HTML and CSS Reference
Figure 3-18. soundcloud.com search options
Pick any song that has a high frequency range (something from the dub step
genre would be a good choice) and download it. This should give you an
uncompressed WAV or AIFF file to experiment with.
Our aim for this music track is to get the file size to between 0.5 and 1 MB for
every minute of audio. This should equate to taking 4--8 seconds to load 1
minute of audio on HSDPA or 1--2 seconds on 3G. Table 3-8 should be used
when trying to calculate how long it may take to download 1 MB of data on
mobile data networks.
Table 3-8. Average Download Times for Audio
Average Download Speed
Average Download Time (per MB)
The sample track for this topic is a WAV file with these settings: 86.1 MB, 4:59 in
time size, averaging at 18.75 MB per minute. The target file size for this track for
each format will be between 4 and 5 MB.
You will encode the audio file in the OGG format first. It's the simpler of the two,
as Audacity provides a single option to configure. Open Audacity and open your
file by going to File Open, and select the file you have just downloaded. If you
are presented with the warning shown in Figure 3-19, ensure that ''Make a copy
of the files before editing (safer)'' and ''Don't warn again and always use my
choice above'' are both checked.