通过Android中的OpenMAX访问摄像头

Question

我目前正试图弄清楚如何通过Android 4.0中的OpenMAX访问相机.文档对我来说还不够,所以我目前很难找到如何XADataSource为以下调用检索正确的文档.

(*_engine)->CreateMediaRecorder(_engine,
                                &_mediaRecorder, //pRecorder
                                nullptr, //pAudioSrc
                                XADataSource *, //pImageVideoSrc
                                XADataSink *, //pDataSnk
                                XAuint32, // numInterfaces
                                const XAInterfaceID *, //pInterfaceIds
                                const XAboolean *, //pInterfaceRequired
);

请不要让我使用Java - "答案".

Answer 1

这基本上是 XADataSource 的定义，取自http://www.khronos.org/registry/omxal/specs/OpenMAX_AL_1_1_Specification.pdf

typedef struct XADataSource_ {
    void * pLocator;
    void * pFormat;
} XADataSource;

字段包括：

Field        Description
pLocator Pointer to the specified data locator structure. This may point to any of the       following structures. 
    XADataLocator_Address
    XADataLocator_IODevice
    XADataLocator_URI
    XADataLocator_MediaObject
    XADataLocator_Null
    XADataLocator_ContentPipe
The first field of each of these structures includes the 32 bit locatorType field,   which identifies 
the locator type (see XA_DATALOCATOR definitions) and hence the structure pointed to.
Note: The available XA_DATALOCATOR definitions may be extended through an API   extension.

pFormat A pointer to the specified format structure. This may point to any of the following structures. 
    XADataFormat_PCM (Deprecated)
    XADataFormat_PCM_EX
    XADataFormat_MIME
    XADataFormat_RawImage
The first field of each of these structures includes the 32 bit formatType field, which identifies the 
format type (XA_DATAFORMAT definitions) and hence the structure pointed to. pFormat is ignored 
if pLocator is XADataLocator_IODevice

抱歉，无法更好地格式化它，但如果您还没有这样做，我建议您还是检查一下该文档。