I encoded a new album (Black Sabbath - Live Evil) with oggencGT3b1 at -q 6 and I realized, that the encoding speed increased during the first five tracks. How is this possible? I already had tested encoding the same track many times. The encoding speed rised until the third try. Then it kept constant.

btw. I'm using an Ahtlon XP @ 1.100MHz with 200MHz FSB, 256 MB SD-RAM PC 100

I made a list with the track lenght, the encoding speed and the average bitrate. This refers all to oggencgt3b1. Just for the ones who like to compare, I also did encoding with oggdropXPd 1.6.9 also -q 6. I don't know the rate...

It is interesting, that the difference between the average bitrate differs between 0 and 12kbps, I can not see a connection between the bitrate and the difference; I mean: A high bitrate with gt3b1 does not mean a higher difference between 1.0 and gt3b1 than a low bitrate.

Can someone explain the increasion of the encoding speed?

fragtal

edit: the tabs do not work properly... The first coloum is the track length, the second the encoding speed, the third the bitrate with oggencgt3b1 and the fourth with oggdropXPd1.0

Hmm, generally:

less kbps (averange bitrate of encoded file) = faster encoding. You can encode same file with Q=6 and with Q=-1 and compare speed.

EDIT: This affects also Ogg Vorbis 1.0

That is theoretically correct but in fact is not right. I achieved max encoding speed at -q 6 (Athlon XP 1700+, 256 MB PC133 SD RAM, oggenc x.x (it was a vorbis 1.0, but I can't remember the version of oggenc) which was 11,6. It was even faster than MP3pro with 11,0 @ 64kbps. I reached only 11x and below with higher and lower bitrates of vorbis.

fragtal

Ehh, this affect specific encoder only.

For Ogg Vorbis files encoded with higher bitrates need more time to encode than files encoded with Ogg Vorbis with lower bitrate.

For mp3PRO files encoded with higher bitrates need more time to encode than files encoded with mp3PRO with lower bitrate.

But Ogg Vorbis and mp3PRO are different...

You asked why speed increased, so You know - because of lower bitrate. Why Encoder X for ~160kbps encodes faster than Encoder Y for ~64kbps - this is another question.