gsm_decode.c

mediastreamer2是开源的网络传输媒体流的库

/*
 * 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: /antisip/cvs/amsip/codecs/gsm/src/gsm_decode.c,v 1.1 2006-07-05 10:28:50 jack Exp $ */

#include "private.h"

#include "gsm.h"
#include "proto.h"

int gsm_decode P3((s, c, target), gsm s, gsm_byte * c, gsm_signal * target)
{
	word  	LARc[8], Nc[4], Mc[4], bc[4], xmaxc[4], xmc[13*4];

#ifdef WAV49
	if (s->wav_fmt) {

		uword sr = 0;

		s->frame_index = !s->frame_index;
		if (s->frame_index) {

			sr = *c++;
			LARc[0] = sr & 0x3f;  sr >>= 6;
			sr |= (uword)*c++ << 2;
			LARc[1] = sr & 0x3f;  sr >>= 6;
			sr |= (uword)*c++ << 4;
			LARc[2] = sr & 0x1f;  sr >>= 5;
			LARc[3] = sr & 0x1f;  sr >>= 5;
			sr |= (uword)*c++ << 2;
			LARc[4] = sr & 0xf;  sr >>= 4;
			LARc[5] = sr & 0xf;  sr >>= 4;
			sr |= (uword)*c++ << 2;			/* 5 */
			LARc[6] = sr & 0x7;  sr >>= 3;
			LARc[7] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 4;
			Nc[0] = sr & 0x7f;  sr >>= 7;
			bc[0] = sr & 0x3;  sr >>= 2;
			Mc[0] = sr & 0x3;  sr >>= 2;
			sr |= (uword)*c++ << 1;
			xmaxc[0] = sr & 0x3f;  sr >>= 6;
			xmc[0] = sr & 0x7;  sr >>= 3;
			sr = *c++;
			xmc[1] = sr & 0x7;  sr >>= 3;
			xmc[2] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 2;
			xmc[3] = sr & 0x7;  sr >>= 3;
			xmc[4] = sr & 0x7;  sr >>= 3;
			xmc[5] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 1;			/* 10 */
			xmc[6] = sr & 0x7;  sr >>= 3;
			xmc[7] = sr & 0x7;  sr >>= 3;
			xmc[8] = sr & 0x7;  sr >>= 3;
			sr = *c++;
			xmc[9] = sr & 0x7;  sr >>= 3;
			xmc[10] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 2;
			xmc[11] = sr & 0x7;  sr >>= 3;
			xmc[12] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 4;
			Nc[1] = sr & 0x7f;  sr >>= 7;
			bc[1] = sr & 0x3;  sr >>= 2;
			Mc[1] = sr & 0x3;  sr >>= 2;
			sr |= (uword)*c++ << 1;
			xmaxc[1] = sr & 0x3f;  sr >>= 6;
			xmc[13] = sr & 0x7;  sr >>= 3;
			sr = *c++;				/* 15 */
			xmc[14] = sr & 0x7;  sr >>= 3;
			xmc[15] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 2;
			xmc[16] = sr & 0x7;  sr >>= 3;
			xmc[17] = sr & 0x7;  sr >>= 3;
			xmc[18] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 1;
			xmc[19] = sr & 0x7;  sr >>= 3;
			xmc[20] = sr & 0x7;  sr >>= 3;
			xmc[21] = sr & 0x7;  sr >>= 3;
			sr = *c++;
			xmc[22] = sr & 0x7;  sr >>= 3;
			xmc[23] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 2;
			xmc[24] = sr & 0x7;  sr >>= 3;
			xmc[25] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 4;			/* 20 */
			Nc[2] = sr & 0x7f;  sr >>= 7;
			bc[2] = sr & 0x3;  sr >>= 2;
			Mc[2] = sr & 0x3;  sr >>= 2;
			sr |= (uword)*c++ << 1;
			xmaxc[2] = sr & 0x3f;  sr >>= 6;
			xmc[26] = sr & 0x7;  sr >>= 3;
			sr = *c++;
			xmc[27] = sr & 0x7;  sr >>= 3;
			xmc[28] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 2;
			xmc[29] = sr & 0x7;  sr >>= 3;
			xmc[30] = sr & 0x7;  sr >>= 3;
			xmc[31] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 1;
			xmc[32] = sr & 0x7;  sr >>= 3;
			xmc[33] = sr & 0x7;  sr >>= 3;
			xmc[34] = sr & 0x7;  sr >>= 3;
			sr = *c++;				/* 25 */
			xmc[35] = sr & 0x7;  sr >>= 3;
			xmc[36] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 2;
			xmc[37] = sr & 0x7;  sr >>= 3;
			xmc[38] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 4;
			Nc[3] = sr & 0x7f;  sr >>= 7;
			bc[3] = sr & 0x3;  sr >>= 2;
			Mc[3] = sr & 0x3;  sr >>= 2;
			sr |= (uword)*c++ << 1;
			xmaxc[3] = sr & 0x3f;  sr >>= 6;
			xmc[39] = sr & 0x7;  sr >>= 3;
			sr = *c++;
			xmc[40] = sr & 0x7;  sr >>= 3;
			xmc[41] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 2;			/* 30 */
			xmc[42] = sr & 0x7;  sr >>= 3;
			xmc[43] = sr & 0x7;  sr >>= 3;
			xmc[44] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 1;
			xmc[45] = sr & 0x7;  sr >>= 3;
			xmc[46] = sr & 0x7;  sr >>= 3;
			xmc[47] = sr & 0x7;  sr >>= 3;
			sr = *c++;
			xmc[48] = sr & 0x7;  sr >>= 3;
			xmc[49] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 2;
			xmc[50] = sr & 0x7;  sr >>= 3;
			xmc[51] = sr & 0x7;  sr >>= 3;

			s->frame_chain = sr & 0xf;
		}
		else {
			sr = s->frame_chain;
			sr |= (uword)*c++ << 4;			/* 1 */
			LARc[0] = sr & 0x3f;  sr >>= 6;
			LARc[1] = sr & 0x3f;  sr >>= 6;
			sr = *c++;
			LARc[2] = sr & 0x1f;  sr >>= 5;
			sr |= (uword)*c++ << 3;
			LARc[3] = sr & 0x1f;  sr >>= 5;
			LARc[4] = sr & 0xf;  sr >>= 4;
			sr |= (uword)*c++ << 2;
			LARc[5] = sr & 0xf;  sr >>= 4;
			LARc[6] = sr & 0x7;  sr >>= 3;
			LARc[7] = sr & 0x7;  sr >>= 3;
			sr = *c++;				/* 5 */
			Nc[0] = sr & 0x7f;  sr >>= 7;
			sr |= (uword)*c++ << 1;
			bc[0] = sr & 0x3;  sr >>= 2;
			Mc[0] = sr & 0x3;  sr >>= 2;
			sr |= (uword)*c++ << 5;
			xmaxc[0] = sr & 0x3f;  sr >>= 6;
			xmc[0] = sr & 0x7;  sr >>= 3;
			xmc[1] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 1;
			xmc[2] = sr & 0x7;  sr >>= 3;
			xmc[3] = sr & 0x7;  sr >>= 3;
			xmc[4] = sr & 0x7;  sr >>= 3;
			sr = *c++;
			xmc[5] = sr & 0x7;  sr >>= 3;
			xmc[6] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 2;			/* 10 */
			xmc[7] = sr & 0x7;  sr >>= 3;
			xmc[8] = sr & 0x7;  sr >>= 3;
			xmc[9] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 1;
			xmc[10] = sr & 0x7;  sr >>= 3;
			xmc[11] = sr & 0x7;  sr >>= 3;
			xmc[12] = sr & 0x7;  sr >>= 3;
			sr = *c++;
			Nc[1] = sr & 0x7f;  sr >>= 7;
			sr |= (uword)*c++ << 1;
			bc[1] = sr & 0x3;  sr >>= 2;
			Mc[1] = sr & 0x3;  sr >>= 2;
			sr |= (uword)*c++ << 5;
			xmaxc[1] = sr & 0x3f;  sr >>= 6;
			xmc[13] = sr & 0x7;  sr >>= 3;
			xmc[14] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 1;			/* 15 */
			xmc[15] = sr & 0x7;  sr >>= 3;
			xmc[16] = sr & 0x7;  sr >>= 3;
			xmc[17] = sr & 0x7;  sr >>= 3;
			sr = *c++;
			xmc[18] = sr & 0x7;  sr >>= 3;
			xmc[19] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 2;
			xmc[20] = sr & 0x7;  sr >>= 3;
			xmc[21] = sr & 0x7;  sr >>= 3;
			xmc[22] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 1;
			xmc[23] = sr & 0x7;  sr >>= 3;
			xmc[24] = sr & 0x7;  sr >>= 3;
			xmc[25] = sr & 0x7;  sr >>= 3;
			sr = *c++;
			Nc[2] = sr & 0x7f;  sr >>= 7;
			sr |= (uword)*c++ << 1;			/* 20 */
			bc[2] = sr & 0x3;  sr >>= 2;
			Mc[2] = sr & 0x3;  sr >>= 2;
			sr |= (uword)*c++ << 5;
			xmaxc[2] = sr & 0x3f;  sr >>= 6;
			xmc[26] = sr & 0x7;  sr >>= 3;
			xmc[27] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 1;	
			xmc[28] = sr & 0x7;  sr >>= 3;
			xmc[29] = sr & 0x7;  sr >>= 3;
			xmc[30] = sr & 0x7;  sr >>= 3;
			sr = *c++;
			xmc[31] = sr & 0x7;  sr >>= 3;
			xmc[32] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 2;
			xmc[33] = sr & 0x7;  sr >>= 3;
			xmc[34] = sr & 0x7;  sr >>= 3;
			xmc[35] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 1;			/* 25 */
			xmc[36] = sr & 0x7;  sr >>= 3;
			xmc[37] = sr & 0x7;  sr >>= 3;
			xmc[38] = sr & 0x7;  sr >>= 3;
			sr = *c++;
			Nc[3] = sr & 0x7f;  sr >>= 7;
			sr |= (uword)*c++ << 1;		
			bc[3] = sr & 0x3;  sr >>= 2;
			Mc[3] = sr & 0x3;  sr >>= 2;
			sr |= (uword)*c++ << 5;
			xmaxc[3] = sr & 0x3f;  sr >>= 6;
			xmc[39] = sr & 0x7;  sr >>= 3;
			xmc[40] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 1;
			xmc[41] = sr & 0x7;  sr >>= 3;
			xmc[42] = sr & 0x7;  sr >>= 3;
			xmc[43] = sr & 0x7;  sr >>= 3;
			sr = *c++;				/* 30 */
			xmc[44] = sr & 0x7;  sr >>= 3;
			xmc[45] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 2;
			xmc[46] = sr & 0x7;  sr >>= 3;
			xmc[47] = sr & 0x7;  sr >>= 3;
			xmc[48] = sr & 0x7;  sr >>= 3;
			sr |= (uword)*c++ << 1;
			xmc[49] = sr & 0x7;  sr >>= 3;
			xmc[50] = sr & 0x7;  sr >>= 3;
			xmc[51] = sr & 0x7;  sr >>= 3;
		}
	}
	else
#endif
	{
		/* GSM_MAGIC  = (*c >> 4) & 0xF; */

		if (((*c >> 4) & 0x0F) != GSM_MAGIC) return -1;

		LARc[0]  = (*c++ & 0xF) << 2;		/* 1 */
		LARc[0] |= (*c >> 6) & 0x3;
		LARc[1]  = *c++ & 0x3F;
		LARc[2]  = (*c >> 3) & 0x1F;
		LARc[3]  = (*c++ & 0x7) << 2;
		LARc[3] |= (*c >> 6) & 0x3;
		LARc[4]  = (*c >> 2) & 0xF;
		LARc[5]  = (*c++ & 0x3) << 2;
		LARc[5] |= (*c >> 6) & 0x3;
		LARc[6]  = (*c >> 3) & 0x7;
		LARc[7]  = *c++ & 0x7;
		Nc[0]  = (*c >> 1) & 0x7F;
		bc[0]  = (*c++ & 0x1) << 1;
		bc[0] |= (*c >> 7) & 0x1;
		Mc[0]  = (*c >> 5) & 0x3;
		xmaxc[0]  = (*c++ & 0x1F) << 1;
		xmaxc[0] |= (*c >> 7) & 0x1;
		xmc[0]  = (*c >> 4) & 0x7;
		xmc[1]  = (*c >> 1) & 0x7;
		xmc[2]  = (*c++ & 0x1) << 2;
		xmc[2] |= (*c >> 6) & 0x3;
		xmc[3]  = (*c >> 3) & 0x7;
		xmc[4]  = *c++ & 0x7;
		xmc[5]  = (*c >> 5) & 0x7;
		xmc[6]  = (*c >> 2) & 0x7;
		xmc[7]  = (*c++ & 0x3) << 1;		/* 10 */
		xmc[7] |= (*c >> 7) & 0x1;
		xmc[8]  = (*c >> 4) & 0x7;
		xmc[9]  = (*c >> 1) & 0x7;
		xmc[10]  = (*c++ & 0x1) << 2;
		xmc[10] |= (*c >> 6) & 0x3;
		xmc[11]  = (*c >> 3) & 0x7;
		xmc[12]  = *c++ & 0x7;
		Nc[1]  = (*c >> 1) & 0x7F;
		bc[1]  = (*c++ & 0x1) << 1;
		bc[1] |= (*c >> 7) & 0x1;
		Mc[1]  = (*c >> 5) & 0x3;
		xmaxc[1]  = (*c++ & 0x1F) << 1;
		xmaxc[1] |= (*c >> 7) & 0x1;
		xmc[13]  = (*c >> 4) & 0x7;
		xmc[14]  = (*c >> 1) & 0x7;
		xmc[15]  = (*c++ & 0x1) << 2;
		xmc[15] |= (*c >> 6) & 0x3;
		xmc[16]  = (*c >> 3) & 0x7;
		xmc[17]  = *c++ & 0x7;
		xmc[18]  = (*c >> 5) & 0x7;
		xmc[19]  = (*c >> 2) & 0x7;
		xmc[20]  = (*c++ & 0x3) << 1;
		xmc[20] |= (*c >> 7) & 0x1;
		xmc[21]  = (*c >> 4) & 0x7;
		xmc[22]  = (*c >> 1) & 0x7;
		xmc[23]  = (*c++ & 0x1) << 2;
		xmc[23] |= (*c >> 6) & 0x3;
		xmc[24]  = (*c >> 3) & 0x7;
		xmc[25]  = *c++ & 0x7;
		Nc[2]  = (*c >> 1) & 0x7F;
		bc[2]  = (*c++ & 0x1) << 1;		/* 20 */
		bc[2] |= (*c >> 7) & 0x1;
		Mc[2]  = (*c >> 5) & 0x3;
		xmaxc[2]  = (*c++ & 0x1F) << 1;
		xmaxc[2] |= (*c >> 7) & 0x1;
		xmc[26]  = (*c >> 4) & 0x7;
		xmc[27]  = (*c >> 1) & 0x7;
		xmc[28]  = (*c++ & 0x1) << 2;
		xmc[28] |= (*c >> 6) & 0x3;
		xmc[29]  = (*c >> 3) & 0x7;
		xmc[30]  = *c++ & 0x7;
		xmc[31]  = (*c >> 5) & 0x7;
		xmc[32]  = (*c >> 2) & 0x7;
		xmc[33]  = (*c++ & 0x3) << 1;
		xmc[33] |= (*c >> 7) & 0x1;
		xmc[34]  = (*c >> 4) & 0x7;
		xmc[35]  = (*c >> 1) & 0x7;
		xmc[36]  = (*c++ & 0x1) << 2;
		xmc[36] |= (*c >> 6) & 0x3;
		xmc[37]  = (*c >> 3) & 0x7;
		xmc[38]  = *c++ & 0x7;
		Nc[3]  = (*c >> 1) & 0x7F;
		bc[3]  = (*c++ & 0x1) << 1;
		bc[3] |= (*c >> 7) & 0x1;
		Mc[3]  = (*c >> 5) & 0x3;
		xmaxc[3]  = (*c++ & 0x1F) << 1;
		xmaxc[3] |= (*c >> 7) & 0x1;
		xmc[39]  = (*c >> 4) & 0x7;
		xmc[40]  = (*c >> 1) & 0x7;
		xmc[41]  = (*c++ & 0x1) << 2;
		xmc[41] |= (*c >> 6) & 0x3;
		xmc[42]  = (*c >> 3) & 0x7;
		xmc[43]  = *c++ & 0x7;			/* 30  */
		xmc[44]  = (*c >> 5) & 0x7;
		xmc[45]  = (*c >> 2) & 0x7;
		xmc[46]  = (*c++ & 0x3) << 1;
		xmc[46] |= (*c >> 7) & 0x1;
		xmc[47]  = (*c >> 4) & 0x7;
		xmc[48]  = (*c >> 1) & 0x7;
		xmc[49]  = (*c++ & 0x1) << 2;
		xmc[49] |= (*c >> 6) & 0x3;
		xmc[50]  = (*c >> 3) & 0x7;
		xmc[51]  = *c & 0x7;			/* 33 */
	}

	Gsm_Decoder(s, LARc, Nc, bc, Mc, xmaxc, xmc, target);

	return 0;
}