问题
Given an audio file of duration 10s, if I want to seek to 2s, how do I obtain the sample frame offset?
回答1:
if it's LPCM (e.g. not compressed), then use the sample rate.
in pseudocode:
double sampleRate = audioFile.getSampleRate();
size_t offsetInSeconds = 2;
size_t sampleToRead = sampleRate * offsetInSeconds * audioFile.getChannelCount();
AudioSample sample = audioFile.getSampleAt(sampleToRead);
来源：https://stackoverflow.com/questions/4896472/obtain-sample-frame-offset-corresponding-to-certain-time-in-audio-file-iphone