&fmt=18 does not give the same quality as playing by "high quality

[arminio]

Famous Youtube "&fmt" parametter has bug or what?!

Video encoded in H.264 in 640x360 after upload and encoding has "high quality" link which give very good and superior quality than "normal" playback. Now, if I try to play it with &fmt=18 parametter, youtube plays it with something between normal and high!?

Check this video to see what I mean:

normal quality: http://www.youtube.com/watch?v=XXXJ28OLg3Y - playback is bad

Click on "hight quality" - playback is very good

&fmt=18: http://www.youtube.com/watch?v=XXXJ28OLg3Y&fmt=18 - clearly better than norman but also less quality than playback after clicking on "high quality"

This is particulary visible at the begining when logo fades in and out...

It is obvious that &fmt=18 does not give the same quality as clicking on "high quality" below video! Any ideas why and how to force that "clicked" high quality in URL?

[k.]

It was always that way. I don't know if it was confirmed but there were speculations that the &fmt=18 version was for apple tv.
The "watch in high quality" button gives you &fmt=6 or &fmt=35.

[arminio]

Thanks for info!

See, I already tried 35 and 6 and both values gave me low ("normal") quality. Video is uploaded yesterday and I tried every known fmt value since then and last time I checked (before 2 hours) nothing except 18 worked! But now, 35 works! Looks like youtube needs long time to proccess video in all formats...

Thanks!