it at the same size. It's just my all purpose setting. For the ME function I choose "Exhaustive." For more info on the Options tab check out their page here.
Well, those are all the settings that I personally use. If you have different settings you like more then let me know.
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