I have a huge number of low-res Flash videos (480x270, 30 fps, 800 Kbps) and I want to resample all those videos in 1280x720 with some added spatial sharpening and lomo filters to make them look nicer. I intend to store these larger videos on a HDD and also upload them on YouTube.
The total running time of the videos is around 50 days, so I'm not going to use a lossless codec. I experimented a bit and found that anything over 2 Mbps (H.264) didn't result in a noticeable increase in visual quality, which isn't surprising considering the tiny original resolution. 50 days at 2 Mbps is about 1 TB which would be great.
The problem is that YouTube seems hell-bent on re-encoding anything that is being uploaded regardless of the actual bitrate, so even though the local 1280x720 videos look great the uploaded 1280x720 videos look awful. I found some official recommended upload encoding settings but using those settings still results in compression artefacts.
How can I avoid the artefacts from YouTube's lossy re-encode without uploading videos of a significantly higher bitrate?
(I'm currently using Avidemux for resampling/re-encoding but from what I've read most people use Handbrake or MeGUI; should I switch or is Avidemux fine for my purposes?)