1/*
2 * MSMPEG4 backend for encoder and decoder
3 * Copyright (c) 2001 Fabrice Bellard
4 * Copyright (c) 2002-2013 Michael Niedermayer <michaelni@gmx.at>
5 *
6 * msmpeg4v1 & v2 stuff by Michael Niedermayer <michaelni@gmx.at>
7 *
8 * This file is part of FFmpeg.
9 *
10 * FFmpeg 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.
14 *
15 * FFmpeg 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.
19 *
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with FFmpeg; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 */
24
25#include "config_components.h"
26
27#include "libavutil/thread.h"
28
29#include "avcodec.h"
30#include "codec_internal.h"
31#include "mpegutils.h"
32#include "mpegvideo.h"
33#include "msmpeg4.h"
34#include "msmpeg4dec.h"
35#include "libavutil/imgutils.h"
36#include "h263.h"
37#include "h263data.h"
38#include "h263dec.h"
39#include "mpeg4videodec.h"
40#include "msmpeg4data.h"
41#include "wmv2dec.h"
42
43#define DC_VLC_BITS 9
44#define V2_INTRA_CBPC_VLC_BITS 3
45#define V2_MB_TYPE_VLC_BITS 7
46#define MV_VLC_BITS 9
47#define TEX_VLC_BITS 9
48
49#define DEFAULT_INTER_INDEX 3
50
51static inline int msmpeg4v1_pred_dc(MpegEncContext * s, int n,
52                                    int32_t **dc_val_ptr)
53{
54    int i;
55
56    if (n < 4) {
57        i= 0;
58    } else {
59        i= n-3;
60    }
61
62    *dc_val_ptr= &s->last_dc[i];
63    return s->last_dc[i];
64}
65
66/****************************************/
67/* decoding stuff */
68
69VLC ff_mb_non_intra_vlc[4];
70static VLC v2_dc_lum_vlc;
71static VLC v2_dc_chroma_vlc;
72static VLC v2_intra_cbpc_vlc;
73static VLC v2_mb_type_vlc;
74VLC ff_inter_intra_vlc;
75
76/* This is identical to H.263 except that its range is multiplied by 2. */
77static int msmpeg4v2_decode_motion(MpegEncContext * s, int pred, int f_code)
78{
79    int code, val, sign, shift;
80
81    code = get_vlc2(&s->gb, ff_h263_mv_vlc.table, H263_MV_VLC_BITS, 2);
82    ff_dlog(s, "MV code %d at %d %d pred: %d\n", code, s->mb_x,s->mb_y, pred);
83    if (code < 0)
84        return 0xffff;
85
86    if (code == 0)
87        return pred;
88    sign = get_bits1(&s->gb);
89    shift = f_code - 1;
90    val = code;
91    if (shift) {
92        val = (val - 1) << shift;
93        val |= get_bits(&s->gb, shift);
94        val++;
95    }
96    if (sign)
97        val = -val;
98
99    val += pred;
100    if (val <= -64)
101        val += 64;
102    else if (val >= 64)
103        val -= 64;
104
105    return val;
106}
107
108static int msmpeg4v12_decode_mb(MpegEncContext *s, int16_t block[6][64])
109{
110    int cbp, code, i;
111    uint32_t * const mb_type_ptr = &s->current_picture.mb_type[s->mb_x + s->mb_y*s->mb_stride];
112
113    if (s->pict_type == AV_PICTURE_TYPE_P) {
114        if (s->use_skip_mb_code) {
115            if (get_bits1(&s->gb)) {
116                /* skip mb */
117                s->mb_intra = 0;
118                for(i=0;i<6;i++)
119                    s->block_last_index[i] = -1;
120                s->mv_dir = MV_DIR_FORWARD;
121                s->mv_type = MV_TYPE_16X16;
122                s->mv[0][0][0] = 0;
123                s->mv[0][0][1] = 0;
124                s->mb_skipped = 1;
125                *mb_type_ptr = MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
126                return 0;
127            }
128        }
129
130        if(s->msmpeg4_version==2)
131            code = get_vlc2(&s->gb, v2_mb_type_vlc.table, V2_MB_TYPE_VLC_BITS, 1);
132        else
133            code = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
134        if(code<0 || code>7){
135            av_log(s->avctx, AV_LOG_ERROR, "cbpc %d invalid at %d %d\n", code, s->mb_x, s->mb_y);
136            return -1;
137        }
138
139        s->mb_intra = code >>2;
140
141        cbp = code & 0x3;
142    } else {
143        s->mb_intra = 1;
144        if(s->msmpeg4_version==2)
145            cbp= get_vlc2(&s->gb, v2_intra_cbpc_vlc.table, V2_INTRA_CBPC_VLC_BITS, 1);
146        else
147            cbp= get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
148        if(cbp<0 || cbp>3){
149            av_log(s->avctx, AV_LOG_ERROR, "cbpc %d invalid at %d %d\n", cbp, s->mb_x, s->mb_y);
150            return -1;
151        }
152    }
153
154    if (!s->mb_intra) {
155        int mx, my, cbpy;
156
157        cbpy= get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
158        if(cbpy<0){
159            av_log(s->avctx, AV_LOG_ERROR, "cbpy %d invalid at %d %d\n", cbp, s->mb_x, s->mb_y);
160            return -1;
161        }
162
163        cbp|= cbpy<<2;
164        if(s->msmpeg4_version==1 || (cbp&3) != 3) cbp^= 0x3C;
165
166        ff_h263_pred_motion(s, 0, 0, &mx, &my);
167        mx= msmpeg4v2_decode_motion(s, mx, 1);
168        my= msmpeg4v2_decode_motion(s, my, 1);
169
170        s->mv_dir = MV_DIR_FORWARD;
171        s->mv_type = MV_TYPE_16X16;
172        s->mv[0][0][0] = mx;
173        s->mv[0][0][1] = my;
174        *mb_type_ptr = MB_TYPE_L0 | MB_TYPE_16x16;
175    } else {
176        int v;
177        if(s->msmpeg4_version==2){
178            s->ac_pred = get_bits1(&s->gb);
179            v = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
180            if (v < 0) {
181                av_log(s->avctx, AV_LOG_ERROR, "cbpy vlc invalid\n");
182                return -1;
183            }
184            cbp|= v<<2;
185        } else{
186            s->ac_pred = 0;
187            v = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
188            if (v < 0) {
189                av_log(s->avctx, AV_LOG_ERROR, "cbpy vlc invalid\n");
190                return -1;
191            }
192            cbp|= v<<2;
193            if(s->pict_type==AV_PICTURE_TYPE_P) cbp^=0x3C;
194        }
195        *mb_type_ptr = MB_TYPE_INTRA;
196    }
197
198    s->bdsp.clear_blocks(s->block[0]);
199    for (i = 0; i < 6; i++) {
200        if (ff_msmpeg4_decode_block(s, block[i], i, (cbp >> (5 - i)) & 1, NULL) < 0)
201        {
202             av_log(s->avctx, AV_LOG_ERROR, "\nerror while decoding block: %d x %d (%d)\n", s->mb_x, s->mb_y, i);
203             return -1;
204        }
205    }
206    return 0;
207}
208
209static int msmpeg4v34_decode_mb(MpegEncContext *s, int16_t block[6][64])
210{
211    int cbp, code, i;
212    uint8_t *coded_val;
213    uint32_t * const mb_type_ptr = &s->current_picture.mb_type[s->mb_x + s->mb_y*s->mb_stride];
214
215    if (get_bits_left(&s->gb) <= 0)
216        return AVERROR_INVALIDDATA;
217
218    if (s->pict_type == AV_PICTURE_TYPE_P) {
219        if (s->use_skip_mb_code) {
220            if (get_bits1(&s->gb)) {
221                /* skip mb */
222                s->mb_intra = 0;
223                for(i=0;i<6;i++)
224                    s->block_last_index[i] = -1;
225                s->mv_dir = MV_DIR_FORWARD;
226                s->mv_type = MV_TYPE_16X16;
227                s->mv[0][0][0] = 0;
228                s->mv[0][0][1] = 0;
229                s->mb_skipped = 1;
230                *mb_type_ptr = MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
231
232                return 0;
233            }
234        }
235
236        code = get_vlc2(&s->gb, ff_mb_non_intra_vlc[DEFAULT_INTER_INDEX].table, MB_NON_INTRA_VLC_BITS, 3);
237        //s->mb_intra = (code & 0x40) ? 0 : 1;
238        s->mb_intra = (~code & 0x40) >> 6;
239
240        cbp = code & 0x3f;
241    } else {
242        s->mb_intra = 1;
243        code = get_vlc2(&s->gb, ff_msmp4_mb_i_vlc.table, MB_INTRA_VLC_BITS, 2);
244        /* predict coded block pattern */
245        cbp = 0;
246        for(i=0;i<6;i++) {
247            int val = ((code >> (5 - i)) & 1);
248            if (i < 4) {
249                int pred = ff_msmpeg4_coded_block_pred(s, i, &coded_val);
250                val = val ^ pred;
251                *coded_val = val;
252            }
253            cbp |= val << (5 - i);
254        }
255    }
256
257    if (!s->mb_intra) {
258        int mx, my;
259        if(s->per_mb_rl_table && cbp){
260            s->rl_table_index = decode012(&s->gb);
261            s->rl_chroma_table_index = s->rl_table_index;
262        }
263        ff_h263_pred_motion(s, 0, 0, &mx, &my);
264        ff_msmpeg4_decode_motion(s, &mx, &my);
265        s->mv_dir = MV_DIR_FORWARD;
266        s->mv_type = MV_TYPE_16X16;
267        s->mv[0][0][0] = mx;
268        s->mv[0][0][1] = my;
269        *mb_type_ptr = MB_TYPE_L0 | MB_TYPE_16x16;
270    } else {
271        ff_dlog(s, "I at %d %d %d %06X\n", s->mb_x, s->mb_y,
272                ((cbp & 3) ? 1 : 0) +((cbp & 0x3C)? 2 : 0),
273                show_bits(&s->gb, 24));
274        s->ac_pred = get_bits1(&s->gb);
275        *mb_type_ptr = MB_TYPE_INTRA;
276        if(s->inter_intra_pred){
277            s->h263_aic_dir= get_vlc2(&s->gb, ff_inter_intra_vlc.table, INTER_INTRA_VLC_BITS, 1);
278            ff_dlog(s, "%d%d %d %d/",
279                    s->ac_pred, s->h263_aic_dir, s->mb_x, s->mb_y);
280        }
281        if(s->per_mb_rl_table && cbp){
282            s->rl_table_index = decode012(&s->gb);
283            s->rl_chroma_table_index = s->rl_table_index;
284        }
285    }
286
287    s->bdsp.clear_blocks(s->block[0]);
288    for (i = 0; i < 6; i++) {
289        if (ff_msmpeg4_decode_block(s, block[i], i, (cbp >> (5 - i)) & 1, NULL) < 0)
290        {
291            av_log(s->avctx, AV_LOG_ERROR, "\nerror while decoding block: %d x %d (%d)\n", s->mb_x, s->mb_y, i);
292            return -1;
293        }
294    }
295
296    return 0;
297}
298
299/* init all vlc decoding tables */
300static av_cold void msmpeg4_decode_init_static(void)
301{
302    MVTable *mv;
303
304    INIT_FIRST_VLC_RL(ff_rl_table[0], 642);
305    INIT_FIRST_VLC_RL(ff_rl_table[1], 1104);
306    INIT_FIRST_VLC_RL(ff_rl_table[2], 554);
307    INIT_VLC_RL(ff_rl_table[3], 940);
308    INIT_VLC_RL(ff_rl_table[4], 962);
309    /* ff_rl_table[5] coincides with ff_h263_rl_inter which has just been
310     * initialized in ff_h263_decode_init() earlier. So just copy the VLCs. */
311    av_assert1(ff_h263_rl_inter.rl_vlc[0]);
312    memcpy(ff_rl_table[5].rl_vlc, ff_h263_rl_inter.rl_vlc, sizeof(ff_rl_table[5].rl_vlc));
313
314    mv = &ff_mv_tables[0];
315    INIT_VLC_STATIC(&mv->vlc, MV_VLC_BITS, MSMPEG4_MV_TABLES_NB_ELEMS + 1,
316                    mv->table_mv_bits, 1, 1,
317                    mv->table_mv_code, 2, 2, 3714);
318    mv = &ff_mv_tables[1];
319    INIT_VLC_STATIC(&mv->vlc, MV_VLC_BITS, MSMPEG4_MV_TABLES_NB_ELEMS + 1,
320                    mv->table_mv_bits, 1, 1,
321                    mv->table_mv_code, 2, 2, 2694);
322
323    INIT_VLC_STATIC(&ff_msmp4_dc_luma_vlc[0], DC_VLC_BITS, 120,
324                    &ff_table0_dc_lum[0][1], 8, 4,
325                    &ff_table0_dc_lum[0][0], 8, 4, 1158);
326    INIT_VLC_STATIC(&ff_msmp4_dc_chroma_vlc[0], DC_VLC_BITS, 120,
327                    &ff_table0_dc_chroma[0][1], 8, 4,
328                    &ff_table0_dc_chroma[0][0], 8, 4, 1118);
329    INIT_VLC_STATIC(&ff_msmp4_dc_luma_vlc[1], DC_VLC_BITS, 120,
330                    &ff_table1_dc_lum[0][1], 8, 4,
331                    &ff_table1_dc_lum[0][0], 8, 4, 1476);
332    INIT_VLC_STATIC(&ff_msmp4_dc_chroma_vlc[1], DC_VLC_BITS, 120,
333                    &ff_table1_dc_chroma[0][1], 8, 4,
334                    &ff_table1_dc_chroma[0][0], 8, 4, 1216);
335
336    INIT_VLC_STATIC(&v2_dc_lum_vlc, DC_VLC_BITS, 512,
337                    &ff_v2_dc_lum_table[0][1], 8, 4,
338                    &ff_v2_dc_lum_table[0][0], 8, 4, 1472);
339    INIT_VLC_STATIC(&v2_dc_chroma_vlc, DC_VLC_BITS, 512,
340                    &ff_v2_dc_chroma_table[0][1], 8, 4,
341                    &ff_v2_dc_chroma_table[0][0], 8, 4, 1506);
342
343    INIT_VLC_STATIC(&v2_intra_cbpc_vlc, V2_INTRA_CBPC_VLC_BITS, 4,
344                    &ff_v2_intra_cbpc[0][1], 2, 1,
345                    &ff_v2_intra_cbpc[0][0], 2, 1, 8);
346    INIT_VLC_STATIC(&v2_mb_type_vlc, V2_MB_TYPE_VLC_BITS, 8,
347                    &ff_v2_mb_type[0][1], 2, 1,
348                    &ff_v2_mb_type[0][0], 2, 1, 128);
349
350    for (unsigned i = 0, offset = 0; i < 4; i++) {
351        static VLCElem vlc_buf[1636 + 2648 + 1532 + 2488];
352        ff_mb_non_intra_vlc[i].table           = &vlc_buf[offset];
353        ff_mb_non_intra_vlc[i].table_allocated = FF_ARRAY_ELEMS(vlc_buf) - offset;
354        init_vlc(&ff_mb_non_intra_vlc[i], MB_NON_INTRA_VLC_BITS, 128,
355                 &ff_wmv2_inter_table[i][0][1], 8, 4,
356                 &ff_wmv2_inter_table[i][0][0], 8, 4,
357                 INIT_VLC_STATIC_OVERLONG);
358        offset += ff_mb_non_intra_vlc[i].table_size;
359    }
360
361    INIT_VLC_STATIC(&ff_msmp4_mb_i_vlc, MB_INTRA_VLC_BITS, 64,
362                    &ff_msmp4_mb_i_table[0][1], 4, 2,
363                    &ff_msmp4_mb_i_table[0][0], 4, 2, 536);
364
365    INIT_VLC_STATIC(&ff_inter_intra_vlc, INTER_INTRA_VLC_BITS, 4,
366                    &ff_table_inter_intra[0][1], 2, 1,
367                    &ff_table_inter_intra[0][0], 2, 1, 8);
368}
369
370av_cold int ff_msmpeg4_decode_init(AVCodecContext *avctx)
371{
372    static AVOnce init_static_once = AV_ONCE_INIT;
373    MpegEncContext *s = avctx->priv_data;
374    int ret;
375
376    if ((ret = av_image_check_size(avctx->width, avctx->height, 0, avctx)) < 0)
377        return ret;
378
379    if (ff_h263_decode_init(avctx) < 0)
380        return -1;
381
382    ff_msmpeg4_common_init(s);
383
384    switch(s->msmpeg4_version){
385    case 1:
386    case 2:
387        s->decode_mb= msmpeg4v12_decode_mb;
388        break;
389    case 3:
390    case 4:
391        s->decode_mb= msmpeg4v34_decode_mb;
392        break;
393    case 5:
394        if (CONFIG_WMV2_DECODER)
395            s->decode_mb= ff_wmv2_decode_mb;
396    case 6:
397        //FIXME + TODO VC1 decode mb
398        break;
399    }
400
401    s->slice_height= s->mb_height; //to avoid 1/0 if the first frame is not a keyframe
402
403    ff_thread_once(&init_static_once, msmpeg4_decode_init_static);
404
405    return 0;
406}
407
408int ff_msmpeg4_decode_picture_header(MpegEncContext * s)
409{
410    int code;
411
412    // at minimum one bit per macroblock is required at least in a valid frame,
413    // we discard frames much smaller than this. Frames smaller than 1/8 of the
414    // smallest "black/skip" frame generally contain not much recoverable content
415    // while at the same time they have the highest computational requirements
416    // per byte
417    if (get_bits_left(&s->gb) * 8LL < (s->width+15)/16 * ((s->height+15)/16))
418        return AVERROR_INVALIDDATA;
419
420    if(s->msmpeg4_version==1){
421        int start_code = get_bits_long(&s->gb, 32);
422        if(start_code!=0x00000100){
423            av_log(s->avctx, AV_LOG_ERROR, "invalid startcode\n");
424            return -1;
425        }
426
427        skip_bits(&s->gb, 5); // frame number */
428    }
429
430    s->pict_type = get_bits(&s->gb, 2) + 1;
431    if (s->pict_type != AV_PICTURE_TYPE_I &&
432        s->pict_type != AV_PICTURE_TYPE_P){
433        av_log(s->avctx, AV_LOG_ERROR, "invalid picture type\n");
434        return -1;
435    }
436    s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
437    if(s->qscale==0){
438        av_log(s->avctx, AV_LOG_ERROR, "invalid qscale\n");
439        return -1;
440    }
441
442    if (s->pict_type == AV_PICTURE_TYPE_I) {
443        code = get_bits(&s->gb, 5);
444        if(s->msmpeg4_version==1){
445            if(code==0 || code>s->mb_height){
446                av_log(s->avctx, AV_LOG_ERROR, "invalid slice height %d\n", code);
447                return -1;
448            }
449
450            s->slice_height = code;
451        }else{
452            /* 0x17: one slice, 0x18: two slices, ... */
453            if (code < 0x17){
454                av_log(s->avctx, AV_LOG_ERROR, "error, slice code was %X\n", code);
455                return -1;
456            }
457
458            s->slice_height = s->mb_height / (code - 0x16);
459        }
460
461        switch(s->msmpeg4_version){
462        case 1:
463        case 2:
464            s->rl_chroma_table_index = 2;
465            s->rl_table_index = 2;
466
467            s->dc_table_index = 0; //not used
468            break;
469        case 3:
470            s->rl_chroma_table_index = decode012(&s->gb);
471            s->rl_table_index = decode012(&s->gb);
472
473            s->dc_table_index = get_bits1(&s->gb);
474            break;
475        case 4:
476            ff_msmpeg4_decode_ext_header(s, (2+5+5+17+7)/8);
477
478            if(s->bit_rate > MBAC_BITRATE) s->per_mb_rl_table= get_bits1(&s->gb);
479            else                           s->per_mb_rl_table= 0;
480
481            if(!s->per_mb_rl_table){
482                s->rl_chroma_table_index = decode012(&s->gb);
483                s->rl_table_index = decode012(&s->gb);
484            }
485
486            s->dc_table_index = get_bits1(&s->gb);
487            s->inter_intra_pred= 0;
488            break;
489        }
490        s->no_rounding = 1;
491        if(s->avctx->debug&FF_DEBUG_PICT_INFO)
492            av_log(s->avctx, AV_LOG_DEBUG, "qscale:%d rlc:%d rl:%d dc:%d mbrl:%d slice:%d   \n",
493                s->qscale,
494                s->rl_chroma_table_index,
495                s->rl_table_index,
496                s->dc_table_index,
497                s->per_mb_rl_table,
498                s->slice_height);
499    } else {
500        switch(s->msmpeg4_version){
501        case 1:
502        case 2:
503            if(s->msmpeg4_version==1)
504                s->use_skip_mb_code = 1;
505            else
506                s->use_skip_mb_code = get_bits1(&s->gb);
507            s->rl_table_index = 2;
508            s->rl_chroma_table_index = s->rl_table_index;
509            s->dc_table_index = 0; //not used
510            s->mv_table_index = 0;
511            break;
512        case 3:
513            s->use_skip_mb_code = get_bits1(&s->gb);
514            s->rl_table_index = decode012(&s->gb);
515            s->rl_chroma_table_index = s->rl_table_index;
516
517            s->dc_table_index = get_bits1(&s->gb);
518
519            s->mv_table_index = get_bits1(&s->gb);
520            break;
521        case 4:
522            s->use_skip_mb_code = get_bits1(&s->gb);
523
524            if(s->bit_rate > MBAC_BITRATE) s->per_mb_rl_table= get_bits1(&s->gb);
525            else                           s->per_mb_rl_table= 0;
526
527            if(!s->per_mb_rl_table){
528                s->rl_table_index = decode012(&s->gb);
529                s->rl_chroma_table_index = s->rl_table_index;
530            }
531
532            s->dc_table_index = get_bits1(&s->gb);
533
534            s->mv_table_index = get_bits1(&s->gb);
535            s->inter_intra_pred= (s->width*s->height < 320*240 && s->bit_rate<=II_BITRATE);
536            break;
537        }
538
539        if(s->avctx->debug&FF_DEBUG_PICT_INFO)
540            av_log(s->avctx, AV_LOG_DEBUG, "skip:%d rl:%d rlc:%d dc:%d mv:%d mbrl:%d qp:%d   \n",
541                s->use_skip_mb_code,
542                s->rl_table_index,
543                s->rl_chroma_table_index,
544                s->dc_table_index,
545                s->mv_table_index,
546                s->per_mb_rl_table,
547                s->qscale);
548
549        if(s->flipflop_rounding){
550            s->no_rounding ^= 1;
551        }else{
552            s->no_rounding = 0;
553        }
554    }
555    ff_dlog(s->avctx, "%d %"PRId64" %d %d %d\n", s->pict_type, s->bit_rate,
556            s->inter_intra_pred, s->width, s->height);
557
558    s->esc3_level_length= 0;
559    s->esc3_run_length= 0;
560
561    return 0;
562}
563
564int ff_msmpeg4_decode_ext_header(MpegEncContext * s, int buf_size)
565{
566    int left= buf_size*8 - get_bits_count(&s->gb);
567    int length= s->msmpeg4_version>=3 ? 17 : 16;
568    /* the alt_bitstream reader could read over the end so we need to check it */
569    if(left>=length && left<length+8)
570    {
571        skip_bits(&s->gb, 5); /* fps */
572        s->bit_rate= get_bits(&s->gb, 11)*1024;
573        if(s->msmpeg4_version>=3)
574            s->flipflop_rounding= get_bits1(&s->gb);
575        else
576            s->flipflop_rounding= 0;
577    }
578    else if(left<length+8)
579    {
580        s->flipflop_rounding= 0;
581        if(s->msmpeg4_version != 2)
582            av_log(s->avctx, AV_LOG_ERROR, "ext header missing, %d left\n", left);
583    }
584    else
585    {
586        av_log(s->avctx, AV_LOG_ERROR, "I-frame too long, ignoring ext header\n");
587    }
588
589    return 0;
590}
591
592static int msmpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr)
593{
594    int level, pred;
595
596    if(s->msmpeg4_version<=2){
597        if (n < 4) {
598            level = get_vlc2(&s->gb, v2_dc_lum_vlc.table, DC_VLC_BITS, 3);
599        } else {
600            level = get_vlc2(&s->gb, v2_dc_chroma_vlc.table, DC_VLC_BITS, 3);
601        }
602        if (level < 0) {
603            av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
604            *dir_ptr = 0;
605            return -1;
606        }
607        level-=256;
608    }else{  //FIXME optimize use unified tables & index
609        if (n < 4) {
610            level = get_vlc2(&s->gb, ff_msmp4_dc_luma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
611        } else {
612            level = get_vlc2(&s->gb, ff_msmp4_dc_chroma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
613        }
614
615        if (level == DC_MAX) {
616            level = get_bits(&s->gb, 8);
617            if (get_bits1(&s->gb))
618                level = -level;
619        } else if (level != 0) {
620            if (get_bits1(&s->gb))
621                level = -level;
622        }
623    }
624
625    if(s->msmpeg4_version==1){
626        int32_t *dc_val;
627        pred = msmpeg4v1_pred_dc(s, n, &dc_val);
628        level += pred;
629
630        /* update predictor */
631        *dc_val= level;
632    }else{
633        int16_t *dc_val;
634        pred   = ff_msmpeg4_pred_dc(s, n, &dc_val, dir_ptr);
635        level += pred;
636
637        /* update predictor */
638        if (n < 4) {
639            *dc_val = level * s->y_dc_scale;
640        } else {
641            *dc_val = level * s->c_dc_scale;
642        }
643    }
644
645    return level;
646}
647
648int ff_msmpeg4_decode_block(MpegEncContext * s, int16_t * block,
649                              int n, int coded, const uint8_t *scan_table)
650{
651    int level, i, last, run, run_diff;
652    int av_uninit(dc_pred_dir);
653    RLTable *rl;
654    RL_VLC_ELEM *rl_vlc;
655    int qmul, qadd;
656
657    if (s->mb_intra) {
658        qmul=1;
659        qadd=0;
660
661        /* DC coef */
662        level = msmpeg4_decode_dc(s, n, &dc_pred_dir);
663
664        if (level < 0){
665            av_log(s->avctx, AV_LOG_ERROR, "dc overflow- block: %d qscale: %d//\n", n, s->qscale);
666            if(s->inter_intra_pred) level=0;
667        }
668        if (n < 4) {
669            rl = &ff_rl_table[s->rl_table_index];
670            if(level > 256*s->y_dc_scale){
671                av_log(s->avctx, AV_LOG_ERROR, "dc overflow+ L qscale: %d//\n", s->qscale);
672                if(!s->inter_intra_pred) return -1;
673            }
674        } else {
675            rl = &ff_rl_table[3 + s->rl_chroma_table_index];
676            if(level > 256*s->c_dc_scale){
677                av_log(s->avctx, AV_LOG_ERROR, "dc overflow+ C qscale: %d//\n", s->qscale);
678                if(!s->inter_intra_pred) return -1;
679            }
680        }
681        block[0] = level;
682
683        run_diff = s->msmpeg4_version >= 4;
684        i = 0;
685        if (!coded) {
686            goto not_coded;
687        }
688        if (s->ac_pred) {
689            if (dc_pred_dir == 0)
690                scan_table = s->intra_v_scantable.permutated; /* left */
691            else
692                scan_table = s->intra_h_scantable.permutated; /* top */
693        } else {
694            scan_table = s->intra_scantable.permutated;
695        }
696        rl_vlc= rl->rl_vlc[0];
697    } else {
698        qmul = s->qscale << 1;
699        qadd = (s->qscale - 1) | 1;
700        i = -1;
701        rl = &ff_rl_table[3 + s->rl_table_index];
702
703        if(s->msmpeg4_version==2)
704            run_diff = 0;
705        else
706            run_diff = 1;
707
708        if (!coded) {
709            s->block_last_index[n] = i;
710            return 0;
711        }
712        if(!scan_table)
713            scan_table = s->inter_scantable.permutated;
714        rl_vlc= rl->rl_vlc[s->qscale];
715    }
716  {
717    OPEN_READER(re, &s->gb);
718    for(;;) {
719        UPDATE_CACHE(re, &s->gb);
720        GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
721        if (level==0) {
722            int cache;
723            cache= GET_CACHE(re, &s->gb);
724            /* escape */
725            if (s->msmpeg4_version==1 || (cache&0x80000000)==0) {
726                if (s->msmpeg4_version==1 || (cache&0x40000000)==0) {
727                    /* third escape */
728                    if(s->msmpeg4_version!=1) LAST_SKIP_BITS(re, &s->gb, 2);
729                    UPDATE_CACHE(re, &s->gb);
730                    if(s->msmpeg4_version<=3){
731                        last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
732                        run=   SHOW_UBITS(re, &s->gb, 6); SKIP_CACHE(re, &s->gb, 6);
733                        level= SHOW_SBITS(re, &s->gb, 8);
734                        SKIP_COUNTER(re, &s->gb, 1+6+8);
735                    }else{
736                        int sign;
737                        last=  SHOW_UBITS(re, &s->gb, 1); SKIP_BITS(re, &s->gb, 1);
738                        if(!s->esc3_level_length){
739                            int ll;
740                            ff_dlog(s->avctx, "ESC-3 %X at %d %d\n",
741                                    show_bits(&s->gb, 24), s->mb_x, s->mb_y);
742                            if(s->qscale<8){
743                                ll= SHOW_UBITS(re, &s->gb, 3); SKIP_BITS(re, &s->gb, 3);
744                                if(ll==0){
745                                    ll= 8+SHOW_UBITS(re, &s->gb, 1); SKIP_BITS(re, &s->gb, 1);
746                                }
747                            }else{
748                                ll=2;
749                                while(ll<8 && SHOW_UBITS(re, &s->gb, 1)==0){
750                                    ll++;
751                                    SKIP_BITS(re, &s->gb, 1);
752                                }
753                                if(ll<8) SKIP_BITS(re, &s->gb, 1);
754                            }
755
756                            s->esc3_level_length= ll;
757                            s->esc3_run_length= SHOW_UBITS(re, &s->gb, 2) + 3; SKIP_BITS(re, &s->gb, 2);
758                            UPDATE_CACHE(re, &s->gb);
759                        }
760                        run=   SHOW_UBITS(re, &s->gb, s->esc3_run_length);
761                        SKIP_BITS(re, &s->gb, s->esc3_run_length);
762
763                        sign=  SHOW_UBITS(re, &s->gb, 1);
764                        SKIP_BITS(re, &s->gb, 1);
765
766                        level= SHOW_UBITS(re, &s->gb, s->esc3_level_length);
767                        SKIP_BITS(re, &s->gb, s->esc3_level_length);
768                        if(sign) level= -level;
769                    }
770
771                    //level = level * qmul + (level>0) * qadd - (level<=0) * qadd ;
772                    if (level>0) level= level * qmul + qadd;
773                    else         level= level * qmul - qadd;
774                    i+= run + 1;
775                    if(last) i+=192;
776                } else {
777                    /* second escape */
778                    SKIP_BITS(re, &s->gb, 2);
779                    GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
780                    i+= run + rl->max_run[run>>7][level/qmul] + run_diff; //FIXME opt indexing
781                    level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
782                    LAST_SKIP_BITS(re, &s->gb, 1);
783                }
784            } else {
785                /* first escape */
786                SKIP_BITS(re, &s->gb, 1);
787                GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
788                i+= run;
789                level = level + rl->max_level[run>>7][(run-1)&63] * qmul;//FIXME opt indexing
790                level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
791                LAST_SKIP_BITS(re, &s->gb, 1);
792            }
793        } else {
794            i+= run;
795            level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
796            LAST_SKIP_BITS(re, &s->gb, 1);
797        }
798        if (i > 62){
799            i-= 192;
800            if(i&(~63)){
801                const int left= get_bits_left(&s->gb);
802                if (((i + 192 == 64 && level / qmul == -1) ||
803                     !(s->avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT))) &&
804                    left >= 0) {
805                    av_log(s->avctx, AV_LOG_ERROR, "ignoring overflow at %d %d\n", s->mb_x, s->mb_y);
806                    i = 63;
807                    break;
808                }else{
809                    av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
810                    return -1;
811                }
812            }
813
814            block[scan_table[i]] = level;
815            break;
816        }
817
818        block[scan_table[i]] = level;
819    }
820    CLOSE_READER(re, &s->gb);
821  }
822 not_coded:
823    if (s->mb_intra) {
824        ff_mpeg4_pred_ac(s, block, n, dc_pred_dir);
825        if (s->ac_pred) {
826            i = 63; /* XXX: not optimal */
827        }
828    }
829    if(s->msmpeg4_version>=4 && i>0) i=63; //FIXME/XXX optimize
830    s->block_last_index[n] = i;
831
832    return 0;
833}
834
835void ff_msmpeg4_decode_motion(MpegEncContext *s, int *mx_ptr, int *my_ptr)
836{
837    MVTable *mv;
838    int code, mx, my;
839
840    mv = &ff_mv_tables[s->mv_table_index];
841
842    code = get_vlc2(&s->gb, mv->vlc.table, MV_VLC_BITS, 2);
843    if (code == MSMPEG4_MV_TABLES_NB_ELEMS) {
844        mx = get_bits(&s->gb, 6);
845        my = get_bits(&s->gb, 6);
846    } else {
847        mx = mv->table_mvx[code];
848        my = mv->table_mvy[code];
849    }
850
851    mx += *mx_ptr - 32;
852    my += *my_ptr - 32;
853    /* WARNING : they do not do exactly modulo encoding */
854    if (mx <= -64)
855        mx += 64;
856    else if (mx >= 64)
857        mx -= 64;
858
859    if (my <= -64)
860        my += 64;
861    else if (my >= 64)
862        my -= 64;
863    *mx_ptr = mx;
864    *my_ptr = my;
865}
866
867const FFCodec ff_msmpeg4v1_decoder = {
868    .p.name         = "msmpeg4v1",
869    .p.long_name    = NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 1"),
870    .p.type         = AVMEDIA_TYPE_VIDEO,
871    .p.id           = AV_CODEC_ID_MSMPEG4V1,
872    .priv_data_size = sizeof(MpegEncContext),
873    .init           = ff_msmpeg4_decode_init,
874    .close          = ff_h263_decode_end,
875    FF_CODEC_DECODE_CB(ff_h263_decode_frame),
876    .p.capabilities = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1,
877    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
878                      FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
879    .p.max_lowres   = 3,
880    .p.pix_fmts     = (const enum AVPixelFormat[]) {
881        AV_PIX_FMT_YUV420P,
882        AV_PIX_FMT_NONE
883    },
884};
885
886const FFCodec ff_msmpeg4v2_decoder = {
887    .p.name         = "msmpeg4v2",
888    .p.long_name    = NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 2"),
889    .p.type         = AVMEDIA_TYPE_VIDEO,
890    .p.id           = AV_CODEC_ID_MSMPEG4V2,
891    .priv_data_size = sizeof(MpegEncContext),
892    .init           = ff_msmpeg4_decode_init,
893    .close          = ff_h263_decode_end,
894    FF_CODEC_DECODE_CB(ff_h263_decode_frame),
895    .p.capabilities = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1,
896    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
897                      FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
898    .p.max_lowres   = 3,
899    .p.pix_fmts     = (const enum AVPixelFormat[]) {
900        AV_PIX_FMT_YUV420P,
901        AV_PIX_FMT_NONE
902    },
903};
904
905const FFCodec ff_msmpeg4v3_decoder = {
906    .p.name         = "msmpeg4",
907    .p.long_name    = NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 3"),
908    .p.type         = AVMEDIA_TYPE_VIDEO,
909    .p.id           = AV_CODEC_ID_MSMPEG4V3,
910    .priv_data_size = sizeof(MpegEncContext),
911    .init           = ff_msmpeg4_decode_init,
912    .close          = ff_h263_decode_end,
913    FF_CODEC_DECODE_CB(ff_h263_decode_frame),
914    .p.capabilities = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1,
915    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
916                      FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
917    .p.max_lowres   = 3,
918    .p.pix_fmts     = (const enum AVPixelFormat[]) {
919        AV_PIX_FMT_YUV420P,
920        AV_PIX_FMT_NONE
921    },
922};
923
924const FFCodec ff_wmv1_decoder = {
925    .p.name         = "wmv1",
926    .p.long_name    = NULL_IF_CONFIG_SMALL("Windows Media Video 7"),
927    .p.type         = AVMEDIA_TYPE_VIDEO,
928    .p.id           = AV_CODEC_ID_WMV1,
929    .priv_data_size = sizeof(MpegEncContext),
930    .init           = ff_msmpeg4_decode_init,
931    .close          = ff_h263_decode_end,
932    FF_CODEC_DECODE_CB(ff_h263_decode_frame),
933    .p.capabilities = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1,
934    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
935                      FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
936    .p.max_lowres   = 3,
937    .p.pix_fmts     = (const enum AVPixelFormat[]) {
938        AV_PIX_FMT_YUV420P,
939        AV_PIX_FMT_NONE
940    },
941};
942