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  1. /*
  2. * Beam Software VB decoder
  3. * Copyright (c) 2007 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. * @file
  23. * VB Video decoder
  24. */
  25. #include <stdio.h>
  26. #include <stdlib.h>
  27. #include "avcodec.h"
  28. #include "bytestream.h"
  29. enum VBFlags{
  30. VB_HAS_GMC = 0x01,
  31. VB_HAS_AUDIO = 0x04,
  32. VB_HAS_VIDEO = 0x08,
  33. VB_HAS_PALETTE = 0x10,
  34. VB_HAS_LENGTH = 0x20
  35. };
  36. typedef struct VBDecContext {
  37. AVCodecContext *avctx;
  38. AVFrame pic;
  39. uint8_t *frame, *prev_frame;
  40. uint32_t pal[AVPALETTE_COUNT];
  41. GetByteContext stream;
  42. } VBDecContext;
  43. static const uint16_t vb_patterns[64] = {
  44. 0x0660, 0xFF00, 0xCCCC, 0xF000, 0x8888, 0x000F, 0x1111, 0xFEC8,
  45. 0x8CEF, 0x137F, 0xF731, 0xC800, 0x008C, 0x0013, 0x3100, 0xCC00,
  46. 0x00CC, 0x0033, 0x3300, 0x0FF0, 0x6666, 0x00F0, 0x0F00, 0x2222,
  47. 0x4444, 0xF600, 0x8CC8, 0x006F, 0x1331, 0x318C, 0xC813, 0x33CC,
  48. 0x6600, 0x0CC0, 0x0066, 0x0330, 0xF900, 0xC88C, 0x009F, 0x3113,
  49. 0x6000, 0x0880, 0x0006, 0x0110, 0xCC88, 0xFC00, 0x00CF, 0x88CC,
  50. 0x003F, 0x1133, 0x3311, 0xF300, 0x6FF6, 0x0603, 0x08C6, 0x8C63,
  51. 0xC631, 0x6310, 0xC060, 0x0136, 0x136C, 0x36C8, 0x6C80, 0x324C
  52. };
  53. static void vb_decode_palette(VBDecContext *c, int data_size)
  54. {
  55. int start, size, i;
  56. start = bytestream2_get_byte(&c->stream);
  57. size = (bytestream2_get_byte(&c->stream) - 1) & 0xFF;
  58. if(start + size > 255){
  59. av_log(c->avctx, AV_LOG_ERROR, "Palette change runs beyond entry 256\n");
  60. return;
  61. }
  62. if(size*3+2 > data_size){
  63. av_log(c->avctx, AV_LOG_ERROR, "Palette data runs beyond chunk size\n");
  64. return;
  65. }
  66. for(i = start; i <= start + size; i++)
  67. c->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&c->stream);
  68. }
  69. static inline int check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end)
  70. {
  71. return buf >= start && buf < end;
  72. }
  73. static inline int check_line(uint8_t *buf, uint8_t *start, uint8_t *end)
  74. {
  75. return buf >= start && (buf + 4) <= end;
  76. }
  77. static int vb_decode_framedata(VBDecContext *c, int offset)
  78. {
  79. GetByteContext g;
  80. uint8_t *prev, *cur;
  81. int blk, blocks, t, blk2;
  82. int blocktypes = 0;
  83. int x, y, a, b;
  84. int pattype, pattern;
  85. const int width = c->avctx->width;
  86. uint8_t *pstart = c->prev_frame;
  87. uint8_t *pend = c->prev_frame + width*c->avctx->height;
  88. g = c->stream;
  89. prev = c->prev_frame + offset;
  90. cur = c->frame;
  91. blocks = (c->avctx->width >> 2) * (c->avctx->height >> 2);
  92. blk2 = 0;
  93. for(blk = 0; blk < blocks; blk++){
  94. if(!(blk & 3)) {
  95. blocktypes = bytestream2_get_byte(&g);
  96. }
  97. switch(blocktypes & 0xC0){
  98. case 0x00: //skip
  99. for(y = 0; y < 4; y++)
  100. if(check_line(prev + y*width, pstart, pend))
  101. memcpy(cur + y*width, prev + y*width, 4);
  102. else
  103. memset(cur + y*width, 0, 4);
  104. break;
  105. case 0x40:
  106. t = bytestream2_get_byte(&g);
  107. if(!t){ //raw block
  108. if (bytestream2_get_bytes_left(&g) < 16) {
  109. av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
  110. return -1;
  111. }
  112. for(y = 0; y < 4; y++)
  113. bytestream2_get_buffer(&g, cur + y * width, 4);
  114. }else{ // motion compensation
  115. x = ((t & 0xF)^8) - 8;
  116. y = ((t >> 4) ^8) - 8;
  117. t = x + y*width;
  118. for(y = 0; y < 4; y++)
  119. if(check_line(prev + t + y*width, pstart, pend))
  120. memcpy(cur + y*width, prev + t + y*width, 4);
  121. else
  122. memset(cur + y*width, 0, 4);
  123. }
  124. break;
  125. case 0x80: // fill
  126. t = bytestream2_get_byte(&g);
  127. for(y = 0; y < 4; y++)
  128. memset(cur + y*width, t, 4);
  129. break;
  130. case 0xC0: // pattern fill
  131. t = bytestream2_get_byte(&g);
  132. pattype = t >> 6;
  133. pattern = vb_patterns[t & 0x3F];
  134. switch(pattype){
  135. case 0:
  136. a = bytestream2_get_byte(&g);
  137. b = bytestream2_get_byte(&g);
  138. for(y = 0; y < 4; y++)
  139. for(x = 0; x < 4; x++, pattern >>= 1)
  140. cur[x + y*width] = (pattern & 1) ? b : a;
  141. break;
  142. case 1:
  143. pattern = ~pattern;
  144. case 2:
  145. a = bytestream2_get_byte(&g);
  146. for(y = 0; y < 4; y++)
  147. for(x = 0; x < 4; x++, pattern >>= 1)
  148. if(pattern & 1 && check_pixel(prev + x + y*width, pstart, pend))
  149. cur[x + y*width] = prev[x + y*width];
  150. else
  151. cur[x + y*width] = a;
  152. break;
  153. case 3:
  154. av_log(c->avctx, AV_LOG_ERROR, "Invalid opcode seen @%d\n",blk);
  155. return -1;
  156. }
  157. break;
  158. }
  159. blocktypes <<= 2;
  160. cur += 4;
  161. prev += 4;
  162. blk2++;
  163. if(blk2 == (width >> 2)){
  164. blk2 = 0;
  165. cur += width * 3;
  166. prev += width * 3;
  167. }
  168. }
  169. return 0;
  170. }
  171. static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
  172. {
  173. VBDecContext * const c = avctx->priv_data;
  174. uint8_t *outptr, *srcptr;
  175. int i, j;
  176. int flags;
  177. uint32_t size;
  178. int offset = 0;
  179. bytestream2_init(&c->stream, avpkt->data, avpkt->size);
  180. if(c->pic.data[0])
  181. avctx->release_buffer(avctx, &c->pic);
  182. c->pic.reference = 3;
  183. if(avctx->get_buffer(avctx, &c->pic) < 0){
  184. av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
  185. return -1;
  186. }
  187. flags = bytestream2_get_le16(&c->stream);
  188. if(flags & VB_HAS_GMC){
  189. i = (int16_t)bytestream2_get_le16(&c->stream);
  190. j = (int16_t)bytestream2_get_le16(&c->stream);
  191. offset = i + j * avctx->width;
  192. }
  193. if(flags & VB_HAS_VIDEO){
  194. size = bytestream2_get_le32(&c->stream);
  195. if(size > bytestream2_get_bytes_left(&c->stream)+4 || size<4){
  196. av_log(avctx, AV_LOG_ERROR, "Frame size invalid\n");
  197. return -1;
  198. }
  199. vb_decode_framedata(c, offset);
  200. bytestream2_skip(&c->stream, size - 4);
  201. }
  202. if(flags & VB_HAS_PALETTE){
  203. size = bytestream2_get_le32(&c->stream);
  204. vb_decode_palette(c, size);
  205. }
  206. memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
  207. c->pic.palette_has_changed = flags & VB_HAS_PALETTE;
  208. outptr = c->pic.data[0];
  209. srcptr = c->frame;
  210. for(i = 0; i < avctx->height; i++){
  211. memcpy(outptr, srcptr, avctx->width);
  212. srcptr += avctx->width;
  213. outptr += c->pic.linesize[0];
  214. }
  215. FFSWAP(uint8_t*, c->frame, c->prev_frame);
  216. *data_size = sizeof(AVFrame);
  217. *(AVFrame*)data = c->pic;
  218. /* always report that the buffer was completely consumed */
  219. return avpkt->size;
  220. }
  221. static av_cold int decode_init(AVCodecContext *avctx)
  222. {
  223. VBDecContext * const c = avctx->priv_data;
  224. c->avctx = avctx;
  225. avctx->pix_fmt = PIX_FMT_PAL8;
  226. avcodec_get_frame_defaults(&c->pic);
  227. c->frame = av_mallocz(avctx->width * avctx->height);
  228. c->prev_frame = av_mallocz(avctx->width * avctx->height);
  229. return 0;
  230. }
  231. static av_cold int decode_end(AVCodecContext *avctx)
  232. {
  233. VBDecContext *c = avctx->priv_data;
  234. av_freep(&c->frame);
  235. av_freep(&c->prev_frame);
  236. if(c->pic.data[0])
  237. avctx->release_buffer(avctx, &c->pic);
  238. return 0;
  239. }
  240. AVCodec ff_vb_decoder = {
  241. .name = "vb",
  242. .type = AVMEDIA_TYPE_VIDEO,
  243. .id = AV_CODEC_ID_VB,
  244. .priv_data_size = sizeof(VBDecContext),
  245. .init = decode_init,
  246. .close = decode_end,
  247. .decode = decode_frame,
  248. .long_name = NULL_IF_CONFIG_SMALL("Beam Software VB"),
  249. };