Utility functions

Utility functions which help to operate with data. More...

Functions
MP4Err	MP4NewHandle (u32 handleSize, MP4Handle *outHandle)
	Creates a new handle, and allocates handleSize bytes for it.
MP4Err	MP4SetHandleSize (MP4Handle theHandle, u32 handleSize)
	Sets the logical size of the handle to requestedSize bytes.
MP4Err	MP4DisposeHandle (MP4Handle theHandle)
	Frees the memory that was allocated for a handle.
MP4Err	MP4GetHandleSize (MP4Handle theHandle, u32 *outSize)
	Use this to determine the present logical size (in bytes) of a handle.
MP4Err	MP4HandleCat (MP4Handle theDstHandle, MP4Handle theSrcHandle)
	Appends the data contained in theSrcHandle to data contained in theDstHandle by reallocating, if necessary, the number of bytes allocated for theDstHandle.
MP4Err	MP4SetHandleOffset (MP4Handle theHandle, u32 offset)
	Sets the handle so that subsequent de-references of it refer to the data starting at the given byte offset.

Detailed Description

Utility functions which help to operate with data.

Function Documentation

MP4DisposeHandle()

MP4Err MP4DisposeHandle

(

MP4Handle

theHandle

)

Frees the memory that was allocated for a handle.

Parameters

theHandle

input handle to kill

Returns

MP4Err error code

MP4GetHandleSize()

MP4Err MP4GetHandleSize	(	MP4Handle	theHandle,
		u32 *	outSize
	)

Use this to determine the present logical size (in bytes) of a handle.

Parameters

theHandle	input handle
outSize	output size in bytes

Returns

MP4Err error code

MP4HandleCat()

MP4Err MP4HandleCat	(	MP4Handle	theDstHandle,
		MP4Handle	theSrcHandle
	)

Appends the data contained in theSrcHandle to data contained in theDstHandle by reallocating, if necessary, the number of bytes allocated for theDstHandle.

Parameters

theDstHandle	destination handle
theSrcHandle	source handle

Returns

MP4Err error code

MP4NewHandle()

MP4Err MP4NewHandle	(	u32	handleSize,
		MP4Handle *	outHandle
	)

Creates a new handle, and allocates handleSize bytes for it.

It is OK to call this with a size of zero. This is commonly done when the handle will be used as a parameter to a function that will size it appropriately.

Parameters

handleSize	number of bytes to allocate
outHandle	output handle

Returns

MP4Err error code

MP4SetHandleOffset()

MP4Err MP4SetHandleOffset	(	MP4Handle	theHandle,
		u32	offset
	)

Sets the handle so that subsequent de-references of it refer to the data starting at the given byte offset.

This can be used to cause data to be read from or written to locations after the beginning, leaving room (for example) for an encryption header.

Parameters

theHandle	input handle
offset	byte offset

Returns

MP4Err error code

MP4SetHandleSize()

MP4Err MP4SetHandleSize	(	MP4Handle	theHandle,
		u32	handleSize
	)

Sets the logical size of the handle to requestedSize bytes.

If this is larger than the number of bytes allocated for this handle, the handle will be grown accordingly. If the new size is smaller than the allocated size the memory is not freed. The only way to free this memory is to dispose of the handle.

Parameters

theHandle	input handle
requestedSize	new size in bytes

Returns

MP4Err error code