FreeCalypso > hg > gsm-codec-lib
view libgsmefr/tls_flags.c @ 183:452c1d5a6268
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 | 38326102fc43 |
children |
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/* * Unfortunately the code we got from ETSI makes heavy use of two global * Boolean flags named Carry and Overflow that function like equally named * processor state flags on many CPU architectures. They are not part * of persistent codec session state for either the encoder or the decoder, * instead they are "short-term" globals much like UNIX errno. * * Given this unfortunate reality plus the natural desire to make our * EFR library thread-safe (a transcoding MGW handling a large volume of * simultaneous calls is exactly the kind of application that would benefit * from utilitizing all CPU cores), our current workaround is to use * thread-local storage. */ #include <stdint.h> #include "typedef.h" __thread Flag EFR__Carry, EFR__Overflow;