这是我们将要使用的标准 Quicktime 组件导出设置对话框：
该对话框仅在 Quicktime 框架中可用（不要与 QTKit 混淆），因此有以下限制：
- 仅限 32 位版本
- 没有任何 iOS 集成。
您需要做的第一件事是将您的应用程序与 Quiktime 框架链接，确保您在 32 位 Intel 架构中构建它并打开 Build Active Architecture Only 设置。
目标是打开对话框，设置必要的导出设置并使用它们导出电影。
我将以相反的顺序提供代码片段，从实际的对话框调用开始，再回到所需结构的使用。我们必须使用很多代码，所以需要一些耐心。
对话框需要 Quicktime 组件。在我们的示例中，我们将使用 MPEG4 组件。我们提供组件、先前存储的设置并打开对话框：
#import <QuickTime/QuickTimeComponents.h>
- (void)editExportSetting:(JSMovieExportSetting*)setting
{
MovieExportComponent exporter = OpenComponent(_MPEG4Component.component);
Boolean canceled;
[self updateMovieExportComponent:exporter withExportSetting:setting];
ComponentResult err = MovieExportDoUserDialog(exporter, NULL, NULL, 0, 0, &canceled);
if (!canceled)
{
if (err == 0)
{
[self updateExportSetting:setting withMovieExportComponent:exporter];
}
}
CloseComponent(exporter);
}
当用户完成编辑并单击“确定”按钮时，我们会存储设置以供以后使用。
OpenComponent 函数需要 Component 数据类型。我已经为它构建了一个便利类包装器，请参见下面的清单。
现在我们需要获取 MPEG4 组件：
- (JSQTComponent*)MPEG4Component
{
/*
MPEG-4
*/
ComponentDescription description;
description.componentType = 1936746868;
description.componentSubType = 1836082996;
description.componentManufacturer = 1634758764;
description.componentFlags = 269058096;
description.componentFlagsMask = 66207;
return [self componentWithDescription:description];
}
- (JSQTComponent*)componentWithDescription:(ComponentDescription)description
{
JSQTComponent* result = nil;
for (JSQTComponent* component in [self components])
{
if ([component isEqualToComponentDescription:description])
{
result = component;
break;
}
}
return result;
}
- (NSArray*)components
{
if (_components == nil)
{
_components = [NSMutableArray new];
QTAtomContainer resources = NULL;
OSErr err = GetComponentPublicResourceList(kQTPresetsListResourceType, 1, 0, &_componentDescription, nil, nil, &resources);
if (err != noErr)
{
NSLog(@"JSQTComponentDataModel error: %d", err);
}
else if (resources != NULL)
{
QTAtom currChild = 0;
QTAtom nextChild = 0;
OSErr err;
unsigned atomsCount = QTCountChildrenOfType(resources, kParentAtomIsContainer, 0);
for (UInt16 i=0; i < atomsCount; i++)
{
QTAtom compAtomId = 0;
if (QTFindChildByIndex(resources, kParentAtomIsContainer, kQTMetaDataCommonKeyComposer, i+1, &compAtomId))
{
Component component = (Component)compAtomId;
err = QTNextChildAnyType(resources, kParentAtomIsContainer, currChild, &nextChild);
if (err == noErr && nextChild)
{
[_components addObject:[[[JSQTComponent alloc] initWithComponent:component] autorelease]];
}
else
{
NSLog(@"Error %d getting item %d\n", err, i);
}
currChild = nextChild;
}
}
QTDisposeAtomContainer(resources);
}
}
return _components;
}
基本上，我们在列表中寻找具有我们需要的描述的组件。该列表是为了获取某种类型的组件而构建的，因为 Quicktime 曾经有很多不同的地方。
我们只对那些曾经为电影导出而创建的内容感兴趣。
ComponentDescription _componentDescription;
_componentDescription.componentType = MovieExportType;
_componentDescription.componentSubType = kAnyComponentSubType;
_componentDescription.componentManufacturer = kAnyComponentManufacturer;
_componentDescription.componentFlags = canMovieExportFiles;
_componentDescription.componentFlagsMask = canMovieExportFiles;
该列表已缓存以供进一步使用，不要忘记在您的 dealloc 中释放它。
到目前为止，我们进展顺利。我们得到了我们的 MPEG4 组件对象，从中得到了Component 结构。现在我们需要将上次存储的设置应用到组件。
- (void)updateMovieExportComponent:(MovieExportComponent)component withExportSetting:(JSMovieExportSetting*)movieExportSetting
{
NSData* presetSettings = movieExportSetting.exportSettings;
Handle settings = NewHandleClear([presetSettings length]);
if (settings)
{
memcpy(*settings, [presetSettings bytes], GetHandleSize(settings));
// Set movie export settings from the settings QTAtomContainer
MovieExportSetSettingsFromAtomContainer(component, (QTAtomContainer)settings);
DisposeHandle(settings);
}
}
如果您第一次使用该组件而没有任何设置，对话框将显示一次默认值。
用户完成编辑并按下确定后，我们需要存储设置：
- (void)updateExportSetting:(JSMovieExportSetting*)movieExportSetting withMovieExportComponent:(MovieExportComponent)component
{
QTAtomContainer settings;
ComponentResult err = MovieExportGetSettingsAsAtomContainer(component, &settings);
if (err == 0)
{
NSData* exportSettings = [NSData dataWithBytes:*settings length:GetHandleSize(settings)];
movieExportSetting.exportSettings = exportSettings;
}
}
JSMovieExportSetting 是一个包装器，请参见下面的清单。您可以轻松地将其序列化为文件以存储设置。
最后一步是使用我们刚刚获得的电影转换设置。
好消息是我们不再需要使用 Quicktime，我们可以使用 QTKit 方法。
QTMovie* movie = [QTMovie movieWithFile:sourceFilePath error:outError];
NSDictionary* settings = [movieExportSetting movieAttributes];
[movie writeToFile:outputFilePath withAttributes:settings error:outError]
设置电影委托并实现movie: shouldContinueOperation: withPhase: atPercent: withAttributes: 以查看进度（如果需要）。
您可以在下面找到所用类的列表。我希望这会有所帮助。
JSQT组件
@interface JSQTComponent : NSObject
{
Component _component;
ComponentDescription _componentDescription;
NSString* _name;
NSString* _info;
NSString* _icon;
}
- (id)initWithComponent:(Component)component;
@property (nonatomic, readonly) Component component;
@property (nonatomic, readonly) ComponentDescription componentDescription;
@property (nonatomic, retain) NSString* name;
@property (nonatomic, retain) NSString* info;
@property (nonatomic, retain) NSString* icon;
- (BOOL)isEqualToComponentDescription:(ComponentDescription)anotherComponentDescription;
@end
@implementation JSQTComponent
@synthesize 组件 = _component;
@synthesize componentDescription = _componentDescription;
@synthesize name = _name;
@synthesize info = _info;
@synthesize 图标 = _icon;
(id)initWithComponent:(组件)组件
{
self = [超级初始化];
如果（自我！=零）
{
_component = 组件；
[自我获取描述];
}
回归自我；
}
(void)dealloc
{
[_名称释放]；
[_信息发布];
[_icon 发布];
[超级释放];
}
-
(void)getDescription
{
OSErr 错误；
句柄 aName = NewHandleClear(255);
句柄 anInfo = NewHandleClear(255);
处理 anIcon = NewHandleClear(255);
处理 iconSuite = NULL;
err = GetComponentInfo(_component, &_componentDescription, aName, anInfo, anIcon);
如果（错误 == 0）
{
self.name = [NSString stringWithPStringHandle:aName];
self.info = [NSString stringWithPStringHandle:anInfo];
self.icon = [NSString stringWithPStringHandle:anIcon];
//err = GetComponentIconSuite(aComponent, &iconSuite);
}
DisposeHandle(aName);
DisposeHandle(anInfo);
DisposeHandle(anIcon);
DisposeHandle(iconSuite);
}
(BOOL)isEqualToComponentDescription:(ComponentDescription)anotherComponentDescription
{
return (_componentDescription.componentType == anotherComponentDescription.componentType) &&
(_componentDescription.componentSubType == anotherComponentDescription.componentSubType) &&
(_componentDescription.componentManufacturer == anotherComponentDescription.componentManufacturer);
}
@结束
JSMovieExportSetting
@interface JSMovieExportSetting : NSObject <NSCoding>
{
NSString* _name;
NSNumber* _componentSubType;
NSNumber* _componentManufacturer;
NSData* _exportSettings;
NSDictionary* _movieAttributes;
}
- (id)initWithName:(NSString*)name attributes:(NSDictionary*)attributes;
@property (nonatomic, retain) NSString* name;
@property (nonatomic, retain) NSNumber* componentSubType;
@property (nonatomic, retain) NSNumber* componentManufacturer;
@property (nonatomic, retain) NSData* exportSettings;
@property (nonatomic, readonly) NSDictionary* movieAttributes;
@end
@implementation JSMovieExportSetting
...
- (NSDictionary*)movieAttributes
{
if (_movieAttributes == nil)
_movieAttributes = [[NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], QTMovieExport,
_componentSubType, QTMovieExportType,
_componentManufacturer, QTMovieExportManufacturer,
_exportSettings, QTMovieExportSettings, nil] retain];
return _movieAttributes;
}
- (void)setExportSettings:(NSData*)exportSettings
{
if (_exportSettings != exportSettings)
{
[_exportSettings release];
_exportSettings = [exportSettings retain];
[_movieAttributes release];
_movieAttributes = nil;
}
}
...
@end