+++ /dev/null
-#include "../libzmpeg3.h"
-
-/* calculate motion vector component */
-
-static void
-calc_mv(int *pred, int r_size, int motion_code, int motion_r, int full_pel_vector)
-{
- int lim = 16 << r_size;
- int vec = full_pel_vector ? (*pred >> 1) : (*pred);
-
- if( motion_code > 0 ) {
- vec += ((motion_code - 1) << r_size) + motion_r + 1;
- if( vec >= lim ) vec -= lim + lim;
- }
- else if( motion_code < 0 ) {
- vec -= ((-motion_code - 1) << r_size) + motion_r + 1;
- if( vec < -lim ) vec += lim + lim;
- }
- *pred = full_pel_vector ? (vec << 1) : vec;
-}
-
-
-/*
-int *dmvector, * differential motion vector *
-int mvx, int mvy * decoded mv components (always in field format) *
-*/
-void zvideo_t::
-calc_dmv(int DMV[][2], int *dmvector, int mvx, int mvy)
-{
- if( pict_struct == pics_FRAME_PICTURE ) {
- if( topfirst ) {
- /* vector for prediction of top field from bottom field */
- DMV[0][0] = ((mvx + (mvx>0)) >> 1) + dmvector[0];
- DMV[0][1] = ((mvy + (mvy>0)) >> 1) + dmvector[1] - 1;
-
- /* vector for prediction of bottom field from top field */
- DMV[1][0] = ((3 * mvx + (mvx > 0)) >> 1) + dmvector[0];
- DMV[1][1] = ((3 * mvy + (mvy > 0)) >> 1) + dmvector[1] + 1;
- }
- else {
- /* vector for prediction of top field from bottom field */
- DMV[0][0] = ((3 * mvx + (mvx>0)) >> 1) + dmvector[0];
- DMV[0][1] = ((3 * mvy + (mvy>0)) >> 1) + dmvector[1] - 1;
- /* vector for prediction of bottom field from top field */
- DMV[1][0] = ((mvx + (mvx>0)) >> 1) + dmvector[0];
- DMV[1][1] = ((mvy + (mvy>0)) >> 1) + dmvector[1] + 1;
- }
- }
- else {
- /* vector for prediction from field of opposite 'parity' */
- DMV[0][0] = ((mvx + (mvx > 0)) >> 1) + dmvector[0];
- DMV[0][1] = ((mvy + (mvy > 0)) >> 1) + dmvector[1];
- /* correct for vertical field shift */
- if( pict_struct == pics_TOP_FIELD )
- --DMV[0][1];
- else
- ++DMV[0][1];
- }
-}
-
-int zslice_decoder_t::
-get_mv()
-{
- int zcode;
- if( slice_buffer->get_bit() ) return 0;
-
- if( (zcode=slice_buffer->show_bits(9)) >= 64 ) {
- zcode >>= 6;
- slice_buffer->flush_bits(MVtab0[zcode].len);
- return slice_buffer->get_bit() ?
- -MVtab0[zcode].val : MVtab0[zcode].val;
- }
-
- if( zcode >= 24 ) {
- zcode >>= 3;
- slice_buffer->flush_bits(MVtab1[zcode].len);
- return slice_buffer->get_bit() ?
- -MVtab1[zcode].val : MVtab1[zcode].val;
- }
-
- if( (zcode-=12) < 0 ) {
-//zerrs("invalid motion_vector code %d\n",zcode+12);
- fault = 1;
- return 1;
- }
- slice_buffer->flush_bits(MVtab2[zcode].len);
- return slice_buffer->get_bit() ?
- -MVtab2[zcode].val : MVtab2[zcode].val;
-}
-
-/* get differential motion vector (for dual prime prediction) */
-int zslice_decoder_t::
-get_dmv()
-{
- if( slice_buffer->get_bit() )
- return slice_buffer->get_bit() ? -1 : 1;
- return 0;
-}
-
-
-/* get and decode motion vector and differential motion vector */
-void zslice_decoder_t::
-motion_vector(int *PMV, int *dmvector, int h_r_size, int v_r_size,
- int dmv, int mvscale, int full_pel_vector)
-{
- int motion_r;
- int motion_code = get_mv();
- if( fault ) return;
- motion_r = (h_r_size != 0 && motion_code != 0) ?
- slice_buffer->get_bits(h_r_size) : 0;
- calc_mv(&PMV[0], h_r_size, motion_code, motion_r, full_pel_vector);
- if( dmv ) dmvector[0] = get_dmv();
- motion_code = get_mv();
- if( fault ) return;
- motion_r = (v_r_size != 0 && motion_code != 0) ?
- slice_buffer->get_bits(v_r_size) : 0;
-
- /* DIV 2 */
- if( mvscale ) PMV[1] >>= 1;
- calc_mv(&PMV[1], v_r_size, motion_code, motion_r, full_pel_vector);
- if( mvscale ) PMV[1] <<= 1;
- if( dmv ) dmvector[1] = get_dmv();
-}
-
-int zslice_decoder_t::
-motion_vectors( int PMV[2][2][2], int dmvector[2], int mv_field_sel[2][2],
- int s, int mv_count, int mv_format, int h_r_size, int v_r_size,
- int dmv, int mvscale)
-{
- if( mv_count == 1 ) {
- if( mv_format == mv_FIELD && !dmv )
- mv_field_sel[1][s] = mv_field_sel[0][s] = slice_buffer->get_bit();
- motion_vector(PMV[0][s], dmvector, h_r_size, v_r_size, dmv, mvscale, 0);
- if( fault ) return 1;
-
- /* update other motion vector predictors */
- PMV[1][s][0] = PMV[0][s][0];
- PMV[1][s][1] = PMV[0][s][1];
- }
- else {
- mv_field_sel[0][s] = slice_buffer->get_bit();
- motion_vector(PMV[0][s], dmvector, h_r_size, v_r_size, dmv, mvscale, 0);
- if( fault ) return 1;
- mv_field_sel[1][s] = slice_buffer->get_bit();
- motion_vector(PMV[1][s], dmvector, h_r_size, v_r_size, dmv, mvscale, 0);
- if( fault ) return 1;
- }
- return 0;
-}
-