CMSampleBufferGetSampleSizeArray(_:entryCount:arrayToFill:entriesNeededOut:)
Retrieves an array of sample sizes that represents each sample in a sample buffer.
Declaration
func CMSampleBufferGetSampleSizeArray(_ sbuf: CMSampleBuffer, entryCount sizeArrayEntries: CMItemCount, arrayToFill sizeArrayOut: UnsafeMutablePointer<Int>?, entriesNeededOut sizeArrayEntriesNeededOut: UnsafeMutablePointer<CMItemCount>?) -> OSStatusParameters
- sbuf:
The
CMSampleBufferbeing interrogated. - sizeArrayEntries:
Number of entries in
sizeArray. - sizeArrayOut:
Reference to an array of
size_tvalues to receive the sample sizes. - sizeArrayEntriesNeededOut:
Number of entries needed for the result.
Return Value
A result code. See Sample Buffer Error Codes.
Discussion
If only one size entry is returned, all samples in the buffer are of this size. The sizeArrayOut must be allocated by the caller, and the number of entries allocated must be passed in sizeArrayEntries. If sizeArrayOut is NULL, sizeArrayEntriesNeededOut will return the required number of entries. Similarly, if sizeArrayEntries is too small, CMSampleBuffer will be returned, and sizeArrayEntriesNeededOut will return the required number of entries. The caller can then make an appropriately-sized sizeArrayOut and call again. For example, the caller might pass the address of a size_t variable on the stack (as sizeArrayOut), and 1 as sizeArrayEntries. If all samples are the same size (or there’s only one sample in the CMSampleBuffer), this call would succeed. If not, it will fail, and will return the number of entries required in sizeArrayEntriesNeededOut. Only in this case (multiple samples of different sizes) will the caller need to allocate an array. 0 entries will be returned if the samples in the buffer are non-contiguous (for example, non-interleaved audio, where the channel values for a single sample are scattered through the buffer). If there are no sample sizes in this CMSampleBuffer, CMSampleBuffer will be returned, and *sizeArrayEntriesNeededOut will be set to 0. This will be true, for example, if the samples in the buffer are non-contiguous (for example, non-interleaved audio, where the channel values for a single sample are scattered through the buffer), or if this CMSampleBuffer contains a CVImageBuffer.