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/*
* libmm-common
*
* Copyright (c) 2000 - 2011 Samsung Electronics Co., Ltd. All rights reserved.
*
* Contact: Jonghyuk Choi <jhchoi.choi@samsung.com>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#ifndef __MM_H__
#define __MM_H__
#include <stdbool.h>
#include <mm_types.h>
#include <mm_error.h>
#include <mm_message.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
@addtogroup COMMON
@{
* @file mm.h
* @author
* @version 1.0
* @brief This file includes all the necessary header files of multimediaframework.
@mainpage Multimedia Framework
@par
This document provides necessary information for developers who are going
to implement multimedia application such as media player, voice recorder,
and camera application and so on. Before entering into the detailed
information, this also has described the overview, architecture design and
each component of multimedia framework for the purpose of helping
developers to understand concept or basic knowledge in relation to API for
themselves.
@par
Here is outline as below.
@par
- @ref OVERVIEW
- @ref ARCHITECTURE
- @ref COMPONENT
- @ref CONCEPT
@section OVERVIEW Overview
@par
Multimedia Framework is designed to provide easy to use services for
developing multimedia applications based on an embedded Linux platform.
@par
Multimedia framework API reference has defined APIs to support functions
as below;
@par
- Playback of multimedia contents.
- Playing system sounds.
- Controlling volume information.
- Controlling direction of sound input / output path.
- Recording video stream from video input device such as camera
- Recording audio stream from audio input device such as microphone
- Capturing still image from video input device
- Extract meta data information from file
@par
This document will describe architecture of multimedia framework, basic
concept of design of application programming, and explain how to use this
framework
@section ARCHITECTURE Architecture Design
@par
The multimedia framework can be divided into three parts as follows;
@par
- Application Layer that provide high-level APIs to multimedia applications.
- Internal Layer of Multimedia Framework.
- Hardware/Platform Dependent Layer.
@par
Libraries which provide high-level APIs can be divided into five components
again; Player, Sound, File, Image, and Camcorder. Basically each component
can be loaded to memory independently to decrease memory foot print.
@par
The internal library is a library which is responsible for encoding /
decoding multimedia stream. Application layer library uses this library
for playback, or recording.
@par
Hardware / Platform dependent layer has dependency on hardware or platform.
If hardware or platform has been changed, this layer library must be ported
to that environment. So this can be called as Porting Layer.
@par
This architecture diagram below is a high-level diagram of multimedia
framework and then also shows how multimedia framework works as well as its
components.
@image html architecture.png "Architecture Diagram" width=12cm
@image latex architecture.png "Architecture Diagram" width=12cm
@par
Each components will be describes in more detail on Component Description
section.
@section COMPONENT Component Description
@par
As mentioned previous section, Multimedia Framework can be divided into
3 layers. Components for each layer of Multimedia Framework are as below;
@par
Application Export Layer
@par
- @ref MMFW ATTRS LIBRARY
- @ref MMFW PLAYER LIBRARY
- @ref MMFW CAMCORDER LIBRARY
- @ref MMFW SOUND LIBRARY
- @ref MMFW FILE LIBRARY
@par
Internal (Not exported) Layer
@par
- Multimedia Codec (Encoder / Decoder)
@par
Hardware/Platform Dependent Layer
@par
- MHAL (Multimedia Hardware Abstraction Layer)
- AV System (Audio Video Input / Output System)
@par
Please refer to link for the further detailed description of each component.
@section CONCEPT Basic Concept
@par
Basic design concept of Multimedia Framework API will be described in this
section.
@par
1. Naming Convention
@par
- Multimedia Framework APIs have a prefix with "MM" (stands for
<B>M</B>ulti<B>M</B>edia <B>F</B>ramework). After this prefix, module name
is followed by such as "MMPlayer_, MMSnd_, MMCam_".
@par
2. Controlled by handle
@par
- Basically Multimedia Framework manipulates each instance by handle.
Camcorder Library, Attributes Library belongs to this case. Sound Library
does not have instance because it applies attributes directly to system.
@par
3. Understand Attributes
@par
- Attributes are set of properties which each instance are configured.
Basic understand is required for manipulating attributes. Please refer to
@ref MMFW ATTRS LIBRARY "Attribute Library Description" to know how to use.
@par
4. Messages
@par
- Application can be notified that change of state, error occurs, how much
time has been elapsed after playing or recording through message callback.
Message callback will be called as deferred, so any API can be called in
this callback function.
@par
5. Errors
@par
- Basically all Multimedia Framework API returns error code as return value.
It returns zero (MM_ERROR_NONE) on success, or returns error code which is
negative value. Each error code and range is defined in <mm_error.h> file.
@par
6. How to build
@par
- Each library for offering high level API will provide Package Config file
to support pkg-config command. Be sure to that it will be installed on your
platform SDK directory. If you want to use player library, you just append
"pkg-config" line to your build script. For example, just append
"pkg-config --libs --cflags mmplayer" to your build script if you want to
use player library. The dependency with respect of MMPlayer is already
described within package config file. Therefore, all of developers have to
do is just use it by themselves.
*/
#ifdef __cplusplus
}
#endif
/**
@}
*/
#endif /* __MM_H__ */
|
