ComponentResult ConfigureGain(SGChannel inChannel)

{

    QTAtomContainer         atomContainer;

    QTAtom                  featureAtom;

    VDIIDCFeatureSettings   settings;

    VideoDigitizerComponent vd;

    ComponentDescription    desc;

    ComponentResult         result = paramErr;

    if (NULL == inChannel) goto bail;

    // get the digitizer and make sure it's legit

    vd = SGGetVideoDigitizerComponent(inChannel);

    if (NULL == vd) goto bail;

    GetComponentInfo((Component)vd, &desc, NULL, NULL, NULL);

    if (vdSubtypeIIDC != desc.componentSubType) goto bail;

    // *** now do the real work ***

    // return the gain feature in an atom container

    result = VDIIDCGetFeaturesForSpecifier(vd, vdIIDCFeatureGain, &atomContainer);

    if (noErr == result) {

        // find the feature atom

        featureAtom = QTFindChildByIndex(atomContainer, kParentAtomIsContainer,

                                         vdIIDCAtomTypeFeature, 1, NULL);

        if (0 == featureAtom) { result = cannotFindAtomErr; goto bail; }

        // find the gain settings from the feature atom and copy the data

        // into our settings

        result = QTCopyAtomDataToPtr(atomContainer,

                                     QTFindChildByID(atomContainer, featureAtom,

                                     vdIIDCAtomTypeFeatureSettings,

                                     vdIIDCAtomIDFeatureSettings, NULL),

                                     true, sizeof(settings), &settings, NULL);

        if (noErr == result) {

            /* When indicating capabilities, the flag being set indicates that the

               feature can be put into the given state.

               When indicating/setting state, the flag represents the current/desired

               state. Note that certain combinations of flags are valid for capabilities

               (i.e. vdIIDCFeatureFlagOn | vdIIDCFeatureFlagOff) but are mutually

               exclusive for state.

             */

            // is the setting supported?

            if (settings.capabilities.flags & (vdIIDCFeatureFlagOn |

                                               vdIIDCFeatureFlagManual |

                                               vdIIDCFeatureFlagRawControl)) {

                // set state flags

                settings.state.flags = (vdIIDCFeatureFlagOn |

                                        vdIIDCFeatureFlagManual |

                                        vdIIDCFeatureFlagRawControl);

                // set value - will either be 500 or the max value supported by

                // the camera represented in a float between 0 and 1.0

                settings.state.value = (1.0 / settings.capabilities.rawMaximum) *

                                       ((settings.capabilities.rawMaximum > 500) ? 500 :

                                       settings.capabilities.rawMaximum);

                // store the result back in the container

                result = QTSetAtomData(atomContainer,

                                       QTFindChildByID(atomContainer, featureAtom,

                                       vdIIDCAtomTypeFeatureSettings,

                                       vdIIDCAtomIDFeatureSettings, NULL),

                                       sizeof(settings), &settings);

                if (noErr == result) {

                    // set it on the device

                    result = VDIIDCSetFeatures(vd, atomContainer);

                }

            } else {

                // can't do it!

                result = featureUnsupported;

            }

        }

    }

bail:

    return result;

}