Opencore and OMX core/component interaction Wednesday, March 31, 2010

http://android.git.kernel.org/?p=platform/external/opencore.git;a=blob_plain;f=doc/openmax_call_sequences.pdf

It's from PacketVideo. It's very useful and powerful.

Bellagio OpenMAX Integration Layer Wednesday, March 24, 2010

Bellagio is an opensource implementation of the Khronos OpenMAX Integration Layer API to access multimedia components.

You can take it as a demo to investigate OMX IL.

The link is belowing
http://sourceforge.net/projects/omxil/files/

List header files of OpenMAX IL(v.1.1.2) Tuesday, March 23, 2010

IL（V1.1.2）中每个头文件的作用是什么：

• OMX_Types.h: Data types used in the OpenMAX IL

• OMX_Core.h: OpenMAX IL core API

• OMX_Component.h: OpenMAX IL component API

• OMX_Audio.h: OpenMAX IL audio domain data structures

• OMX_IVCommon.h: OpenMAX IL structures common to image and video domains

• OMX_Video.h: OpenMAX IL video domain data structures

• OMX_Image.h: OpenMAX IL image domain data structures

• OMX_Other.h: OpenMAX IL other domain data structures (includes A/V synchronization)

• OMX_Index.h: Index of all OpenMAX IL-defined data structures

• OMX_ContentPipe.h: Content pipe definition

OpenMAX入门 Monday, October 12, 2009

1.         Khronos

       OpenMAX接口由Khronos工作组制定和颁布的行业标准接口。说起Khronos也许没有几个人知道，但是说起OpenGL应该都知道吧？OpenGL也是Khronos制定的行业标准接口之一。

    访问 http://www.khronos.org/ 可以获得更多关于Khronos的信息。

2.         OpenMAX是什么

OpenMAX是一个免费的（royalty-free）、跨平台的应用编程接口。它实现了comprehensive streaming media codec and application portability by enabling accelerated multimedia components to be developed, integrated and programmed across multiple operating systems and silicon platforms。这句话是我从OpenMAX的官方介绍中摘出来的，高度概括了OpenMAX的功能。结合下面的图就可以明白这句话的意思了。

顺便说一句，这个图少了AL层，不能真实反映OpenMAX的层次结构。

3.         OpenMAX接口的好处

1)        应用程序移植很容易。比如，只要windows上的MediaPlayer兼容OpenMAX的接口，移植到Symbian上是件很容易的事情

2)        Codec的移植也变得很容易了

3)        替换硬件对系统的影响将变得很小

4)        可以直接用高级语言写codec了，不再需要用汇编来提高性能了

5)        使用OpenMAX接口将成为行业标准

4.         OpenMAX的三个层次

1)        AL（Application Layer）应用程序接口层

2)        IL（Integration Layer）Codec接口层

3)        DL（Development Layer），硬件抽象层