# CMSampleBufferCreateReady(allocator:dataBuffer:formatDescription:sampleCount:sampleTimingEntryCount:sampleTimingArray:sampleSizeEntryCount:sampleSizeArray:sampleBufferOut:) Creates a sample buffer with media data. ``` func CMSampleBufferCreateReady(allocator: CFAllocator?, dataBuffer: CMBlockBuffer?, formatDescription: CMFormatDescription?, sampleCount numSamples: CMItemCount, sampleTimingEntryCount numSampleTimingEntries: CMItemCount, sampleTimingArray: UnsafePointer?, sampleSizeEntryCount numSampleSizeEntries: CMItemCount, sampleSizeArray: UnsafePointer?, sampleBufferOut: UnsafeMutablePointer) -> OSStatus ``` ## Parameters `allocator` The allocator to use for allocating the `CMSampleBuffer` object. Pass `kCFAllocatorDefault` to use the default allocator. `dataBuffer` `CMBlockBuffer` that already contains the media data. Must not be `NULL`. `formatDescription` A description of the media data’s format. Can be `NULL`. `numSamples` Number of samples in the `CMSampleBuffer`. Can be 0. `numSampleTimingEntries` Number of entries in sampleTimingArray. Must be 0, 1, or `numSamples`. `sampleTimingArray` Array of `CMSampleTimingInfo` structs, one struct per sample. If all samples have the same duration and are in presentation order, you can pass a single `CMSampleTimingInfo` struct with duration set to the duration of one sample, `presentationTimeStamp` set to the presentation time of the numerically earliest sample, and `decodeTimeStamp` set to `kCMTimeInvalid`. The behavior is undefined if samples in a `CMSampleBuffer` (or even in multiple buffers in the same stream) have the same `presentationTimeStamp`. Can be `NULL`. `numSampleSizeEntries` Number of entries in `sampleSizeArray`. Must be 0, 1, or `numSamples`. `sampleSizeArray` Array of size entries, one entry per sample. If all samples have the same size, you can pass a single size entry containing the size of one sample. Can be `NULL`. Must be `NULL` if the samples are non-contiguous in the buffer (eg. non-interleaved audio, where the channel values for a single sample are scattered through the buffer). `sampleBufferOut` Returned newly created `CMSampleBuffer`. ## Discussion This function is identical to [`CMSampleBufferCreate(allocator:dataBuffer:dataReady:makeDataReadyCallback:refcon:formatDescription:sampleCount:sampleTimingEntryCount:sampleTimingArray:sampleSizeEntryCount:sampleSizeArray:sampleBufferOut:)`](/documentation/CoreMedia/CMSampleBufferCreate(allocator:dataBuffer:dataReady:makeDataReadyCallback:refcon:formatDescription:sampleCount:sampleTimingEntryCount:sampleTimingArray:sampleSizeEntryCount:sampleSizeArray:sampleBufferOut:)) except that `dataReady` is always `true`, and so no `makeDataReadyCallback` or `refcon` needs to be passed. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)