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annotate dmbstr.c @ 570:a26636faa6b7

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Update copyright.
author Matti Hamalainen <ccr@tnsp.org>
date Sat, 05 Jan 2013 19:58:23 +0200
parents a7ab6bf5b012
children 136d4ddc7438
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1 /*
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2 * DMLib
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3 * -- Simple bitstream I/O functions
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4 * Programmed and designed by Matti 'ccr' Hamalainen
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5 * (C) Copyright 2012 Tecnic Software productions (TNSP)
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6 */
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7 #include "dmbstr.h"
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8
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9
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10 int dmInitBitStream(DMBitStream *ctx, FILE *fp)
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11 {
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12 if (ctx == NULL || fp == NULL)
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13 return DMERR_NULLPTR;
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14
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15 ctx->fp = fp;
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16 ctx->buf = 0;
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17 ctx->bytecnt = 0;
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18 ctx->bitcnt = 8;
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19
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20 return DMERR_OK;
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21 }
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22
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23
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24 BOOL dmPutBits(DMBitStream *ctx, const int val, const int n)
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25 {
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26 int i;
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27 unsigned int mask = 1 << (n - 1);
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28
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29 for (i = 0; i < n; i++)
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30 {
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31 ctx->buf <<= 1;
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32
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33 if (val & mask)
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34 ctx->buf |= 1;
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35
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36 mask >>= 1;
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37 ctx->bitcnt--;
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38
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39 if (ctx->bitcnt == 0)
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40 {
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41 if (fputc((ctx->buf & 0xff), ctx->fp) == EOF)
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42 return FALSE;
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43
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44 ctx->bitcnt = 8;
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45 ctx->bytecnt++;
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46 }
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47 }
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48
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49 return TRUE;
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50 }
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51
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52
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53 int dmFlushBitStream(DMBitStream *ctx)
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54 {
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55 if (ctx == NULL)
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56 return DMERR_NULLPTR;
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57
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58 if (ctx->bitcnt != 8)
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59 dmPutBits(ctx, 0, ctx->bitcnt);
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60
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61 return 0;
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62 }
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