Class MediaSource

Represents a media source that handles reading and decoding of media data from various input sources.

Inheritance

object

MediaSource

Implements

IDisposable

Inherited Members

object.GetType()

object.MemberwiseClone()

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

Namespace: FFmpeg

Assembly: FFmpeg.dll

Syntax

public class MediaSource : IDisposable

Constructors

View Source

MediaSource(DemuxerContext)

Initializes a new instance of the MediaSource class with a specified format context.

Declaration

public MediaSource(DemuxerContext context)

Parameters

Type	Name	Description
DemuxerContext	context	The format context to associate with this media source.

View Source

MediaSource(DemuxerContext, DeviceType)

Initializes a new instance of the MediaSource class with a specified format context and device type.

Declaration

public MediaSource(DemuxerContext context, DeviceType deviceType)

Parameters

Type	Name	Description
DemuxerContext	context	The format context to associate with this media source.
DeviceType	deviceType	The device type for hardware-accelerated decoding.

Fields

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GetCodec

A function to retrieve a codec by its ID. This can be set to provide custom codec retrieval logic.

Declaration

public Func<AVStream, Codec?>? GetCodec

Field Value

Type	Description
Func<AVStream, Codec?>

Properties

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CodecContexts

Gets the list of codec contexts for the streams in this media source.

Declaration

public IReadOnlyList<CodecContext> CodecContexts { get; }

Property Value

Type	Description
IReadOnlyList<CodecContext>

Remarks

This property initializes codec contexts lazily based on the number of streams. It also sets up codec contexts for each stream, guessing the frame rate for video streams and adjusting codec parameters as needed.

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FormatContext

Gets the format context associated with this media source.

Declaration

public DemuxerContext FormatContext { get; }

Property Value

Type	Description
DemuxerContext

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Metadata

Gets the metadata associated with the format context.

Declaration

public AVDictionary_ref Metadata { get; }

Property Value

Type	Description
AVDictionary_ref

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Seekable

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

Declaration

public Seekable Seekable { get; }

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.

View Source

Streams

Gets the list of streams available in this media source.

Declaration

public IReadOnlyList<AVStream> Streams { get; }

Property Value

Type	Description
IReadOnlyList<AVStream>

Methods

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Decode(AVPacket, AVFrame)

Decodes a packet and writes the next available decoded frame into the specified AVFrame.

Declaration

public AVResult32 Decode(AVPacket packet, AVFrame frame)

Parameters

Type	Name	Description
AVPacket	packet	The encoded packet to submit to the decoder.
AVFrame	frame	Receives the decoded frame if one is available.

Returns

Type	Description
AVResult32	An AVResult32 indicating the result of the decoding operation.

Remarks

This method forwards the packet to the decoder associated with StreamIndex.

A successful return value indicates that a decoded frame was written to frame.

TryAgain indicates that the decoder requires additional input packets before it can produce another frame.

EndOfFile indicates that the decoder has been fully drained and no more frames are available.

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DecodeSubtitle(AVPacket, Subtitle)

Decodes a subtitle from the given AVPacket and outputs the result as a Subtitle.

Declaration

public AVResult32 DecodeSubtitle(AVPacket srcPacket, Subtitle subtitle)

Parameters

Type	Name	Description
AVPacket	srcPacket
Subtitle	subtitle	The decoded subtitle output as a Subtitle.

Returns

Type	Description
AVResult32	The result of the decoding operation as AVResult32. This result indicates whether the operation was successful or if an error occurred.

Remarks

This method is specific to subtitle codecs. If the codec type is not set to Subtitle, the operation will throw a NotSupportedException.

Exceptions

Type	Condition
NotSupportedException	Thrown if the codec is not of type subtitle.

View Source

Dispose()

Releases all resources used by the MediaSource object.

Declaration

public void Dispose()

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Dispose(bool)

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

Declaration

protected virtual void Dispose(bool disposing)

Parameters

Type	Name	Description
bool	disposing	A boolean indicating whether to release both managed and unmanaged resources (true), or only unmanaged resources (false).

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FindBestStream(MediaType)

Finds the best stream of the specified media type within this media source.

Declaration

public int FindBestStream(MediaType type)

Parameters

Type	Name	Description
MediaType	type	The media type to search for (e.g., audio or video).

Returns

Type	Description
int	The index of the best stream of the specified type, or -1 if no suitable stream is found.

View Source

FlushBuffers()

Flushes the buffers of all codec contexts, clearing any buffered data.

Declaration

public void FlushBuffers()

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GuessFramerate(AVStream)

Guesses the frame rate of the given stream.

Declaration

public Rational GuessFramerate(AVStream stream)

Parameters

Type	Name	Description
AVStream	stream

Returns

Type	Description
Rational	A Rational representing the guessed frame rate.

View Source

GuessFramerate(int)

Estimates the frame rate of the specified stream.

Declaration

public Rational GuessFramerate(int streamIndex)

Parameters

Type	Name	Description
int	streamIndex

Returns

Type	Description
Rational	The estimated frame rate.

View Source

Open(DemuxerContext, DeviceType)

Creates a new MediaSource instance from an existing format context.

Declaration

public static MediaSource Open(DemuxerContext file, DeviceType deviceType = DeviceType.None)

Parameters

Type	Name	Description
DemuxerContext	file	The format context representing the media source.
DeviceType	deviceType	The device type for hardware-accelerated decoding (default is None).

Returns

Type	Description
MediaSource	A new MediaSource instance.

View Source

Open(IOContext, InputFormat?, IDictionary<string, string>?, DeviceType)

Opens a media source from an I/O context.

Declaration

public static MediaSource Open(IOContext io, InputFormat? format = null, IDictionary<string, string>? options = null, DeviceType deviceType = DeviceType.None)

Parameters

Type	Name	Description
IOContext	io	The I/O context representing the media source.
InputFormat?	format	Optional input format.
IDictionary<string, string>	options	Optional options for opening the media source.
DeviceType	deviceType	Optional device type for hardware-accelerated decoding.

Returns

Type	Description
MediaSource	A new MediaSource instance if successful; otherwise, null.

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Open(Stream, InputFormat?, IDictionary<string, string>?, DeviceType)

Opens a media source from a stream.

Declaration

public static MediaSource Open(Stream stream, InputFormat? format = null, IDictionary<string, string>? options = null, DeviceType deviceType = DeviceType.None)

Parameters

Type	Name	Description
Stream	stream	The stream representing the media source.
InputFormat?	format	Optional input format.
IDictionary<string, string>	options	Optional options for opening the media source.
DeviceType	deviceType	Optional device type for hardware-accelerated decoding.

Returns

Type	Description
MediaSource	A new MediaSource instance if successful; otherwise, null.

View Source

Open(string, InputFormat?, IDictionary<string, string>?, DeviceType)

Opens a media source from a URL.

Declaration

public static MediaSource Open(string url, InputFormat? format = null, IDictionary<string, string>? options = null, DeviceType deviceType = DeviceType.None)

Parameters

Type	Name	Description
string	url	The URL of the media source.
InputFormat?	format	Optional input format.
IDictionary<string, string>	options	Optional options for opening the media source.
DeviceType	deviceType	Optional device type for hardware-accelerated decoding.

Returns

Type	Description
MediaSource	A new MediaSource instance if successful; otherwise, null.

View Source

ReadAndDecodeAVFrame(AVFrame)

Reads a packet and decodes it into a frame. Continues until a frame is successfully decoded or no more frames can be read.

Declaration

public AVResult32 ReadAndDecodeAVFrame(AVFrame frame)

Parameters

Type	Name	Description
AVFrame	frame	The AVFrame to populate with the decoded frame.

Returns

Type	Description
AVResult32	An AVResult32 indicating the result of the operation. Returns the stream index if successful; otherwise, the error result.

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ReadAndDecodeHWAVFrame(AVFrame)

Reads a packet and decodes it into a frame. Continues until a frame is successfully decoded or no more frames can be read.
This methods does not transfer a HwFrame to Ram.

Declaration

public AVResult32 ReadAndDecodeHWAVFrame(AVFrame frame)

Parameters

Type	Name	Description
AVFrame	frame	The AVFrame to populate with the decoded frame.

Returns

Type	Description
AVResult32	An AVResult32 indicating the result of the operation. Returns the stream index if successful; otherwise, the error result.

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ReadFrame(AVPacket, AVFrame)

Sends a packet to the codec context and attempts to receive a frame.

Declaration

[Obsolete("Use Decode")]
public AVResult32 ReadFrame(AVPacket srcPacket, AVFrame dstFrame)

Parameters

Type	Name	Description
AVPacket	srcPacket	The AVPacket to send to the codec context.
AVFrame	dstFrame	The AVFrame to receive the decoded frame.

Returns

Type	Description
AVResult32	An AVResult32 indicating the result of the operation.

View Source

ReadPacket(AVPacket)

Reads a packet of data from the media source into the provided AVPacket instance.

Declaration

public AVResult32 ReadPacket(AVPacket packet)

Parameters

Type	Name	Description
AVPacket	packet	The AVPacket instance to populate with data.

Returns

Type	Description
AVResult32	An AVResult32 indicating the result of the operation.

View Source

Seek(long)

Seeks to the specified frame number within the media stream.

Declaration

public AVResult32 Seek(long frame)

Parameters

Type	Name	Description
long	frame	The frame number to seek to.

Returns

Type	Description
AVResult32	An AVResult32 indicating the result of the seek operation.

View Source

Seek(long, int)

Seeks to the specified frame number within the media stream for a specific stream index.

Declaration

public AVResult32 Seek(long frame, int streamIndex)

Parameters

Type	Name	Description
long	frame	The frame number to seek to.
int	streamIndex	The index of the stream to seek within.

Returns

Type	Description
AVResult32	An AVResult32 indicating the result of the seek operation.

View Source

Seek(TimeSpan)

Seeks to the specified time position within the media stream.

Declaration

public AVResult32 Seek(TimeSpan time)

Parameters

Type	Name	Description
TimeSpan	time	The time position to seek to.

Returns

Type	Description
AVResult32	An AVResult32 indicating the result of the seek operation.

View Source

Seek(TimeSpan, int)

Seeks to the specified time position within the media stream for a specific stream index.

Declaration

public AVResult32 Seek(TimeSpan time, int streamIndex)

Parameters

Type	Name	Description
TimeSpan	time	The time position to seek to.
int	streamIndex	The index of the stream to seek within.

Returns

Type	Description
AVResult32	An AVResult32 indicating the result of the seek operation.

View Source

SeekExactly(TimeSpan, int)

Seeks exactly to the specified time position within the media stream for a specific stream index.

Declaration

public AVResult32 SeekExactly(TimeSpan timeSpan, int streamIndex)

Parameters

Type	Name	Description
TimeSpan	timeSpan	The position to seek to.
int	streamIndex	The stream index.

Returns

Type	Description
AVResult32	Negative if error.

View Source

SetCodec(Codec, int)

Replaces the codec context for the specified stream with a new context using the specified codec.

Declaration

public CodecContext SetCodec(Codec codec, int streamIndex)

Parameters

Type	Name	Description
Codec	codec	The codec to use for the new codec context.
int	streamIndex	The zero-based index of the stream whose codec context should be replaced.

Returns

Type	Description
CodecContext	The newly created CodecContext.

Remarks

The existing codec context for the stream, if any, is disposed before the new context is created.

The new codec context is initialized from the stream's CodecParameters, configured with the current hardware device type, and assigned the stream's packet time base.

For video streams, the frame rate is initialized using GuessFrameRate(AVStream, AVFrame?).

Exceptions

Type	Condition
ArgumentOutOfRangeException	`streamIndex` is outside the range of available streams.

Implements

IDisposable