A PSF format bug

[umjammer]

as for DQ samples

some songs are silent.

opus5 said

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A bug in aosdk that I faithfully reproduced. In psx_bios_hle, DeliverEvent (B0 0x07) leaves the function with a bare return when the target event isn't active:

if (Event[ev][spec].status != LE32(EvStACTIVE))
{
    printf("event not active\n");
    return;            /* skips the "PC = RA" every other path falls through to */
}

That leaves the pc sitting on the HLECALL instruction that got us there, so the next step runs the same call again — for ever. The sound driver never advances, no voice is ever keyed, and the output is silence.

The probe made it obvious. In a track that works, the CPU idles in the driver's main loop; in a silent one it never leaves the kernel vector:

916 (plays)   peak=9500   pc 800f01a4 ×1306   pc 800f01a8 ×461
917 (silent)  peak=0      pc 000000b0 ×1950   ← t1=0x07, a0=0xf0000009

PsxHw now breaks instead, falling through to PC = RA like every other call.

---

-                    return;
+                    // Nothing to deliver, but the call still has to return: aosdk leaves the
+                    // function here instead, which skips the "PC = RA" at the bottom and leaves
+                    // the pc on the HLECALL that got us here, so the next step runs the same
+                    // call again and the song spins at 0xb0 for ever. Fourteen of the forty six
+                    // tracks of Dragon Quest Monsters 1+2 are silent in aosdk for this reason.
+                    break;