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annotate src/dmbstr.c @ 1091:988a3397839e

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Move functions around for saner order.
author Matti Hamalainen <ccr@tnsp.org>
date Mon, 02 Mar 2015 20:30:25 +0200
parents 27d041472c8f
children e06abfde6c39
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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 void dmInitBitStreamContext(DMBitStreamContext *ctx)
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11 {
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12 ctx->outBuf = 0;
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13 ctx->outByteCount = 0;
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14 ctx->outBitCount = 8;
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15 }
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16
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17
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18 BOOL dmPutBits(DMBitStreamContext *ctx, const int val, const int n)
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19 {
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20 int i;
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21 unsigned int mask = 1 << (n - 1);
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22
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23 for (i = 0; i < n; i++)
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24 {
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25 ctx->outBuf <<= 1;
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26
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27 if (val & mask)
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28 ctx->outBuf |= 1;
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29
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30 mask >>= 1;
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31 ctx->outBitCount--;
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32
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33 if (ctx->outBitCount == 0)
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34 {
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35 if (!ctx->putByte(ctx, ctx->outBuf & 0xff))
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36 return FALSE;
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37
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38 ctx->outBitCount = 8;
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39 ctx->outByteCount++;
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40 }
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41 }
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42
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43 return TRUE;
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44 }
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45
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46
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47 int dmFlushBitStream(DMBitStreamContext *ctx)
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48 {
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49 if (ctx == NULL)
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50 return DMERR_NULLPTR;
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51
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52 if (ctx->outBitCount != 8)
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53 dmPutBits(ctx, 0, ctx->outBitCount);
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54
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55 return 0;
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56 }
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58
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59 static BOOL dmPutByteFILE(DMBitStreamContext *ctx, const Uint8 val)
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60 {
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61 return fputc(val, (FILE *) ctx->fp) == val;
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62 }
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63
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64
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65 int dmInitBitStreamFILE(DMBitStreamContext *ctx, FILE *fp)
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66 {
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67 if (ctx == NULL || fp == NULL)
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68 return DMERR_NULLPTR;
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69
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70 ctx->putByte = dmPutByteFILE;
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71 ctx->fp = (void *) fp;
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72
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73 dmInitBitStreamContext(ctx);
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74
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75 return DMERR_OK;
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76 }