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1 /*
2  * Go2Webinar / Go2Meeting decoder
3  * Copyright (c) 2012 Konstantin Shishkov
4  * Copyright (c) 2013 Maxim Poliakovski
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /**
24  * @file
25  * Go2Webinar / Go2Meeting decoder
26  */
27 
28 #include <inttypes.h>
29 #include <zlib.h>
30 
31 #include "libavutil/imgutils.h"
32 #include "libavutil/intreadwrite.h"
33 #include "libavutil/mem_internal.h"
34 
35 #include "avcodec.h"
36 #include "blockdsp.h"
37 #include "bytestream.h"
38 #include "codec_internal.h"
39 #include "elsdec.h"
40 #include "get_bits.h"
41 #include "idctdsp.h"
42 #include "internal.h"
43 #include "jpegtables.h"
44 #include "mjpeg.h"
45 #include "mjpegdec.h"
46 
47 #define EPIC_PIX_STACK_SIZE 1024
48 #define EPIC_PIX_STACK_MAX  (EPIC_PIX_STACK_SIZE - 1)
49 
50 enum ChunkType {
51     DISPLAY_INFO = 0xC8,
52     TILE_DATA,
53     CURSOR_POS,
54     CURSOR_SHAPE,
55     CHUNK_CC,
56     CHUNK_CD
57 };
58 
59 enum Compression {
60     COMPR_EPIC_J_B = 2,
61     COMPR_KEMPF_J_B,
62 };
63 
64 static const uint8_t luma_quant[64] = {
65      8,  6,  5,  8, 12, 20, 26, 31,
66      6,  6,  7, 10, 13, 29, 30, 28,
67      7,  7,  8, 12, 20, 29, 35, 28,
68      7,  9, 11, 15, 26, 44, 40, 31,
69      9, 11, 19, 28, 34, 55, 52, 39,
70     12, 18, 28, 32, 41, 52, 57, 46,
71     25, 32, 39, 44, 52, 61, 60, 51,
72     36, 46, 48, 49, 56, 50, 52, 50
73 };
74 
75 static const uint8_t chroma_quant[64] = {
76      9,  9, 12, 24, 50, 50, 50, 50,
77      9, 11, 13, 33, 50, 50, 50, 50,
78     12, 13, 28, 50, 50, 50, 50, 50,
79     24, 33, 50, 50, 50, 50, 50, 50,
80     50, 50, 50, 50, 50, 50, 50, 50,
81     50, 50, 50, 50, 50, 50, 50, 50,
82     50, 50, 50, 50, 50, 50, 50, 50,
83     50, 50, 50, 50, 50, 50, 50, 50,
84 };
85 
86 typedef struct ePICPixListElem {
87     struct ePICPixListElem *next;
88     uint32_t               pixel;
89     uint8_t                rung;
90 } ePICPixListElem;
91 
92 typedef struct ePICPixHashElem {
93     uint32_t                pix_id;
94     struct ePICPixListElem  *list;
95 } ePICPixHashElem;
96 
97 #define EPIC_HASH_SIZE 256
98 typedef struct ePICPixHash {
99     ePICPixHashElem *bucket[EPIC_HASH_SIZE];
100     int              bucket_size[EPIC_HASH_SIZE];
101     int              bucket_fill[EPIC_HASH_SIZE];
102 } ePICPixHash;
103 
104 typedef struct ePICContext {
105     ElsDecCtx        els_ctx;
106     int              next_run_pos;
107     ElsUnsignedRung  unsigned_rung;
108     uint8_t          W_flag_rung;
109     uint8_t          N_flag_rung;
110     uint8_t          W_ctx_rung[256];
111     uint8_t          N_ctx_rung[512];
112     uint8_t          nw_pred_rung[256];
113     uint8_t          ne_pred_rung[256];
114     uint8_t          prev_row_rung[14];
115     uint8_t          runlen_zeroes[14];
116     uint8_t          runlen_one;
117     int              stack_pos;
118     uint32_t         stack[EPIC_PIX_STACK_SIZE];
119     ePICPixHash      hash;
120 } ePICContext;
121 
122 typedef struct JPGContext {
123     BlockDSPContext bdsp;
124     IDCTDSPContext idsp;
125     ScanTable  scantable;
126 
127     VLC        dc_vlc[2], ac_vlc[2];
128     int        prev_dc[3];
129     DECLARE_ALIGNED(32, int16_t, block)[6][64];
130 
131     uint8_t    *buf;
132 } JPGContext;
133 
134 typedef struct G2MContext {
135     ePICContext ec;
136     JPGContext jc;
137 
138     int        version;
139 
140     int        compression;
141     int        width, height, bpp;
142     int        orig_width, orig_height;
143     int        tile_width, tile_height;
144     int        tiles_x, tiles_y, tile_x, tile_y;
145 
146     int        got_header;
147 
148     uint8_t    *framebuf;
149     int        framebuf_stride;
150     unsigned int framebuf_allocated;
151 
152     uint8_t    *synth_tile, *jpeg_tile, *epic_buf, *epic_buf_base;
153     int        tile_stride, epic_buf_stride, old_tile_w, old_tile_h;
154     int        swapuv;
155 
156     uint8_t    *kempf_buf, *kempf_flags;
157 
158     uint8_t    *cursor;
159     int        cursor_stride;
160     int        cursor_fmt;
161     int        cursor_w, cursor_h, cursor_x, cursor_y;
162     int        cursor_hot_x, cursor_hot_y;
163 } G2MContext;
164 
jpg_init(AVCodecContext * avctx,JPGContext * c)165 static av_cold int jpg_init(AVCodecContext *avctx, JPGContext *c)
166 {
167     int ret;
168 
169     ret = ff_mjpeg_build_vlc(&c->dc_vlc[0], ff_mjpeg_bits_dc_luminance,
170                              ff_mjpeg_val_dc, 0, avctx);
171     if (ret)
172         return ret;
173     ret = ff_mjpeg_build_vlc(&c->dc_vlc[1], ff_mjpeg_bits_dc_chrominance,
174                              ff_mjpeg_val_dc, 0, avctx);
175     if (ret)
176         return ret;
177     ret = ff_mjpeg_build_vlc(&c->ac_vlc[0], ff_mjpeg_bits_ac_luminance,
178                              ff_mjpeg_val_ac_luminance, 1, avctx);
179     if (ret)
180         return ret;
181     ret = ff_mjpeg_build_vlc(&c->ac_vlc[1], ff_mjpeg_bits_ac_chrominance,
182                              ff_mjpeg_val_ac_chrominance, 1, avctx);
183     if (ret)
184         return ret;
185 
186     ff_blockdsp_init(&c->bdsp, avctx);
187     ff_idctdsp_init(&c->idsp, avctx);
188     ff_init_scantable(c->idsp.idct_permutation, &c->scantable,
189                       ff_zigzag_direct);
190 
191     return 0;
192 }
193 
jpg_free_context(JPGContext * ctx)194 static av_cold void jpg_free_context(JPGContext *ctx)
195 {
196     int i;
197 
198     for (i = 0; i < 2; i++) {
199         ff_free_vlc(&ctx->dc_vlc[i]);
200         ff_free_vlc(&ctx->ac_vlc[i]);
201     }
202 
203     av_freep(&ctx->buf);
204 }
205 
jpg_unescape(const uint8_t * src,int src_size,uint8_t * dst,int * dst_size)206 static void jpg_unescape(const uint8_t *src, int src_size,
207                          uint8_t *dst, int *dst_size)
208 {
209     const uint8_t *src_end = src + src_size;
210     uint8_t *dst_start = dst;
211 
212     while (src < src_end) {
213         uint8_t x = *src++;
214 
215         *dst++ = x;
216 
217         if (x == 0xFF && !*src)
218             src++;
219     }
220     *dst_size = dst - dst_start;
221 }
222 
jpg_decode_block(JPGContext * c,GetBitContext * gb,int plane,int16_t * block)223 static int jpg_decode_block(JPGContext *c, GetBitContext *gb,
224                             int plane, int16_t *block)
225 {
226     int dc, val, pos;
227     const int is_chroma = !!plane;
228     const uint8_t *qmat = is_chroma ? chroma_quant : luma_quant;
229 
230     if (get_bits_left(gb) < 1)
231         return AVERROR_INVALIDDATA;
232 
233     c->bdsp.clear_block(block);
234     dc = get_vlc2(gb, c->dc_vlc[is_chroma].table, 9, 2);
235     if (dc < 0)
236         return AVERROR_INVALIDDATA;
237     if (dc)
238         dc = get_xbits(gb, dc);
239     dc                = dc * qmat[0] + c->prev_dc[plane];
240     block[0]          = dc;
241     c->prev_dc[plane] = dc;
242 
243     pos = 0;
244     while (pos < 63) {
245         val = get_vlc2(gb, c->ac_vlc[is_chroma].table, 9, 2);
246         if (val < 0)
247             return AVERROR_INVALIDDATA;
248         pos += val >> 4;
249         val &= 0xF;
250         if (pos > 63)
251             return val ? AVERROR_INVALIDDATA : 0;
252         if (val) {
253             int nbits = val;
254 
255             val                                 = get_xbits(gb, nbits);
256             val                                *= qmat[ff_zigzag_direct[pos]];
257             block[c->scantable.permutated[pos]] = val;
258         }
259     }
260     return 0;
261 }
262 
yuv2rgb(uint8_t * out,int ridx,int Y,int U,int V)263 static inline void yuv2rgb(uint8_t *out, int ridx, int Y, int U, int V)
264 {
265     out[ridx]     = av_clip_uint8(Y +              (91881 * V + 32768 >> 16));
266     out[1]        = av_clip_uint8(Y + (-22554 * U - 46802 * V + 32768 >> 16));
267     out[2 - ridx] = av_clip_uint8(Y + (116130 * U             + 32768 >> 16));
268 }
269 
jpg_decode_data(JPGContext * c,int width,int height,const uint8_t * src,int src_size,uint8_t * dst,int dst_stride,const uint8_t * mask,int mask_stride,int num_mbs,int swapuv)270 static int jpg_decode_data(JPGContext *c, int width, int height,
271                            const uint8_t *src, int src_size,
272                            uint8_t *dst, int dst_stride,
273                            const uint8_t *mask, int mask_stride, int num_mbs,
274                            int swapuv)
275 {
276     GetBitContext gb;
277     int mb_w, mb_h, mb_x, mb_y, i, j;
278     int bx, by;
279     int unesc_size;
280     int ret;
281     const int ridx = swapuv ? 2 : 0;
282 
283     if ((ret = av_reallocp(&c->buf,
284                            src_size + AV_INPUT_BUFFER_PADDING_SIZE)) < 0)
285         return ret;
286     jpg_unescape(src, src_size, c->buf, &unesc_size);
287     memset(c->buf + unesc_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
288     if((ret = init_get_bits8(&gb, c->buf, unesc_size)) < 0)
289         return ret;
290 
291     width = FFALIGN(width, 16);
292     mb_w  =  width        >> 4;
293     mb_h  = (height + 15) >> 4;
294 
295     if (!num_mbs)
296         num_mbs = mb_w * mb_h * 4;
297 
298     for (i = 0; i < 3; i++)
299         c->prev_dc[i] = 1024;
300     bx =
301     by = 0;
302     c->bdsp.clear_blocks(c->block[0]);
303     for (mb_y = 0; mb_y < mb_h; mb_y++) {
304         for (mb_x = 0; mb_x < mb_w; mb_x++) {
305             if (mask && !mask[mb_x * 2] && !mask[mb_x * 2 + 1] &&
306                 !mask[mb_x * 2 +     mask_stride] &&
307                 !mask[mb_x * 2 + 1 + mask_stride]) {
308                 bx += 16;
309                 continue;
310             }
311             for (j = 0; j < 2; j++) {
312                 for (i = 0; i < 2; i++) {
313                     if (mask && !mask[mb_x * 2 + i + j * mask_stride])
314                         continue;
315                     num_mbs--;
316                     if ((ret = jpg_decode_block(c, &gb, 0,
317                                                 c->block[i + j * 2])) != 0)
318                         return ret;
319                     c->idsp.idct(c->block[i + j * 2]);
320                 }
321             }
322             for (i = 1; i < 3; i++) {
323                 if ((ret = jpg_decode_block(c, &gb, i, c->block[i + 3])) != 0)
324                     return ret;
325                 c->idsp.idct(c->block[i + 3]);
326             }
327 
328             for (j = 0; j < 16; j++) {
329                 uint8_t *out = dst + bx * 3 + (by + j) * dst_stride;
330                 for (i = 0; i < 16; i++) {
331                     int Y, U, V;
332 
333                     Y = c->block[(j >> 3) * 2 + (i >> 3)][(i & 7) + (j & 7) * 8];
334                     U = c->block[4][(i >> 1) + (j >> 1) * 8] - 128;
335                     V = c->block[5][(i >> 1) + (j >> 1) * 8] - 128;
336                     yuv2rgb(out + i * 3, ridx, Y, U, V);
337                 }
338             }
339 
340             if (!num_mbs)
341                 return 0;
342             bx += 16;
343         }
344         bx  = 0;
345         by += 16;
346         if (mask)
347             mask += mask_stride * 2;
348     }
349 
350     return 0;
351 }
352 
353 #define LOAD_NEIGHBOURS(x)      \
354     W   = curr_row[(x)   - 1];  \
355     N   = above_row[(x)];       \
356     WW  = curr_row[(x)   - 2];  \
357     NW  = above_row[(x)  - 1];  \
358     NE  = above_row[(x)  + 1];  \
359     NN  = above2_row[(x)];      \
360     NNW = above2_row[(x) - 1];  \
361     NWW = above_row[(x)  - 2];  \
362     NNE = above2_row[(x) + 1]
363 
364 #define UPDATE_NEIGHBOURS(x)    \
365     NNW = NN;                   \
366     NN  = NNE;                  \
367     NWW = NW;                   \
368     NW  = N;                    \
369     N   = NE;                   \
370     NE  = above_row[(x)  + 1];  \
371     NNE = above2_row[(x) + 1]
372 
373 #define R_shift 16
374 #define G_shift  8
375 #define B_shift  0
376 
377 /* improved djb2 hash from http://www.cse.yorku.ca/~oz/hash.html */
djb2_hash(uint32_t key)378 static int djb2_hash(uint32_t key)
379 {
380     uint32_t h = 5381;
381 
382     h = (h * 33) ^ ((key >> 24) & 0xFF); // xxx: probably not needed at all
383     h = (h * 33) ^ ((key >> 16) & 0xFF);
384     h = (h * 33) ^ ((key >>  8) & 0xFF);
385     h = (h * 33) ^  (key        & 0xFF);
386 
387     return h & (EPIC_HASH_SIZE - 1);
388 }
389 
epic_hash_init(ePICPixHash * hash)390 static void epic_hash_init(ePICPixHash *hash)
391 {
392     memset(hash, 0, sizeof(*hash));
393 }
394 
epic_hash_find(const ePICPixHash * hash,uint32_t key)395 static ePICPixHashElem *epic_hash_find(const ePICPixHash *hash, uint32_t key)
396 {
397     int i, idx = djb2_hash(key);
398     ePICPixHashElem *bucket = hash->bucket[idx];
399 
400     for (i = 0; i < hash->bucket_fill[idx]; i++)
401         if (bucket[i].pix_id == key)
402             return &bucket[i];
403 
404     return NULL;
405 }
406 
epic_hash_add(ePICPixHash * hash,uint32_t key)407 static ePICPixHashElem *epic_hash_add(ePICPixHash *hash, uint32_t key)
408 {
409     ePICPixHashElem *bucket, *ret;
410     int idx = djb2_hash(key);
411 
412     if (hash->bucket_size[idx] > INT_MAX / sizeof(**hash->bucket))
413         return NULL;
414 
415     if (!(hash->bucket_fill[idx] < hash->bucket_size[idx])) {
416         int new_size = hash->bucket_size[idx] + 16;
417         bucket = av_realloc(hash->bucket[idx], new_size * sizeof(*bucket));
418         if (!bucket)
419             return NULL;
420         hash->bucket[idx]      = bucket;
421         hash->bucket_size[idx] = new_size;
422     }
423 
424     ret = &hash->bucket[idx][hash->bucket_fill[idx]++];
425     memset(ret, 0, sizeof(*ret));
426     ret->pix_id = key;
427     return ret;
428 }
429 
epic_add_pixel_to_cache(ePICPixHash * hash,uint32_t key,uint32_t pix)430 static int epic_add_pixel_to_cache(ePICPixHash *hash, uint32_t key, uint32_t pix)
431 {
432     ePICPixListElem *new_elem;
433     ePICPixHashElem *hash_elem = epic_hash_find(hash, key);
434 
435     if (!hash_elem) {
436         if (!(hash_elem = epic_hash_add(hash, key)))
437             return AVERROR(ENOMEM);
438     }
439 
440     new_elem = av_mallocz(sizeof(*new_elem));
441     if (!new_elem)
442         return AVERROR(ENOMEM);
443 
444     new_elem->pixel = pix;
445     new_elem->next  = hash_elem->list;
446     hash_elem->list = new_elem;
447 
448     return 0;
449 }
450 
epic_cache_entries_for_pixel(const ePICPixHash * hash,uint32_t pix)451 static inline int epic_cache_entries_for_pixel(const ePICPixHash *hash,
452                                                uint32_t pix)
453 {
454     ePICPixHashElem *hash_elem = epic_hash_find(hash, pix);
455 
456     if (hash_elem != NULL && hash_elem->list != NULL)
457         return 1;
458 
459     return 0;
460 }
461 
epic_free_pixel_cache(ePICPixHash * hash)462 static void epic_free_pixel_cache(ePICPixHash *hash)
463 {
464     int i, j;
465 
466     for (i = 0; i < EPIC_HASH_SIZE; i++) {
467         for (j = 0; j < hash->bucket_fill[i]; j++) {
468             ePICPixListElem *list_elem = hash->bucket[i][j].list;
469             while (list_elem) {
470                 ePICPixListElem *tmp = list_elem->next;
471                 av_free(list_elem);
472                 list_elem = tmp;
473             }
474         }
475         av_freep(&hash->bucket[i]);
476         hash->bucket_size[i] =
477         hash->bucket_fill[i] = 0;
478     }
479 }
480 
is_pixel_on_stack(const ePICContext * dc,uint32_t pix)481 static inline int is_pixel_on_stack(const ePICContext *dc, uint32_t pix)
482 {
483     int i;
484 
485     for (i = 0; i < dc->stack_pos; i++)
486         if (dc->stack[i] == pix)
487             break;
488 
489     return i != dc->stack_pos;
490 }
491 
492 #define TOSIGNED(val) (((val) >> 1) ^ -((val) & 1))
493 
epic_decode_component_pred(ePICContext * dc,int N,int W,int NW)494 static inline int epic_decode_component_pred(ePICContext *dc,
495                                              int N, int W, int NW)
496 {
497     unsigned delta = ff_els_decode_unsigned(&dc->els_ctx, &dc->unsigned_rung);
498     return mid_pred(N, N + W - NW, W) - TOSIGNED(delta);
499 }
500 
epic_decode_pixel_pred(ePICContext * dc,int x,int y,const uint32_t * curr_row,const uint32_t * above_row)501 static uint32_t epic_decode_pixel_pred(ePICContext *dc, int x, int y,
502                                        const uint32_t *curr_row,
503                                        const uint32_t *above_row)
504 {
505     uint32_t N, W, NW, pred;
506     unsigned delta;
507     int GN, GW, GNW, R, G, B;
508 
509     if (x && y) {
510         W  = curr_row[x  - 1];
511         N  = above_row[x];
512         NW = above_row[x - 1];
513 
514         GN  = (N  >> G_shift) & 0xFF;
515         GW  = (W  >> G_shift) & 0xFF;
516         GNW = (NW >> G_shift) & 0xFF;
517 
518         G = epic_decode_component_pred(dc, GN, GW, GNW);
519 
520         R = G + epic_decode_component_pred(dc,
521                                            ((N  >> R_shift) & 0xFF) - GN,
522                                            ((W  >> R_shift) & 0xFF) - GW,
523                                            ((NW >> R_shift) & 0xFF) - GNW);
524 
525         B = G + epic_decode_component_pred(dc,
526                                            ((N  >> B_shift) & 0xFF) - GN,
527                                            ((W  >> B_shift) & 0xFF) - GW,
528                                            ((NW >> B_shift) & 0xFF) - GNW);
529     } else {
530         if (x)
531             pred = curr_row[x - 1];
532         else
533             pred = above_row[x];
534 
535         delta = ff_els_decode_unsigned(&dc->els_ctx, &dc->unsigned_rung);
536         R     = ((pred >> R_shift) & 0xFF) - TOSIGNED(delta);
537 
538         delta = ff_els_decode_unsigned(&dc->els_ctx, &dc->unsigned_rung);
539         G     = ((pred >> G_shift) & 0xFF) - TOSIGNED(delta);
540 
541         delta = ff_els_decode_unsigned(&dc->els_ctx, &dc->unsigned_rung);
542         B     = ((pred >> B_shift) & 0xFF) - TOSIGNED(delta);
543     }
544 
545     if (R<0 || G<0 || B<0 || R > 255 || G > 255 || B > 255) {
546         avpriv_request_sample(NULL, "RGB %d %d %d (out of range)", R, G, B);
547         return 0;
548     }
549 
550     return (R << R_shift) | (G << G_shift) | (B << B_shift);
551 }
552 
epic_predict_pixel(ePICContext * dc,uint8_t * rung,uint32_t * pPix,uint32_t pix)553 static int epic_predict_pixel(ePICContext *dc, uint8_t *rung,
554                               uint32_t *pPix, uint32_t pix)
555 {
556     if (!ff_els_decode_bit(&dc->els_ctx, rung)) {
557         *pPix = pix;
558         return 1;
559     }
560     dc->stack[dc->stack_pos++ & EPIC_PIX_STACK_MAX] = pix;
561     return 0;
562 }
563 
epic_handle_edges(ePICContext * dc,int x,int y,const uint32_t * curr_row,const uint32_t * above_row,uint32_t * pPix)564 static int epic_handle_edges(ePICContext *dc, int x, int y,
565                              const uint32_t *curr_row,
566                              const uint32_t *above_row, uint32_t *pPix)
567 {
568     uint32_t pix;
569 
570     if (!x && !y) { /* special case: top-left pixel */
571         /* the top-left pixel is coded independently with 3 unsigned numbers */
572         *pPix = (ff_els_decode_unsigned(&dc->els_ctx, &dc->unsigned_rung) << R_shift) |
573                 (ff_els_decode_unsigned(&dc->els_ctx, &dc->unsigned_rung) << G_shift) |
574                 (ff_els_decode_unsigned(&dc->els_ctx, &dc->unsigned_rung) << B_shift);
575         return 1;
576     }
577 
578     if (x) { /* predict from W first */
579         pix = curr_row[x - 1];
580         if (epic_predict_pixel(dc, &dc->W_flag_rung, pPix, pix))
581             return 1;
582     }
583 
584     if (y) { /* then try to predict from N */
585         pix = above_row[x];
586         if (!dc->stack_pos || dc->stack[0] != pix) {
587             if (epic_predict_pixel(dc, &dc->N_flag_rung, pPix, pix))
588                 return 1;
589         }
590     }
591 
592     return 0;
593 }
594 
epic_decode_run_length(ePICContext * dc,int x,int y,int tile_width,const uint32_t * curr_row,const uint32_t * above_row,const uint32_t * above2_row,uint32_t * pPix,int * pRun)595 static int epic_decode_run_length(ePICContext *dc, int x, int y, int tile_width,
596                                   const uint32_t *curr_row,
597                                   const uint32_t *above_row,
598                                   const uint32_t *above2_row,
599                                   uint32_t *pPix, int *pRun)
600 {
601     int idx, got_pixel = 0, WWneW, old_WWneW = 0;
602     uint32_t W, WW, N, NN, NW, NE, NWW, NNW, NNE;
603 
604     *pRun = 0;
605 
606     LOAD_NEIGHBOURS(x);
607 
608     if (dc->next_run_pos == x) {
609         /* can't reuse W for the new pixel in this case */
610         WWneW = 1;
611     } else {
612         idx = (WW  != W)  << 7 |
613               (NW  != W)  << 6 |
614               (N   != NE) << 5 |
615               (NW  != N)  << 4 |
616               (NWW != NW) << 3 |
617               (NNE != NE) << 2 |
618               (NN  != N)  << 1 |
619               (NNW != NW);
620         WWneW = ff_els_decode_bit(&dc->els_ctx, &dc->W_ctx_rung[idx]);
621         if (WWneW < 0)
622             return WWneW;
623     }
624 
625     if (WWneW)
626         dc->stack[dc->stack_pos++ & EPIC_PIX_STACK_MAX] = W;
627     else {
628         *pPix     = W;
629         got_pixel = 1;
630     }
631 
632     do {
633         int NWneW = 1;
634         if (got_pixel) // pixel value already known (derived from either W or N)
635             NWneW = *pPix != N;
636         else { // pixel value is unknown and will be decoded later
637             NWneW = *pRun ? NWneW : NW != W;
638 
639             /* TODO: RFC this mess! */
640             switch (((NW != N) << 2) | (NWneW << 1) | WWneW) {
641             case 0:
642                 break; // do nothing here
643             case 3:
644             case 5:
645             case 6:
646             case 7:
647                 if (!is_pixel_on_stack(dc, N)) {
648                     idx = WWneW       << 8 |
649                           (*pRun ? old_WWneW : WW != W) << 7 |
650                           NWneW       << 6 |
651                           (N   != NE) << 5 |
652                           (NW  != N)  << 4 |
653                           (NWW != NW) << 3 |
654                           (NNE != NE) << 2 |
655                           (NN  != N)  << 1 |
656                           (NNW != NW);
657                     if (!ff_els_decode_bit(&dc->els_ctx, &dc->N_ctx_rung[idx])) {
658                         NWneW = 0;
659                         *pPix = N;
660                         got_pixel = 1;
661                         break;
662                     }
663                 }
664                 /* fall through */
665             default:
666                 NWneW = 1;
667                 old_WWneW = WWneW;
668                 if (!is_pixel_on_stack(dc, N))
669                     dc->stack[dc->stack_pos++ & EPIC_PIX_STACK_MAX] = N;
670             }
671         }
672 
673         (*pRun)++;
674         if (x + *pRun >= tile_width - 1)
675             break;
676 
677         UPDATE_NEIGHBOURS(x + *pRun);
678 
679         if (!NWneW && NW == N && N == NE) {
680             int pos, run, rle;
681             int start_pos = x + *pRun;
682 
683             /* scan for a run of pix in the line above */
684             uint32_t pix = above_row[start_pos + 1];
685             for (pos = start_pos + 2; pos < tile_width; pos++)
686                 if (!(above_row[pos] == pix))
687                     break;
688             run = pos - start_pos - 1;
689             idx = av_ceil_log2(run);
690             if (ff_els_decode_bit(&dc->els_ctx, &dc->prev_row_rung[idx]))
691                 *pRun += run;
692             else {
693                 int flag;
694                 /* run-length is coded as plain binary number of idx - 1 bits */
695                 for (pos = idx - 1, rle = 0, flag = 0; pos >= 0; pos--) {
696                     if ((1 << pos) + rle < run &&
697                         ff_els_decode_bit(&dc->els_ctx,
698                                           flag ? &dc->runlen_one
699                                                : &dc->runlen_zeroes[pos])) {
700                         flag = 1;
701                         rle |= 1 << pos;
702                     }
703                 }
704                 *pRun += rle;
705                 break; // return immediately
706             }
707             if (x + *pRun >= tile_width - 1)
708                 break;
709 
710             LOAD_NEIGHBOURS(x + *pRun);
711             WWneW = 0;
712             NWneW = 0;
713         }
714 
715         idx = WWneW       << 7 |
716               NWneW       << 6 |
717               (N   != NE) << 5 |
718               (NW  != N)  << 4 |
719               (NWW != NW) << 3 |
720               (NNE != NE) << 2 |
721               (NN  != N)  << 1 |
722               (NNW != NW);
723         WWneW = ff_els_decode_bit(&dc->els_ctx, &dc->W_ctx_rung[idx]);
724     } while (!WWneW);
725 
726     dc->next_run_pos = x + *pRun;
727     return got_pixel;
728 }
729 
epic_predict_pixel2(ePICContext * dc,uint8_t * rung,uint32_t * pPix,uint32_t pix)730 static int epic_predict_pixel2(ePICContext *dc, uint8_t *rung,
731                                uint32_t *pPix, uint32_t pix)
732 {
733     if (ff_els_decode_bit(&dc->els_ctx, rung)) {
734         *pPix = pix;
735         return 1;
736     }
737     dc->stack[dc->stack_pos++ & EPIC_PIX_STACK_MAX] = pix;
738     return 0;
739 }
740 
epic_predict_from_NW_NE(ePICContext * dc,int x,int y,int run,int tile_width,const uint32_t * curr_row,const uint32_t * above_row,uint32_t * pPix)741 static int epic_predict_from_NW_NE(ePICContext *dc, int x, int y, int run,
742                                    int tile_width, const uint32_t *curr_row,
743                                    const uint32_t *above_row, uint32_t *pPix)
744 {
745     int pos;
746 
747     /* try to reuse the NW pixel first */
748     if (x && y) {
749         uint32_t NW = above_row[x - 1];
750         if (NW != curr_row[x - 1] && NW != above_row[x] && !is_pixel_on_stack(dc, NW)) {
751             if (epic_predict_pixel2(dc, &dc->nw_pred_rung[NW & 0xFF], pPix, NW))
752                 return 1;
753         }
754     }
755 
756     /* try to reuse the NE[x + run, y] pixel */
757     pos = x + run - 1;
758     if (pos < tile_width - 1 && y) {
759         uint32_t NE = above_row[pos + 1];
760         if (NE != above_row[pos] && !is_pixel_on_stack(dc, NE)) {
761             if (epic_predict_pixel2(dc, &dc->ne_pred_rung[NE & 0xFF], pPix, NE))
762                 return 1;
763         }
764     }
765 
766     return 0;
767 }
768 
epic_decode_from_cache(ePICContext * dc,uint32_t W,uint32_t * pPix)769 static int epic_decode_from_cache(ePICContext *dc, uint32_t W, uint32_t *pPix)
770 {
771     ePICPixListElem *list, *prev = NULL;
772     ePICPixHashElem *hash_elem = epic_hash_find(&dc->hash, W);
773 
774     if (!hash_elem || !hash_elem->list)
775         return 0;
776 
777     list = hash_elem->list;
778     while (list) {
779         if (!is_pixel_on_stack(dc, list->pixel)) {
780             if (ff_els_decode_bit(&dc->els_ctx, &list->rung)) {
781                 *pPix = list->pixel;
782                 if (list != hash_elem->list) {
783                     prev->next      = list->next;
784                     list->next      = hash_elem->list;
785                     hash_elem->list = list;
786                 }
787                 return 1;
788             }
789             dc->stack[dc->stack_pos++ & EPIC_PIX_STACK_MAX] = list->pixel;
790         }
791         prev = list;
792         list = list->next;
793     }
794 
795     return 0;
796 }
797 
epic_decode_tile(ePICContext * dc,uint8_t * out,int tile_height,int tile_width,int stride)798 static int epic_decode_tile(ePICContext *dc, uint8_t *out, int tile_height,
799                             int tile_width, int stride)
800 {
801     int x, y;
802     uint32_t pix;
803     uint32_t *curr_row = NULL, *above_row = NULL, *above2_row;
804 
805     for (y = 0; y < tile_height; y++, out += stride) {
806         above2_row = above_row;
807         above_row  = curr_row;
808         curr_row   = (uint32_t *) out;
809 
810         for (x = 0, dc->next_run_pos = 0; x < tile_width;) {
811             if (dc->els_ctx.err)
812                 return AVERROR_INVALIDDATA; // bail out in the case of ELS overflow
813 
814             pix = curr_row[x - 1]; // get W pixel
815 
816             if (y >= 1 && x >= 2 &&
817                 pix != curr_row[x - 2]  && pix != above_row[x - 1] &&
818                 pix != above_row[x - 2] && pix != above_row[x] &&
819                 !epic_cache_entries_for_pixel(&dc->hash, pix)) {
820                 curr_row[x] = epic_decode_pixel_pred(dc, x, y, curr_row, above_row);
821                 x++;
822             } else {
823                 int got_pixel, run;
824                 dc->stack_pos = 0; // empty stack
825 
826                 if (y < 2 || x < 2 || x == tile_width - 1) {
827                     run       = 1;
828                     got_pixel = epic_handle_edges(dc, x, y, curr_row, above_row, &pix);
829                 } else {
830                     got_pixel = epic_decode_run_length(dc, x, y, tile_width,
831                                                        curr_row, above_row,
832                                                        above2_row, &pix, &run);
833                     if (got_pixel < 0)
834                         return got_pixel;
835                 }
836 
837                 if (!got_pixel && !epic_predict_from_NW_NE(dc, x, y, run,
838                                                            tile_width, curr_row,
839                                                            above_row, &pix)) {
840                     uint32_t ref_pix = curr_row[x - 1];
841                     if (!x || !epic_decode_from_cache(dc, ref_pix, &pix)) {
842                         pix = epic_decode_pixel_pred(dc, x, y, curr_row, above_row);
843                         if (is_pixel_on_stack(dc, pix))
844                             return AVERROR_INVALIDDATA;
845 
846                         if (x) {
847                             int ret = epic_add_pixel_to_cache(&dc->hash,
848                                                               ref_pix,
849                                                               pix);
850                             if (ret)
851                                 return ret;
852                         }
853                     }
854                 }
855                 for (; run > 0; x++, run--)
856                     curr_row[x] = pix;
857             }
858         }
859     }
860 
861     return 0;
862 }
863 
epic_jb_decode_tile(G2MContext * c,int tile_x,int tile_y,const uint8_t * src,size_t src_size,AVCodecContext * avctx)864 static int epic_jb_decode_tile(G2MContext *c, int tile_x, int tile_y,
865                                const uint8_t *src, size_t src_size,
866                                AVCodecContext *avctx)
867 {
868     uint8_t prefix, mask = 0x80;
869     int extrabytes, tile_width, tile_height, awidth, aheight;
870     size_t els_dsize;
871     uint8_t *dst;
872 
873     if (!src_size)
874         return 0;
875 
876     /* get data size of the ELS partition as unsigned variable-length integer */
877     prefix = *src++;
878     src_size--;
879     for (extrabytes = 0; (prefix & mask) && (extrabytes < 7); extrabytes++)
880         mask >>= 1;
881     if (extrabytes > 3 || src_size < extrabytes) {
882         av_log(avctx, AV_LOG_ERROR, "ePIC: invalid data size VLI\n");
883         return AVERROR_INVALIDDATA;
884     }
885 
886     els_dsize = prefix & ((0x80 >> extrabytes) - 1); // mask out the length prefix
887     while (extrabytes-- > 0) {
888         els_dsize = (els_dsize << 8) | *src++;
889         src_size--;
890     }
891 
892     if (src_size < els_dsize) {
893         av_log(avctx, AV_LOG_ERROR, "ePIC: data too short, needed %"SIZE_SPECIFIER", got %"SIZE_SPECIFIER"\n",
894                els_dsize, src_size);
895         return AVERROR_INVALIDDATA;
896     }
897 
898     tile_width  = FFMIN(c->width  - tile_x * c->tile_width,  c->tile_width);
899     tile_height = FFMIN(c->height - tile_y * c->tile_height, c->tile_height);
900     awidth      = FFALIGN(tile_width,  16);
901     aheight     = FFALIGN(tile_height, 16);
902 
903     if (tile_width > (1 << FF_ARRAY_ELEMS(c->ec.prev_row_rung))) {
904         avpriv_request_sample(avctx, "large tile width");
905         return AVERROR_INVALIDDATA;
906     }
907 
908     if (els_dsize) {
909         int ret, i, j, k;
910         uint8_t tr_r, tr_g, tr_b, *buf;
911         uint32_t *in;
912         /* ELS decoder initializations */
913         memset(&c->ec, 0, sizeof(c->ec));
914         ff_els_decoder_init(&c->ec.els_ctx, src, els_dsize);
915         epic_hash_init(&c->ec.hash);
916 
917         /* decode transparent pixel value */
918         tr_r = ff_els_decode_unsigned(&c->ec.els_ctx, &c->ec.unsigned_rung);
919         tr_g = ff_els_decode_unsigned(&c->ec.els_ctx, &c->ec.unsigned_rung);
920         tr_b = ff_els_decode_unsigned(&c->ec.els_ctx, &c->ec.unsigned_rung);
921         if (c->ec.els_ctx.err != 0) {
922             av_log(avctx, AV_LOG_ERROR,
923                    "ePIC: couldn't decode transparency pixel!\n");
924             ff_els_decoder_uninit(&c->ec.unsigned_rung);
925             return AVERROR_INVALIDDATA;
926         }
927 
928         ret = epic_decode_tile(&c->ec, c->epic_buf, tile_height, tile_width,
929                                c->epic_buf_stride);
930 
931         epic_free_pixel_cache(&c->ec.hash);
932         ff_els_decoder_uninit(&c->ec.unsigned_rung);
933 
934         if (ret) {
935             av_log(avctx, AV_LOG_ERROR,
936                    "ePIC: tile decoding failed, frame=%d, tile_x=%d, tile_y=%d\n",
937                    avctx->frame_number, tile_x, tile_y);
938             return AVERROR_INVALIDDATA;
939         }
940 
941         buf = c->epic_buf;
942         dst = c->framebuf + tile_x * c->tile_width * 3 +
943               tile_y * c->tile_height * c->framebuf_stride;
944 
945         for (j = 0; j < tile_height; j++) {
946             uint8_t *out = dst;
947             in  = (uint32_t *) buf;
948             for (i = 0; i < tile_width; i++) {
949                 out[0] = (in[i] >> R_shift) & 0xFF;
950                 out[1] = (in[i] >> G_shift) & 0xFF;
951                 out[2] = (in[i] >> B_shift) & 0xFF;
952                 out   += 3;
953             }
954             buf += c->epic_buf_stride;
955             dst += c->framebuf_stride;
956         }
957 
958         if (src_size > els_dsize) {
959             uint8_t *jpg;
960             uint32_t tr;
961             int bstride = FFALIGN(tile_width, 16) >> 3;
962             int nblocks = 0;
963             int estride = c->epic_buf_stride >> 2;
964 
965             src      += els_dsize;
966             src_size -= els_dsize;
967 
968             in = (uint32_t *) c->epic_buf;
969             tr = (tr_r << R_shift) | (tr_g << G_shift) | (tr_b << B_shift);
970 
971             memset(c->kempf_flags, 0,
972                    (aheight >> 3) * bstride * sizeof(*c->kempf_flags));
973             for (j = 0; j < tile_height; j += 8) {
974                 for (i = 0; i < tile_width; i += 8) {
975                     c->kempf_flags[(i >> 3) + (j >> 3) * bstride] = 0;
976                     for (k = 0; k < 8 * 8; k++) {
977                         if (in[i + (k & 7) + (k >> 3) * estride] == tr) {
978                             c->kempf_flags[(i >> 3) + (j >> 3) * bstride] = 1;
979                             nblocks++;
980                             break;
981                         }
982                     }
983                 }
984                 in += 8 * estride;
985             }
986 
987             memset(c->jpeg_tile, 0, c->tile_stride * aheight);
988             jpg_decode_data(&c->jc, awidth, aheight, src, src_size,
989                             c->jpeg_tile, c->tile_stride,
990                             c->kempf_flags, bstride, nblocks, c->swapuv);
991 
992             in  = (uint32_t *) c->epic_buf;
993             dst = c->framebuf + tile_x * c->tile_width * 3 +
994                   tile_y * c->tile_height * c->framebuf_stride;
995             jpg = c->jpeg_tile;
996             for (j = 0; j < tile_height; j++) {
997                 for (i = 0; i < tile_width; i++)
998                     if (in[i] == tr)
999                         memcpy(dst + i * 3, jpg + i * 3, 3);
1000                 in  += c->epic_buf_stride >> 2;
1001                 dst += c->framebuf_stride;
1002                 jpg += c->tile_stride;
1003             }
1004         }
1005     } else {
1006         dst = c->framebuf + tile_x * c->tile_width * 3 +
1007               tile_y * c->tile_height * c->framebuf_stride;
1008         return jpg_decode_data(&c->jc, tile_width, tile_height, src, src_size,
1009                                dst, c->framebuf_stride, NULL, 0, 0, c->swapuv);
1010     }
1011 
1012     return 0;
1013 }
1014 
kempf_restore_buf(const uint8_t * src,int len,uint8_t * dst,int stride,const uint8_t * jpeg_tile,int tile_stride,int width,int height,const uint8_t * pal,int npal,int tidx)1015 static int kempf_restore_buf(const uint8_t *src, int len,
1016                               uint8_t *dst, int stride,
1017                               const uint8_t *jpeg_tile, int tile_stride,
1018                               int width, int height,
1019                               const uint8_t *pal, int npal, int tidx)
1020 {
1021     GetBitContext gb;
1022     int i, j, nb, col;
1023     int ret;
1024     int align_width = FFALIGN(width, 16);
1025 
1026     if ((ret = init_get_bits8(&gb, src, len)) < 0)
1027         return ret;
1028 
1029     if (npal <= 2)       nb = 1;
1030     else if (npal <= 4)  nb = 2;
1031     else if (npal <= 16) nb = 4;
1032     else                 nb = 8;
1033 
1034     for (j = 0; j < height; j++, dst += stride, jpeg_tile = FF_PTR_ADD(jpeg_tile, tile_stride)) {
1035         if (get_bits(&gb, 8))
1036             continue;
1037         for (i = 0; i < width; i++) {
1038             col = get_bits(&gb, nb);
1039             if (col != tidx)
1040                 memcpy(dst + i * 3, pal + col * 3, 3);
1041             else
1042                 memcpy(dst + i * 3, jpeg_tile + i * 3, 3);
1043         }
1044         skip_bits_long(&gb, nb * (align_width - width));
1045     }
1046 
1047     return 0;
1048 }
1049 
kempf_decode_tile(G2MContext * c,int tile_x,int tile_y,const uint8_t * src,int src_size)1050 static int kempf_decode_tile(G2MContext *c, int tile_x, int tile_y,
1051                              const uint8_t *src, int src_size)
1052 {
1053     int width, height;
1054     int hdr, zsize, npal, tidx = -1, ret;
1055     int i, j;
1056     const uint8_t *src_end = src + src_size;
1057     uint8_t pal[768], transp[3];
1058     uLongf dlen = (c->tile_width + 1) * c->tile_height;
1059     int sub_type;
1060     int nblocks, cblocks, bstride;
1061     int bits, bitbuf, coded;
1062     uint8_t *dst = c->framebuf + tile_x * c->tile_width * 3 +
1063                    tile_y * c->tile_height * c->framebuf_stride;
1064 
1065     if (src_size < 2)
1066         return AVERROR_INVALIDDATA;
1067 
1068     width  = FFMIN(c->width  - tile_x * c->tile_width,  c->tile_width);
1069     height = FFMIN(c->height - tile_y * c->tile_height, c->tile_height);
1070 
1071     hdr      = *src++;
1072     sub_type = hdr >> 5;
1073     if (sub_type == 0) {
1074         int j;
1075         memcpy(transp, src, 3);
1076         src += 3;
1077         for (j = 0; j < height; j++, dst += c->framebuf_stride)
1078             for (i = 0; i < width; i++)
1079                 memcpy(dst + i * 3, transp, 3);
1080         return 0;
1081     } else if (sub_type == 1) {
1082         return jpg_decode_data(&c->jc, width, height, src, src_end - src,
1083                                dst, c->framebuf_stride, NULL, 0, 0, 0);
1084     }
1085 
1086     if (sub_type != 2) {
1087         memcpy(transp, src, 3);
1088         src += 3;
1089     }
1090     npal = *src++ + 1;
1091     if (src_end - src < npal * 3)
1092         return AVERROR_INVALIDDATA;
1093     memcpy(pal, src, npal * 3);
1094     src += npal * 3;
1095     if (sub_type != 2) {
1096         for (i = 0; i < npal; i++) {
1097             if (!memcmp(pal + i * 3, transp, 3)) {
1098                 tidx = i;
1099                 break;
1100             }
1101         }
1102     }
1103 
1104     if (src_end - src < 2)
1105         return 0;
1106     zsize = (src[0] << 8) | src[1];
1107     src  += 2;
1108 
1109     if (src_end - src < zsize + (sub_type != 2))
1110         return AVERROR_INVALIDDATA;
1111 
1112     ret = uncompress(c->kempf_buf, &dlen, src, zsize);
1113     if (ret)
1114         return AVERROR_INVALIDDATA;
1115     src += zsize;
1116 
1117     if (sub_type == 2) {
1118         kempf_restore_buf(c->kempf_buf, dlen, dst, c->framebuf_stride,
1119                           NULL, 0, width, height, pal, npal, tidx);
1120         return 0;
1121     }
1122 
1123     nblocks = *src++ + 1;
1124     cblocks = 0;
1125     bstride = FFALIGN(width, 16) >> 3;
1126     // blocks are coded LSB and we need normal bitreader for JPEG data
1127     bits = 0;
1128     for (i = 0; i < (FFALIGN(height, 16) >> 4); i++) {
1129         for (j = 0; j < (FFALIGN(width, 16) >> 4); j++) {
1130             if (!bits) {
1131                 if (src >= src_end)
1132                     return AVERROR_INVALIDDATA;
1133                 bitbuf = *src++;
1134                 bits   = 8;
1135             }
1136             coded = bitbuf & 1;
1137             bits--;
1138             bitbuf >>= 1;
1139             cblocks += coded;
1140             if (cblocks > nblocks)
1141                 return AVERROR_INVALIDDATA;
1142             c->kempf_flags[j * 2 +      i * 2      * bstride] =
1143             c->kempf_flags[j * 2 + 1 +  i * 2      * bstride] =
1144             c->kempf_flags[j * 2 +     (i * 2 + 1) * bstride] =
1145             c->kempf_flags[j * 2 + 1 + (i * 2 + 1) * bstride] = coded;
1146         }
1147     }
1148 
1149     memset(c->jpeg_tile, 0, c->tile_stride * height);
1150     jpg_decode_data(&c->jc, width, height, src, src_end - src,
1151                     c->jpeg_tile, c->tile_stride,
1152                     c->kempf_flags, bstride, nblocks * 4, 0);
1153 
1154     kempf_restore_buf(c->kempf_buf, dlen, dst, c->framebuf_stride,
1155                       c->jpeg_tile, c->tile_stride,
1156                       width, height, pal, npal, tidx);
1157 
1158     return 0;
1159 }
1160 
g2m_init_buffers(G2MContext * c)1161 static int g2m_init_buffers(G2MContext *c)
1162 {
1163     int aligned_height;
1164 
1165     c->framebuf_stride = FFALIGN(c->width + 15, 16) * 3;
1166     aligned_height = c->height + 15;
1167 
1168     av_fast_mallocz(&c->framebuf, &c->framebuf_allocated, c->framebuf_stride * aligned_height);
1169     if (!c->framebuf)
1170         return AVERROR(ENOMEM);
1171 
1172     if (!c->synth_tile || !c->jpeg_tile ||
1173         (c->compression == 2 && !c->epic_buf_base) ||
1174         c->old_tile_w < c->tile_width ||
1175         c->old_tile_h < c->tile_height) {
1176         c->tile_stride     = FFALIGN(c->tile_width, 16) * 3;
1177         c->epic_buf_stride = FFALIGN(c->tile_width * 4, 16);
1178         aligned_height     = FFALIGN(c->tile_height,    16);
1179         av_freep(&c->synth_tile);
1180         av_freep(&c->jpeg_tile);
1181         av_freep(&c->kempf_buf);
1182         av_freep(&c->kempf_flags);
1183         av_freep(&c->epic_buf_base);
1184         c->epic_buf    = NULL;
1185         c->synth_tile  = av_mallocz(c->tile_stride      * aligned_height);
1186         c->jpeg_tile   = av_mallocz(c->tile_stride      * aligned_height);
1187         c->kempf_buf   = av_mallocz((c->tile_width + 1) * aligned_height +
1188                                     AV_INPUT_BUFFER_PADDING_SIZE);
1189         c->kempf_flags = av_mallocz(c->tile_width       * aligned_height);
1190         if (!c->synth_tile || !c->jpeg_tile ||
1191             !c->kempf_buf || !c->kempf_flags)
1192             return AVERROR(ENOMEM);
1193         if (c->compression == 2) {
1194             c->epic_buf_base = av_mallocz(c->epic_buf_stride * aligned_height + 4);
1195             if (!c->epic_buf_base)
1196                 return AVERROR(ENOMEM);
1197             c->epic_buf = c->epic_buf_base + 4;
1198         }
1199     }
1200 
1201     return 0;
1202 }
1203 
g2m_load_cursor(AVCodecContext * avctx,G2MContext * c,GetByteContext * gb)1204 static int g2m_load_cursor(AVCodecContext *avctx, G2MContext *c,
1205                            GetByteContext *gb)
1206 {
1207     int i, j, k;
1208     uint8_t *dst;
1209     uint32_t bits;
1210     uint32_t cur_size, cursor_w, cursor_h, cursor_stride;
1211     uint32_t cursor_hot_x, cursor_hot_y;
1212     int cursor_fmt, err;
1213 
1214     cur_size     = bytestream2_get_be32(gb);
1215     cursor_w     = bytestream2_get_byte(gb);
1216     cursor_h     = bytestream2_get_byte(gb);
1217     cursor_hot_x = bytestream2_get_byte(gb);
1218     cursor_hot_y = bytestream2_get_byte(gb);
1219     cursor_fmt   = bytestream2_get_byte(gb);
1220 
1221     cursor_stride = FFALIGN(cursor_w, cursor_fmt==1 ? 32 : 1) * 4;
1222 
1223     if (cursor_w < 1 || cursor_w > 256 ||
1224         cursor_h < 1 || cursor_h > 256) {
1225         av_log(avctx, AV_LOG_ERROR, "Invalid cursor dimensions %"PRIu32"x%"PRIu32"\n",
1226                cursor_w, cursor_h);
1227         return AVERROR_INVALIDDATA;
1228     }
1229     if (cursor_hot_x > cursor_w || cursor_hot_y > cursor_h) {
1230         av_log(avctx, AV_LOG_WARNING, "Invalid hotspot position %"PRIu32",%"PRIu32"\n",
1231                cursor_hot_x, cursor_hot_y);
1232         cursor_hot_x = FFMIN(cursor_hot_x, cursor_w - 1);
1233         cursor_hot_y = FFMIN(cursor_hot_y, cursor_h - 1);
1234     }
1235     if (cur_size - 9 > bytestream2_get_bytes_left(gb) ||
1236         c->cursor_w * c->cursor_h / 4 > cur_size) {
1237         av_log(avctx, AV_LOG_ERROR, "Invalid cursor data size %"PRIu32"/%u\n",
1238                cur_size, bytestream2_get_bytes_left(gb));
1239         return AVERROR_INVALIDDATA;
1240     }
1241     if (cursor_fmt != 1 && cursor_fmt != 32) {
1242         avpriv_report_missing_feature(avctx, "Cursor format %d",
1243                                       cursor_fmt);
1244         return AVERROR_PATCHWELCOME;
1245     }
1246 
1247     if ((err = av_reallocp(&c->cursor, cursor_stride * cursor_h)) < 0) {
1248         av_log(avctx, AV_LOG_ERROR, "Cannot allocate cursor buffer\n");
1249         return err;
1250     }
1251 
1252     c->cursor_w      = cursor_w;
1253     c->cursor_h      = cursor_h;
1254     c->cursor_hot_x  = cursor_hot_x;
1255     c->cursor_hot_y  = cursor_hot_y;
1256     c->cursor_fmt    = cursor_fmt;
1257     c->cursor_stride = cursor_stride;
1258 
1259     dst = c->cursor;
1260     switch (c->cursor_fmt) {
1261     case 1: // old monochrome
1262         for (j = 0; j < c->cursor_h; j++) {
1263             for (i = 0; i < c->cursor_w; i += 32) {
1264                 bits = bytestream2_get_be32(gb);
1265                 for (k = 0; k < 32; k++) {
1266                     dst[0] = !!(bits & 0x80000000);
1267                     dst   += 4;
1268                     bits <<= 1;
1269                 }
1270             }
1271         }
1272 
1273         dst = c->cursor;
1274         for (j = 0; j < c->cursor_h; j++) {
1275             for (i = 0; i < c->cursor_w; i += 32) {
1276                 bits = bytestream2_get_be32(gb);
1277                 for (k = 0; k < 32; k++) {
1278                     int mask_bit = !!(bits & 0x80000000);
1279                     switch (dst[0] * 2 + mask_bit) {
1280                     case 0:
1281                         dst[0] = 0xFF;
1282                         dst[1] = 0x00;
1283                         dst[2] = 0x00;
1284                         dst[3] = 0x00;
1285                         break;
1286                     case 1:
1287                         dst[0] = 0xFF;
1288                         dst[1] = 0xFF;
1289                         dst[2] = 0xFF;
1290                         dst[3] = 0xFF;
1291                         break;
1292                     default:
1293                         dst[0] = 0x00;
1294                         dst[1] = 0x00;
1295                         dst[2] = 0x00;
1296                         dst[3] = 0x00;
1297                     }
1298                     dst   += 4;
1299                     bits <<= 1;
1300                 }
1301             }
1302         }
1303         break;
1304     case 32: // full colour
1305         /* skip monochrome version of the cursor and decode RGBA instead */
1306         bytestream2_skip(gb, c->cursor_h * (FFALIGN(c->cursor_w, 32) >> 3));
1307         for (j = 0; j < c->cursor_h; j++) {
1308             for (i = 0; i < c->cursor_w; i++) {
1309                 int val = bytestream2_get_be32(gb);
1310                 *dst++ = val >>  0;
1311                 *dst++ = val >>  8;
1312                 *dst++ = val >> 16;
1313                 *dst++ = val >> 24;
1314             }
1315         }
1316         break;
1317     default:
1318         return AVERROR_PATCHWELCOME;
1319     }
1320     return 0;
1321 }
1322 
1323 #define APPLY_ALPHA(src, new, alpha) \
1324     src = (src * (256 - alpha) + new * alpha) >> 8
1325 
g2m_paint_cursor(G2MContext * c,uint8_t * dst,int stride)1326 static void g2m_paint_cursor(G2MContext *c, uint8_t *dst, int stride)
1327 {
1328     int i, j;
1329     int x, y, w, h;
1330     const uint8_t *cursor;
1331 
1332     if (!c->cursor)
1333         return;
1334 
1335     x = c->cursor_x - c->cursor_hot_x;
1336     y = c->cursor_y - c->cursor_hot_y;
1337 
1338     cursor = c->cursor;
1339     w      = c->cursor_w;
1340     h      = c->cursor_h;
1341 
1342     if (x + w > c->width)
1343         w = c->width - x;
1344     if (y + h > c->height)
1345         h = c->height - y;
1346     if (x < 0) {
1347         w      +=  x;
1348         cursor += -x * 4;
1349     } else {
1350         dst    +=  x * 3;
1351     }
1352 
1353     if (y < 0)
1354         h      +=  y;
1355     if (w < 0 || h < 0)
1356         return;
1357     if (y < 0) {
1358         cursor += -y * c->cursor_stride;
1359     } else {
1360         dst    +=  y * stride;
1361     }
1362 
1363     for (j = 0; j < h; j++) {
1364         for (i = 0; i < w; i++) {
1365             uint8_t alpha = cursor[i * 4];
1366             APPLY_ALPHA(dst[i * 3 + 0], cursor[i * 4 + 1], alpha);
1367             APPLY_ALPHA(dst[i * 3 + 1], cursor[i * 4 + 2], alpha);
1368             APPLY_ALPHA(dst[i * 3 + 2], cursor[i * 4 + 3], alpha);
1369         }
1370         dst    += stride;
1371         cursor += c->cursor_stride;
1372     }
1373 }
1374 
g2m_decode_frame(AVCodecContext * avctx,AVFrame * pic,int * got_picture_ptr,AVPacket * avpkt)1375 static int g2m_decode_frame(AVCodecContext *avctx, AVFrame *pic,
1376                             int *got_picture_ptr, AVPacket *avpkt)
1377 {
1378     const uint8_t *buf = avpkt->data;
1379     int buf_size = avpkt->size;
1380     G2MContext *c = avctx->priv_data;
1381     GetByteContext bc, tbc;
1382     int magic;
1383     int got_header = 0;
1384     uint32_t chunk_size, r_mask, g_mask, b_mask;
1385     int chunk_type, chunk_start;
1386     int i;
1387     int ret;
1388 
1389     if (buf_size < 12) {
1390         av_log(avctx, AV_LOG_ERROR,
1391                "Frame should have at least 12 bytes, got %d instead\n",
1392                buf_size);
1393         return AVERROR_INVALIDDATA;
1394     }
1395 
1396     bytestream2_init(&bc, buf, buf_size);
1397 
1398     magic = bytestream2_get_be32(&bc);
1399     if ((magic & ~0xF) != MKBETAG('G', '2', 'M', '0') ||
1400         (magic & 0xF) < 2 || (magic & 0xF) > 5) {
1401         av_log(avctx, AV_LOG_ERROR, "Wrong magic %08X\n", magic);
1402         return AVERROR_INVALIDDATA;
1403     }
1404 
1405     c->swapuv = magic == MKBETAG('G', '2', 'M', '2');
1406 
1407     while (bytestream2_get_bytes_left(&bc) > 5) {
1408         chunk_size  = bytestream2_get_le32(&bc) - 1;
1409         chunk_type  = bytestream2_get_byte(&bc);
1410         chunk_start = bytestream2_tell(&bc);
1411         if (chunk_size > bytestream2_get_bytes_left(&bc)) {
1412             av_log(avctx, AV_LOG_ERROR, "Invalid chunk size %"PRIu32" type %02X\n",
1413                    chunk_size, chunk_type);
1414             break;
1415         }
1416         switch (chunk_type) {
1417         case DISPLAY_INFO:
1418             got_header =
1419             c->got_header = 0;
1420             if (chunk_size < 21) {
1421                 av_log(avctx, AV_LOG_ERROR, "Invalid display info size %"PRIu32"\n",
1422                        chunk_size);
1423                 break;
1424             }
1425             c->width  = bytestream2_get_be32(&bc);
1426             c->height = bytestream2_get_be32(&bc);
1427             if (c->width < 16 || c->height < 16) {
1428                 av_log(avctx, AV_LOG_ERROR,
1429                        "Invalid frame dimensions %dx%d\n",
1430                        c->width, c->height);
1431                 ret = AVERROR_INVALIDDATA;
1432                 goto header_fail;
1433             }
1434             if (c->width != avctx->width || c->height != avctx->height) {
1435                 ret = ff_set_dimensions(avctx, c->width, c->height);
1436                 if (ret < 0)
1437                     goto header_fail;
1438             }
1439             c->compression = bytestream2_get_be32(&bc);
1440             if (c->compression != 2 && c->compression != 3) {
1441                 avpriv_report_missing_feature(avctx, "Compression method %d",
1442                                               c->compression);
1443                 ret = AVERROR_PATCHWELCOME;
1444                 goto header_fail;
1445             }
1446             c->tile_width  = bytestream2_get_be32(&bc);
1447             c->tile_height = bytestream2_get_be32(&bc);
1448             if (c->tile_width <= 0 || c->tile_height <= 0 ||
1449                 ((c->tile_width | c->tile_height) & 0xF) ||
1450                 c->tile_width * (uint64_t)c->tile_height >= INT_MAX / 4 ||
1451                 av_image_check_size2(c->tile_width, c->tile_height, avctx->max_pixels, avctx->pix_fmt, 0, avctx) < 0
1452             ) {
1453                 av_log(avctx, AV_LOG_ERROR,
1454                        "Invalid tile dimensions %dx%d\n",
1455                        c->tile_width, c->tile_height);
1456                 ret = AVERROR_INVALIDDATA;
1457                 goto header_fail;
1458             }
1459             c->tiles_x = (c->width  + c->tile_width  - 1) / c->tile_width;
1460             c->tiles_y = (c->height + c->tile_height - 1) / c->tile_height;
1461             c->bpp     = bytestream2_get_byte(&bc);
1462             if (c->bpp == 32) {
1463                 if (bytestream2_get_bytes_left(&bc) < 16 ||
1464                     (chunk_size - 21) < 16) {
1465                     av_log(avctx, AV_LOG_ERROR,
1466                            "Display info: missing bitmasks!\n");
1467                     ret = AVERROR_INVALIDDATA;
1468                     goto header_fail;
1469                 }
1470                 r_mask = bytestream2_get_be32(&bc);
1471                 g_mask = bytestream2_get_be32(&bc);
1472                 b_mask = bytestream2_get_be32(&bc);
1473                 if (r_mask != 0xFF0000 || g_mask != 0xFF00 || b_mask != 0xFF) {
1474                     avpriv_report_missing_feature(avctx,
1475                                                   "Bitmasks: R=%"PRIX32", G=%"PRIX32", B=%"PRIX32,
1476                                                   r_mask, g_mask, b_mask);
1477                     ret = AVERROR_PATCHWELCOME;
1478                     goto header_fail;
1479                 }
1480             } else {
1481                 avpriv_request_sample(avctx, "bpp=%d", c->bpp);
1482                 ret = AVERROR_PATCHWELCOME;
1483                 goto header_fail;
1484             }
1485             if (g2m_init_buffers(c)) {
1486                 ret = AVERROR(ENOMEM);
1487                 goto header_fail;
1488             }
1489             got_header = 1;
1490             break;
1491         case TILE_DATA:
1492             if (!c->tiles_x || !c->tiles_y) {
1493                 av_log(avctx, AV_LOG_WARNING,
1494                        "No display info - skipping tile\n");
1495                 break;
1496             }
1497             if (chunk_size < 2) {
1498                 av_log(avctx, AV_LOG_ERROR, "Invalid tile data size %"PRIu32"\n",
1499                        chunk_size);
1500                 break;
1501             }
1502             c->tile_x = bytestream2_get_byte(&bc);
1503             c->tile_y = bytestream2_get_byte(&bc);
1504             if (c->tile_x >= c->tiles_x || c->tile_y >= c->tiles_y) {
1505                 av_log(avctx, AV_LOG_ERROR,
1506                        "Invalid tile pos %d,%d (in %dx%d grid)\n",
1507                        c->tile_x, c->tile_y, c->tiles_x, c->tiles_y);
1508                 break;
1509             }
1510             ret = 0;
1511             switch (c->compression) {
1512             case COMPR_EPIC_J_B:
1513                 ret = epic_jb_decode_tile(c, c->tile_x, c->tile_y,
1514                                           buf + bytestream2_tell(&bc),
1515                                           chunk_size - 2, avctx);
1516                 break;
1517             case COMPR_KEMPF_J_B:
1518                 ret = kempf_decode_tile(c, c->tile_x, c->tile_y,
1519                                         buf + bytestream2_tell(&bc),
1520                                         chunk_size - 2);
1521                 break;
1522             }
1523             if (ret && c->framebuf)
1524                 av_log(avctx, AV_LOG_ERROR, "Error decoding tile %d,%d\n",
1525                        c->tile_x, c->tile_y);
1526             break;
1527         case CURSOR_POS:
1528             if (chunk_size < 5) {
1529                 av_log(avctx, AV_LOG_ERROR, "Invalid cursor pos size %"PRIu32"\n",
1530                        chunk_size);
1531                 break;
1532             }
1533             c->cursor_x = bytestream2_get_be16(&bc);
1534             c->cursor_y = bytestream2_get_be16(&bc);
1535             break;
1536         case CURSOR_SHAPE:
1537             if (chunk_size < 8) {
1538                 av_log(avctx, AV_LOG_ERROR, "Invalid cursor data size %"PRIu32"\n",
1539                        chunk_size);
1540                 break;
1541             }
1542             bytestream2_init(&tbc, buf + bytestream2_tell(&bc),
1543                              chunk_size - 4);
1544             g2m_load_cursor(avctx, c, &tbc);
1545             break;
1546         case CHUNK_CC:
1547         case CHUNK_CD:
1548             break;
1549         default:
1550             av_log(avctx, AV_LOG_WARNING, "Skipping chunk type %02d\n",
1551                    chunk_type);
1552         }
1553 
1554         /* navigate to next chunk */
1555         bytestream2_skip(&bc, chunk_start + chunk_size - bytestream2_tell(&bc));
1556     }
1557     if (got_header)
1558         c->got_header = 1;
1559 
1560     if (c->width && c->height && c->framebuf) {
1561         if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
1562             return ret;
1563 
1564         pic->key_frame = got_header;
1565         pic->pict_type = got_header ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
1566 
1567         for (i = 0; i < avctx->height; i++)
1568             memcpy(pic->data[0] + i * pic->linesize[0],
1569                    c->framebuf + i * c->framebuf_stride,
1570                    c->width * 3);
1571         g2m_paint_cursor(c, pic->data[0], pic->linesize[0]);
1572 
1573         *got_picture_ptr = 1;
1574     }
1575 
1576     return buf_size;
1577 
1578 header_fail:
1579     c->width   =
1580     c->height  = 0;
1581     c->tiles_x =
1582     c->tiles_y = 0;
1583     c->tile_width =
1584     c->tile_height = 0;
1585     return ret;
1586 }
1587 
g2m_decode_init(AVCodecContext * avctx)1588 static av_cold int g2m_decode_init(AVCodecContext *avctx)
1589 {
1590     G2MContext *const c = avctx->priv_data;
1591     int ret;
1592 
1593     if ((ret = jpg_init(avctx, &c->jc)) != 0) {
1594         av_log(avctx, AV_LOG_ERROR, "Cannot initialise VLCs\n");
1595         return AVERROR(ENOMEM);
1596     }
1597 
1598     avctx->pix_fmt = AV_PIX_FMT_RGB24;
1599 
1600     // store original sizes and check against those if resize happens
1601     c->orig_width  = avctx->width;
1602     c->orig_height = avctx->height;
1603 
1604     return 0;
1605 }
1606 
g2m_decode_end(AVCodecContext * avctx)1607 static av_cold int g2m_decode_end(AVCodecContext *avctx)
1608 {
1609     G2MContext *const c = avctx->priv_data;
1610 
1611     jpg_free_context(&c->jc);
1612 
1613     av_freep(&c->epic_buf_base);
1614     c->epic_buf = NULL;
1615     av_freep(&c->kempf_buf);
1616     av_freep(&c->kempf_flags);
1617     av_freep(&c->synth_tile);
1618     av_freep(&c->jpeg_tile);
1619     av_freep(&c->cursor);
1620     av_freep(&c->framebuf);
1621     c->framebuf_allocated = 0;
1622 
1623     return 0;
1624 }
1625 
1626 const FFCodec ff_g2m_decoder = {
1627     .p.name         = "g2m",
1628     .p.long_name    = NULL_IF_CONFIG_SMALL("Go2Meeting"),
1629     .p.type         = AVMEDIA_TYPE_VIDEO,
1630     .p.id           = AV_CODEC_ID_G2M,
1631     .priv_data_size = sizeof(G2MContext),
1632     .init           = g2m_decode_init,
1633     .close          = g2m_decode_end,
1634     FF_CODEC_DECODE_CB(g2m_decode_frame),
1635     .p.capabilities = AV_CODEC_CAP_DR1,
1636     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
1637 };
1638