| The STM32 speech-codec software library enables you to transmit longer messages and store more speech data. The Speex codec high-compressionformat and small embedded-memory footprint allows you to design cost-effective solutions for narrowband bitrates. Speech is sampled at 8 kHz by the STM32’s on-chip 12-bit 1 µs ADC and encoded and compressed at a 16:1 ratio fixed 8 Kbit/s bitrate. Encoded compressed data is stored in the STM32 embedded Flash (1 Kbyte/s of speech). Speech decoded data is output by the STM32 16-bit PWM timer. |
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| STM32 speech codec software library - 32-bit microcontroller families |
| The STM32 speech codec software library includes: |
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Playback: decoding and playing of a Speex-encoded message stored in the embedded STM32 microcontroller Flash memory |
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Record and play: storing voice messages in the STM32 embedded Flash and playback |
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Loopback: encoding and decoding processes are executed in real-time |
| The STM32 speech codec software library is developed in C and assembled on the latest IAR and KEIL tool chains. It is supported by well-documented application notes for the STM32 family. |
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| STM32 Speex-codec resources: |
STM32 Speex-codec narrowband mode resources |
| Encoder |
Program memory size |
32 KB |
| RAM memory size |
6.5 KB |
| Encoder CPU load @ 72 MHz |
52 % |
| Decoder |
Program memory size |
32 KB |
| RAM memory size |
3.7 KB |
| Decoder CPU load @ 72 MHz |
8 % |
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Applications |
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Software and documents |
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