mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
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ac036272b9
Original commit message from CVS: Moved generic function implementations into gstgetbits_generic.c, and tidy up a bit.
119 lines
2.7 KiB
C
119 lines
2.7 KiB
C
#include <glib.h>
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#include "gstgetbits.h"
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unsigned long _gst_getbits_int_cb(gst_getbits_t *gb, unsigned long bits);
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unsigned long _gst_get1bit_int(gst_getbits_t *gb, unsigned long bits);
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unsigned long _gst_getbits_int(gst_getbits_t *gb, unsigned long bits);
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unsigned long _gst_getbits_fast_int(gst_getbits_t *gb, unsigned long bits);
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unsigned long _gst_showbits_int(gst_getbits_t *gb, unsigned long bits);
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void _gst_flushbits_int(gst_getbits_t *gb, unsigned long bits);
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void _gst_getbits_back_int(gst_getbits_t *gb, unsigned long bits);
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unsigned long _gst_getbits_int_cb(gst_getbits_t *gb, unsigned long bits) {
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int result;
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int bitsleft;
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//printf("gst_getbits%lu %ld %p %08x\n", bits, gb->bits, gb->ptr, gb->dword);
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if (!bits) return 0;
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gb->bits -= bits;
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result = gb->dword >> (32-bits);
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if (gb->bits < 0) {
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gb->ptr += 4;
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bitsleft = (gb->endptr - gb->ptr)*8;
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bits = -gb->bits;
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gb->bits += (bitsleft>32? 32 : bitsleft);
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if (gb->endptr <= gb->ptr) {
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(gb->callback)(gb, gb->data);
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gb->bits -= bits;
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}
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gb->dword = swab32(*((unsigned long *)(gb->ptr)));
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result |= (gb->dword >> (32-bits));
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}
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gb->dword <<= bits;
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return result;
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}
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unsigned long _gst_get1bit_int(gst_getbits_t *gb, unsigned long bits) {
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unsigned char rval;
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rval = *gb->ptr << gb->bits;
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gb->bits++;
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gb->ptr += (gb->bits>>3);
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gb->bits &= 0x7;
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DEBUG("getbits%d, %08x\n", bits, rval);
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return rval>>7;
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}
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unsigned long _gst_getbits_int(gst_getbits_t *gb, unsigned long bits) {
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unsigned long rval;
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if (bits == 0) return 0;
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rval = swab32(*((unsigned long *)(gb->ptr)));
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rval <<= gb->bits;
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gb->bits += bits;
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rval >>= (32-bits);
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gb->ptr += (gb->bits>>3);
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gb->bits &= 0x7;
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DEBUG("getbits%d, %08x\n", bits, rval);
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return rval;
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}
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unsigned long _gst_getbits_fast_int(gst_getbits_t *gb, unsigned long bits) {
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unsigned long rval;
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rval = (unsigned char) (gb->ptr[0] << gb->bits);
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rval |= ((unsigned int) gb->ptr[1] << gb->bits)>>8;
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rval <<= bits;
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rval >>= 8;
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gb->bits += bits;
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gb->ptr += (gb->bits>>3);
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gb->bits &= 0x7;
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DEBUG("getbits%d, %08x\n", bits, rval);
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return rval;
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}
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unsigned long _gst_showbits_int(gst_getbits_t *gb, unsigned long bits) {
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unsigned long rval;
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if (bits == 0) return 0;
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rval = swab32(*((unsigned long *)(gb->ptr)));
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rval <<= gb->bits;
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rval >>= (32-bits);
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DEBUG("showbits%d, %08x\n", bits, rval);
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return rval;
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}
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void _gst_flushbits_int(gst_getbits_t *gb, unsigned long bits) {
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gb->bits += bits;
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gb->ptr += (gb->bits>>3);
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gb->bits &= 0x7;
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DEBUG("flushbits%d\n", bits);
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}
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void _gst_getbits_back_int(gst_getbits_t *gb, unsigned long bits) {
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gb->bits -= bits;
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gb->ptr += (gb->bits>>3);
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gb->bits &= 0x7;
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}
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