Guide to Preparing Video for YouTube
This guide covers some tricks that I think I have learned via some experimenting. Click here to skip down to my QuickTime Settings. Much of this may be applicable to others such sites.
YouTube, the popular free video distribution system, re-encodes any video you supply to it. They highly compress the result and many people complain of very poor video quality. The trick, if you will, is to upload the very best quality that you can supply. Since this is controlled from your editing software, and I am a Mac user, here are tips for using the advanced QuickTime export options on software such as iMovie. If you are unfamiliar with that option, then please refer to my iMovie Export Guide.
The first thing you must recognize, is that the better the quality of your upload file, the better that the YouTube result can turn out. Often it is difficult to tell a difference when you only make minor tweaks to your video file. I've found that exploiting every possible option can make a large difference in the video played back from YouTube.
To start with you need to choose a high quality video format (codec). I like the results of H.264 so I choose that. The Apple software allows me many options to get a great looking video. Some of the other codecs have limited settings.
For this guide, I experimented with DV footage & video made from stills, and usually found it best to leave the frames per second setting at 29.97fps for my video. When I originally wrote this guide, I found I could upload 15fps video and the result was great. The reason I did that was because I was trying to get the file size under 100MB that was imposed at the time. As of June 2010, Youtube now allows uploads of up to 2GB.
Data Rate is a key value to success. Think of this as the number of bits (information) for each second of video. The higher the number, the more information that is available to construct a cleaner looking image. I either choose to let the software automatically set it, or I set it manually to get a file size under the upload limit.
Frame rate should be left at the natural frame rate of the material you are editing. Changing it up or down, especially between 24fps & 30fps can cause odd display effects. Youtube say they do not alter your frame rate, while other sites might. Check their help pages for an answer.
Key Frames are frames with full information, while frames between them only contain partial information. The software that decodes (plays back) your digital video knows how to use the keyframes and partial frames to present you with a reasonable representation of a full image. The more keyframes you supply, the better that the software can reconstruct the in-between frames. I have actually set the key frames to every 1 frame. This is extreme but I did see some improvement in the YouTube result, although another time I would describe the result as disappointing when using a low Data Rate. So as with most of the encoding process, this is another balancing act.
Encoding is the action of converting the file from your editor to an output file. The encoder software can do a better job if it performs what is referred to as multi-pass encoding. What happens is that the software reads the entire content one time to find hints that can improve the results during the second pass where the file is finalized into your output file. Choose this option if available, but keep in mind it takes much more time.
In the past, YouTube had converted video uploads to 320x240 resolution and then would expand that by about 50% in the viewer. This is another reason YouTube videos looked like junk. They still up-res smaller videos but no longer seem to have the switch that allowed you to view the video at actual resolution.
Size options have been upgraded to pleasing affect. Youtube now supports HD up to 1080p, although as of June 2010, they still say they are experimenting with that size. The recommendation is to upload your video in it's original resolution.
Deinterlacing is the process of taking interlaced video (DV content mainly) meant for television and filling in the missing information for each frame. Television only draws half a frame at a time, although you don't normally notice it. By using deinterlacing, you give a better result to YouTube.
Audio settings also has a bit rate. Reducing the quality by reducing the bit rate, using variable bit rate and otherwise choosing lower quality options, will leave you a bit more space available that can be used for your image quality of the video. So if you do not require high quality audio, and you are hitting the upload size limit, this is an area you can further experiment with. If you don't require stereo then choose mono for your video.
Keep in mind that there is no 'one' formula. When ever I export video I often try several formulas and pick the best one for the intended use.
My starting QuickTime YouTube settings for Standard Def. Material:
- Compressor Type: H.264.
- Frame Rate: 29.97fps.
- Key Frames: Every 30 frames, up to every 60. Experiment.
- Data Rate: Automatic, or set to keep file under upload limit.
- Compressor Quality: Best.
- Encoding: Best quality (Multi-pass).
- Size: 640x480. Remember to keep the aspect ratio correct.
- Preserve aspect ratio: Select appropriate result if needed.
- Deinterlace Source Video: Select if interlaced source, such as mini DV.
Sound Settings:Since writing the above, YouTube and many sites now support HD. I do not recommend up sizing smaller video to be HD. Without high end software, the result will be pixelated, or washed out.
- Format: AAC.
- Channels: Stereo or Mono.
- Rate: I leave it, but you can probably lower it.
Show Advanced Settings:
- Render Settings:
- Quality: Normal.
- AAC Encoder Settings:
- Bit Rate Format: Variable Bit Rate.
- Target Bit Rate: 80-91 kbps.
- Precedence: Bit Rate.
Start at YouTubes Help Center page to stay current with YouTube recommendations and tips.
Sometimes the QuickTime export fails for unknown reasons. I've found that changing the Data Rate up or down can allow the export to complete.