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author | russell <russell@f38db490-d61c-443f-a65b-d21fe96a405b> | 2008-01-19 00:19:29 +0000 |
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committer | russell <russell@f38db490-d61c-443f-a65b-d21fe96a405b> | 2008-01-19 00:19:29 +0000 |
commit | f8247040e6231c4b3b5099ea3a526348b7941566 (patch) | |
tree | 0cc92ad6ebf6ae49a62f6e7ef8ec819121d63630 /trunk/codecs/gsm/src/decode.c | |
parent | d88e56c61ce2042544c1a8a71c93b69ab2e6ffba (diff) |
Creating tag for the release of asterisk-1.6.0-beta1v1.6.0-beta1
git-svn-id: http://svn.digium.com/svn/asterisk/tags/1.6.0-beta1@99163 f38db490-d61c-443f-a65b-d21fe96a405b
Diffstat (limited to 'trunk/codecs/gsm/src/decode.c')
-rw-r--r-- | trunk/codecs/gsm/src/decode.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/trunk/codecs/gsm/src/decode.c b/trunk/codecs/gsm/src/decode.c new file mode 100644 index 000000000..093ac64df --- /dev/null +++ b/trunk/codecs/gsm/src/decode.c @@ -0,0 +1,62 @@ +/* + * Copyright 1992 by Jutta Degener and Carsten Bormann, Technische + * Universitaet Berlin. See the accompanying file "COPYRIGHT" for + * details. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE. + */ + +/* $Header$ */ + +#include <stdio.h> + +#include "private.h" +#include "gsm.h" +#include "proto.h" + +/* + * 4.3 FIXED POINT IMPLEMENTATION OF THE RPE-LTP DECODER + */ + +static void Postprocessing P2((S,s), + struct gsm_state * S, + register word * s) +{ + register int k; + register word msr = S->msr; + register word tmp; + + for (k = 160; k--; s++) { + tmp = (word)GSM_MULT_R( msr, 28180 ); + msr = GSM_ADD(*s, tmp); /* Deemphasis */ + *s = GSM_ADD(msr, msr) & 0xFFF8; /* Truncation & Upscaling */ + } + S->msr = msr; +} + +void Gsm_Decoder P8((S,LARcr, Ncr,bcr,Mcr,xmaxcr,xMcr,s), + struct gsm_state * S, + + word * LARcr, /* [0..7] IN */ + + word * Ncr, /* [0..3] IN */ + word * bcr, /* [0..3] IN */ + word * Mcr, /* [0..3] IN */ + word * xmaxcr, /* [0..3] IN */ + word * xMcr, /* [0..13*4] IN */ + + word * s) /* [0..159] OUT */ +{ + int j, k; + word erp[40], wt[160]; + word * drp = S->dp0 + 120; + + for (j=0; j <= 3; j++, xmaxcr++, bcr++, Ncr++, Mcr++, xMcr += 13) { + + Gsm_RPE_Decoding( S, *xmaxcr, *Mcr, xMcr, erp ); + Gsm_Long_Term_Synthesis_Filtering( S, *Ncr, *bcr, erp, drp ); + + for (k = 0; k <= 39; k++) wt[ j * 40 + k ] = drp[ k ]; + } + + Gsm_Short_Term_Synthesis_Filter( S, LARcr, wt, s ); + Postprocessing(S, s); +} |