Joseph Garvin wrote:

I tried:

struct dsp_config* dsp = (struct dsp_config *)rb->dsp_configure(NULL, DSP_MYDSP, CODEC_IDX_AUDIO);
    rb->dsp_configure(dsp, DSP_SWITCH_FREQUENCY, 22050);
    rb->pcm_set_frequency(22050);
    rb->pcm_apply_settings();

But this still had no effect, at least in the simulator. Do I need to use dsp_process somehow? It's unclear to me how it works. I'm still playing the sound with pcm_play_data.

Ah, yes. pcm_play_data is a low-level interface, which is only capable of playing what the hardware supports. dsp.c can be used to do the conversions needed, as well as some other audio processing (like the equalizer). As this is "apps" code, the DSP works fine in the simulator.

By the way, from what I can tell, on Sansas (and most PortalPlayer targets), the frequency argument in pcm_set_frequency is ignored.

  Magnus

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