Ratefix
Introduction
How a Sample Rate Error Occurs.
The Effects of a Sample Rate Error.
Limitations. (This doc)
How Ratefix works
Limitations
- Ratefix can salvage files with some but not all Sample Rate Error problems.
It will only tackle situations where the source sample rate was lower than the destination sample rate. If the source sample rate is higher than the destination rate, instead of repeated samples there will be missing samples. This is much harder to detect and correct reliably. This version of Ratefix does not address this situation.
- There is no certainty how a device will behave when fed with data at a different rate to its clock. Many devices seem to either repeat a sample or insert a random value (seen as a spike). Other devices may behave differently. In particular if a device detects it has lost sync it may mute the input for a period of many, many samples. There is nothing Ratefix can do in such circumstances.
- Spikes are typically either random values or full scale values (+ve or -ve). Random values may not be readily detectable if they happen to fall close to a valid data value.
- Ratefix works best where the audio is at a reasonable level. If the audio is at very low level many samples will be close to zero making Ratefix's job harder.
