1 /* putbits.c, bit-level output */
3 /* Copyright (C) 1996, MPEG Software Simulation Group. All Rights Reserved. */
6 * Disclaimer of Warranty
8 * These software programs are available to the user without any license fee or
9 * royalty on an "as is" basis. The MPEG Software Simulation Group disclaims
10 * any and all warranties, whether express, implied, or statuary, including any
11 * implied warranties or merchantability or of fitness for a particular
12 * purpose. In no event shall the copyright-holder be liable for any
13 * incidental, punitive, or consequential damages of any kind whatsoever
14 * arising from the use of these programs.
16 * This disclaimer of warranty extends to the user of these programs and user's
17 * customers, employees, agents, transferees, successors, and assigns.
19 * The MPEG Software Simulation Group does not represent or warrant that the
20 * programs furnished hereunder are free of infringement of any third-party
23 * Commercial implementations of MPEG-1 and MPEG-2 video, including shareware,
24 * are subject to royalty fees to patent holders. Many of these patents are
25 * general enough such that they are unavoidable regardless of implementation
36 extern FILE *outfile; /* the only global var we need here */
39 static unsigned char outbfr;
43 void slice_initbits(slice_engine_t *engine)
46 engine->slice_size = 0;
49 void slice_testbits(slice_engine_t *engine)
51 printf("slice test size %lx outcnt %d outbfr %x\n", engine->slice_size, engine->outcnt, engine->outbfr << engine->outcnt);
53 * for(i = 0; i < engine->slice_size; i++)
54 * printf("%02x ", engine->slice_buffer[i]);
55 * printf("%x\n", engine->outbfr << engine->outcnt); }
59 void slice_putc(slice_engine_t *engine, unsigned char c)
61 if(engine->slice_size >= engine->slice_allocated)
63 long new_allocation = (engine->slice_allocated > 0) ? (engine->slice_allocated * 2) : 64;
64 unsigned char *new_buffer = calloc(1, new_allocation);
65 if(engine->slice_buffer)
67 memcpy(new_buffer, engine->slice_buffer, engine->slice_size);
68 free(engine->slice_buffer);
70 engine->slice_buffer = new_buffer;
71 engine->slice_allocated = new_allocation;
73 engine->slice_buffer[engine->slice_size++] = c;
76 void slice_putbits(slice_engine_t *engine, long val, int n)
81 mask = 1 << (n - 1); /* selects first (leftmost) bit */
83 for(i = 0; i < n; i++)
90 mask >>= 1; /* select next bit */
93 if(engine->outcnt == 0) /* 8 bit buffer full */
95 slice_putc(engine, engine->outbfr);
102 /* zero bit stuffing to next byte boundary (5.2.3, 6.2.1) */
103 void slice_alignbits(slice_engine_t *engine)
105 if(engine->outcnt != 8)
106 slice_putbits(engine, 0, engine->outcnt);
109 void slice_finishslice(slice_engine_t *engine)
111 slice_alignbits(engine);
112 if( !engine->slice_size ) return;
114 if(!fwrite(engine->slice_buffer, 1, engine->slice_size, outfile))
116 perror("Write error");
118 bytecnt += engine->slice_size;
123 /* initialize buffer, call once before first putbits or alignbits */
124 void mpeg2_initbits()
131 /* write rightmost n (0<=n<=32) bits of val to outfile */
132 void mpeg2enc_putbits(val,n)
139 mask = 1 << (n-1); /* selects first (leftmost) bit */
148 mask >>= 1; /* select next bit */
151 if (outcnt==0) /* 8 bit buffer full */
153 putc(outbfr,outfile);
160 /* zero bit stuffing to next byte boundary (5.2.3, 6.2.1) */
164 mpeg2enc_putbits(0,outcnt);
167 /* return total number of generated bits */
170 return (double)8 * bytecnt + (8 - outcnt);