2 * MSMPEG4 backend for encoder and decoder
3 * Copyright (c) 2001 Fabrice Bellard
4 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
6 * msmpeg4v1 & v2 stuff by Michael Niedermayer <michaelni@gmx.at>
8 * This file is part of Libav.
10 * Libav is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Lesser General Public
12 * License as published by the Free Software Foundation; either
13 * version 2.1 of the License, or (at your option) any later version.
15 * Libav is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Lesser General Public License for more details.
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with Libav; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
27 * MSMPEG4 backend for encoder and decoder
32 #include "mpegvideo.h"
34 #include "libavutil/x86/asm.h"
36 #include "mpeg4video.h"
37 #include "msmpeg4data.h"
38 #include "mpegvideodata.h"
42 * You can also call this codec: MPEG-4 with a twist!
45 * - (encoding) select best mv table (two choices)
46 * - (encoding) select best vlc/dc table
49 /* This table is practically identical to the one from H.263
50 * except that it is inverted. */
51 static av_cold void init_h263_dc_for_msmpeg4(void)
53 int level, uni_code, uni_len;
55 for(level=-256; level<256; level++){
57 /* find number of bits */
66 l= (-level) ^ ((1 << size) - 1);
71 uni_code= ff_mpeg4_DCtab_lum[size][0];
72 uni_len = ff_mpeg4_DCtab_lum[size][1];
73 uni_code ^= (1<<uni_len)-1; //M$ does not like compatibility
76 uni_code<<=size; uni_code|=l;
79 uni_code<<=1; uni_code|=1;
83 ff_v2_dc_lum_table[level + 256][0] = uni_code;
84 ff_v2_dc_lum_table[level + 256][1] = uni_len;
86 /* chrominance H.263 */
87 uni_code= ff_mpeg4_DCtab_chrom[size][0];
88 uni_len = ff_mpeg4_DCtab_chrom[size][1];
89 uni_code ^= (1<<uni_len)-1; //M$ does not like compatibility
92 uni_code<<=size; uni_code|=l;
95 uni_code<<=1; uni_code|=1;
99 ff_v2_dc_chroma_table[level + 256][0] = uni_code;
100 ff_v2_dc_chroma_table[level + 256][1] = uni_len;
105 av_cold void ff_msmpeg4_common_init(MpegEncContext *s)
107 static int initialized=0;
109 switch(s->msmpeg4_version){
113 s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
116 if(s->workaround_bugs){
117 s->y_dc_scale_table= ff_old_ff_y_dc_scale_table;
118 s->c_dc_scale_table= ff_wmv1_c_dc_scale_table;
120 s->y_dc_scale_table= ff_mpeg4_y_dc_scale_table;
121 s->c_dc_scale_table= ff_mpeg4_c_dc_scale_table;
126 s->y_dc_scale_table= ff_wmv1_y_dc_scale_table;
127 s->c_dc_scale_table= ff_wmv1_c_dc_scale_table;
129 #if CONFIG_VC1_DECODER
131 s->y_dc_scale_table= ff_wmv3_dc_scale_table;
132 s->c_dc_scale_table= ff_wmv3_dc_scale_table;
139 if(s->msmpeg4_version>=4){
140 ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_wmv1_scantable[1]);
141 ff_init_scantable(s->idsp.idct_permutation, &s->intra_h_scantable, ff_wmv1_scantable[2]);
142 ff_init_scantable(s->idsp.idct_permutation, &s->intra_v_scantable, ff_wmv1_scantable[3]);
143 ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_wmv1_scantable[0]);
145 //Note the default tables are set in common_init in mpegvideo.c
150 init_h263_dc_for_msmpeg4();
154 /* predict coded block */
155 int ff_msmpeg4_coded_block_pred(MpegEncContext * s, int n, uint8_t **coded_block_ptr)
157 int xy, wrap, pred, a, b, c;
159 xy = s->block_index[n];
165 a = s->coded_block[xy - 1 ];
166 b = s->coded_block[xy - 1 - wrap];
167 c = s->coded_block[xy - wrap];
176 *coded_block_ptr = &s->coded_block[xy];
181 static int get_dc(uint8_t *src, int stride, int scale)
188 sum+=src[x + y*stride];
191 return FASTDIV((sum + (scale>>1)), scale);
194 /* dir = 0: left, dir = 1: top prediction */
195 int ff_msmpeg4_pred_dc(MpegEncContext *s, int n,
196 int16_t **dc_val_ptr, int *dir_ptr)
198 int a, b, c, wrap, pred, scale;
201 /* find prediction */
203 scale = s->y_dc_scale;
205 scale = s->c_dc_scale;
208 wrap = s->block_wrap[n];
209 dc_val= s->dc_val[0] + s->block_index[n];
215 b = dc_val[ - 1 - wrap];
218 if(s->first_slice_line && (n&2)==0 && s->msmpeg4_version<4){
222 /* XXX: the following solution consumes divisions, but it does not
223 necessitate to modify mpegvideo.c. The problem comes from the
224 fact they decided to store the quantized DC (which would lead
225 to problems if Q could vary !) */
226 #if ARCH_X86 && HAVE_7REGS && HAVE_EBX_AVAILABLE
228 "movl %3, %%eax \n\t"
229 "shrl $1, %%eax \n\t"
230 "addl %%eax, %2 \n\t"
231 "addl %%eax, %1 \n\t"
232 "addl %0, %%eax \n\t"
234 "movl %%edx, %0 \n\t"
235 "movl %1, %%eax \n\t"
237 "movl %%edx, %1 \n\t"
238 "movl %2, %%eax \n\t"
240 "movl %%edx, %2 \n\t"
241 : "+b" (a), "+c" (b), "+D" (c)
242 : "g" (scale), "S" (ff_inverse[scale])
246 /* Divisions are costly everywhere; optimize the most common case. */
248 a = (a + (8 >> 1)) / 8;
249 b = (b + (8 >> 1)) / 8;
250 c = (c + (8 >> 1)) / 8;
252 a = FASTDIV((a + (scale >> 1)), scale);
253 b = FASTDIV((b + (scale >> 1)), scale);
254 c = FASTDIV((c + (scale >> 1)), scale);
257 /* XXX: WARNING: they did not choose the same test as MPEG-4. This
258 is very important ! */
259 if(s->msmpeg4_version>3){
260 if(s->inter_intra_pred){
271 if (abs(a - b) < abs(b - c)) {
281 dest= s->current_picture.f->data[0] + (((n >> 1) + 2*s->mb_y) * 8* wrap ) + ((n & 1) + 2*s->mb_x) * 8;
284 dest= s->current_picture.f->data[n - 3] + (s->mb_y * 8 * wrap) + s->mb_x * 8;
286 if(s->mb_x==0) a= (1024 + (scale>>1))/scale;
287 else a= get_dc(dest-8, wrap, scale*8);
288 if(s->mb_y==0) c= (1024 + (scale>>1))/scale;
289 else c= get_dc(dest-8*wrap, wrap, scale*8);
291 if (s->h263_aic_dir==0) {
294 }else if (s->h263_aic_dir==1) {
302 }else if (s->h263_aic_dir==2) {
316 if (abs(a - b) < abs(b - c)) {
325 if (abs(a - b) <= abs(b - c)) {
334 /* update predictor */
335 *dc_val_ptr = &dc_val[0];