Comment 3 for bug 797439

OK, after thinking about it there's no real way around these sort of problems (file corruption) so the best we can do is be consistent. The waveform and sample count is coming from libmad but the samplerate is coming from taglib. I just changed WaveformRenderBeat to use the libmad samplerate from the track_samplerate CO so at least if the waveform and beats will be consistent if they are wrong.