| See INSTALL file for instruction on how to install Speex. |
| |
| The Speex project aims to build an open-source patent-free voice codec. |
| Unlike other codecs like MP3 and Ogg Vorbis, Speex is specially designed |
| for compressing voice at low bit-rates for applications such as voice over |
| IP (VoIP). In some sense, it is meant to be complementary to the Ogg |
| Vorbis codec. |
| |
| Although we aim at providing a patent-free codec, we strongly suggest you |
| have a look at patent issues if you are thinking about using Speex |
| commercially. The speech coding field is a real patent minefield and |
| the scope and enforceability of all these patents is sometimes unclear, |
| not to mention that each country has different laws. |
| |
| To use Speex: |
| |
| % speexenc [-n or -w] input_file.sw compressed_file.spx |
| |
| % speexdec compressed_file.spx output_file.sw |
| |
| where -n is for narrowband (8 kHz sampling) and -w is wideband (16 kHz |
| sampling). |
| |
| All audio files are assumed to be raw (no header) 16-bit PCM files. To |
| convert a .wav file into this format: |
| % sox my_file.wav -t sw my_file.sw |
| |
| Note that if the original sampling frequency of the wav is not 8 kHz or 16 kHz, |
| you will need to add "-r 8000" or "-r 16000" (without the quotes). |
| |
| To create a .wav file: |
| % sox -t sw my_file.sw my_file.wav |
