/* Generates a constant square wave sound with a given frequency in Hertz for
a duration in milliseconds */
void beep_play(unsigned int frequency, unsigned int duration,
unsigned int amplitude)
{
mixer_channel_stop(PCM_MIXER_CHAN_BEEP);
if (frequency == 0 || duration == 0 || amplitude == 0)
return;
if (amplitude > INT16_MAX)
amplitude = INT16_MAX;
/* Setup the parameters for the square wave generator */
beep_phase = 0;
beep_step = 0xffffffffu / NATIVE_FREQUENCY * frequency;
beep_count = NATIVE_FREQUENCY / 1000 * duration;
#ifdef BEEP_GENERIC
beep_amplitude = amplitude;
#else
/* Optimized routines do XOR with phase sign bit in both channels at once */
beep_amplitude = amplitude | (amplitude << 16); /* Word:|AMP16|AMP16| */
#endif
/* If it fits - avoid cb overhead */
const void *start;
size_t size;
/* Generate first frame here */
beep_get_more(&start, &size);
mixer_channel_set_amplitude(PCM_MIXER_CHAN_BEEP, MIX_AMP_UNITY);
mixer_channel_play_data(PCM_MIXER_CHAN_BEEP,
beep_count ? beep_get_more : NULL,
start, size);
}
static int
dissect_beep_more(tvbuff_t *tvb, int offset,
proto_tree *tree)
{
proto_item *hidden_item;
int ret = 0;
switch (beep_get_more(tvb_get_guint8(tvb, offset))) {
case BEEP_COMPLETE:
if (tree) {
hidden_item = proto_tree_add_boolean(tree, hf_beep_complete, tvb, offset, 1, TRUE);
PROTO_ITEM_SET_HIDDEN(hidden_item);
proto_tree_add_text(tree, tvb, offset, 1, "More: Complete");
}
ret = 0;
break;
case BEEP_INTERMEDIATE:
if (tree) {
hidden_item = proto_tree_add_boolean(tree, hf_beep_intermediate, tvb, offset, 1, TRUE);
PROTO_ITEM_SET_HIDDEN(hidden_item);
proto_tree_add_text(tree, tvb, offset, 1, "More: Intermediate");
}
ret = 1;
break;
default:
if (tree) {
hidden_item = proto_tree_add_boolean(tree, hf_beep_proto_viol, tvb, offset, 1, TRUE);
PROTO_ITEM_SET_HIDDEN(hidden_item);
proto_tree_add_text(tree, tvb, offset, 1, "PROTOCOL VIOLATION: Expected More Flag (* or .)");
}
ret = -1;
break;
}
return ret;
}
