Hardware Codec Support in AVStream

In Windows 7 and later versions of Windows, AVStream-based media devices can be presented as Media Foundation Transform (MFT) filters to user-mode applications.

This feature enables the hardware vendor to present hardware-based decoders, encoders, and video processors as user-mode Media Foundation Transforms (MFTs).

Hardware-based encoding and decoding greatly improves the user experience.

To enable hardware codec support in AVStream, the vendor provides an AVStream-based minidriver that exposes decoding, encoding, and video processing, each as a separate AVStream filter. The operating system then creates a user-mode MFT that corresponds to each AVStream filter. User-mode applications can then submit transcoding requests to the MFTs by using IMFTransform interface functions that are defined in the Media Foundation SDK.

This section describes the changes that are required for AVStream drivers to use this feature.

This section contains the following topics:

Getting Started with Hardware Codec Support in AVStream

Handling Data Type Negotiation in AVStream Codecs

Using Hardware Mediums in AVStream Codecs

Specifying Allocator Framing in AVStream Codecs

Describing Extended Sample Information in AVStream Codecs

Supporting Dynamic Format Changes in AVStream Codecs

Handling End of Stream in AVStream Codecs

Resetting State in AVStream Codecs

Handling Stride in AVStream Codecs

Installing an AVStream-based Hardware Codec Driver