12 Oct
2002
12 Oct
'02
1 p.m.
Hi,
Laura Conrad hat gesagt: // Laura Conrad wrote:
A technical but mostly non-linux friend was asking me
about where Ogg
Vorbis is relative to MP3's, given the current status of MP3 encoding
software.
I did a quick test of making an ogg from a wav, and my naive version
produced:
[lconrad@tuba renfaire]$ ls -l hercules*
-rw-rw-r-- 1 lconrad lconrad 4526080 Aug 18 14:14 hercules2.mp3
-rw-rw-r-- 1 lconrad lconrad 12220015 Sep 3 12:30 hercules2.ogg
-rw-rw-r-- 1 lconrad lconrad 49956104 Aug 18 14:09 hercules2.wav
I used ecasound to do the encoding, but what my ecasoundrc says it did
is:
ext-ogg-output-cmd = oggenc --raw -o %f
oggenc is:
[lconrad@tuba renfaire]$ oggenc -v
OggEnc v0.8 (libvorbis rc2)
oggenc 1.0 is out. You maybe should upgrade.
So my question is, is there a way to get the ogg file
down closer to
the size of the mp3 file?
You can encode ogg files in various ways:
1) Quality 0-10 (--quality)
gives you a file with a variable bitrate. The actual filesize is a bit
difficult to predict, but if you experiment, this is the preferred way
of ogg-encoding.
2) min-max (--max-bitrate --min-bitrate)
here you specify borders for the bitrate. This way, your file will
never be bigger than max-bitrate * duration and never be smaller than
min-bitrate * duration
With these options you could get a very small oggfile :)
3) Bitrate (--bitrate)
This is a variable bitrate like 1) but should have a bitrate around
the value you have chosen. Although this is very much like you would
use a mp3-encoder like lame or gogo, it is not recommended by the
Ogg-Team: "This uses the bitrate management engine, and is not
recommended for most users." In my observations ogg-files encoded with
--bitrate do not keep this bitrate very well, they use bitrates much
lower. So the quality isn't as good as I expected from the bitrate
option. But YMMV.
So, as with all lossy encoders, you will have to find a compromise
between filesize and audio quality.
ciao
--
Frank Barknecht _ ______footils.org__