FreeCalypso > hg > gsm-codec-lib
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libgsmefr BFI w/o data: emit zero output after decoder reset
In real-life usage, each EFR decoder session will most likely begin
with lots of BFI frames before the first real frame arrives. However,
because the spec-defined home state of the decoder is speech rather
than CN, our regular logic for BFI w/o data would have to feed
pseudorandom noise to the decoder (in the "fixed codebook excitation
pulses" part), which is silly to do at the beginning of the decoder
session right out of reset. Therefore, let's check reset_flag_old,
and if we are still in the reset state, simply emit zero output.
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Tue, 03 Jan 2023 00:12:18 +0000 |
| parents | b45bb0f9bdfc |
| children | 1b8cb3490d48 |
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The present source repository is intended to be a collection of C libraries (each at least conceptually independent and free-standing) providing functionality in a spirit similar to the venerable libgsm (GSM 06.10 implementation) from 1990s. The following libraries are currently envisioned: libgsmfrp A preprocessor to be invoked prior to gsm_decode() from classic libgsm, implementing GSM 06.11, 06.12 and 06.31 functionality in the Rx direction. libgsmefr An implementation of EFR codec in the same spirit as classic libgsm, i.e., like libgsm, but for EFR instead of 06.10. It will be based on the reference code from ETSI. libgsmamr A similar deal for AMR, only a fuzzy idea currently.