Table of Contents

Class H264ParseBlock

Namespace
VisioForge.Core.MediaBlocks.Parsers
Assembly
VisioForge.Core.dll

Parses H.264/AVC (Advanced Video Coding) bitstreams for NAL unit processing and frame boundary detection.

public class H264ParseBlock : MediaBlock, IMediaBlock, IDisposable, IMediaBlockInternals

Inheritance

Implements

Inherited Members

Extension Methods

Remarks

The H264ParseBlock processes H.264 encoded video streams, parsing NAL (Network Abstraction Layer) units, extracting SPS/PPS parameters, and ensuring proper access unit boundaries. H.264 is the most widely adopted video codec for streaming, broadcasting, and video storage.

Key features: - NAL unit parsing and validation (start codes and length-prefixed) - SPS (Sequence Parameter Set) and PPS (Picture Parameter Set) extraction - Access unit boundary detection based on H.264 specification - SEI (Supplemental Enhancement Information) message parsing - Slice header analysis for frame type detection - Support for both Annex B (start codes) and AVCC (length-prefixed) formats

Common use cases: - Streaming: Preparing H.264 for HLS, DASH, or RTP transmission - Muxing: Packaging H.264 into MP4, MKV, or TS containers - Analysis: Extracting codec parameters and stream properties - Transcoding: Providing properly parsed NAL units to decoders - Video editing: Frame-accurate cutting and splicing

The parser handles various H.264 profiles (Baseline, Main, High) and levels, automatically adapting to the stream's characteristics and ensuring compliance with the H.264 specification (ITU-T H.264 / ISO/IEC 14496-10).

Constructors

H264ParseBlock()

Initializes a new instance of the VisioForge.Core.MediaBlocks.Parsers.H264ParseBlock class.

public H264ParseBlock()

Remarks

Creates input and output pads configured for video media type. The parser will automatically detect the H.264 stream format (Annex B with start codes or AVCC with length prefixes) and handle it appropriately.

Properties

Input

Gets the primary input pad for receiving H.264 bitstream data.

public override MediaBlockPad Input { get; }

Property Value

MediaBlockPad

Inputs

Gets all input pads available on this block.

public override MediaBlockPad[] Inputs { get; }

Property Value

MediaBlockPad[]

Output

Gets the primary output pad that provides parsed H.264 access units.

public override MediaBlockPad Output { get; }

Property Value

MediaBlockPad

Outputs

Gets all output pads available on this block.

public override MediaBlockPad[] Outputs { get; }

Property Value

MediaBlockPad[]

Type

Gets the type of this media block.

public override MediaBlockType Type { get; }

Property Value

MediaBlockType

Methods

Build()

Builds and initializes the H.264 parser element within the media pipeline.

public override bool Build()

Returns

bool

true if the parser was successfully created and configured; false if initialization failed or required plugins are missing.

Remarks

This method creates the GStreamer H.264 parser element, initializes it within the pipeline context, and connects the input/output pads. The parser will begin processing NAL units once the pipeline transitions to the playing state.

CleanUp()

Performs cleanup of the parser resources and resets the build state.

public void CleanUp()

Remarks

This method disposes of the GStreamer element and resets internal state. It is called during disposal to ensure proper resource cleanup.

Dispose(bool)

Releases unmanaged and - optionally - managed resources.

protected override void Dispose(bool disposing)

Parameters

disposing bool

true to release both managed and unmanaged resources; false to release only unmanaged resources.

GetCore()

Gets the core GStreamer element wrapper.

public BaseElement GetCore()

Returns

BaseElement

The base element wrapper providing access to common GStreamer functionality.

GetElement()

Gets the underlying native GStreamer element.

public Element GetElement()

Returns

Element

The native GStreamer element instance used for H.264 NAL unit parsing.

IsAvailable()

Determines whether the H.264 parser is available in the current GStreamer installation.

public static bool IsAvailable()

Returns

bool

true if the H.264 parser plugin is available; otherwise, false. This requires the GStreamer base plugins to be installed.

Remarks

The H.264 parser is provided by the GStreamer base plugins collection. Ensure the appropriate VisioForge SDK redistribution package is included in your project.

IMediaBlockInternals.SetContext(MediaBlocksPipeline)

Sets the media pipeline context for this block.

void IMediaBlockInternals.SetContext(MediaBlocksPipeline pipeline)

Parameters

pipeline MediaBlocksPipeline

The media pipeline that will contain this parser block.

See Also