Windows Media Foundation Learning note 1--MF Core concepts

This note refers to the book "Developing Microsift Media foundataion Application", so there are many excerpts from the book, if there is infringement, the fear!

MF Core concept: Component (component), where the component is similar to the DirectShow filter, which is encapsulated as a component for a particular function, which can be decoded, encoded, rendered, etc., by combining these component, Form pipeline, you can complete the various functions required for multimedia applications, as with the DirectShow link filter, keep the filter function independent while providing a flexible combination of functions. In fact, OpenGL also has pipeline said, through a process to complete the final screen in the desired output of the graphic image.

A full file playback pipeline as shown (copied from the developing Microsift Media foundataion application book):

small rectangular boxes, such as "Audio decoder", "Video decoder" are component components, the entire chain link forms a pipeline, complete the file playback function. The link can be cut into 3 parts: file source, data decoding, rendering, in the dshow corresponding to the source Filter,transform filter,render filter, but there are special terminology in MF, the following one by one describes:

1. MF Sources: The file source in the corresponding diagram, the source meaning, used to generate data for the next component processing, where the data can be from local files (such as), or from the network. It should also be noted that the file source actually does the audio and video data separation work, respectively, for subsequent components (audio decoding and video decoding).

2. Media Foundation transforms (mfts): The audio decoder and video decoder in the corresponding diagram are used to "convert" (transforms), decoding, it is obvious.

3. MF Sinks: The audio render and video render,sink in the corresponding diagram literally explain "infiltration", "sinking", which can be used to render the final data, or can be used to send data to the other end of the network, such as video calls in the local video encoding and in the MF The sinks stream is sent to the other end of the network.

The above three types of component connections are based on their respective input and output type, for example, assuming that the input of the video decoder is H. s stream, the output is YUV image, then its upstream file The output of the source can at least support the output of H. Component, otherwise the two connections are unsuccessful, and the input type of downstream video render of video decoder is also supported by YUV image input. Perhaps the above description is not rigorous, but this is basically the meaning, to the specific code time to add detailed analysis.

The next thing to describe is the data transfer between components, in MF, which describes the data passed in media sample, and media sample also includes the properties of the data (not just raw). DShow is also used imediasample to pass data, very harmonious ah.

The final description is the MF debugging tool, obediently, the name is "Topoedit", Sao years, DShow is "GraphEdit"! Windows SDK also has topoedit source code, good yo, can study under.

Talk about feelings, read the chapter feel and DShow structure model similar, just changed some of the words, have not realized the essence of MF AH! Cond...

Windows Media Foundation Learning note 1--MF Core concepts