Which codec should I use for HD YouTube Videos?
We wanted to upload some of our video projects to YouTube. But which format would produce the highest quality, after YouTube's processing? We decided to test four of the most popular formats: MPEG-2, AVC, Windows Media, (16Mbit/sec each) and uncompressed (over 800 gigabytes per hour!). Which do you like best?
In terms of artifacts in the image, we did not notice any differences between the formats, with the naked eye. We did notice colour shifts, but none were dramatic enough for us to be able to decide that one format was clearly better than another.
Here is the amount of time it took our hardware to encode each version:
MainConcept MPEG-2 16Mbps - 10:01
Uncompressed - 13:19
AVC 16Mbps - 36:24
Windows Media 16Mbps - 24:14
For future projects, we anticipate using MPEG-2. Since it encoded in the shortest amount of time, it is an excellent choice for our purposes. It's true that AVC can theoretically produce a better quality image at the same bitrate, however since YouTube videos are re-encoded at a compartively low bitrate, we do not find the improvement worthwhile.
The above samples, in order: MPEG-2, Uncompressed, AVC, Windows Media.
I wold love to know what youtube's actual transcoding settings are for their various resolutions etc, as theoretically, if you transcode you video directly to the youtube HQ settings, they may not re-encode that version... resulting in no loss of transcoding quality to what you have given them.
From what I could tell it looks like MPEG-2 and AVC have more artifacting then the others. Even with a Cinema display I can't really tell a difference in color between them, except for the occasional moment.