Class IOContext

Represents a custom FFmpeg I/O context backed by managed code.

Inheritance

object

AVIOContext

IOContext

IOStreamContext

Implements

IDisposable

IAVPointer<_AVIOContext>

Inherited Members

AVIOContext.SetContext(_AVIOContext**)

AVIOContext.Dispose()

AVIOContext.Flush()

AVIOContext.EOF

AVIOContext.ErrorCode

object.GetType()

object.MemberwiseClone()

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

Namespace: FFmpeg.IO

Assembly: FFmpeg.dll

Syntax

public abstract class IOContext : AVIOContext, IDisposable, IAVPointer<_AVIOContext>

Remarks

IOContext provides the callback implementations used by FFmpeg's AVIOContext, allowing media data to be read from or written to arbitrary managed sources such as Stream instances, memory buffers, network transports, or custom storage.

Constructors

IOContext()

Initializes a new IOContext

Declaration

public IOContext()

IOContext(FormatContext, IOOptions, int)

Initializes a new IOContext and attaches it to the specified format context.

Declaration

protected IOContext(FormatContext formatContext, IOOptions options, int buffer_size = 32768)

Parameters

Type	Name	Description
FormatContext	formatContext	The FormatContext to associate with this I/O context.
IOOptions	options	The I/O operations that this context will support, such as reading, writing, and seeking.
int	buffer_size	The size of the buffer to allocate for I/O operations. Defaults to 32,768 bytes.

Properties

CanSeek

Gets a value indicating whether this I/O context supports seeking.

Declaration

public abstract bool CanSeek { get; }

Property Value

Type	Description
bool

Remarks

If this property returns false, FFmpeg treats the stream as non-seekable.

FormatContext

Gets the FormatContext associated with this I/O context.

Declaration

public FormatContext FormatContext { get; }

Property Value

Type	Description
FormatContext

Remarks

This property is assigned when the I/O context is attached to a format context and remains valid until the context is disposed.

Seekable

Gets or sets the types of seeking supported by the underlying I/O context.

Declaration

public Seekable Seekable { get; protected set; }

Property Value

Type	Description
Seekable

Remarks

The value indicates which seeking operations are supported by the underlying AVIOContext. Derived classes can modify this value when creating or configuring a custom I/O context.

Methods

Dispose(bool)

Releases the unmanaged resources used by the IOContext and optionally releases the managed resources.

Declaration

protected override void Dispose(bool disposing)

Parameters

Type	Name	Description
bool	disposing	true to release both managed and unmanaged resources; false to release only unmanaged resources.

Overrides

AVIOContext.Dispose(bool)

~IOContext()

Declaration

protected ~IOContext()

InitContext(FormatContext, IOOptions, int)

Attaches this I/O context to the specified format context.

Declaration

public void InitContext(FormatContext formatContext, IOOptions options, int buffer_size = 32768)

Parameters

Type	Name	Description
FormatContext	formatContext	The format context that will use this custom I/O implementation.
IOOptions	options	Specifies which callback operations should be enabled.
int	buffer_size	The size, in bytes, of the internal FFmpeg I/O buffer.

Remarks

This method allocates a native AVIOContext and installs the managed callback functions required by FFmpeg.

ReadPacket(Span<byte>)

Reads data into the provided buffer.

Declaration

protected abstract AVResult32 ReadPacket(Span<byte> buffer)

Parameters

Type	Name	Description
Span<byte>	buffer	The buffer to read data into.

Returns

Type	Description
AVResult32	The number of bytes read, zero to indicate end-of-file, or a negative FFmpeg error code.

Seek(long, AVSeek)

Seeks to the specified offset in the stream.

Declaration

protected abstract AVResult64 Seek(long offset, AVSeek whence)

Parameters

Type	Name	Description
long	offset	The offset to seek to.
AVSeek	whence	The seek mode (e.g., from the start, from the current position, etc.).

Returns

Type	Description
AVResult64	The new position within the stream, or a negative value on error.

Remarks

This method is called only if CanSeek is true and the context was initialized with Seek.

WritePacket(Span<byte>)

Writes data from the provided buffer into the stream.

Declaration

protected abstract AVResult32 WritePacket(Span<byte> buffer)

Parameters

Type	Name	Description
Span<byte>	buffer	The buffer containing the data to write.

Returns

Type	Description
AVResult32	The number of bytes written, or a negative value on error.

Implements

IDisposable

IAVPointer<T>