SwrContext

public final class SwrContext

Undocumented

  • Create SwrContext.

    If you use this function you will need to set the parameters before calling initialize().

    Declaration

    Swift

    public init()

  • Create SwrContext if needed and set/reset common parameters.

    Declaration

    Swift

    public init(
    dstChannelLayout: AVChannelLayout,
    dstSampleFormat: AVSampleFormat,
    dstSampleRate: Int,
    srcChannelLayout: AVChannelLayout,
    srcSampleFormat: AVSampleFormat,
    srcSampleRate: Int
)

    Parameters

    dstChannelLayout

    output channel layout
    dstSampleFormat

    output sample format
    dstSampleRate

    output sample rate (frequency in Hz)
    srcChannelLayout

    input channel layout
    srcSampleFormat

    input sample format
    srcSampleRate

    input sample rate (frequency in Hz)

  • A Boolean value indicating whether the context has been initialized or not.

    Declaration

    Swift

    public var isInitialized: Bool { get }

  • Set/reset common parameters.

    Throws

    AVError

    Declaration

    Swift

    public func setOptions(
    dstChannelLayout: AVChannelLayout,
    dstSampleFormat: AVSampleFormat,
    dstSampleRate: Int,
    srcChannelLayout: AVChannelLayout,
    srcSampleFormat: AVSampleFormat,
    srcSampleRate: Int
) throws

    Parameters

    dstChannelLayout

    output channel layout
    dstSampleFormat

    output sample format
    dstSampleRate

    output sample rate (frequency in Hz)
    srcChannelLayout

    input channel layout
    srcSampleFormat

    input sample format
    srcSampleRate

    input sample rate (frequency in Hz)

  • Initialize context after user parameters have been set.

    Throws

    AVError

    Declaration

    Swift

    public func initialize() throws

  • Closes the context so that isInitialized returns false.

    The context can be brought back to life by running initialize(), initialize() can also be used without close(). This function is mainly provided for simplifying the usecase where one tries to support libavresample and libswresample.

    Declaration

    Swift

    public func close()

  • Gets the delay the next input sample will experience relative to the next output sample.

    Declaration

    Swift

    public func getDelay(_ timebase: Int64) -> Int

    Parameters

    timebase

    timebase in which the returned delay will be

    • if it’s set to 1 the returned delay is in seconds
    • if it’s set to 1000 the returned delay is in milliseconds
    • if it’s set to the input sample rate then the returned delay is in input samples
    • if it’s set to the output sample rate then the returned delay is in output samples
    • if it’s the least common multiple of in_sample_rate and out_sample_rate then an exact rounding-free delay will be returned

    Return Value

    the delay in 1 / base units.

  • Find an upper bound on the number of samples that the next convert(dst:dstCount:src:srcCount:) call will output, if called with sampleCount of input samples. This depends on the internal state, and anything changing the internal state (like further convert(dst:dstCount:src:srcCount:) calls) will may change the number of samples getOutSamples(_:) returns for the same number of input samples.

    Note

    any call to swr_inject_silence(), swr_convert(), swr_next_pts() or swr_set_compensation() invalidates this limit

    Note

    it is recommended to pass the correct available buffer size to all functions like convert(dst:dstCount:src:srcCount:) even if getOutSamples(_:) indicates that less would be used.

    Throws

    AVError

    Declaration

    Swift

    public func getOutSamples(_ sampleCount: Int64) throws -> Int

    Parameters

    sampleCount

    number of input samples

    Return Value

    an upper bound on the number of samples that the next convert(dst:dstCount:src:srcCount:) will output

  • Convert audio.

    dst and dstCount can be set to 0 to flush the last few samples out at the end.

    If more input is provided than output space, then the input will be buffered. You can avoid this buffering by using getOutSamples(_:) to retrieve an upper bound on the required number of output samples for the given number of input samples. Conversion will run directly without copying whenever possible.

    Throws

    AVError

    Declaration

    Swift

    @discardableResult
public func convert(
    dst: UnsafeMutablePointer<UnsafeMutablePointer<UInt8>?>,
    dstCount: Int,
    src: UnsafeMutablePointer<UnsafePointer<UInt8>?>,
    srcCount: Int
) throws -> Int

    Parameters

    dst

    output buffers, only the first one need be set in case of packed audio
    dstCount

    amount of space available for output in samples per channel
    src

    input buffers, only the first one need to be set in case of packed audio
    srcCount

    number of input samples available in one channel

    Return Value

    number of samples output per channel

  • Undocumented

    Declaration

    Swift

    public static let `class`: AVClass

  • Undocumented

    Declaration

    Swift

    public func withUnsafeClassObjectPointer<T>(_ body: (UnsafeMutableRawPointer) throws -> T) rethrows -> T

  • Undocumented

    Declaration

    Swift

    public func withUnsafeObjectPointer<T>(_ body: (UnsafeMutableRawPointer) throws -> T) rethrows -> T