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/intreadwrite.h"
32#include "avcodec.h"
33
34enum EncTypes {
35    MAGIC_WMVd = 0x574D5664,
36    MAGIC_WMVe,
37    MAGIC_WMVf,
38    MAGIC_WMVg,
39    MAGIC_WMVh,
40    MAGIC_WMVi,
41    MAGIC_WMVj
42};
43
44enum HexTile_Flags {
45    HT_RAW =  1, // tile is raw
46    HT_BKG =  2, // background color is present
47    HT_FG  =  4, // foreground color is present
48    HT_SUB =  8, // subrects are present
49    HT_CLR = 16  // each subrect has own color
50};
51
52/*
53 * Decoder context
54 */
55typedef struct VmncContext {
56    AVCodecContext *avctx;
57    AVFrame pic;
58
59    int bpp;
60    int bpp2;
61    int bigendian;
62    uint8_t pal[768];
63    int width, height;
64
65    /* cursor data */
66    int cur_w, cur_h;
67    int cur_x, cur_y;
68    int cur_hx, cur_hy;
69    uint8_t* curbits, *curmask;
70    uint8_t* screendta;
71} VmncContext;
72
73/* read pixel value from stream */
74static av_always_inline int vmnc_get_pixel(const uint8_t* buf, int bpp, int be) {
75    switch(bpp * 2 + be) {
76    case 2:
77    case 3: return *buf;
78    case 4: return AV_RL16(buf);
79    case 5: return AV_RB16(buf);
80    case 8: return AV_RL32(buf);
81    case 9: return AV_RB32(buf);
82    default: return 0;
83    }
84}
85
86static void load_cursor(VmncContext *c, const uint8_t *src)
87{
88    int i, j, p;
89    const int bpp = c->bpp2;
90    uint8_t  *dst8  = c->curbits;
91    uint16_t *dst16 = (uint16_t*)c->curbits;
92    uint32_t *dst32 = (uint32_t*)c->curbits;
93
94    for(j = 0; j < c->cur_h; j++) {
95        for(i = 0; i < c->cur_w; i++) {
96            p = vmnc_get_pixel(src, bpp, c->bigendian);
97            src += bpp;
98            if(bpp == 1) *dst8++ = p;
99            if(bpp == 2) *dst16++ = p;
100            if(bpp == 4) *dst32++ = p;
101        }
102    }
103    dst8 = c->curmask;
104    dst16 = (uint16_t*)c->curmask;
105    dst32 = (uint32_t*)c->curmask;
106    for(j = 0; j < c->cur_h; j++) {
107        for(i = 0; i < c->cur_w; i++) {
108            p = vmnc_get_pixel(src, bpp, c->bigendian);
109            src += bpp;
110            if(bpp == 1) *dst8++ = p;
111            if(bpp == 2) *dst16++ = p;
112            if(bpp == 4) *dst32++ = p;
113        }
114    }
115}
116
117static void put_cursor(uint8_t *dst, int stride, VmncContext *c, int dx, int dy)
118{
119    int i, j;
120    int w, h, x, y;
121    w = c->cur_w;
122    if(c->width < c->cur_x + c->cur_w) w = c->width - c->cur_x;
123    h = c->cur_h;
124    if(c->height < c->cur_y + c->cur_h) h = c->height - c->cur_y;
125    x = c->cur_x;
126    y = c->cur_y;
127    if(x < 0) {
128        w += x;
129        x = 0;
130    }
131    if(y < 0) {
132        h += y;
133        y = 0;
134    }
135
136    if((w < 1) || (h < 1)) return;
137    dst += x * c->bpp2 + y * stride;
138
139    if(c->bpp2 == 1) {
140        uint8_t* cd = c->curbits, *msk = c->curmask;
141        for(j = 0; j < h; j++) {
142            for(i = 0; i < w; i++)
143                dst[i] = (dst[i] & cd[i]) ^ msk[i];
144            msk += c->cur_w;
145            cd += c->cur_w;
146            dst += stride;
147        }
148    } else if(c->bpp2 == 2) {
149        uint16_t* cd = (uint16_t*)c->curbits, *msk = (uint16_t*)c->curmask;
150        uint16_t* dst2;
151        for(j = 0; j < h; j++) {
152            dst2 = (uint16_t*)dst;
153            for(i = 0; i < w; i++)
154                dst2[i] = (dst2[i] & cd[i]) ^ msk[i];
155            msk += c->cur_w;
156            cd += c->cur_w;
157            dst += stride;
158        }
159    } else if(c->bpp2 == 4) {
160        uint32_t* cd = (uint32_t*)c->curbits, *msk = (uint32_t*)c->curmask;
161        uint32_t* dst2;
162        for(j = 0; j < h; j++) {
163            dst2 = (uint32_t*)dst;
164            for(i = 0; i < w; i++)
165                dst2[i] = (dst2[i] & cd[i]) ^ msk[i];
166            msk += c->cur_w;
167            cd += c->cur_w;
168            dst += stride;
169        }
170    }
171}
172
173/* fill rectangle with given color */
174static av_always_inline void paint_rect(uint8_t *dst, int dx, int dy, int w, int h, int color, int bpp, int stride)
175{
176    int i, j;
177    dst += dx * bpp + dy * stride;
178    if(bpp == 1){
179        for(j = 0; j < h; j++) {
180            memset(dst, color, w);
181            dst += stride;
182        }
183    }else if(bpp == 2){
184        uint16_t* dst2;
185        for(j = 0; j < h; j++) {
186            dst2 = (uint16_t*)dst;
187            for(i = 0; i < w; i++) {
188                *dst2++ = color;
189            }
190            dst += stride;
191        }
192    }else if(bpp == 4){
193        uint32_t* dst2;
194        for(j = 0; j < h; j++) {
195            dst2 = (uint32_t*)dst;
196            for(i = 0; i < w; i++) {
197                dst2[i] = color;
198            }
199            dst += stride;
200        }
201    }
202}
203
204static av_always_inline void paint_raw(uint8_t *dst, int w, int h, const uint8_t* src, int bpp, int be, int stride)
205{
206    int i, j, p;
207    for(j = 0; j < h; j++) {
208        for(i = 0; i < w; i++) {
209            p = vmnc_get_pixel(src, bpp, be);
210            src += bpp;
211            switch(bpp){
212            case 1:
213                dst[i] = p;
214                break;
215            case 2:
216                ((uint16_t*)dst)[i] = p;
217                break;
218            case 4:
219                ((uint32_t*)dst)[i] = p;
220                break;
221            }
222        }
223        dst += stride;
224    }
225}
226
227static int decode_hextile(VmncContext *c, uint8_t* dst, const uint8_t* src, int ssize, int w, int h, int stride)
228{
229    int i, j, k;
230    int bg = 0, fg = 0, rects, color, flags, xy, wh;
231    const int bpp = c->bpp2;
232    uint8_t *dst2;
233    int bw = 16, bh = 16;
234    const uint8_t *ssrc=src;
235
236    for(j = 0; j < h; j += 16) {
237        dst2 = dst;
238        bw = 16;
239        if(j + 16 > h) bh = h - j;
240        for(i = 0; i < w; i += 16, dst2 += 16 * bpp) {
241            if(src - ssrc >= ssize) {
242                av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
243                return -1;
244            }
245            if(i + 16 > w) bw = w - i;
246            flags = *src++;
247            if(flags & HT_RAW) {
248                if(src - ssrc > ssize - bw * bh * bpp) {
249                    av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
250                    return -1;
251                }
252                paint_raw(dst2, bw, bh, src, bpp, c->bigendian, stride);
253                src += bw * bh * bpp;
254            } else {
255                if(flags & HT_BKG) {
256                    bg = vmnc_get_pixel(src, bpp, c->bigendian); src += bpp;
257                }
258                if(flags & HT_FG) {
259                    fg = vmnc_get_pixel(src, bpp, c->bigendian); src += bpp;
260                }
261                rects = 0;
262                if(flags & HT_SUB)
263                    rects = *src++;
264                color = !!(flags & HT_CLR);
265
266                paint_rect(dst2, 0, 0, bw, bh, bg, bpp, stride);
267
268                if(src - ssrc > ssize - rects * (color * bpp + 2)) {
269                    av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
270                    return -1;
271                }
272                for(k = 0; k < rects; k++) {
273                    if(color) {
274                        fg = vmnc_get_pixel(src, bpp, c->bigendian); src += bpp;
275                    }
276                    xy = *src++;
277                    wh = *src++;
278                    paint_rect(dst2, xy >> 4, xy & 0xF, (wh>>4)+1, (wh & 0xF)+1, fg, bpp, stride);
279                }
280            }
281        }
282        dst += stride * 16;
283    }
284    return src - ssrc;
285}
286
287static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
288{
289    const uint8_t *buf = avpkt->data;
290    int buf_size = avpkt->size;
291    VmncContext * const c = avctx->priv_data;
292    uint8_t *outptr;
293    const uint8_t *src = buf;
294    int dx, dy, w, h, depth, enc, chunks, res, size_left;
295
296    c->pic.reference = 1;
297    c->pic.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
298    if(avctx->reget_buffer(avctx, &c->pic) < 0){
299        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
300        return -1;
301    }
302
303    c->pic.key_frame = 0;
304    c->pic.pict_type = FF_P_TYPE;
305
306    //restore screen after cursor
307    if(c->screendta) {
308        int i;
309        w = c->cur_w;
310        if(c->width < c->cur_x + w) w = c->width - c->cur_x;
311        h = c->cur_h;
312        if(c->height < c->cur_y + h) h = c->height - c->cur_y;
313        dx = c->cur_x;
314        if(dx < 0) {
315            w += dx;
316            dx = 0;
317        }
318        dy = c->cur_y;
319        if(dy < 0) {
320            h += dy;
321            dy = 0;
322        }
323        if((w > 0) && (h > 0)) {
324            outptr = c->pic.data[0] + dx * c->bpp2 + dy * c->pic.linesize[0];
325            for(i = 0; i < h; i++) {
326                memcpy(outptr, c->screendta + i * c->cur_w * c->bpp2, w * c->bpp2);
327                outptr += c->pic.linesize[0];
328            }
329        }
330    }
331    src += 2;
332    chunks = AV_RB16(src); src += 2;
333    while(chunks--) {
334        dx = AV_RB16(src); src += 2;
335        dy = AV_RB16(src); src += 2;
336        w  = AV_RB16(src); src += 2;
337        h  = AV_RB16(src); src += 2;
338        enc = AV_RB32(src); src += 4;
339        outptr = c->pic.data[0] + dx * c->bpp2 + dy * c->pic.linesize[0];
340        size_left = buf_size - (src - buf);
341        switch(enc) {
342        case MAGIC_WMVd: // cursor
343            if(size_left < 2 + w * h * c->bpp2 * 2) {
344                av_log(avctx, AV_LOG_ERROR, "Premature end of data! (need %i got %i)\n", 2 + w * h * c->bpp2 * 2, size_left);
345                return -1;
346            }
347            src += 2;
348            c->cur_w = w;
349            c->cur_h = h;
350            c->cur_hx = dx;
351            c->cur_hy = dy;
352            if((c->cur_hx > c->cur_w) || (c->cur_hy > c->cur_h)) {
353                av_log(avctx, AV_LOG_ERROR, "Cursor hot spot is not in image: %ix%i of %ix%i cursor size\n", c->cur_hx, c->cur_hy, c->cur_w, c->cur_h);
354                c->cur_hx = c->cur_hy = 0;
355            }
356            c->curbits = av_realloc(c->curbits, c->cur_w * c->cur_h * c->bpp2);
357            c->curmask = av_realloc(c->curmask, c->cur_w * c->cur_h * c->bpp2);
358            c->screendta = av_realloc(c->screendta, c->cur_w * c->cur_h * c->bpp2);
359            load_cursor(c, src);
360            src += w * h * c->bpp2 * 2;
361            break;
362        case MAGIC_WMVe: // unknown
363            src += 2;
364            break;
365        case MAGIC_WMVf: // update cursor position
366            c->cur_x = dx - c->cur_hx;
367            c->cur_y = dy - c->cur_hy;
368            break;
369        case MAGIC_WMVg: // unknown
370            src += 10;
371            break;
372        case MAGIC_WMVh: // unknown
373            src += 4;
374            break;
375        case MAGIC_WMVi: // ServerInitialization struct
376            c->pic.key_frame = 1;
377            c->pic.pict_type = FF_I_TYPE;
378            depth = *src++;
379            if(depth != c->bpp) {
380                av_log(avctx, AV_LOG_INFO, "Depth mismatch. Container %i bpp, Frame data: %i bpp\n", c->bpp, depth);
381            }
382            src++;
383            c->bigendian = *src++;
384            if(c->bigendian & (~1)) {
385                av_log(avctx, AV_LOG_INFO, "Invalid header: bigendian flag = %i\n", c->bigendian);
386                return -1;
387            }
388            //skip the rest of pixel format data
389            src += 13;
390            break;
391        case MAGIC_WMVj: // unknown
392            src += 2;
393            break;
394        case 0x00000000: // raw rectangle data
395            if((dx + w > c->width) || (dy + h > c->height)) {
396                av_log(avctx, AV_LOG_ERROR, "Incorrect frame size: %ix%i+%ix%i of %ix%i\n", w, h, dx, dy, c->width, c->height);
397                return -1;
398            }
399            if(size_left < w * h * c->bpp2) {
400                av_log(avctx, AV_LOG_ERROR, "Premature end of data! (need %i got %i)\n", w * h * c->bpp2, size_left);
401                return -1;
402            }
403            paint_raw(outptr, w, h, src, c->bpp2, c->bigendian, c->pic.linesize[0]);
404            src += w * h * c->bpp2;
405            break;
406        case 0x00000005: // HexTile encoded rectangle
407            if((dx + w > c->width) || (dy + h > c->height)) {
408                av_log(avctx, AV_LOG_ERROR, "Incorrect frame size: %ix%i+%ix%i of %ix%i\n", w, h, dx, dy, c->width, c->height);
409                return -1;
410            }
411            res = decode_hextile(c, outptr, src, size_left, w, h, c->pic.linesize[0]);
412            if(res < 0)
413                return -1;
414            src += res;
415            break;
416        default:
417            av_log(avctx, AV_LOG_ERROR, "Unsupported block type 0x%08X\n", enc);
418            chunks = 0; // leave chunks decoding loop
419        }
420    }
421    if(c->screendta){
422        int i;
423        //save screen data before painting cursor
424        w = c->cur_w;
425        if(c->width < c->cur_x + w) w = c->width - c->cur_x;
426        h = c->cur_h;
427        if(c->height < c->cur_y + h) h = c->height - c->cur_y;
428        dx = c->cur_x;
429        if(dx < 0) {
430            w += dx;
431            dx = 0;
432        }
433        dy = c->cur_y;
434        if(dy < 0) {
435            h += dy;
436            dy = 0;
437        }
438        if((w > 0) && (h > 0)) {
439            outptr = c->pic.data[0] + dx * c->bpp2 + dy * c->pic.linesize[0];
440            for(i = 0; i < h; i++) {
441                memcpy(c->screendta + i * c->cur_w * c->bpp2, outptr, w * c->bpp2);
442                outptr += c->pic.linesize[0];
443            }
444            outptr = c->pic.data[0];
445            put_cursor(outptr, c->pic.linesize[0], c, c->cur_x, c->cur_y);
446        }
447    }
448    *data_size = sizeof(AVFrame);
449    *(AVFrame*)data = c->pic;
450
451    /* always report that the buffer was completely consumed */
452    return buf_size;
453}
454
455
456
457/*
458 *
459 * Init VMnc decoder
460 *
461 */
462static av_cold int decode_init(AVCodecContext *avctx)
463{
464    VmncContext * const c = avctx->priv_data;
465
466    c->avctx = avctx;
467
468    c->width = avctx->width;
469    c->height = avctx->height;
470
471    c->bpp = avctx->bits_per_coded_sample;
472    c->bpp2 = c->bpp/8;
473
474    switch(c->bpp){
475    case 8:
476        avctx->pix_fmt = PIX_FMT_PAL8;
477        break;
478    case 16:
479        avctx->pix_fmt = PIX_FMT_RGB555;
480        break;
481    case 32:
482        avctx->pix_fmt = PIX_FMT_RGB32;
483        break;
484    default:
485        av_log(avctx, AV_LOG_ERROR, "Unsupported bitdepth %i\n", c->bpp);
486    }
487
488    return 0;
489}
490
491
492
493/*
494 *
495 * Uninit VMnc decoder
496 *
497 */
498static av_cold int decode_end(AVCodecContext *avctx)
499{
500    VmncContext * const c = avctx->priv_data;
501
502    if (c->pic.data[0])
503        avctx->release_buffer(avctx, &c->pic);
504
505    av_free(c->curbits);
506    av_free(c->curmask);
507    av_free(c->screendta);
508    return 0;
509}
510
511AVCodec vmnc_decoder = {
512    "vmnc",
513    AVMEDIA_TYPE_VIDEO,
514    CODEC_ID_VMNC,
515    sizeof(VmncContext),
516    decode_init,
517    NULL,
518    decode_end,
519    decode_frame,
520    CODEC_CAP_DR1,
521    .long_name = NULL_IF_CONFIG_SMALL("VMware Screen Codec / VMware Video"),
522};
523
524