Contents

• Disclaimer
• List of Tables
• Introduction to Speex
• Introduction to CELP Coding
  • Linear Prediction
  • Pitch Prediction
  • Innovation Codebook
  • Analysis-by-Synthesis and Error Weighting
  
  
• Speex narrowband mode
  • LPC Analysis
  • Pitch Prediction (adaptive codebook)
  • Innovation Codebook
  • Bit allocation
  • Perceptual enhancement
  
  
• Speex wideband mode (sub-band CELP)
  • Linear Prediction
  • Pitch Prediction
  • Excitation Quantization
  • Bit allocation
  
  
• Command-line encoder/decoder
  • speexenc
  • speexdec
  
  
• Programming with Speex (the libspeex API)
  • Encoding
  • Decoding
  • Codec Options (speex_*_ctl)
  • Packing more than one frame per packet
  
  
• Formats and standards
  • RTP Payload Format
  • Ogg file format
  
  
• FAQ
  • Vorbis is open-source and patent-free, why do we need Speex?
  • Can I use Speex for compressing music?
  • I converted some MP3's to Speex and the quality is bad. What's wrong?
  • Why is encoding so slow compared to decoding?
  • Why is Speex so slow on my iPaq (or insert any platform without an FPU)?
  • I'm getting unusual background noise (hiss) when using libspeex in my application. How do I fix that?
  • I get very distorted speech when using libspeex in my application. What's wrong?
  • Can Speex pass DTMF?
  • Can Speex pass V.9x modem signals correctly?
  • What is your (Jean-Marc) relationship with the University of Sherbrooke and how does Speex fit into that?
  • CELP, ACELP, what's the difference?
  
  
• GNU Free Documentation License
  • 0. PREAMBLE
  • 1. APPLICABILITY AND DEFINITIONS
  • 2. VERBATIM COPYING
  • 3. COPYING IN QUANTITY
  • 4. MODIFICATIONS
  • 5. COMBINING DOCUMENTS
  • 6. COLLECTIONS OF DOCUMENTS
  • 7. AGGREGATION WITH INDEPENDENT WORKS
  • 8. TRANSLATION
  • 9. TERMINATION
  • 10. FUTURE REVISIONS OF THIS LICENSE
  
  
• About this document ...