Pro-Codec User Manual

5.5 Data Compression Factor (COMP Tab) 5 THE PRO-CODEC PLUG-IN
are not exactly repeatable from one cycle to the next. Furthermore, in some host
applications, repeatedly rewinding to the beginning of the track will also result in
unrepeatable maximum values. The discrepancies in both cases should be minor, and
not all source audio and not all codecs will be affected. So, it is not always possible to
trim exactly while auditioning, because a subsequent pass might have a slightly different
maximum value.
There is a technical reason for this, stemming from the difficulty of synchronizing the start
point of the buffer that is used to input data to the codecs.
Note:
In some situations this will be important and, for those occasions, we recommend
encoding the file offline using the Manager application. Offline encoding is exactly
repeatable however many times the file is encoded.
5.5 Data Compression Factor (COMP Tab)
The COMP tab shows the data compression
ratio for each of the selected codecs.
All of the available codecs
compress an audio data bitstream. Different
codecs compress using different algorithms,
and will compress to very different degrees.
The more recent AAC family codecs, such as
HE-AAC, HE-AACv2, and the latest xHE-AAC offer
much increased quality even at very low bit rates
and can thus produce very small files (potentially
down to around 1% of the uncompressed input file
size). As a comparison, the legacy MP3 codec results in compression factors of typically
around 12.
A yellow asterisk (if present) indicates that the figure is approximate.
Note:
Remember that using perceptual coding is always a trade-off between more accurate
reproduction of the original on the one hand, against a higher compression ratio and
smaller files on the other hand.
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