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g2meet.c
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1 /*
2  * Go2Webinar decoder
3  * Copyright (c) 2012 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  * Go2Webinar decoder
25  */
26 
27 #include <zlib.h>
28 
29 #include "libavutil/intreadwrite.h"
30 #include "avcodec.h"
31 #include "bytestream.h"
32 #include "dsputil.h"
33 #include "get_bits.h"
34 #include "internal.h"
35 #include "mjpeg.h"
36 
37 enum ChunkType {
38  DISPLAY_INFO = 0xC8,
39  TILE_DATA,
40  CURSOR_POS,
41  CURSOR_SHAPE,
42  CHUNK_CC,
43  CHUNK_CD
44 };
45 
46 enum Compression {
47  COMPR_EPIC_J_B = 2,
48  COMPR_KEMPF_J_B,
49 };
50 
51 static const uint8_t luma_quant[64] = {
52  8, 6, 5, 8, 12, 20, 26, 31,
53  6, 6, 7, 10, 13, 29, 30, 28,
54  7, 7, 8, 12, 20, 29, 35, 28,
55  7, 9, 11, 15, 26, 44, 40, 31,
56  9, 11, 19, 28, 34, 55, 52, 39,
57  12, 18, 28, 32, 41, 52, 57, 46,
58  25, 32, 39, 44, 52, 61, 60, 51,
59  36, 46, 48, 49, 56, 50, 52, 50
60 };
61 
62 static const uint8_t chroma_quant[64] = {
63  9, 9, 12, 24, 50, 50, 50, 50,
64  9, 11, 13, 33, 50, 50, 50, 50,
65  12, 13, 28, 50, 50, 50, 50, 50,
66  24, 33, 50, 50, 50, 50, 50, 50,
67  50, 50, 50, 50, 50, 50, 50, 50,
68  50, 50, 50, 50, 50, 50, 50, 50,
69  50, 50, 50, 50, 50, 50, 50, 50,
70  50, 50, 50, 50, 50, 50, 50, 50,
71 };
72 
73 typedef struct JPGContext {
74  DSPContext dsp;
75  ScanTable scantable;
76 
77  VLC dc_vlc[2], ac_vlc[2];
78  int prev_dc[3];
79  DECLARE_ALIGNED(16, int16_t, block)[6][64];
80 
81  uint8_t *buf;
82 } JPGContext;
83 
84 typedef struct G2MContext {
85  JPGContext jc;
86  int version;
87 
88  int compression;
89  int width, height, bpp;
90  int tile_width, tile_height;
91  int tiles_x, tiles_y, tile_x, tile_y;
92 
93  int got_header;
94 
95  uint8_t *framebuf;
96  int framebuf_stride, old_width, old_height;
97 
98  uint8_t *synth_tile, *jpeg_tile;
99  int tile_stride, old_tile_w, old_tile_h;
100 
101  uint8_t *kempf_buf, *kempf_flags;
102 
103  uint8_t *cursor;
104  int cursor_stride;
105  int cursor_fmt;
106  int cursor_w, cursor_h, cursor_x, cursor_y;
107  int cursor_hot_x, cursor_hot_y;
108 } G2MContext;
109 
110 static av_cold int build_vlc(VLC *vlc, const uint8_t *bits_table,
111  const uint8_t *val_table, int nb_codes,
112  int is_ac)
113 {
114  uint8_t huff_size[256] = { 0 };
115  uint16_t huff_code[256];
116  uint16_t huff_sym[256];
117  int i;
118 
119  ff_mjpeg_build_huffman_codes(huff_size, huff_code, bits_table, val_table);
120 
121  for (i = 0; i < 256; i++)
122  huff_sym[i] = i + 16 * is_ac;
123 
124  if (is_ac)
125  huff_sym[0] = 16 * 256;
126 
127  return ff_init_vlc_sparse(vlc, 9, nb_codes, huff_size, 1, 1,
128  huff_code, 2, 2, huff_sym, 2, 2, 0);
129 }
130 
131 static av_cold int jpg_init(AVCodecContext *avctx, JPGContext *c)
132 {
133  int ret;
134 
135  ret = build_vlc(&c->dc_vlc[0], avpriv_mjpeg_bits_dc_luminance,
136  avpriv_mjpeg_val_dc, 12, 0);
137  if (ret)
138  return ret;
139  ret = build_vlc(&c->dc_vlc[1], avpriv_mjpeg_bits_dc_chrominance,
140  avpriv_mjpeg_val_dc, 12, 0);
141  if (ret)
142  return ret;
143  ret = build_vlc(&c->ac_vlc[0], avpriv_mjpeg_bits_ac_luminance,
144  avpriv_mjpeg_val_ac_luminance, 251, 1);
145  if (ret)
146  return ret;
147  ret = build_vlc(&c->ac_vlc[1], avpriv_mjpeg_bits_ac_chrominance,
148  avpriv_mjpeg_val_ac_chrominance, 251, 1);
149  if (ret)
150  return ret;
151 
152  ff_dsputil_init(&c->dsp, avctx);
153  ff_init_scantable(c->dsp.idct_permutation, &c->scantable,
154  ff_zigzag_direct);
155 
156  return 0;
157 }
158 
159 static av_cold void jpg_free_context(JPGContext *ctx)
160 {
161  int i;
162 
163  for (i = 0; i < 2; i++) {
164  ff_free_vlc(&ctx->dc_vlc[i]);
165  ff_free_vlc(&ctx->ac_vlc[i]);
166  }
167 
168  av_freep(&ctx->buf);
169 }
170 
171 static void jpg_unescape(const uint8_t *src, int src_size,
172  uint8_t *dst, int *dst_size)
173 {
174  const uint8_t *src_end = src + src_size;
175  uint8_t *dst_start = dst;
176 
177  while (src < src_end) {
178  uint8_t x = *src++;
179 
180  *dst++ = x;
181 
182  if (x == 0xFF && !*src)
183  src++;
184  }
185  *dst_size = dst - dst_start;
186 }
187 
188 static int jpg_decode_block(JPGContext *c, GetBitContext *gb,
189  int plane, int16_t *block)
190 {
191  int dc, val, pos;
192  const int is_chroma = !!plane;
193  const uint8_t *qmat = is_chroma ? chroma_quant : luma_quant;
194 
195  c->dsp.clear_block(block);
196  dc = get_vlc2(gb, c->dc_vlc[is_chroma].table, 9, 3);
197  if (dc < 0)
198  return AVERROR_INVALIDDATA;
199  if (dc)
200  dc = get_xbits(gb, dc);
201  dc = dc * qmat[0] + c->prev_dc[plane];
202  block[0] = dc;
203  c->prev_dc[plane] = dc;
204 
205  pos = 0;
206  while (pos < 63) {
207  val = get_vlc2(gb, c->ac_vlc[is_chroma].table, 9, 3);
208  if (val < 0)
209  return AVERROR_INVALIDDATA;
210  pos += val >> 4;
211  val &= 0xF;
212  if (pos > 63)
213  return val ? AVERROR_INVALIDDATA : 0;
214  if (val) {
215  int nbits = val;
216 
217  val = get_xbits(gb, nbits);
218  val *= qmat[ff_zigzag_direct[pos]];
219  block[c->scantable.permutated[pos]] = val;
220  }
221  }
222  return 0;
223 }
224 
225 static inline void yuv2rgb(uint8_t *out, int Y, int U, int V)
226 {
227  out[0] = av_clip_uint8(Y + ( 91881 * V + 32768 >> 16));
228  out[1] = av_clip_uint8(Y + (-22554 * U - 46802 * V + 32768 >> 16));
229  out[2] = av_clip_uint8(Y + (116130 * U + 32768 >> 16));
230 }
231 
232 static int jpg_decode_data(JPGContext *c, int width, int height,
233  const uint8_t *src, int src_size,
234  uint8_t *dst, int dst_stride,
235  const uint8_t *mask, int mask_stride, int num_mbs,
236  int swapuv)
237 {
238  GetBitContext gb;
239  int mb_w, mb_h, mb_x, mb_y, i, j;
240  int bx, by;
241  int unesc_size;
242  int ret;
243 
244  if ((ret = av_reallocp(&c->buf,
245  src_size + FF_INPUT_BUFFER_PADDING_SIZE)) < 0)
246  return ret;
247  jpg_unescape(src, src_size, c->buf, &unesc_size);
248  memset(c->buf + unesc_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
249  init_get_bits(&gb, c->buf, unesc_size * 8);
250 
251  width = FFALIGN(width, 16);
252  mb_w = width >> 4;
253  mb_h = (height + 15) >> 4;
254 
255  if (!num_mbs)
256  num_mbs = mb_w * mb_h * 4;
257 
258  for (i = 0; i < 3; i++)
259  c->prev_dc[i] = 1024;
260  bx = by = 0;
261  c->dsp.clear_blocks(c->block[0]);
262  for (mb_y = 0; mb_y < mb_h; mb_y++) {
263  for (mb_x = 0; mb_x < mb_w; mb_x++) {
264  if (mask && !mask[mb_x * 2] && !mask[mb_x * 2 + 1] &&
265  !mask[mb_x * 2 + mask_stride] &&
266  !mask[mb_x * 2 + 1 + mask_stride]) {
267  bx += 16;
268  continue;
269  }
270  for (j = 0; j < 2; j++) {
271  for (i = 0; i < 2; i++) {
272  if (mask && !mask[mb_x * 2 + i + j * mask_stride])
273  continue;
274  num_mbs--;
275  if ((ret = jpg_decode_block(c, &gb, 0,
276  c->block[i + j * 2])) != 0)
277  return ret;
278  c->dsp.idct(c->block[i + j * 2]);
279  }
280  }
281  for (i = 1; i < 3; i++) {
282  if ((ret = jpg_decode_block(c, &gb, i, c->block[i + 3])) != 0)
283  return ret;
284  c->dsp.idct(c->block[i + 3]);
285  }
286 
287  for (j = 0; j < 16; j++) {
288  uint8_t *out = dst + bx * 3 + (by + j) * dst_stride;
289  for (i = 0; i < 16; i++) {
290  int Y, U, V;
291 
292  Y = c->block[(j >> 3) * 2 + (i >> 3)][(i & 7) + (j & 7) * 8];
293  U = c->block[4 ^ swapuv][(i >> 1) + (j >> 1) * 8] - 128;
294  V = c->block[5 ^ swapuv][(i >> 1) + (j >> 1) * 8] - 128;
295  yuv2rgb(out + i * 3, Y, U, V);
296  }
297  }
298 
299  if (!num_mbs)
300  return 0;
301  bx += 16;
302  }
303  bx = 0;
304  by += 16;
305  if (mask)
306  mask += mask_stride * 2;
307  }
308 
309  return 0;
310 }
311 
312 static void kempf_restore_buf(const uint8_t *src, int len,
313  uint8_t *dst, int stride,
314  const uint8_t *jpeg_tile, int tile_stride,
315  int width, int height,
316  const uint8_t *pal, int npal, int tidx)
317 {
318  GetBitContext gb;
319  int i, j, nb, col;
320 
321  init_get_bits(&gb, src, len * 8);
322 
323  if (npal <= 2) nb = 1;
324  else if (npal <= 4) nb = 2;
325  else if (npal <= 16) nb = 4;
326  else nb = 8;
327 
328  for (j = 0; j < height; j++, dst += stride, jpeg_tile += tile_stride) {
329  if (get_bits(&gb, 8))
330  continue;
331  for (i = 0; i < width; i++) {
332  col = get_bits(&gb, nb);
333  if (col != tidx)
334  memcpy(dst + i * 3, pal + col * 3, 3);
335  else
336  memcpy(dst + i * 3, jpeg_tile + i * 3, 3);
337  }
338  }
339 }
340 
341 static int kempf_decode_tile(G2MContext *c, int tile_x, int tile_y,
342  const uint8_t *src, int src_size)
343 {
344  int width, height;
345  int hdr, zsize, npal, tidx = -1, ret;
346  int i, j;
347  const uint8_t *src_end = src + src_size;
348  uint8_t pal[768], transp[3];
349  uLongf dlen = (c->tile_width + 1) * c->tile_height;
350  int sub_type;
351  int nblocks, cblocks, bstride;
352  int bits, bitbuf, coded;
353  uint8_t *dst = c->framebuf + tile_x * c->tile_width * 3 +
354  tile_y * c->tile_height * c->framebuf_stride;
355 
356  if (src_size < 2)
357  return AVERROR_INVALIDDATA;
358 
359  width = FFMIN(c->width - tile_x * c->tile_width, c->tile_width);
360  height = FFMIN(c->height - tile_y * c->tile_height, c->tile_height);
361 
362  hdr = *src++;
363  sub_type = hdr >> 5;
364  if (sub_type == 0) {
365  int j;
366  memcpy(transp, src, 3);
367  src += 3;
368  for (j = 0; j < height; j++, dst += c->framebuf_stride)
369  for (i = 0; i < width; i++)
370  memcpy(dst + i * 3, transp, 3);
371  return 0;
372  } else if (sub_type == 1) {
373  return jpg_decode_data(&c->jc, width, height, src, src_end - src,
374  dst, c->framebuf_stride, NULL, 0, 0, 0);
375  }
376 
377  if (sub_type != 2) {
378  memcpy(transp, src, 3);
379  src += 3;
380  }
381  npal = *src++ + 1;
382  if (src_end - src < npal * 3)
383  return AVERROR_INVALIDDATA;
384  memcpy(pal, src, npal * 3); src += npal * 3;
385  if (sub_type != 2) {
386  for (i = 0; i < npal; i++) {
387  if (!memcmp(pal + i * 3, transp, 3)) {
388  tidx = i;
389  break;
390  }
391  }
392  }
393 
394  if (src_end - src < 2)
395  return 0;
396  zsize = (src[0] << 8) | src[1]; src += 2;
397 
398  if (src_end - src < zsize + (sub_type != 2))
399  return AVERROR_INVALIDDATA;
400 
401  ret = uncompress(c->kempf_buf, &dlen, src, zsize);
402  if (ret)
403  return AVERROR_INVALIDDATA;
404  src += zsize;
405 
406  if (sub_type == 2) {
407  kempf_restore_buf(c->kempf_buf, dlen, dst, c->framebuf_stride,
408  NULL, 0, width, height, pal, npal, tidx);
409  return 0;
410  }
411 
412  nblocks = *src++ + 1;
413  cblocks = 0;
414  bstride = FFALIGN(width, 16) >> 3;
415  // blocks are coded LSB and we need normal bitreader for JPEG data
416  bits = 0;
417  for (i = 0; i < (FFALIGN(height, 16) >> 4); i++) {
418  for (j = 0; j < (FFALIGN(width, 16) >> 4); j++) {
419  if (!bits) {
420  if (src >= src_end)
421  return AVERROR_INVALIDDATA;
422  bitbuf = *src++;
423  bits = 8;
424  }
425  coded = bitbuf & 1;
426  bits--;
427  bitbuf >>= 1;
428  cblocks += coded;
429  if (cblocks > nblocks)
430  return AVERROR_INVALIDDATA;
431  c->kempf_flags[j * 2 + i * 2 * bstride] =
432  c->kempf_flags[j * 2 + 1 + i * 2 * bstride] =
433  c->kempf_flags[j * 2 + (i * 2 + 1) * bstride] =
434  c->kempf_flags[j * 2 + 1 + (i * 2 + 1) * bstride] = coded;
435  }
436  }
437 
438  memset(c->jpeg_tile, 0, c->tile_stride * height);
439  jpg_decode_data(&c->jc, width, height, src, src_end - src,
440  c->jpeg_tile, c->tile_stride,
441  c->kempf_flags, bstride, nblocks * 4, 0);
442 
443  kempf_restore_buf(c->kempf_buf, dlen, dst, c->framebuf_stride,
444  c->jpeg_tile, c->tile_stride,
445  width, height, pal, npal, tidx);
446 
447  return 0;
448 }
449 
450 static int g2m_init_buffers(G2MContext *c)
451 {
452  int aligned_height;
453 
454  if (!c->framebuf || c->old_width < c->width || c->old_height < c->height) {
455  c->framebuf_stride = FFALIGN(c->width + 15, 16) * 3;
456  aligned_height = c->height + 15;
457  av_free(c->framebuf);
458  c->framebuf = av_mallocz(c->framebuf_stride * aligned_height);
459  if (!c->framebuf)
460  return AVERROR(ENOMEM);
461  }
462  if (!c->synth_tile || !c->jpeg_tile ||
463  c->old_tile_w < c->tile_width ||
464  c->old_tile_h < c->tile_height) {
465  c->tile_stride = FFALIGN(c->tile_width, 16) * 3;
466  aligned_height = FFALIGN(c->tile_height, 16);
467  av_free(c->synth_tile);
468  av_free(c->jpeg_tile);
469  av_free(c->kempf_buf);
470  av_free(c->kempf_flags);
471  c->synth_tile = av_mallocz(c->tile_stride * aligned_height);
472  c->jpeg_tile = av_mallocz(c->tile_stride * aligned_height);
473  c->kempf_buf = av_mallocz((c->tile_width + 1) * aligned_height
474  + FF_INPUT_BUFFER_PADDING_SIZE);
475  c->kempf_flags = av_mallocz( c->tile_width * aligned_height);
476  if (!c->synth_tile || !c->jpeg_tile ||
477  !c->kempf_buf || !c->kempf_flags)
478  return AVERROR(ENOMEM);
479  }
480 
481  return 0;
482 }
483 
484 static int g2m_load_cursor(AVCodecContext *avctx, G2MContext *c,
485  GetByteContext *gb)
486 {
487  int i, j, k;
488  uint8_t *dst;
489  uint32_t bits;
490  uint32_t cur_size, cursor_w, cursor_h, cursor_stride;
491  uint32_t cursor_hot_x, cursor_hot_y;
492  int cursor_fmt, err;
493 
494  cur_size = bytestream2_get_be32(gb);
495  cursor_w = bytestream2_get_byte(gb);
496  cursor_h = bytestream2_get_byte(gb);
497  cursor_hot_x = bytestream2_get_byte(gb);
498  cursor_hot_y = bytestream2_get_byte(gb);
499  cursor_fmt = bytestream2_get_byte(gb);
500 
501  cursor_stride = FFALIGN(cursor_w, cursor_fmt==1 ? 32 : 1) * 4;
502 
503  if (cursor_w < 1 || cursor_w > 256 ||
504  cursor_h < 1 || cursor_h > 256) {
505  av_log(avctx, AV_LOG_ERROR, "Invalid cursor dimensions %dx%d\n",
506  cursor_w, cursor_h);
507  return AVERROR_INVALIDDATA;
508  }
509  if (cursor_hot_x > cursor_w || cursor_hot_y > cursor_h) {
510  av_log(avctx, AV_LOG_WARNING, "Invalid hotspot position %d,%d\n",
511  cursor_hot_x, cursor_hot_y);
512  cursor_hot_x = FFMIN(cursor_hot_x, cursor_w - 1);
513  cursor_hot_y = FFMIN(cursor_hot_y, cursor_h - 1);
514  }
515  if (cur_size - 9 > bytestream2_get_bytes_left(gb) ||
516  c->cursor_w * c->cursor_h / 4 > cur_size) {
517  av_log(avctx, AV_LOG_ERROR, "Invalid cursor data size %d/%d\n",
518  cur_size, bytestream2_get_bytes_left(gb));
519  return AVERROR_INVALIDDATA;
520  }
521  if (cursor_fmt != 1 && cursor_fmt != 32) {
522  avpriv_report_missing_feature(avctx, "Cursor format %d",
523  cursor_fmt);
524  return AVERROR_PATCHWELCOME;
525  }
526 
527  if ((err = av_reallocp(&c->cursor, cursor_stride * cursor_h)) < 0) {
528  av_log(avctx, AV_LOG_ERROR, "Cannot allocate cursor buffer\n");
529  return err;
530  }
531 
532  c->cursor_w = cursor_w;
533  c->cursor_h = cursor_h;
534  c->cursor_hot_x = cursor_hot_x;
535  c->cursor_hot_y = cursor_hot_y;
536  c->cursor_fmt = cursor_fmt;
537  c->cursor_stride = cursor_stride;
538 
539  dst = c->cursor;
540  switch (c->cursor_fmt) {
541  case 1: // old monochrome
542  for (j = 0; j < c->cursor_h; j++) {
543  for (i = 0; i < c->cursor_w; i += 32) {
544  bits = bytestream2_get_be32(gb);
545  for (k = 0; k < 32; k++) {
546  dst[0] = !!(bits & 0x80000000);
547  dst += 4;
548  bits <<= 1;
549  }
550  }
551  }
552 
553  dst = c->cursor;
554  for (j = 0; j < c->cursor_h; j++) {
555  for (i = 0; i < c->cursor_w; i += 32) {
556  bits = bytestream2_get_be32(gb);
557  for (k = 0; k < 32; k++) {
558  int mask_bit = !!(bits & 0x80000000);
559  switch (dst[0] * 2 + mask_bit) {
560  case 0:
561  dst[0] = 0xFF; dst[1] = 0x00;
562  dst[2] = 0x00; dst[3] = 0x00;
563  break;
564  case 1:
565  dst[0] = 0xFF; dst[1] = 0xFF;
566  dst[2] = 0xFF; dst[3] = 0xFF;
567  break;
568  default:
569  dst[0] = 0x00; dst[1] = 0x00;
570  dst[2] = 0x00; dst[3] = 0x00;
571  }
572  dst += 4;
573  bits <<= 1;
574  }
575  }
576  }
577  break;
578  case 32: // full colour
579  /* skip monochrome version of the cursor and decode RGBA instead */
580  bytestream2_skip(gb, c->cursor_h * (FFALIGN(c->cursor_w, 32) >> 3));
581  for (j = 0; j < c->cursor_h; j++) {
582  for (i = 0; i < c->cursor_w; i++) {
583  int val = bytestream2_get_be32(gb);
584  *dst++ = val >> 0;
585  *dst++ = val >> 8;
586  *dst++ = val >> 16;
587  *dst++ = val >> 24;
588  }
589  }
590  break;
591  default:
592  return AVERROR_PATCHWELCOME;
593  }
594  return 0;
595 }
596 
597 #define APPLY_ALPHA(src, new, alpha) \
598  src = (src * (256 - alpha) + new * alpha) >> 8
599 
600 static void g2m_paint_cursor(G2MContext *c, uint8_t *dst, int stride)
601 {
602  int i, j;
603  int x, y, w, h;
604  const uint8_t *cursor;
605 
606  if (!c->cursor)
607  return;
608 
609  x = c->cursor_x - c->cursor_hot_x;
610  y = c->cursor_y - c->cursor_hot_y;
611 
612  cursor = c->cursor;
613  w = c->cursor_w;
614  h = c->cursor_h;
615 
616  if (x + w > c->width)
617  w = c->width - x;
618  if (y + h > c->height)
619  h = c->height - y;
620  if (x < 0) {
621  w += x;
622  cursor += -x * 4;
623  } else {
624  dst += x * 3;
625  }
626  if (y < 0) {
627  h += y;
628  cursor += -y * c->cursor_stride;
629  } else {
630  dst += y * stride;
631  }
632  if (w < 0 || h < 0)
633  return;
634 
635  for (j = 0; j < h; j++) {
636  for (i = 0; i < w; i++) {
637  uint8_t alpha = cursor[i * 4];
638  APPLY_ALPHA(dst[i * 3 + 0], cursor[i * 4 + 1], alpha);
639  APPLY_ALPHA(dst[i * 3 + 1], cursor[i * 4 + 2], alpha);
640  APPLY_ALPHA(dst[i * 3 + 2], cursor[i * 4 + 3], alpha);
641  }
642  dst += stride;
643  cursor += c->cursor_stride;
644  }
645 }
646 
647 static int g2m_decode_frame(AVCodecContext *avctx, void *data,
648  int *got_picture_ptr, AVPacket *avpkt)
649 {
650  const uint8_t *buf = avpkt->data;
651  int buf_size = avpkt->size;
652  G2MContext *c = avctx->priv_data;
653  AVFrame *pic = data;
654  GetByteContext bc, tbc;
655  int magic;
656  int got_header = 0;
657  uint32_t chunk_size, r_mask, g_mask, b_mask;
658  int chunk_type, chunk_start;
659  int i;
660  int ret;
661 
662  if (buf_size < 12) {
663  av_log(avctx, AV_LOG_ERROR,
664  "Frame should have at least 12 bytes, got %d instead\n",
665  buf_size);
666  return AVERROR_INVALIDDATA;
667  }
668 
669  bytestream2_init(&bc, buf, buf_size);
670 
671  magic = bytestream2_get_be32(&bc);
672  if ((magic & ~0xF) != MKBETAG('G', '2', 'M', '0') ||
673  (magic & 0xF) < 2 || (magic & 0xF) > 4) {
674  av_log(avctx, AV_LOG_ERROR, "Wrong magic %08X\n", magic);
675  return AVERROR_INVALIDDATA;
676  }
677 
678  if ((magic & 0xF) != 4) {
679  av_log(avctx, AV_LOG_ERROR, "G2M2 and G2M3 are not yet supported\n");
680  return AVERROR(ENOSYS);
681  }
682 
683  while (bytestream2_get_bytes_left(&bc) > 5) {
684  chunk_size = bytestream2_get_le32(&bc) - 1;
685  chunk_type = bytestream2_get_byte(&bc);
686  chunk_start = bytestream2_tell(&bc);
687  if (chunk_size > bytestream2_get_bytes_left(&bc)) {
688  av_log(avctx, AV_LOG_ERROR, "Invalid chunk size %d type %02X\n",
689  chunk_size, chunk_type);
690  break;
691  }
692  switch (chunk_type) {
693  case DISPLAY_INFO:
694  got_header =
695  c->got_header = 0;
696  if (chunk_size < 21) {
697  av_log(avctx, AV_LOG_ERROR, "Invalid display info size %d\n",
698  chunk_size);
699  break;
700  }
701  c->width = bytestream2_get_be32(&bc);
702  c->height = bytestream2_get_be32(&bc);
703  if (c->width < 16 || c->width > avctx->width ||
704  c->height < 16 || c->height > avctx->height) {
705  av_log(avctx, AV_LOG_ERROR,
706  "Invalid frame dimensions %dx%d\n",
707  c->width, c->height);
708  ret = AVERROR_INVALIDDATA;
709  goto header_fail;
710  }
711  if (c->width != avctx->width || c->height != avctx->height) {
712  ret = ff_set_dimensions(avctx, c->width, c->height);
713  if (ret < 0)
714  goto header_fail;
715  }
716  c->compression = bytestream2_get_be32(&bc);
717  if (c->compression != 2 && c->compression != 3) {
718  av_log(avctx, AV_LOG_ERROR,
719  "Unknown compression method %d\n",
720  c->compression);
721  ret = AVERROR_PATCHWELCOME;
722  goto header_fail;
723  }
724  c->tile_width = bytestream2_get_be32(&bc);
725  c->tile_height = bytestream2_get_be32(&bc);
726  if (!c->tile_width || !c->tile_height ||
727  ((c->tile_width | c->tile_height) & 0xF)) {
728  av_log(avctx, AV_LOG_ERROR,
729  "Invalid tile dimensions %dx%d\n",
730  c->tile_width, c->tile_height);
731  ret = AVERROR_INVALIDDATA;
732  goto header_fail;
733  }
734  c->tiles_x = (c->width + c->tile_width - 1) / c->tile_width;
735  c->tiles_y = (c->height + c->tile_height - 1) / c->tile_height;
736  c->bpp = bytestream2_get_byte(&bc);
737  if (c->bpp == 32) {
738  if (bytestream2_get_bytes_left(&bc) < 16 ||
739  (chunk_size - 21) < 16 ) {
740  av_log(avctx, AV_LOG_ERROR,
741  "Display info: missing bitmasks!\n");
742  ret = AVERROR_INVALIDDATA;
743  goto header_fail;
744  }
745  r_mask = bytestream2_get_be32(&bc);
746  g_mask = bytestream2_get_be32(&bc);
747  b_mask = bytestream2_get_be32(&bc);
748  if (r_mask != 0xFF0000 || g_mask != 0xFF00 || b_mask != 0xFF) {
749  av_log(avctx, AV_LOG_ERROR,
750  "Invalid or unsupported bitmasks: R=%X, G=%X, B=%X\n",
751  r_mask, g_mask, b_mask);
752  ret = AVERROR_PATCHWELCOME;
753  goto header_fail;
754  }
755  } else {
756  avpriv_request_sample(avctx, "bpp=%d", c->bpp);
757  ret = AVERROR_PATCHWELCOME;
758  goto header_fail;
759  }
760  if (g2m_init_buffers(c)) {
761  ret = AVERROR(ENOMEM);
762  goto header_fail;
763  }
764  got_header = 1;
765  break;
766  case TILE_DATA:
767  if (!c->tiles_x || !c->tiles_y) {
768  av_log(avctx, AV_LOG_WARNING,
769  "No display info - skipping tile\n");
770  break;
771  }
772  if (chunk_size < 2) {
773  av_log(avctx, AV_LOG_ERROR, "Invalid tile data size %d\n",
774  chunk_size);
775  break;
776  }
777  c->tile_x = bytestream2_get_byte(&bc);
778  c->tile_y = bytestream2_get_byte(&bc);
779  if (c->tile_x >= c->tiles_x || c->tile_y >= c->tiles_y) {
780  av_log(avctx, AV_LOG_ERROR,
781  "Invalid tile pos %d,%d (in %dx%d grid)\n",
782  c->tile_x, c->tile_y, c->tiles_x, c->tiles_y);
783  break;
784  }
785  ret = 0;
786  switch (c->compression) {
787  case COMPR_EPIC_J_B:
788  av_log(avctx, AV_LOG_ERROR,
789  "ePIC j-b compression is not implemented yet\n");
790  return AVERROR(ENOSYS);
791  case COMPR_KEMPF_J_B:
792  ret = kempf_decode_tile(c, c->tile_x, c->tile_y,
793  buf + bytestream2_tell(&bc),
794  chunk_size - 2);
795  break;
796  }
797  if (ret && c->framebuf)
798  av_log(avctx, AV_LOG_ERROR, "Error decoding tile %d,%d\n",
799  c->tile_x, c->tile_y);
800  break;
801  case CURSOR_POS:
802  if (chunk_size < 5) {
803  av_log(avctx, AV_LOG_ERROR, "Invalid cursor pos size %d\n",
804  chunk_size);
805  break;
806  }
807  c->cursor_x = bytestream2_get_be16(&bc);
808  c->cursor_y = bytestream2_get_be16(&bc);
809  break;
810  case CURSOR_SHAPE:
811  if (chunk_size < 8) {
812  av_log(avctx, AV_LOG_ERROR, "Invalid cursor data size %d\n",
813  chunk_size);
814  break;
815  }
816  bytestream2_init(&tbc, buf + bytestream2_tell(&bc),
817  chunk_size - 4);
818  g2m_load_cursor(avctx, c, &tbc);
819  break;
820  case CHUNK_CC:
821  case CHUNK_CD:
822  break;
823  default:
824  av_log(avctx, AV_LOG_WARNING, "Skipping chunk type %02X\n",
825  chunk_type);
826  }
827 
828  /* navigate to next chunk */
829  bytestream2_skip(&bc, chunk_start + chunk_size - bytestream2_tell(&bc));
830  }
831  if (got_header)
832  c->got_header = 1;
833 
834  if (c->width && c->height && c->framebuf) {
835  if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
836  return ret;
837 
838  pic->key_frame = got_header;
839  pic->pict_type = got_header ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
840 
841  for (i = 0; i < avctx->height; i++)
842  memcpy(pic->data[0] + i * pic->linesize[0],
843  c->framebuf + i * c->framebuf_stride,
844  c->width * 3);
845  g2m_paint_cursor(c, pic->data[0], pic->linesize[0]);
846 
847  *got_picture_ptr = 1;
848  }
849 
850  return buf_size;
851 header_fail:
852  c->width = c->height = 0;
853  c->tiles_x = c->tiles_y = 0;
854  return ret;
855 }
856 
857 static av_cold int g2m_decode_init(AVCodecContext *avctx)
858 {
859  G2MContext * const c = avctx->priv_data;
860  int ret;
861 
862  if ((ret = jpg_init(avctx, &c->jc)) != 0) {
863  av_log(avctx, AV_LOG_ERROR, "Cannot initialise VLCs\n");
864  jpg_free_context(&c->jc);
865  return AVERROR(ENOMEM);
866  }
867 
868  avctx->pix_fmt = AV_PIX_FMT_RGB24;
869 
870  return 0;
871 }
872 
873 static av_cold int g2m_decode_end(AVCodecContext *avctx)
874 {
875  G2MContext * const c = avctx->priv_data;
876 
877  jpg_free_context(&c->jc);
878 
879  av_freep(&c->kempf_buf);
880  av_freep(&c->kempf_flags);
881  av_freep(&c->synth_tile);
882  av_freep(&c->jpeg_tile);
883  av_freep(&c->cursor);
884  av_freep(&c->framebuf);
885 
886  return 0;
887 }
888 
889 AVCodec ff_g2m_decoder = {
890  .name = "g2m",
891  .long_name = NULL_IF_CONFIG_SMALL("Go2Meeting"),
892  .type = AVMEDIA_TYPE_VIDEO,
893  .id = AV_CODEC_ID_G2M,
894  .priv_data_size = sizeof(G2MContext),
895  .init = g2m_decode_init,
896  .close = g2m_decode_end,
897  .decode = g2m_decode_frame,
898  .capabilities = CODEC_CAP_DR1,
899 };
Generated on Sun Mar 23 2014 23:49:54 for FFmpeg by   doxygen 1.8.2