ST-Ericsson Sucess Story - PragmaDev

Success storyOpenMAX-IL interfaceimplementation testedwith MSC Tracer.This is a short note on MSC Tracer utilization within oneof the ST-Ericsson's projects. The goal of this projectwas to develop a software layer running on an ARM coreusing the OpenMAX IL standardized media componentinterface. This project has been developed in Sophia-Antipolis by two audio software engineers: SebastianMulewski and Alain Di Piazza.• IL Client : This module represents the applicationwhich uses the OpenMAX services.• IL Core : This module is used to dynamicallyload and unload the different components.• The components: The components can besources, codecs filters, mixers or any otherdata operators.Audio use caseThe example below shows a simple use case, whichconsist in an audio playback processing chain. An MP3file is decoded and sent to a mixer to be eventuallymixed with other audio sources.The companyST-Ericsson is a leading company specialized in audio,video and telecom solutions for the mobile communicationmarket. Created as result of the conglomerationbetween STMicroelectronics and Ericsson, its mission isto provide 2G and 3G mobile platforms and multimediadesigns to the market.The OpenMAX standardThe OpenMAX IL (Integration Layer) API defines a standardizedmedia component interface to enable developersand platform providers to integrate and communicatewith multimedia codecs implemented in hardware orsoftware.On our implementation, the different components (MP3decoder, Mixer, Etc..) are running on an ARM core, butthe processing in itself is entirely performed by a dedicatedDSP.The projectThe Hardware Abstraction Layer (HAL) developed forthis project is using the standardized OpenMAX-IL interface.It controls and abstracts the main audio featuresrunning on the audio DSP subsystem. The interactionbetween the different components has been validatedand tested with PragmaDev MSC Tracer tool in ST-Ericsson'sfacility located in Sophia Antipolis.The OpenMAX IL API strives to give media componentsportability across an array of platforms. Each module isencapsulated in a component interface. OpenMAXdefines three main types of entities:The needsOn this project, it was very important to visualize thecommunication between the ARM processor and theDSP as well as the communication between the differentOpenMAX components.

Success storyWe started looking for a tool that could provide graphicalrepresentation of all tasks, messages and objects implementedin the OpenMAX IL layer. MSC Tracer tool wasselected because it can represent traces on a diagramand it is very easy to use.is shown an example of a scenario ran on ARM wherebasic OpenMAX methods are traced.The solutionMSC Tracer allows showing data exchange betweenentities and can reconstruct any scenario in an easymanner. The diagram is easy to read and based on internationalstandards. MSC Tracer uses socket-basedcommunication to retrieve data from the source; thereforeit can be installed on every station in the network.In addition, the tool allows editing the diagrams: zoom in,zoom out, pause tracing etc. It is also possible to savetraces in order to further retrieve them even if the sourceis not connected. MSC Tracer displays time between theevents which is very useful when checking the correctbehavior of the firmware.Generally speaking the utilization of the tool turned out tobe indispensable in the project. The idea of generatingdiagrams from the traces allows saving time and gettinga better understanding of the global architecture. BelowPragmaDevWe have very good relationships with PragmaDev thatacted like a partner. If requested, they can adapt the toolfor your specific needs.Future workMSC Tracer has been a very suitable solution to test anddemonstrate our software. Its user-friendly interface letssave your time and brings you to work more efficiently.We strongly recommend MSC Tracer to all that are lookingfor a tool to visualize the interaction between modulesor components like in our OpenMAX projects.