Design Of Embedded Media Player Based On FFmpeg Library

At present, the related policies about developing the emerging and strategical industry released by the national twelfth five-year-plan, have definitely announced that we will accelerate tri-networks integration and launch a pilot project, which has been a trend of the communications industry. With the growth of demand for the embedded terminals, it is particularly important for the software develop of the embedded terminals. For the family media devices(such as High-Definition Digital TV Set-Top-Box, family media gateways and so on), the streaming media format supported by the embedded media player need to be more comprehensive and perfect. However the present situation is not very optimistic. This thesis proposes a solution based on FFmpeg library for the embedded media player, which is built on the platform with the low costs of the MIPS hardware architecture and the compact ITRON operating system. In addition, the proposed scheme is not only compatible with the popular audio and video formats such as MP3, DivX and so on, but also adapts for the FLV, MP4 format widely used by youku, tudou, sohu vedio websites.The central hardware device in our proposed solution isμPD61326 chip from Japanese NEC Company. The chip with a high-performance MIPS32 4KEc core and 32-bit RISC MIPS architecture supports both MIPS-I and MIPS-II instructions set. The ITRON operating system, which is quite popular in Japan, is embedded in the MIPS architecture circuit board, the API interfaces are provided by the adaptation layer above the operating system. Then the FFmpeg library is introduced as the middleware upon the adaptation layer and cut out based on understanding its operating principle and process. At the same time, the clipping can reduce the occupation of memory space in condition of guaranteeing the functions demand of users. Moreove, we package the FFmpeg library and reserve the programming interfaces for the application design and development of the upper layer.In the software design of the embedded media player, the modular design solutions are adopted to make the developing easy and make the process structured. The entire design is divided into four modules: file Parsing, Demux, Decoding and Interface of the player. The file parsing model, which is used for reading and parsing the documents and controling the player, is implemented through the API interfaces reserved by the FFmpeg library. The Demux model utilizes the Demux devices and Demux threads to separate the audio and vedio stream from the stream information of the output file parsing model. The Decoding module utilizes the inner hardware decoder to decode the audio and vedio streams. The Interface module finishes interactive operation and performs data transmission with other modules. The interface module can scan and read the audio and vedio documents, receive the user response and enable the users to manipulate the player via the remote controller or key set.The embedded player designed in the paper has been tested and verified via the High-Definition Digital TV Set-Top-Box. The experimental results demonstrate the advantages as follow. First of all, the Set-Top-Box is less expensive and lower occupancy rate of CPU, which well supports various media formats of the tri-networks. Secondly, it provides certain reference value for the tri-networks integration which can be carried out and popularized as soon as possible. Last but not least, it lays a fundation for the rapid expansion of Set-Top-Box in the tri-networks integration business.