# Release Notes for STM32 Audio Utilities - Common drivers Copyright © 2012 STMicroelectronics
## Contents Update history License ## Update history 2 This directory contains the main common drivers used for audio utilities: Output interface: common functions used to output audio data from STM32 to external world (ie. Amplifier, codec..). It is the abstraction layer for the hardware output peripherals (I2S, DMA, Codec controlled by I2C (ie. CS43L22)). It consists on files "stm32_audio_out_if.c/.h" Input Interface: common functions used to get input audio data from external world to STM32 (ie. ADC, MEMS Microphone..). It is the abstraction layer for the hardware input peripherals (ADC, TIM, SPI ...). It consists on files "stm32_audio_in_it.c/.h" Software codecs interfaces: for WAV, MP3 and WMA processing. It allows management of encoded audio files/streams as well as headers parsing and tags information extraction. It consists on files "wavprocess.c/.h", "mp3process.c/.h", "wmaprocess.c./.h", "stm32_audio_decoders.c/.h" and "songutilities.c/.h". The same API is used for all codecs, thus the user application layer remains the same independently of the file/stream coding format (WAV, MP3 or WMA). Synchronization mechanism interface: allowing to synchronize input and output streams using bufferization and Timers (ie. when audio is streamed over USB interface). It consists on files "stm32_audio_correction.c/.h" and "stm32_audio_synchprocess.c/.h". These interfaces might be used in specific cases like USB Device Audio Streaming application. ### V1.0.0 / 31-July-2012 Main Changes First official release ## License Licensed under MCD-ST Liberty SW License Agreement V2, (the "License"); You may not use this package except in compliance with the License. You may obtain a copy of the License at: http://www.st.com/software_license_agreement_liberty_v2 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. For complete documentation on STM32 Microcontrollers visit www.st.com/STM32