On the Zencoder site it's said that there are 1-5 values for the transcoding speed:
A target transcoding speed. Slower transcoding allows for more advanced file compression, while faster transcoding is possible by skipping some advanced compression features. Valid values are 1-5.
And on the ffmpegsite current presets are:
ultrafast, superfast, veryfast, faster, fast, medium, slow, slower, veryslow and placebo
So can me someone tell me please, which value i have to choose if i want as encoding speed 'slow'.
According to the Zencoder Support team it is:
1:Slower
2:Slow
3:Medium
4:Fast
5:Faster