1/*
2 * VMware Screen Codec (VMnc) decoder
3 * Copyright (c) 2006 Konstantin Shishkov
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * VMware Screen Codec (VMnc) decoder
25 * As Alex Beregszaszi discovered, this is effectively RFB data dump
26 */
27
28#include <stdio.h>
29#include <stdlib.h>
30
31#include "libavutil/common.h"
32#include "libavutil/intreadwrite.h"
33#include "avcodec.h"
34#include "internal.h"
35#include "bytestream.h"
36
37enum EncTypes {
38    MAGIC_WMVd = 0x574D5664,
39    MAGIC_WMVe,
40    MAGIC_WMVf,
41    MAGIC_WMVg,
42    MAGIC_WMVh,
43    MAGIC_WMVi,
44    MAGIC_WMVj
45};
46
47enum HexTile_Flags {
48    HT_RAW =  1, // tile is raw
49    HT_BKG =  2, // background color is present
50    HT_FG  =  4, // foreground color is present
51    HT_SUB =  8, // subrects are present
52    HT_CLR = 16  // each subrect has own color
53};
54
55/*
56 * Decoder context
57 */
58typedef struct VmncContext {
59    AVCodecContext *avctx;
60    AVFrame *pic;
61
62    int bpp;
63    int bpp2;
64    int bigendian;
65    uint8_t pal[768];
66    int width, height;
67    GetByteContext gb;
68
69    /* cursor data */
70    int cur_w, cur_h;
71    int cur_x, cur_y;
72    int cur_hx, cur_hy;
73    uint8_t *curbits, *curmask;
74    uint8_t *screendta;
75} VmncContext;
76
77/* read pixel value from stream */
78static av_always_inline int vmnc_get_pixel(GetByteContext *gb, int bpp, int be)
79{
80    switch (bpp * 2 + be) {
81    case 2:
82    case 3:
83        return bytestream2_get_byte(gb);
84    case 4:
85        return bytestream2_get_le16(gb);
86    case 5:
87        return bytestream2_get_be16(gb);
88    case 8:
89        return bytestream2_get_le32(gb);
90    case 9:
91        return bytestream2_get_be32(gb);
92    default: return 0;
93    }
94}
95
96static void load_cursor(VmncContext *c)
97{
98    int i, j, p;
99    const int bpp   = c->bpp2;
100    uint8_t *dst8   =             c->curbits;
101    uint16_t *dst16 = (uint16_t *)c->curbits;
102    uint32_t *dst32 = (uint32_t *)c->curbits;
103
104    for (j = 0; j < c->cur_h; j++) {
105        for (i = 0; i < c->cur_w; i++) {
106            p = vmnc_get_pixel(&c->gb, bpp, c->bigendian);
107            if (bpp == 1)
108                *dst8++ = p;
109            if (bpp == 2)
110                *dst16++ = p;
111            if (bpp == 4)
112                *dst32++ = p;
113        }
114    }
115    dst8  =            c->curmask;
116    dst16 = (uint16_t*)c->curmask;
117    dst32 = (uint32_t*)c->curmask;
118    for (j = 0; j < c->cur_h; j++) {
119        for (i = 0; i < c->cur_w; i++) {
120            p = vmnc_get_pixel(&c->gb, bpp, c->bigendian);
121            if (bpp == 1)
122                *dst8++ = p;
123            if (bpp == 2)
124                *dst16++ = p;
125            if (bpp == 4)
126                *dst32++ = p;
127        }
128    }
129}
130
131static void put_cursor(uint8_t *dst, int stride, VmncContext *c, int dx, int dy)
132{
133    int i, j;
134    int w, h, x, y;
135    w = c->cur_w;
136    if (c->width < c->cur_x + c->cur_w)
137        w = c->width - c->cur_x;
138    h = c->cur_h;
139    if (c->height < c->cur_y + c->cur_h)
140        h = c->height - c->cur_y;
141    x = c->cur_x;
142    y = c->cur_y;
143    if (x < 0) {
144        w += x;
145        x  = 0;
146    }
147    if (y < 0) {
148        h += y;
149        y  = 0;
150    }
151
152    if ((w < 1) || (h < 1))
153        return;
154    dst += x * c->bpp2 + y * stride;
155
156    if (c->bpp2 == 1) {
157        uint8_t *cd = c->curbits, *msk = c->curmask;
158        for (j = 0; j < h; j++) {
159            for (i = 0; i < w; i++)
160                dst[i] = (dst[i] & cd[i]) ^ msk[i];
161            msk += c->cur_w;
162            cd  += c->cur_w;
163            dst += stride;
164        }
165    } else if (c->bpp2 == 2) {
166        uint16_t *cd = (uint16_t*)c->curbits, *msk = (uint16_t*)c->curmask;
167        uint16_t *dst2;
168        for (j = 0; j < h; j++) {
169            dst2 = (uint16_t*)dst;
170            for (i = 0; i < w; i++)
171                dst2[i] = (dst2[i] & cd[i]) ^ msk[i];
172            msk += c->cur_w;
173            cd  += c->cur_w;
174            dst += stride;
175        }
176    } else if (c->bpp2 == 4) {
177        uint32_t *cd = (uint32_t*)c->curbits, *msk = (uint32_t*)c->curmask;
178        uint32_t *dst2;
179        for (j = 0; j < h; j++) {
180            dst2 = (uint32_t*)dst;
181            for (i = 0; i < w; i++)
182                dst2[i] = (dst2[i] & cd[i]) ^ msk[i];
183            msk += c->cur_w;
184            cd  += c->cur_w;
185            dst += stride;
186        }
187    }
188}
189
190/* fill rectangle with given color */
191static av_always_inline void paint_rect(uint8_t *dst, int dx, int dy,
192                                        int w, int h, int color,
193                                        int bpp, int stride)
194{
195    int i, j;
196    dst += dx * bpp + dy * stride;
197    if (bpp == 1) {
198        for (j = 0; j < h; j++) {
199            memset(dst, color, w);
200            dst += stride;
201        }
202    } else if (bpp == 2) {
203        uint16_t *dst2;
204        for (j = 0; j < h; j++) {
205            dst2 = (uint16_t*)dst;
206            for (i = 0; i < w; i++)
207                *dst2++ = color;
208            dst += stride;
209        }
210    } else if (bpp == 4) {
211        uint32_t *dst2;
212        for (j = 0; j < h; j++) {
213            dst2 = (uint32_t*)dst;
214            for (i = 0; i < w; i++)
215                dst2[i] = color;
216            dst += stride;
217        }
218    }
219}
220
221static av_always_inline void paint_raw(uint8_t *dst, int w, int h,
222                                       GetByteContext *gb, int bpp,
223                                       int be, int stride)
224{
225    int i, j, p;
226    for (j = 0; j < h; j++) {
227        for (i = 0; i < w; i++) {
228            p = vmnc_get_pixel(gb, bpp, be);
229            switch (bpp) {
230            case 1:
231                dst[i] = p;
232                break;
233            case 2:
234                ((uint16_t*)dst)[i] = p;
235                break;
236            case 4:
237                ((uint32_t*)dst)[i] = p;
238                break;
239            }
240        }
241        dst += stride;
242    }
243}
244
245static int decode_hextile(VmncContext *c, uint8_t* dst, GetByteContext *gb,
246                          int w, int h, int stride)
247{
248    int i, j, k;
249    int bg = 0, fg = 0, rects, color, flags, xy, wh;
250    const int bpp = c->bpp2;
251    uint8_t *dst2;
252    int bw = 16, bh = 16;
253
254    for (j = 0; j < h; j += 16) {
255        dst2 = dst;
256        bw   = 16;
257        if (j + 16 > h)
258            bh = h - j;
259        for (i = 0; i < w; i += 16, dst2 += 16 * bpp) {
260            if (bytestream2_get_bytes_left(gb) <= 0) {
261                av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
262                return AVERROR_INVALIDDATA;
263            }
264            if (i + 16 > w)
265                bw = w - i;
266            flags = bytestream2_get_byte(gb);
267            if (flags & HT_RAW) {
268                if (bytestream2_get_bytes_left(gb) < bw * bh * bpp) {
269                    av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
270                    return AVERROR_INVALIDDATA;
271                }
272                paint_raw(dst2, bw, bh, gb, bpp, c->bigendian, stride);
273            } else {
274                if (flags & HT_BKG)
275                    bg = vmnc_get_pixel(gb, bpp, c->bigendian);
276                if (flags & HT_FG)
277                    fg = vmnc_get_pixel(gb, bpp, c->bigendian);
278                rects = 0;
279                if (flags & HT_SUB)
280                    rects = bytestream2_get_byte(gb);
281                color = !!(flags & HT_CLR);
282
283                paint_rect(dst2, 0, 0, bw, bh, bg, bpp, stride);
284
285                if (bytestream2_get_bytes_left(gb) < rects * (color * bpp + 2)) {
286                    av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
287                    return AVERROR_INVALIDDATA;
288                }
289                for (k = 0; k < rects; k++) {
290                    if (color)
291                        fg = vmnc_get_pixel(gb, bpp, c->bigendian);
292                    xy = bytestream2_get_byte(gb);
293                    wh = bytestream2_get_byte(gb);
294                    if (   (xy >> 4) + (wh >> 4) + 1 > w - i
295                        || (xy & 0xF) + (wh & 0xF)+1 > h - j) {
296                        av_log(c->avctx, AV_LOG_ERROR, "Rectangle outside picture\n");
297                        return AVERROR_INVALIDDATA;
298                    }
299                    paint_rect(dst2, xy >> 4, xy & 0xF,
300                               (wh>>4)+1, (wh & 0xF)+1, fg, bpp, stride);
301                }
302            }
303        }
304        dst += stride * 16;
305    }
306    return 0;
307}
308
309static void reset_buffers(VmncContext *c)
310{
311    av_freep(&c->curbits);
312    av_freep(&c->curmask);
313    av_freep(&c->screendta);
314    c->cur_w = c->cur_h = 0;
315    c->cur_hx = c->cur_hy = 0;
316
317}
318
319static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
320                        AVPacket *avpkt)
321{
322    const uint8_t *buf = avpkt->data;
323    int buf_size       = avpkt->size;
324    VmncContext * const c = avctx->priv_data;
325    GetByteContext *gb = &c->gb;
326    uint8_t *outptr;
327    int dx, dy, w, h, depth, enc, chunks, res, size_left, ret;
328
329    if ((ret = ff_reget_buffer(avctx, c->pic)) < 0)
330        return ret;
331
332    bytestream2_init(gb, buf, buf_size);
333
334    c->pic->key_frame = 0;
335    c->pic->pict_type = AV_PICTURE_TYPE_P;
336
337    // restore screen after cursor
338    if (c->screendta) {
339        int i;
340        w = c->cur_w;
341        if (c->width < c->cur_x + w)
342            w = c->width - c->cur_x;
343        h = c->cur_h;
344        if (c->height < c->cur_y + h)
345            h = c->height - c->cur_y;
346        dx = c->cur_x;
347        if (dx < 0) {
348            w += dx;
349            dx = 0;
350        }
351        dy = c->cur_y;
352        if (dy < 0) {
353            h += dy;
354            dy = 0;
355        }
356        if ((w > 0) && (h > 0)) {
357            outptr = c->pic->data[0] + dx * c->bpp2 + dy * c->pic->linesize[0];
358            for (i = 0; i < h; i++) {
359                memcpy(outptr, c->screendta + i * c->cur_w * c->bpp2,
360                       w * c->bpp2);
361                outptr += c->pic->linesize[0];
362            }
363        }
364    }
365    bytestream2_skip(gb, 2);
366    chunks = bytestream2_get_be16(gb);
367    while (chunks--) {
368        if (bytestream2_get_bytes_left(gb) < 12) {
369            av_log(avctx, AV_LOG_ERROR, "Premature end of data!\n");
370            return -1;
371        }
372        dx  = bytestream2_get_be16(gb);
373        dy  = bytestream2_get_be16(gb);
374        w   = bytestream2_get_be16(gb);
375        h   = bytestream2_get_be16(gb);
376        enc = bytestream2_get_be32(gb);
377        outptr = c->pic->data[0] + dx * c->bpp2 + dy * c->pic->linesize[0];
378        size_left = bytestream2_get_bytes_left(gb);
379        switch (enc) {
380        case MAGIC_WMVd: // cursor
381            if (w*(int64_t)h*c->bpp2 > INT_MAX/2 - 2) {
382                av_log(avctx, AV_LOG_ERROR, "dimensions too large\n");
383                return AVERROR_INVALIDDATA;
384            }
385            if (size_left < 2 + w * h * c->bpp2 * 2) {
386                av_log(avctx, AV_LOG_ERROR,
387                       "Premature end of data! (need %i got %i)\n",
388                       2 + w * h * c->bpp2 * 2, size_left);
389                return AVERROR_INVALIDDATA;
390            }
391            bytestream2_skip(gb, 2);
392            c->cur_w  = w;
393            c->cur_h  = h;
394            c->cur_hx = dx;
395            c->cur_hy = dy;
396            if ((c->cur_hx > c->cur_w) || (c->cur_hy > c->cur_h)) {
397                av_log(avctx, AV_LOG_ERROR,
398                       "Cursor hot spot is not in image: "
399                       "%ix%i of %ix%i cursor size\n",
400                       c->cur_hx, c->cur_hy, c->cur_w, c->cur_h);
401                c->cur_hx = c->cur_hy = 0;
402            }
403            if (c->cur_w * c->cur_h >= INT_MAX / c->bpp2) {
404                reset_buffers(c);
405                return AVERROR(EINVAL);
406            } else {
407                int screen_size = c->cur_w * c->cur_h * c->bpp2;
408                if ((ret = av_reallocp(&c->curbits, screen_size)) < 0 ||
409                    (ret = av_reallocp(&c->curmask, screen_size)) < 0 ||
410                    (ret = av_reallocp(&c->screendta, screen_size)) < 0) {
411                    reset_buffers(c);
412                    return ret;
413                }
414            }
415            load_cursor(c);
416            break;
417        case MAGIC_WMVe: // unknown
418            bytestream2_skip(gb, 2);
419            break;
420        case MAGIC_WMVf: // update cursor position
421            c->cur_x = dx - c->cur_hx;
422            c->cur_y = dy - c->cur_hy;
423            break;
424        case MAGIC_WMVg: // unknown
425            bytestream2_skip(gb, 10);
426            break;
427        case MAGIC_WMVh: // unknown
428            bytestream2_skip(gb, 4);
429            break;
430        case MAGIC_WMVi: // ServerInitialization struct
431            c->pic->key_frame = 1;
432            c->pic->pict_type = AV_PICTURE_TYPE_I;
433            depth = bytestream2_get_byte(gb);
434            if (depth != c->bpp) {
435                av_log(avctx, AV_LOG_INFO,
436                       "Depth mismatch. Container %i bpp, "
437                       "Frame data: %i bpp\n",
438                       c->bpp, depth);
439            }
440            bytestream2_skip(gb, 1);
441            c->bigendian = bytestream2_get_byte(gb);
442            if (c->bigendian & (~1)) {
443                av_log(avctx, AV_LOG_INFO,
444                       "Invalid header: bigendian flag = %i\n", c->bigendian);
445                return AVERROR_INVALIDDATA;
446            }
447            //skip the rest of pixel format data
448            bytestream2_skip(gb, 13);
449            break;
450        case MAGIC_WMVj: // unknown
451            bytestream2_skip(gb, 2);
452            break;
453        case 0x00000000: // raw rectangle data
454            if ((dx + w > c->width) || (dy + h > c->height)) {
455                av_log(avctx, AV_LOG_ERROR,
456                       "Incorrect frame size: %ix%i+%ix%i of %ix%i\n",
457                       w, h, dx, dy, c->width, c->height);
458                return AVERROR_INVALIDDATA;
459            }
460            if (size_left < w * h * c->bpp2) {
461                av_log(avctx, AV_LOG_ERROR,
462                       "Premature end of data! (need %i got %i)\n",
463                       w * h * c->bpp2, size_left);
464                return AVERROR_INVALIDDATA;
465            }
466            paint_raw(outptr, w, h, gb, c->bpp2, c->bigendian,
467                      c->pic->linesize[0]);
468            break;
469        case 0x00000005: // HexTile encoded rectangle
470            if ((dx + w > c->width) || (dy + h > c->height)) {
471                av_log(avctx, AV_LOG_ERROR,
472                       "Incorrect frame size: %ix%i+%ix%i of %ix%i\n",
473                       w, h, dx, dy, c->width, c->height);
474                return AVERROR_INVALIDDATA;
475            }
476            res = decode_hextile(c, outptr, gb, w, h, c->pic->linesize[0]);
477            if (res < 0)
478                return res;
479            break;
480        default:
481            av_log(avctx, AV_LOG_ERROR, "Unsupported block type 0x%08X\n", enc);
482            chunks = 0; // leave chunks decoding loop
483        }
484    }
485    if (c->screendta) {
486        int i;
487        // save screen data before painting cursor
488        w = c->cur_w;
489        if (c->width < c->cur_x + w)
490            w = c->width - c->cur_x;
491        h = c->cur_h;
492        if (c->height < c->cur_y + h)
493            h = c->height - c->cur_y;
494        dx = c->cur_x;
495        if (dx < 0) {
496            w += dx;
497            dx = 0;
498        }
499        dy = c->cur_y;
500        if (dy < 0) {
501            h += dy;
502            dy = 0;
503        }
504        if ((w > 0) && (h > 0)) {
505            outptr = c->pic->data[0] + dx * c->bpp2 + dy * c->pic->linesize[0];
506            for (i = 0; i < h; i++) {
507                memcpy(c->screendta + i * c->cur_w * c->bpp2, outptr,
508                       w * c->bpp2);
509                outptr += c->pic->linesize[0];
510            }
511            outptr = c->pic->data[0];
512            put_cursor(outptr, c->pic->linesize[0], c, c->cur_x, c->cur_y);
513        }
514    }
515    *got_frame = 1;
516    if ((ret = av_frame_ref(data, c->pic)) < 0)
517        return ret;
518
519    /* always report that the buffer was completely consumed */
520    return buf_size;
521}
522
523static av_cold int decode_init(AVCodecContext *avctx)
524{
525    VmncContext * const c = avctx->priv_data;
526
527    c->avctx  = avctx;
528    c->width  = avctx->width;
529    c->height = avctx->height;
530    c->bpp    = avctx->bits_per_coded_sample;
531    c->bpp2   = c->bpp / 8;
532
533    switch (c->bpp) {
534    case 8:
535        avctx->pix_fmt = AV_PIX_FMT_PAL8;
536        break;
537    case 16:
538        avctx->pix_fmt = AV_PIX_FMT_RGB555;
539        break;
540    case 32:
541        avctx->pix_fmt = AV_PIX_FMT_RGB32;
542        break;
543    default:
544        av_log(avctx, AV_LOG_ERROR, "Unsupported bitdepth %i\n", c->bpp);
545        return AVERROR_INVALIDDATA;
546    }
547
548    c->pic = av_frame_alloc();
549    if (!c->pic)
550        return AVERROR(ENOMEM);
551
552    return 0;
553}
554
555static av_cold int decode_end(AVCodecContext *avctx)
556{
557    VmncContext * const c = avctx->priv_data;
558
559    av_frame_free(&c->pic);
560
561    av_freep(&c->curbits);
562    av_freep(&c->curmask);
563    av_freep(&c->screendta);
564    return 0;
565}
566
567AVCodec ff_vmnc_decoder = {
568    .name           = "vmnc",
569    .long_name      = NULL_IF_CONFIG_SMALL("VMware Screen Codec / VMware Video"),
570    .type           = AVMEDIA_TYPE_VIDEO,
571    .id             = AV_CODEC_ID_VMNC,
572    .priv_data_size = sizeof(VmncContext),
573    .init           = decode_init,
574    .close          = decode_end,
575    .decode         = decode_frame,
576    .capabilities   = CODEC_CAP_DR1,
577};
578