Jeroen,
A MIPS connected to a television... cool !!
The waveform looks like its from the start of decoding (ie the first few frames). If you look at the output after many more frames does it get any closer to what you expect ??
Try zeroing the malloc'ed memory in layer3.c and decoder.c before it is used (or remove the mallocs and use static arrays).
Try defining FPM_64BIT instead of FPM_DEFAULT and recompiling.
Did you have to do anything strange to the source or Makefiles to get libmad to build with the ghs compiler ??
Andre --
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