I used STM32F10x_AN2812_FW_V2.0.0 to have speex encoding /decoding on voice. I applied it on my Discovery board. I used encoding functions and then decoding one and saved the data in .wav format using FATFS on micro SD. It works very well. But I have some problems when I bypass decoding step to have .spx data format. I add speex header to data and write them to micro SD but I can’t play the file. Please help me to add correct header to my file.