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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  FRAME_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  uint8_t *tmp;
240  int mb_w, mb_h, mb_x, mb_y, i, j;
241  int bx, by;
242  int unesc_size;
243  int ret;
244 
245  tmp = av_realloc(c->buf, src_size + FF_INPUT_BUFFER_PADDING_SIZE);
246  if (!tmp)
247  return AVERROR(ENOMEM);
248  c->buf = tmp;
249  jpg_unescape(src, src_size, c->buf, &unesc_size);
250  memset(c->buf + unesc_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
251  init_get_bits(&gb, c->buf, unesc_size * 8);
252 
253  width = FFALIGN(width, 16);
254  mb_w = width >> 4;
255  mb_h = (height + 15) >> 4;
256 
257  if (!num_mbs)
258  num_mbs = mb_w * mb_h;
259 
260  for (i = 0; i < 3; i++)
261  c->prev_dc[i] = 1024;
262  bx = by = 0;
263  for (mb_y = 0; mb_y < mb_h; mb_y++) {
264  for (mb_x = 0; mb_x < mb_w; mb_x++) {
265  if (mask && !mask[mb_x]) {
266  bx += 16;
267  continue;
268  }
269  for (j = 0; j < 2; j++) {
270  for (i = 0; i < 2; i++) {
271  if ((ret = jpg_decode_block(c, &gb, 0,
272  c->block[i + j * 2])) != 0)
273  return ret;
274  c->dsp.idct(c->block[i + j * 2]);
275  }
276  }
277  for (i = 1; i < 3; i++) {
278  if ((ret = jpg_decode_block(c, &gb, i, c->block[i + 3])) != 0)
279  return ret;
280  c->dsp.idct(c->block[i + 3]);
281  }
282 
283  for (j = 0; j < 16; j++) {
284  uint8_t *out = dst + bx * 3 + (by + j) * dst_stride;
285  for (i = 0; i < 16; i++) {
286  int Y, U, V;
287 
288  Y = c->block[(j >> 3) * 2 + (i >> 3)][(i & 7) + (j & 7) * 8];
289  U = c->block[4 ^ swapuv][(i >> 1) + (j >> 1) * 8] - 128;
290  V = c->block[5 ^ swapuv][(i >> 1) + (j >> 1) * 8] - 128;
291  yuv2rgb(out + i * 3, Y, U, V);
292  }
293  }
294 
295  if (!--num_mbs)
296  return 0;
297  bx += 16;
298  }
299  bx = 0;
300  by += 16;
301  if (mask)
302  mask += mask_stride;
303  }
304 
305  return 0;
306 }
307 
308 static void kempf_restore_buf(const uint8_t *src, int len,
309  uint8_t *dst, int stride,
310  const uint8_t *jpeg_tile, int tile_stride,
311  int width, int height,
312  const uint8_t *pal, int npal, int tidx)
313 {
314  GetBitContext gb;
315  int i, j, nb, col;
316 
317  init_get_bits(&gb, src, len * 8);
318 
319  if (npal <= 2) nb = 1;
320  else if (npal <= 4) nb = 2;
321  else if (npal <= 16) nb = 4;
322  else nb = 8;
323 
324  for (j = 0; j < height; j++, dst += stride, jpeg_tile += tile_stride) {
325  if (get_bits(&gb, 8))
326  continue;
327  for (i = 0; i < width; i++) {
328  col = get_bits(&gb, nb);
329  if (col != tidx)
330  memcpy(dst + i * 3, pal + col * 3, 3);
331  else
332  memcpy(dst + i * 3, jpeg_tile + i * 3, 3);
333  }
334  }
335 }
336 
337 static int kempf_decode_tile(G2MContext *c, int tile_x, int tile_y,
338  const uint8_t *src, int src_size)
339 {
340  int width, height;
341  int hdr, zsize, npal, tidx = -1, ret;
342  int i, j;
343  const uint8_t *src_end = src + src_size;
344  uint8_t pal[768], transp[3];
345  uLongf dlen = (c->tile_width + 1) * c->tile_height;
346  int sub_type;
347  int nblocks, cblocks, bstride;
348  int bits, bitbuf, coded;
349  uint8_t *dst = c->framebuf + tile_x * c->tile_width * 3 +
350  tile_y * c->tile_height * c->framebuf_stride;
351 
352  if (src_size < 2)
353  return AVERROR_INVALIDDATA;
354 
355  width = FFMIN(c->width - tile_x * c->tile_width, c->tile_width);
356  height = FFMIN(c->height - tile_y * c->tile_height, c->tile_height);
357 
358  hdr = *src++;
359  sub_type = hdr >> 5;
360  if (sub_type == 0) {
361  int j;
362  memcpy(transp, src, 3);
363  src += 3;
364  for (j = 0; j < height; j++, dst += c->framebuf_stride)
365  for (i = 0; i < width; i++)
366  memcpy(dst + i * 3, transp, 3);
367  return 0;
368  } else if (sub_type == 1) {
369  return jpg_decode_data(&c->jc, width, height, src, src_end - src,
370  dst, c->framebuf_stride, NULL, 0, 0, 0);
371  }
372 
373  if (sub_type != 2) {
374  memcpy(transp, src, 3);
375  src += 3;
376  }
377  npal = *src++ + 1;
378  if (src_end - src < npal * 3)
379  return AVERROR_INVALIDDATA;
380  memcpy(pal, src, npal * 3); src += npal * 3;
381  if (sub_type != 2) {
382  for (i = 0; i < npal; i++) {
383  if (!memcmp(pal + i * 3, transp, 3)) {
384  tidx = i;
385  break;
386  }
387  }
388  }
389 
390  if (src_end - src < 2)
391  return 0;
392  zsize = (src[0] << 8) | src[1]; src += 2;
393 
394  if (src_end - src < zsize + (sub_type != 2))
395  return AVERROR_INVALIDDATA;
396 
397  ret = uncompress(c->kempf_buf, &dlen, src, zsize);
398  if (ret)
399  return AVERROR_INVALIDDATA;
400  src += zsize;
401 
402  if (sub_type == 2) {
403  kempf_restore_buf(c->kempf_buf, dlen, dst, c->framebuf_stride,
404  NULL, 0, width, height, pal, npal, tidx);
405  return 0;
406  }
407 
408  nblocks = *src++ + 1;
409  cblocks = 0;
410  bstride = FFALIGN(width, 16) >> 4;
411  // blocks are coded LSB and we need normal bitreader for JPEG data
412  bits = 0;
413  for (i = 0; i < (FFALIGN(height, 16) >> 4); i++) {
414  for (j = 0; j < (FFALIGN(width, 16) >> 4); j++) {
415  if (!bits) {
416  if (src >= src_end)
417  return AVERROR_INVALIDDATA;
418  bitbuf = *src++;
419  bits = 8;
420  }
421  coded = bitbuf & 1;
422  bits--;
423  bitbuf >>= 1;
424  cblocks += coded;
425  if (cblocks > nblocks)
426  return AVERROR_INVALIDDATA;
427  c->kempf_flags[j + i * bstride] = coded;
428  }
429  }
430 
431  memset(c->jpeg_tile, 0, c->tile_stride * height);
432  jpg_decode_data(&c->jc, width, height, src, src_end - src,
433  c->jpeg_tile, c->tile_stride,
434  c->kempf_flags, bstride, nblocks, 0);
435 
436  kempf_restore_buf(c->kempf_buf, dlen, dst, c->framebuf_stride,
437  c->jpeg_tile, c->tile_stride,
438  width, height, pal, npal, tidx);
439 
440  return 0;
441 }
442 
443 static int g2m_init_buffers(G2MContext *c)
444 {
445  int aligned_height;
446 
447  if (!c->framebuf || c->old_width < c->width || c->old_height < c->height) {
448  c->framebuf_stride = FFALIGN(c->width + 15, 16) * 3;
449  aligned_height = c->height + 15;
450  av_free(c->framebuf);
451  c->framebuf = av_mallocz(c->framebuf_stride * aligned_height);
452  if (!c->framebuf)
453  return AVERROR(ENOMEM);
454  }
455  if (!c->synth_tile || !c->jpeg_tile ||
456  c->old_tile_w < c->tile_width ||
457  c->old_tile_h < c->tile_height) {
458  c->tile_stride = FFALIGN(c->tile_width, 16) * 3;
459  aligned_height = FFALIGN(c->tile_height, 16);
460  av_free(c->synth_tile);
461  av_free(c->jpeg_tile);
462  av_free(c->kempf_buf);
463  av_free(c->kempf_flags);
464  c->synth_tile = av_mallocz(c->tile_stride * aligned_height);
465  c->jpeg_tile = av_mallocz(c->tile_stride * aligned_height);
466  c->kempf_buf = av_mallocz((c->tile_width + 1) * aligned_height
467  + FF_INPUT_BUFFER_PADDING_SIZE);
468  c->kempf_flags = av_mallocz( c->tile_width * aligned_height);
469  if (!c->synth_tile || !c->jpeg_tile ||
470  !c->kempf_buf || !c->kempf_flags)
471  return AVERROR(ENOMEM);
472  }
473 
474  return 0;
475 }
476 
477 static int g2m_load_cursor(AVCodecContext *avctx, G2MContext *c,
478  GetByteContext *gb)
479 {
480  int i, j, k;
481  uint8_t *dst;
482  uint32_t bits;
483  uint32_t cur_size, cursor_w, cursor_h, cursor_stride;
484  uint32_t cursor_hot_x, cursor_hot_y;
485  int cursor_fmt;
486  uint8_t *tmp;
487 
488  cur_size = bytestream2_get_be32(gb);
489  cursor_w = bytestream2_get_byte(gb);
490  cursor_h = bytestream2_get_byte(gb);
491  cursor_hot_x = bytestream2_get_byte(gb);
492  cursor_hot_y = bytestream2_get_byte(gb);
493  cursor_fmt = bytestream2_get_byte(gb);
494 
495  cursor_stride = FFALIGN(cursor_w, cursor_fmt==1 ? 32 : 1) * 4;
496 
497  if (cursor_w < 1 || cursor_w > 256 ||
498  cursor_h < 1 || cursor_h > 256) {
499  av_log(avctx, AV_LOG_ERROR, "Invalid cursor dimensions %dx%d\n",
500  cursor_w, cursor_h);
501  return AVERROR_INVALIDDATA;
502  }
503  if (cursor_hot_x > cursor_w || cursor_hot_y > cursor_h) {
504  av_log(avctx, AV_LOG_WARNING, "Invalid hotspot position %d,%d\n",
505  cursor_hot_x, cursor_hot_y);
506  cursor_hot_x = FFMIN(cursor_hot_x, cursor_w - 1);
507  cursor_hot_y = FFMIN(cursor_hot_y, cursor_h - 1);
508  }
509  if (cur_size - 9 > bytestream2_get_bytes_left(gb) ||
510  c->cursor_w * c->cursor_h / 4 > cur_size) {
511  av_log(avctx, AV_LOG_ERROR, "Invalid cursor data size %d/%d\n",
512  cur_size, bytestream2_get_bytes_left(gb));
513  return AVERROR_INVALIDDATA;
514  }
515  if (cursor_fmt != 1 && cursor_fmt != 32) {
516  avpriv_report_missing_feature(avctx, "Cursor format %d",
517  cursor_fmt);
518  return AVERROR_PATCHWELCOME;
519  }
520 
521  tmp = av_realloc(c->cursor, cursor_stride * cursor_h);
522  if (!tmp) {
523  av_log(avctx, AV_LOG_ERROR, "Cannot allocate cursor buffer\n");
524  return AVERROR(ENOMEM);
525  }
526 
527  c->cursor = tmp;
528  c->cursor_w = cursor_w;
529  c->cursor_h = cursor_h;
530  c->cursor_hot_x = cursor_hot_x;
531  c->cursor_hot_y = cursor_hot_y;
532  c->cursor_fmt = cursor_fmt;
533  c->cursor_stride = cursor_stride;
534 
535  dst = c->cursor;
536  switch (c->cursor_fmt) {
537  case 1: // old monochrome
538  for (j = 0; j < c->cursor_h; j++) {
539  for (i = 0; i < c->cursor_w; i += 32) {
540  bits = bytestream2_get_be32(gb);
541  for (k = 0; k < 32; k++) {
542  dst[0] = !!(bits & 0x80000000);
543  dst += 4;
544  bits <<= 1;
545  }
546  }
547  }
548 
549  dst = c->cursor;
550  for (j = 0; j < c->cursor_h; j++) {
551  for (i = 0; i < c->cursor_w; i += 32) {
552  bits = bytestream2_get_be32(gb);
553  for (k = 0; k < 32; k++) {
554  int mask_bit = !!(bits & 0x80000000);
555  switch (dst[0] * 2 + mask_bit) {
556  case 0:
557  dst[0] = 0xFF; dst[1] = 0x00;
558  dst[2] = 0x00; dst[3] = 0x00;
559  break;
560  case 1:
561  dst[0] = 0xFF; dst[1] = 0xFF;
562  dst[2] = 0xFF; dst[3] = 0xFF;
563  break;
564  default:
565  dst[0] = 0x00; dst[1] = 0x00;
566  dst[2] = 0x00; dst[3] = 0x00;
567  }
568  dst += 4;
569  bits <<= 1;
570  }
571  }
572  }
573  break;
574  case 32: // full colour
575  /* skip monochrome version of the cursor and decode RGBA instead */
576  bytestream2_skip(gb, c->cursor_h * (FFALIGN(c->cursor_w, 32) >> 3));
577  for (j = 0; j < c->cursor_h; j++) {
578  for (i = 0; i < c->cursor_w; i++) {
579  int val = bytestream2_get_be32(gb);
580  *dst++ = val >> 0;
581  *dst++ = val >> 8;
582  *dst++ = val >> 16;
583  *dst++ = val >> 24;
584  }
585  }
586  break;
587  default:
588  return AVERROR_PATCHWELCOME;
589  }
590  return 0;
591 }
592 
593 #define APPLY_ALPHA(src, new, alpha) \
594  src = (src * (256 - alpha) + new * alpha) >> 8
595 
596 static void g2m_paint_cursor(G2MContext *c, uint8_t *dst, int stride)
597 {
598  int i, j;
599  int x, y, w, h;
600  const uint8_t *cursor;
601 
602  if (!c->cursor)
603  return;
604 
605  x = c->cursor_x - c->cursor_hot_x;
606  y = c->cursor_y - c->cursor_hot_y;
607 
608  cursor = c->cursor;
609  w = c->cursor_w;
610  h = c->cursor_h;
611 
612  if (x + w > c->width)
613  w = c->width - x;
614  if (y + h > c->height)
615  h = c->height - y;
616  if (x < 0) {
617  w += x;
618  cursor += -x * 4;
619  } else {
620  dst += x * 3;
621  }
622  if (y < 0) {
623  h += y;
624  cursor += -y * c->cursor_stride;
625  } else {
626  dst += y * stride;
627  }
628  if (w < 0 || h < 0)
629  return;
630 
631  for (j = 0; j < h; j++) {
632  for (i = 0; i < w; i++) {
633  uint8_t alpha = cursor[i * 4];
634  APPLY_ALPHA(dst[i * 3 + 0], cursor[i * 4 + 1], alpha);
635  APPLY_ALPHA(dst[i * 3 + 1], cursor[i * 4 + 2], alpha);
636  APPLY_ALPHA(dst[i * 3 + 2], cursor[i * 4 + 3], alpha);
637  }
638  dst += stride;
639  cursor += c->cursor_stride;
640  }
641 }
642 
643 static int g2m_decode_frame(AVCodecContext *avctx, void *data,
644  int *got_picture_ptr, AVPacket *avpkt)
645 {
646  const uint8_t *buf = avpkt->data;
647  int buf_size = avpkt->size;
648  G2MContext *c = avctx->priv_data;
649  AVFrame *pic = data;
650  GetByteContext bc, tbc;
651  int magic;
652  int got_header = 0;
653  uint32_t chunk_size;
654  int chunk_type;
655  int i;
656  int ret;
657 
658  if (buf_size < 12) {
659  av_log(avctx, AV_LOG_ERROR,
660  "Frame should have at least 12 bytes, got %d instead\n",
661  buf_size);
662  return AVERROR_INVALIDDATA;
663  }
664 
665  bytestream2_init(&bc, buf, buf_size);
666 
667  magic = bytestream2_get_be32(&bc);
668  if ((magic & ~0xF) != MKBETAG('G', '2', 'M', '0') ||
669  (magic & 0xF) < 2 || (magic & 0xF) > 4) {
670  av_log(avctx, AV_LOG_ERROR, "Wrong magic %08X\n", magic);
671  return AVERROR_INVALIDDATA;
672  }
673 
674  if ((magic & 0xF) != 4) {
675  av_log(avctx, AV_LOG_ERROR, "G2M2 and G2M3 are not yet supported\n");
676  return AVERROR(ENOSYS);
677  }
678 
679  while (bytestream2_get_bytes_left(&bc) > 5) {
680  chunk_size = bytestream2_get_le32(&bc) - 1;
681  chunk_type = bytestream2_get_byte(&bc);
682  if (chunk_size > bytestream2_get_bytes_left(&bc)) {
683  av_log(avctx, AV_LOG_ERROR, "Invalid chunk size %d type %02X\n",
684  chunk_size, chunk_type);
685  break;
686  }
687  switch (chunk_type) {
688  case FRAME_INFO:
689  c->got_header = 0;
690  if (chunk_size < 21) {
691  av_log(avctx, AV_LOG_ERROR, "Invalid frame info size %d\n",
692  chunk_size);
693  break;
694  }
695  c->width = bytestream2_get_be32(&bc);
696  c->height = bytestream2_get_be32(&bc);
697  if (c->width < 16 || c->width > avctx->width ||
698  c->height < 16 || c->height > avctx->height) {
699  av_log(avctx, AV_LOG_ERROR,
700  "Invalid frame dimensions %dx%d\n",
701  c->width, c->height);
702  ret = AVERROR_INVALIDDATA;
703  goto header_fail;
704  }
705  if (c->width != avctx->width || c->height != avctx->height)
706  avcodec_set_dimensions(avctx, c->width, c->height);
707  c->compression = bytestream2_get_be32(&bc);
708  if (c->compression != 2 && c->compression != 3) {
709  av_log(avctx, AV_LOG_ERROR,
710  "Unknown compression method %d\n",
711  c->compression);
712  return AVERROR_PATCHWELCOME;
713  }
714  c->tile_width = bytestream2_get_be32(&bc);
715  c->tile_height = bytestream2_get_be32(&bc);
716  if (!c->tile_width || !c->tile_height) {
717  av_log(avctx, AV_LOG_ERROR,
718  "Invalid tile dimensions %dx%d\n",
719  c->tile_width, c->tile_height);
720  ret = AVERROR_INVALIDDATA;
721  goto header_fail;
722  }
723  c->tiles_x = (c->width + c->tile_width - 1) / c->tile_width;
724  c->tiles_y = (c->height + c->tile_height - 1) / c->tile_height;
725  c->bpp = bytestream2_get_byte(&bc);
726  chunk_size -= 21;
727  bytestream2_skip(&bc, chunk_size);
728  if (g2m_init_buffers(c)) {
729  ret = AVERROR(ENOMEM);
730  goto header_fail;
731  }
732  got_header = 1;
733  break;
734  case TILE_DATA:
735  if (!c->tiles_x || !c->tiles_y) {
736  av_log(avctx, AV_LOG_WARNING,
737  "No frame header - skipping tile\n");
738  bytestream2_skip(&bc, bytestream2_get_bytes_left(&bc));
739  break;
740  }
741  if (chunk_size < 2) {
742  av_log(avctx, AV_LOG_ERROR, "Invalid tile data size %d\n",
743  chunk_size);
744  break;
745  }
746  c->tile_x = bytestream2_get_byte(&bc);
747  c->tile_y = bytestream2_get_byte(&bc);
748  if (c->tile_x >= c->tiles_x || c->tile_y >= c->tiles_y) {
749  av_log(avctx, AV_LOG_ERROR,
750  "Invalid tile pos %d,%d (in %dx%d grid)\n",
751  c->tile_x, c->tile_y, c->tiles_x, c->tiles_y);
752  break;
753  }
754  chunk_size -= 2;
755  ret = 0;
756  switch (c->compression) {
757  case COMPR_EPIC_J_B:
758  av_log(avctx, AV_LOG_ERROR,
759  "ePIC j-b compression is not implemented yet\n");
760  return AVERROR(ENOSYS);
761  case COMPR_KEMPF_J_B:
762  ret = kempf_decode_tile(c, c->tile_x, c->tile_y,
763  buf + bytestream2_tell(&bc),
764  chunk_size);
765  break;
766  }
767  if (ret && c->framebuf)
768  av_log(avctx, AV_LOG_ERROR, "Error decoding tile %d,%d\n",
769  c->tile_x, c->tile_y);
770  bytestream2_skip(&bc, chunk_size);
771  break;
772  case CURSOR_POS:
773  if (chunk_size < 5) {
774  av_log(avctx, AV_LOG_ERROR, "Invalid cursor pos size %d\n",
775  chunk_size);
776  break;
777  }
778  c->cursor_x = bytestream2_get_be16(&bc);
779  c->cursor_y = bytestream2_get_be16(&bc);
780  bytestream2_skip(&bc, chunk_size - 4);
781  break;
782  case CURSOR_SHAPE:
783  if (chunk_size < 8) {
784  av_log(avctx, AV_LOG_ERROR, "Invalid cursor data size %d\n",
785  chunk_size);
786  break;
787  }
788  bytestream2_init(&tbc, buf + bytestream2_tell(&bc),
789  chunk_size - 4);
790  g2m_load_cursor(avctx, c, &tbc);
791  bytestream2_skip(&bc, chunk_size);
792  break;
793  case CHUNK_CC:
794  case CHUNK_CD:
795  bytestream2_skip(&bc, chunk_size);
796  break;
797  default:
798  av_log(avctx, AV_LOG_WARNING, "Skipping chunk type %02X\n",
799  chunk_type);
800  bytestream2_skip(&bc, chunk_size);
801  }
802  }
803  if (got_header)
804  c->got_header = 1;
805 
806  if (c->width && c->height && c->framebuf) {
807  if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
808  return ret;
809 
810  pic->key_frame = got_header;
811  pic->pict_type = got_header ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
812 
813  for (i = 0; i < avctx->height; i++)
814  memcpy(pic->data[0] + i * pic->linesize[0],
815  c->framebuf + i * c->framebuf_stride,
816  c->width * 3);
817  g2m_paint_cursor(c, pic->data[0], pic->linesize[0]);
818 
819  *got_picture_ptr = 1;
820  }
821 
822  return buf_size;
823 header_fail:
824  c->width = c->height = 0;
825  c->tiles_x = c->tiles_y = 0;
826  return ret;
827 }
828 
829 static av_cold int g2m_decode_init(AVCodecContext *avctx)
830 {
831  G2MContext * const c = avctx->priv_data;
832  int ret;
833 
834  if ((ret = jpg_init(avctx, &c->jc)) != 0) {
835  av_log(avctx, AV_LOG_ERROR, "Cannot initialise VLCs\n");
836  jpg_free_context(&c->jc);
837  return AVERROR(ENOMEM);
838  }
839 
840  avctx->pix_fmt = AV_PIX_FMT_RGB24;
841 
842  return 0;
843 }
844 
845 static av_cold int g2m_decode_end(AVCodecContext *avctx)
846 {
847  G2MContext * const c = avctx->priv_data;
848 
849  jpg_free_context(&c->jc);
850 
851  av_freep(&c->kempf_buf);
852  av_freep(&c->kempf_flags);
853  av_freep(&c->synth_tile);
854  av_freep(&c->jpeg_tile);
855  av_freep(&c->cursor);
856  av_freep(&c->framebuf);
857 
858  return 0;
859 }
860 
861 AVCodec ff_g2m_decoder = {
862  .name = "g2m",
863  .long_name = NULL_IF_CONFIG_SMALL("Go2Meeting"),
864  .type = AVMEDIA_TYPE_VIDEO,
865  .id = AV_CODEC_ID_G2M,
866  .priv_data_size = sizeof(G2MContext),
867  .init = g2m_decode_init,
868  .close = g2m_decode_end,
869  .decode = g2m_decode_frame,
870  .capabilities = CODEC_CAP_DR1,
871 };
Generated on Sat Jan 25 2014 19:51:47 for FFmpeg by   doxygen 1.8.2