diff options
Diffstat (limited to 'apps/systemlib/mixer.h')
| -rw-r--r-- | apps/systemlib/mixer.h | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/apps/systemlib/mixer.h b/apps/systemlib/mixer.h index cd110f01e..d65041ea7 100644 --- a/apps/systemlib/mixer.h +++ b/apps/systemlib/mixer.h @@ -161,8 +161,8 @@ __EXPORT float mixer_mix(struct MixMixer *mixer, float *controls); /** * Check a mixer configuration for sanity. * - * @param mixer The mixer configuration to be checked. - * @param control_count The number of controls in the system. + * @param mixer The mixer configuration to be checked. + * @param control_count The number of controls in the system. * @return Zero if the mixer configuration is sane, * nonzero otherwise. */ @@ -177,17 +177,18 @@ __EXPORT int mixer_check(struct MixMixer *mixer, unsigned control_count); * scaler in the file is always the output scaler, followed by the input * scalers. * - * M: <control count + 1> + * M: <scaler count> * S: <control> <negative_scale> <positive_scale> <offset> <lower_limit> <upper_limit> * S: ... * - * The <control> value for the output scaler is ignored. + * The <control> value for the output scaler is ignored by the mixer. * * Multiple mixer definitions may be stored in a single file; it is assumed that - * the reader will know how many to expect and read accordingly. Mixers may be - * 'skipped' in a file by setting indicating that the mixer has only one scaler - * (the output scaler). This results in a mixer with zero controls, which will - * always generate output corresponding to the output scaler offset. + * the reader will know how many to expect and read accordingly. + * + * A mixer entry with a scaler count of zero indicates a disabled mixer. This + * will return NULL for the mixer when processed by this function, and will be + * generated by passing NULL as the mixer to mixer_save. * * @param fd The file to read the definitions from. * @param mixer Mixer is returned here. |