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Q: How can I display a limited set of components in
the SCRequestImageSettings dialog? I've been able to select
a component and make it the default, but I cannot remove the
other components from the list. I tried using
scListEveryCodec but that didn't seem to help.
A: Although documented in the 'Sound Dialog
Selectors' section of the QuickTime API reference, the
selector you're looking for is scCompressionListType.
Use this selector with SCSetInfo(). Pass in a
pointer to a handle which contains an array of values of
type OSType indicating the codecs you want presented to the
user. Passing in NULL will reset the list. See Listing
1.
const UInt8 kNumberOfTypes = 4;
Handle theTypesList = NULL;
OSTypePtr pTypesList = NULL;
SCSpatialSettings theDefaultChoice = { kSorenson3CodecType,
(CodecComponent)kSorenson3CodecType,
32,
codecNormalQuality };
...
// limit the list to four - or however many you want
theTypesList = NewHandle(sizeof(OSType) * kNumberOfTypes);
if (theTypesList) {
HLock(theTypeList);
*pTypesList = (OSTypePtr)*theTypesList;
pTypesList[0] = kH261CodecType;
pTypesList[1] = kH263CodecType;
pTypesList[2] = kSorensonCodecType;
pTypesList[3] = kSorenson3CodecType;
SCSetInfo(ci, scCompressionListType, &theTypesList);
DisposeHandle(theTypesList);
}
// set up the default choice
SCSetInfo(ci, scSpatialSettingsType, &theDefaultChoice);
...
SCRequestImageSettings(ci);
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Listing 1.
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You shouldn't need to use scListEveryCodec, it will show
multiple variants for a given codec. For example, if you
have your own JPEG codec it will show yours as well as the
one built into QuickTime.
[Jul 24 2001]
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