Miles Sound System SDK 7.2a

AIL_sample_output_levels

The function AIL_sample_output_levels returns the final mixer level-scaling factors for one or more combinations of source channels and destination speakers.

void AIL_sample_output_levels(
  HSAMPLE S,
  MSS_SPEAKER const * source_speaker_indexes,
  MSS_SPEAKER const * dest_speaker_indexes,
  F32 *level_array,
  S32 n_levels
);

In Parameters

S: indicates the HSAMPLE for which the mixer output levels are to be retrieved.
source_speaker_indexes: specifies an array of one or more channels in the source data.
dest_speaker_indexes: specifies an array of one or more speakers.
n_levels: specifies the number of entries in level_array, source_speaker_indexes, and dest_speaker_indexes.

Out Parameters

level_array: an array of coefficients from 0.0 to 1.0 which represent the amplitude levels of the given sample channels at the given speakers.

Discussion

This function lets you retrieve the per-channel volume scale factors that result from all dry-path attenuation processes inside MSS. These factors are derived from the products of 3D distance and cone attenuation (if any), obstruction, per-sample and per-speaker reverb dry levels, volume/pan control, the DIG_LEVEL_RAMP_SAMPLES process, and per-sample channel levels associated with the AIL_set_sample_channel_levels function. (They do not include any modifications to the actual sample values performed by DSP pipeline filters.)

This function will have no effect with per-voice hardware drivers that don't use the Miles software mixer. Currently, this applies only to the Xbox 1 and MSS_MC_DIRECTSOUND3D and MSS_MC_EAX? values from the MSS_MC_SPEC list.

Uses for this function include dynamic prioritization of samples and audio pipeline debugging.

For a detailed understanding of per-channel level control, you should carefully review the How do I use multi-channel sound output in Miles? FAQ before attempting to use this function. You may also wish to examine the Digital Audio Pipeline section.

Group: Digital Audio Services, The Digital Audio Pipeline
Related Functions: AIL_set_sample_channel_levels
Related Basic Types: F32, HSAMPLE, MILES_PREFERENCES, MSS_MC_SPEC, MSS_SPEAKER, S32, void
Related FAQs: How do I use multi-channel sound output in Miles?