GSM 6.10 codec conversion
From: Dean (dean[no-spam)
Date: 03/29/04
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Date: Mon, 29 Mar 2004 14:27:39 +0100
Please forgive the slightly double-posting with public.delphi.oopdesign, but
having posted there enquiring if anyone has already built a Delphi/Kylix
wrapper for this codec, I wondered whether this might be my opportunity to
get a little more "low level" with Delphi and try and convert the actual
codec to native Delphi.
You guys seemed like the best to ask as I'm sure this all looks positively
simple to you.
A bit about the codec is at:-
http://kbs.cs.tu-berlin.de/~jutta/toast.html
It basically takes 160 16bit PCM samples and encodes to and from GSM (33
byte) frames.
It's open-source. I'm not sure if it's already been converted to Delphi, but
it's a useful codec and I would keep it completely open-source if I did
convert it. I probably won't know whether I'm capable or not unless I have a
go. What do you think - simple or complex job?
The core encode routine in C++ is posted below.
Thanks,
Dean
/*
* 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: /tmp_amd/presto/export/kbs/jutta/src/gsm/RCS/gsm_encode.c,v 1.2
1996/07/02 09:59:05 jutta Exp $ */
#include "private.h"
#include "gsm.h"
#include "proto.h"
void gsm_encode P3((s, source, c), gsm s, gsm_signal * source, gsm_byte * c)
{
word LARc[8], Nc[4], Mc[4], bc[4], xmaxc[4], xmc[13*4];
Gsm_Coder(s, source, LARc, Nc, bc, Mc, xmaxc, xmc);
/* variable size
GSM_MAGIC 4
LARc[0] 6
LARc[1] 6
LARc[2] 5
LARc[3] 5
LARc[4] 4
LARc[5] 4
LARc[6] 3
LARc[7] 3
Nc[0] 7
bc[0] 2
Mc[0] 2
xmaxc[0] 6
xmc[0] 3
xmc[1] 3
xmc[2] 3
xmc[3] 3
xmc[4] 3
xmc[5] 3
xmc[6] 3
xmc[7] 3
xmc[8] 3
xmc[9] 3
xmc[10] 3
xmc[11] 3
xmc[12] 3
Nc[1] 7
bc[1] 2
Mc[1] 2
xmaxc[1] 6
xmc[13] 3
xmc[14] 3
xmc[15] 3
xmc[16] 3
xmc[17] 3
xmc[18] 3
xmc[19] 3
xmc[20] 3
xmc[21] 3
xmc[22] 3
xmc[23] 3
xmc[24] 3
xmc[25] 3
Nc[2] 7
bc[2] 2
Mc[2] 2
xmaxc[2] 6
xmc[26] 3
xmc[27] 3
xmc[28] 3
xmc[29] 3
xmc[30] 3
xmc[31] 3
xmc[32] 3
xmc[33] 3
xmc[34] 3
xmc[35] 3
xmc[36] 3
xmc[37] 3
xmc[38] 3
Nc[3] 7
bc[3] 2
Mc[3] 2
xmaxc[3] 6
xmc[39] 3
xmc[40] 3
xmc[41] 3
xmc[42] 3
xmc[43] 3
xmc[44] 3
xmc[45] 3
xmc[46] 3
xmc[47] 3
xmc[48] 3
xmc[49] 3
xmc[50] 3
xmc[51] 3
*/
#ifdef WAV49
if (s->wav_fmt) {
s->frame_index = !s->frame_index;
if (s->frame_index) {
uword sr;
sr = 0;
sr = sr >> 6 | LARc[0] << 10;
sr = sr >> 6 | LARc[1] << 10;
*c++ = sr >> 4;
sr = sr >> 5 | LARc[2] << 11;
*c++ = sr >> 7;
sr = sr >> 5 | LARc[3] << 11;
sr = sr >> 4 | LARc[4] << 12;
*c++ = sr >> 6;
sr = sr >> 4 | LARc[5] << 12;
sr = sr >> 3 | LARc[6] << 13;
*c++ = sr >> 7;
sr = sr >> 3 | LARc[7] << 13;
sr = sr >> 7 | Nc[0] << 9;
*c++ = sr >> 5;
sr = sr >> 2 | bc[0] << 14;
sr = sr >> 2 | Mc[0] << 14;
sr = sr >> 6 | xmaxc[0] << 10;
*c++ = sr >> 3;
sr = sr >> 3 | xmc[0] << 13;
*c++ = sr >> 8;
sr = sr >> 3 | xmc[1] << 13;
sr = sr >> 3 | xmc[2] << 13;
sr = sr >> 3 | xmc[3] << 13;
*c++ = sr >> 7;
sr = sr >> 3 | xmc[4] << 13;
sr = sr >> 3 | xmc[5] << 13;
sr = sr >> 3 | xmc[6] << 13;
*c++ = sr >> 6;
sr = sr >> 3 | xmc[7] << 13;
sr = sr >> 3 | xmc[8] << 13;
*c++ = sr >> 8;
sr = sr >> 3 | xmc[9] << 13;
sr = sr >> 3 | xmc[10] << 13;
sr = sr >> 3 | xmc[11] << 13;
*c++ = sr >> 7;
sr = sr >> 3 | xmc[12] << 13;
sr = sr >> 7 | Nc[1] << 9;
*c++ = sr >> 5;
sr = sr >> 2 | bc[1] << 14;
sr = sr >> 2 | Mc[1] << 14;
sr = sr >> 6 | xmaxc[1] << 10;
*c++ = sr >> 3;
sr = sr >> 3 | xmc[13] << 13;
*c++ = sr >> 8;
sr = sr >> 3 | xmc[14] << 13;
sr = sr >> 3 | xmc[15] << 13;
sr = sr >> 3 | xmc[16] << 13;
*c++ = sr >> 7;
sr = sr >> 3 | xmc[17] << 13;
sr = sr >> 3 | xmc[18] << 13;
sr = sr >> 3 | xmc[19] << 13;
*c++ = sr >> 6;
sr = sr >> 3 | xmc[20] << 13;
sr = sr >> 3 | xmc[21] << 13;
*c++ = sr >> 8;
sr = sr >> 3 | xmc[22] << 13;
sr = sr >> 3 | xmc[23] << 13;
sr = sr >> 3 | xmc[24] << 13;
*c++ = sr >> 7;
sr = sr >> 3 | xmc[25] << 13;
sr = sr >> 7 | Nc[2] << 9;
*c++ = sr >> 5;
sr = sr >> 2 | bc[2] << 14;
sr = sr >> 2 | Mc[2] << 14;
sr = sr >> 6 | xmaxc[2] << 10;
*c++ = sr >> 3;
sr = sr >> 3 | xmc[26] << 13;
*c++ = sr >> 8;
sr = sr >> 3 | xmc[27] << 13;
sr = sr >> 3 | xmc[28] << 13;
sr = sr >> 3 | xmc[29] << 13;
*c++ = sr >> 7;
sr = sr >> 3 | xmc[30] << 13;
sr = sr >> 3 | xmc[31] << 13;
sr = sr >> 3 | xmc[32] << 13;
*c++ = sr >> 6;
sr = sr >> 3 | xmc[33] << 13;
sr = sr >> 3 | xmc[34] << 13;
*c++ = sr >> 8;
sr = sr >> 3 | xmc[35] << 13;
sr = sr >> 3 | xmc[36] << 13;
sr = sr >> 3 | xmc[37] << 13;
*c++ = sr >> 7;
sr = sr >> 3 | xmc[38] << 13;
sr = sr >> 7 | Nc[3] << 9;
*c++ = sr >> 5;
sr = sr >> 2 | bc[3] << 14;
sr = sr >> 2 | Mc[3] << 14;
sr = sr >> 6 | xmaxc[3] << 10;
*c++ = sr >> 3;
sr = sr >> 3 | xmc[39] << 13;
*c++ = sr >> 8;
sr = sr >> 3 | xmc[40] << 13;
sr = sr >> 3 | xmc[41] << 13;
sr = sr >> 3 | xmc[42] << 13;
*c++ = sr >> 7;
sr = sr >> 3 | xmc[43] << 13;
sr = sr >> 3 | xmc[44] << 13;
sr = sr >> 3 | xmc[45] << 13;
*c++ = sr >> 6;
sr = sr >> 3 | xmc[46] << 13;
sr = sr >> 3 | xmc[47] << 13;
*c++ = sr >> 8;
sr = sr >> 3 | xmc[48] << 13;
sr = sr >> 3 | xmc[49] << 13;
sr = sr >> 3 | xmc[50] << 13;
*c++ = sr >> 7;
sr = sr >> 3 | xmc[51] << 13;
sr = sr >> 4;
*c = sr >> 8;
s->frame_chain = *c;
}
else {
uword sr;
sr = 0;
sr = sr >> 4 | s->frame_chain << 12;
sr = sr >> 6 | LARc[0] << 10;
*c++ = sr >> 6;
sr = sr >> 6 | LARc[1] << 10;
*c++ = sr >> 8;
sr = sr >> 5 | LARc[2] << 11;
sr = sr >> 5 | LARc[3] << 11;
*c++ = sr >> 6;
sr = sr >> 4 | LARc[4] << 12;
sr = sr >> 4 | LARc[5] << 12;
*c++ = sr >> 6;
sr = sr >> 3 | LARc[6] << 13;
sr = sr >> 3 | LARc[7] << 13;
*c++ = sr >> 8;
sr = sr >> 7 | Nc[0] << 9;
sr = sr >> 2 | bc[0] << 14;
*c++ = sr >> 7;
sr = sr >> 2 | Mc[0] << 14;
sr = sr >> 6 | xmaxc[0] << 10;
*c++ = sr >> 7;
sr = sr >> 3 | xmc[0] << 13;
sr = sr >> 3 | xmc[1] << 13;
sr = sr >> 3 | xmc[2] << 13;
*c++ = sr >> 6;
sr = sr >> 3 | xmc[3] << 13;
sr = sr >> 3 | xmc[4] << 13;
*c++ = sr >> 8;
sr = sr >> 3 | xmc[5] << 13;
sr = sr >> 3 | xmc[6] << 13;
sr = sr >> 3 | xmc[7] << 13;
*c++ = sr >> 7;
sr = sr >> 3 | xmc[8] << 13;
sr = sr >> 3 | xmc[9] << 13;
sr = sr >> 3 | xmc[10] << 13;
*c++ = sr >> 6;
sr = sr >> 3 | xmc[11] << 13;
sr = sr >> 3 | xmc[12] << 13;
*c++ = sr >> 8;
sr = sr >> 7 | Nc[1] << 9;
sr = sr >> 2 | bc[1] << 14;
*c++ = sr >> 7;
sr = sr >> 2 | Mc[1] << 14;
sr = sr >> 6 | xmaxc[1] << 10;
*c++ = sr >> 7;
sr = sr >> 3 | xmc[13] << 13;
sr = sr >> 3 | xmc[14] << 13;
sr = sr >> 3 | xmc[15] << 13;
*c++ = sr >> 6;
sr = sr >> 3 | xmc[16] << 13;
sr = sr >> 3 | xmc[17] << 13;
*c++ = sr >> 8;
sr = sr >> 3 | xmc[18] << 13;
sr = sr >> 3 | xmc[19] << 13;
sr = sr >> 3 | xmc[20] << 13;
*c++ = sr >> 7;
sr = sr >> 3 | xmc[21] << 13;
sr = sr >> 3 | xmc[22] << 13;
sr = sr >> 3 | xmc[23] << 13;
*c++ = sr >> 6;
sr = sr >> 3 | xmc[24] << 13;
sr = sr >> 3 | xmc[25] << 13;
*c++ = sr >> 8;
sr = sr >> 7 | Nc[2] << 9;
sr = sr >> 2 | bc[2] << 14;
*c++ = sr >> 7;
sr = sr >> 2 | Mc[2] << 14;
sr = sr >> 6 | xmaxc[2] << 10;
*c++ = sr >> 7;
sr = sr >> 3 | xmc[26] << 13;
sr = sr >> 3 | xmc[27] << 13;
sr = sr >> 3 | xmc[28] << 13;
*c++ = sr >> 6;
sr = sr >> 3 | xmc[29] << 13;
sr = sr >> 3 | xmc[30] << 13;
*c++ = sr >> 8;
sr = sr >> 3 | xmc[31] << 13;
sr = sr >> 3 | xmc[32] << 13;
sr = sr >> 3 | xmc[33] << 13;
*c++ = sr >> 7;
sr = sr >> 3 | xmc[34] << 13;
sr = sr >> 3 | xmc[35] << 13;
sr = sr >> 3 | xmc[36] << 13;
*c++ = sr >> 6;
sr = sr >> 3 | xmc[37] << 13;
sr = sr >> 3 | xmc[38] << 13;
*c++ = sr >> 8;
sr = sr >> 7 | Nc[3] << 9;
sr = sr >> 2 | bc[3] << 14;
*c++ = sr >> 7;
sr = sr >> 2 | Mc[3] << 14;
sr = sr >> 6 | xmaxc[3] << 10;
*c++ = sr >> 7;
sr = sr >> 3 | xmc[39] << 13;
sr = sr >> 3 | xmc[40] << 13;
sr = sr >> 3 | xmc[41] << 13;
*c++ = sr >> 6;
sr = sr >> 3 | xmc[42] << 13;
sr = sr >> 3 | xmc[43] << 13;
*c++ = sr >> 8;
sr = sr >> 3 | xmc[44] << 13;
sr = sr >> 3 | xmc[45] << 13;
sr = sr >> 3 | xmc[46] << 13;
*c++ = sr >> 7;
sr = sr >> 3 | xmc[47] << 13;
sr = sr >> 3 | xmc[48] << 13;
sr = sr >> 3 | xmc[49] << 13;
*c++ = sr >> 6;
sr = sr >> 3 | xmc[50] << 13;
sr = sr >> 3 | xmc[51] << 13;
*c++ = sr >> 8;
}
}
else
#endif /* WAV49 */
{
*c++ = ((GSM_MAGIC & 0xF) << 4) /* 1 */
| ((LARc[0] >> 2) & 0xF);
*c++ = ((LARc[0] & 0x3) << 6)
| (LARc[1] & 0x3F);
*c++ = ((LARc[2] & 0x1F) << 3)
| ((LARc[3] >> 2) & 0x7);
*c++ = ((LARc[3] & 0x3) << 6)
| ((LARc[4] & 0xF) << 2)
| ((LARc[5] >> 2) & 0x3);
*c++ = ((LARc[5] & 0x3) << 6)
| ((LARc[6] & 0x7) << 3)
| (LARc[7] & 0x7);
*c++ = ((Nc[0] & 0x7F) << 1)
| ((bc[0] >> 1) & 0x1);
*c++ = ((bc[0] & 0x1) << 7)
| ((Mc[0] & 0x3) << 5)
| ((xmaxc[0] >> 1) & 0x1F);
*c++ = ((xmaxc[0] & 0x1) << 7)
| ((xmc[0] & 0x7) << 4)
| ((xmc[1] & 0x7) << 1)
| ((xmc[2] >> 2) & 0x1);
*c++ = ((xmc[2] & 0x3) << 6)
| ((xmc[3] & 0x7) << 3)
| (xmc[4] & 0x7);
*c++ = ((xmc[5] & 0x7) << 5) /* 10 */
| ((xmc[6] & 0x7) << 2)
| ((xmc[7] >> 1) & 0x3);
*c++ = ((xmc[7] & 0x1) << 7)
| ((xmc[8] & 0x7) << 4)
| ((xmc[9] & 0x7) << 1)
| ((xmc[10] >> 2) & 0x1);
*c++ = ((xmc[10] & 0x3) << 6)
| ((xmc[11] & 0x7) << 3)
| (xmc[12] & 0x7);
*c++ = ((Nc[1] & 0x7F) << 1)
| ((bc[1] >> 1) & 0x1);
*c++ = ((bc[1] & 0x1) << 7)
| ((Mc[1] & 0x3) << 5)
| ((xmaxc[1] >> 1) & 0x1F);
*c++ = ((xmaxc[1] & 0x1) << 7)
| ((xmc[13] & 0x7) << 4)
| ((xmc[14] & 0x7) << 1)
| ((xmc[15] >> 2) & 0x1);
*c++ = ((xmc[15] & 0x3) << 6)
| ((xmc[16] & 0x7) << 3)
| (xmc[17] & 0x7);
*c++ = ((xmc[18] & 0x7) << 5)
| ((xmc[19] & 0x7) << 2)
| ((xmc[20] >> 1) & 0x3);
*c++ = ((xmc[20] & 0x1) << 7)
| ((xmc[21] & 0x7) << 4)
| ((xmc[22] & 0x7) << 1)
| ((xmc[23] >> 2) & 0x1);
*c++ = ((xmc[23] & 0x3) << 6)
| ((xmc[24] & 0x7) << 3)
| (xmc[25] & 0x7);
*c++ = ((Nc[2] & 0x7F) << 1) /* 20 */
| ((bc[2] >> 1) & 0x1);
*c++ = ((bc[2] & 0x1) << 7)
| ((Mc[2] & 0x3) << 5)
| ((xmaxc[2] >> 1) & 0x1F);
*c++ = ((xmaxc[2] & 0x1) << 7)
| ((xmc[26] & 0x7) << 4)
| ((xmc[27] & 0x7) << 1)
| ((xmc[28] >> 2) & 0x1);
*c++ = ((xmc[28] & 0x3) << 6)
| ((xmc[29] & 0x7) << 3)
| (xmc[30] & 0x7);
*c++ = ((xmc[31] & 0x7) << 5)
| ((xmc[32] & 0x7) << 2)
| ((xmc[33] >> 1) & 0x3);
*c++ = ((xmc[33] & 0x1) << 7)
| ((xmc[34] & 0x7) << 4)
| ((xmc[35] & 0x7) << 1)
| ((xmc[36] >> 2) & 0x1);
*c++ = ((xmc[36] & 0x3) << 6)
| ((xmc[37] & 0x7) << 3)
| (xmc[38] & 0x7);
*c++ = ((Nc[3] & 0x7F) << 1)
| ((bc[3] >> 1) & 0x1);
*c++ = ((bc[3] & 0x1) << 7)
| ((Mc[3] & 0x3) << 5)
| ((xmaxc[3] >> 1) & 0x1F);
*c++ = ((xmaxc[3] & 0x1) << 7)
| ((xmc[39] & 0x7) << 4)
| ((xmc[40] & 0x7) << 1)
| ((xmc[41] >> 2) & 0x1);
*c++ = ((xmc[41] & 0x3) << 6) /* 30 */
| ((xmc[42] & 0x7) << 3)
| (xmc[43] & 0x7);
*c++ = ((xmc[44] & 0x7) << 5)
| ((xmc[45] & 0x7) << 2)
| ((xmc[46] >> 1) & 0x3);
*c++ = ((xmc[46] & 0x1) << 7)
| ((xmc[47] & 0x7) << 4)
| ((xmc[48] & 0x7) << 1)
| ((xmc[49] >> 2) & 0x1);
*c++ = ((xmc[49] & 0x3) << 6)
| ((xmc[50] & 0x7) << 3)
| (xmc[51] & 0x7);
}
}
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