SNDRV_SFNT_SAMPLE_UNSIGNED
if (mode & SNDRV_SFNT_SAMPLE_UNSIGNED)
xor = (sp->v.mode_flags & SNDRV_SFNT_SAMPLE_UNSIGNED) ? 0 : 0x80808080;
xor = (sp->v.mode_flags & SNDRV_SFNT_SAMPLE_UNSIGNED) ? 0x80008000 : 0;
smp->v.mode_flags |= SNDRV_SFNT_SAMPLE_UNSIGNED;