FFmpeg: libavcodec/dxa.c Source File

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dxa.c

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1 /*

2 * Feeble Files/ScummVM DXA decoder

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 */

22 /**

23 * @file

24 * DXA Video decoder

25 */

27 #include <stdio.h>

28 #include <stdlib.h>

30 #include "libavutil/common.h"

31 #include "libavutil/intreadwrite.h"

32 #include "bytestream.h"

33 #include "avcodec.h"

34 #include "internal.h"

36 #include <zlib.h>

38 /*

39 * Decoder context

40 */

41 typedef struct DxaDecContext {

42 AVFrame *prev;

44 int dsize;

45 uint8_t *decomp_buf;

46 uint32_t pal[256];

47 } DxaDecContext;

49 static const int shift1[6] = { 0, 8, 8, 8, 4, 4 };

50 static const int shift2[6] = { 0, 0, 8, 4, 0, 4 };

52 static int decode_13(AVCodecContext *avctx, DxaDecContext *c, uint8_t* dst,

53 int stride, uint8_t *src, uint8_t *ref)

54 {

55 uint8_t *code, *data, *mv, *msk, *tmp, *tmp2;

56 int i, j, k;

57 int type, x, y, d, d2;

58 uint32_t mask;

60 code = src + 12;

61 data = code + ((avctx->width * avctx->height) >> 4);

62 mv = data + AV_RB32(src + 0);

63 msk = mv + AV_RB32(src + 4);

65 for(j = 0; j < avctx->height; j += 4){

66 for(i = 0; i < avctx->width; i += 4){

67 tmp = dst + i;

68 tmp2 = ref + i;

69 type = *code++;

70 switch(type){

71 case 4: // motion compensation

72 x = (*mv) >> 4; if(x & 8) x = 8 - x;

73 y = (*mv++) & 0xF; if(y & 8) y = 8 - y;

74 if (i < -x || avctx->width - i - 4 < x ||

75 j < -y || avctx->height - j - 4 < y) {

76 av_log(avctx, AV_LOG_ERROR, "MV %d %d out of bounds\n", x,y);

77 return AVERROR_INVALIDDATA;

78 }

79 tmp2 += x + y*stride;

80 case 0: // skip

81 case 5: // skip in method 12

82 for(y = 0; y < 4; y++){

83 memcpy(tmp, tmp2, 4);

84 tmp += stride;

85 tmp2 += stride;

86 }

87 break;

88 case 1: // masked change

89 case 10: // masked change with only half of pixels changed

90 case 11: // cases 10-15 are for method 12 only

91 case 12:

92 case 13:

93 case 14:

94 case 15:

95 if(type == 1){

96 mask = AV_RB16(msk);

97 msk += 2;

98 }else{

99 type -= 10;

100 mask = ((msk[0] & 0xF0) << shift1[type]) | ((msk[0] & 0xF) << shift2[type]);

101 msk++;

102 }

103 for(y = 0; y < 4; y++){

104 for(x = 0; x < 4; x++){

105 tmp[x] = (mask & 0x8000) ? *data++ : tmp2[x];

106 mask <<= 1;

107 }

108 tmp += stride;

109 tmp2 += stride;

110 }

111 break;

112 case 2: // fill block

113 for(y = 0; y < 4; y++){

114 memset(tmp, data[0], 4);

115 tmp += stride;

116 }

117 data++;

118 break;

119 case 3: // raw block

120 for(y = 0; y < 4; y++){

121 memcpy(tmp, data, 4);

122 data += 4;

123 tmp += stride;

124 }

125 break;

126 case 8: // subblocks - method 13 only

127 mask = *msk++;

128 for(k = 0; k < 4; k++){

129 d = ((k & 1) << 1) + ((k & 2) * stride);

130 d2 = ((k & 1) << 1) + ((k & 2) * stride);

131 tmp2 = ref + i + d2;

132 switch(mask & 0xC0){

133 case 0x80: // motion compensation

134 x = (*mv) >> 4; if(x & 8) x = 8 - x;

135 y = (*mv++) & 0xF; if(y & 8) y = 8 - y;

136 if (i + 2*(k & 1) < -x || avctx->width - i - 2*(k & 1) - 2 < x ||

137 j + (k & 2) < -y || avctx->height - j - (k & 2) - 2 < y) {

138 av_log(avctx, AV_LOG_ERROR, "MV %d %d out of bounds\n", x,y);

139 return AVERROR_INVALIDDATA;

140 }

141 tmp2 += x + y*stride;

142 case 0x00: // skip

143 tmp[d + 0 ] = tmp2[0];

144 tmp[d + 1 ] = tmp2[1];

145 tmp[d + 0 + stride] = tmp2[0 + stride];

146 tmp[d + 1 + stride] = tmp2[1 + stride];

147 break;

148 case 0x40: // fill

149 tmp[d + 0 ] = data[0];

150 tmp[d + 1 ] = data[0];

151 tmp[d + 0 + stride] = data[0];

152 tmp[d + 1 + stride] = data[0];

153 data++;

154 break;

155 case 0xC0: // raw

156 tmp[d + 0 ] = *data++;

157 tmp[d + 1 ] = *data++;

158 tmp[d + 0 + stride] = *data++;

159 tmp[d + 1 + stride] = *data++;

160 break;

161 }

162 mask <<= 2;

163 }

164 break;

165 case 32: // vector quantization - 2 colors

166 mask = AV_RB16(msk);

167 msk += 2;

168 for(y = 0; y < 4; y++){

169 for(x = 0; x < 4; x++){

170 tmp[x] = data[mask & 1];

171 mask >>= 1;

172 }

173 tmp += stride;

174 tmp2 += stride;

175 }

176 data += 2;

177 break;

178 case 33: // vector quantization - 3 or 4 colors

179 case 34:

180 mask = AV_RB32(msk);

181 msk += 4;

182 for(y = 0; y < 4; y++){

183 for(x = 0; x < 4; x++){

184 tmp[x] = data[mask & 3];

185 mask >>= 2;

186 }

187 tmp += stride;

188 tmp2 += stride;

189 }

190 data += type - 30;

191 break;

192 default:

193 av_log(avctx, AV_LOG_ERROR, "Unknown opcode %d\n", type);

194 return AVERROR_INVALIDDATA;

195 }

196 }

197 dst += stride * 4;

198 ref += stride * 4;

199 }

200 return 0;

201 }

202

203 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)

204 {

205 AVFrame *frame = data;

206 DxaDecContext * const c = avctx->priv_data;

207 uint8_t *outptr, *srcptr, *tmpptr;

208 unsigned long dsize;

209 int i, j, compr, ret;

210 int stride;

211 int pc = 0;

212 GetByteContext gb;

213

214 bytestream2_init(&gb, avpkt->data, avpkt->size);

215

216 /* make the palette available on the way out */

217 if (bytestream2_peek_le32(&gb) == MKTAG('C','M','A','P')) {

218 bytestream2_skip(&gb, 4);

219 for(i = 0; i < 256; i++){

220 c->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&gb);

221 }

222 pc = 1;

223 }

224

225 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)

226 return ret;

227 memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);

228 frame->palette_has_changed = pc;

229

230 outptr = frame->data[0];

231 srcptr = c->decomp_buf;

232 tmpptr = c->prev->data[0];

233 stride = frame->linesize[0];

234

235 if (bytestream2_get_le32(&gb) == MKTAG('N','U','L','L'))

236 compr = -1;

237 else

238 compr = bytestream2_get_byte(&gb);

239

240 dsize = c->dsize;

241 if (compr != 4 && compr != -1) {

242 bytestream2_skip(&gb, 4);

243 if (uncompress(c->decomp_buf, &dsize, avpkt->data + bytestream2_tell(&gb),

244 bytestream2_get_bytes_left(&gb)) != Z_OK) {

245 av_log(avctx, AV_LOG_ERROR, "Uncompress failed!\n");

246 return AVERROR_UNKNOWN;

247 }

248 }

249 switch(compr){

250 case -1:

251 frame->key_frame = 0;

252 frame->pict_type = AV_PICTURE_TYPE_P;

253 if (c->prev->data[0])

254 memcpy(frame->data[0], c->prev->data[0], frame->linesize[0] * avctx->height);

255 else{ // Should happen only when first frame is 'NULL'

256 memset(frame->data[0], 0, frame->linesize[0] * avctx->height);

257 frame->key_frame = 1;

258 frame->pict_type = AV_PICTURE_TYPE_I;

259 }

260 break;

261 case 2:

262 case 3:

263 case 4:

264 case 5:

265 frame->key_frame = !(compr & 1);

266 frame->pict_type = (compr & 1) ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;

267 for(j = 0; j < avctx->height; j++){

268 if((compr & 1) && tmpptr){

269 for(i = 0; i < avctx->width; i++)

270 outptr[i] = srcptr[i] ^ tmpptr[i];

271 tmpptr += stride;

272 }else

273 memcpy(outptr, srcptr, avctx->width);

274 outptr += stride;

275 srcptr += avctx->width;

276 }

277 break;

278 case 12: // ScummVM coding

279 case 13:

280 frame->key_frame = 0;

281 frame->pict_type = AV_PICTURE_TYPE_P;

282 if (!c->prev->data[0]) {

283 av_log(avctx, AV_LOG_ERROR, "Missing reference frame\n");

284 return AVERROR_INVALIDDATA;

285 }

286 decode_13(avctx, c, frame->data[0], frame->linesize[0], srcptr, c->prev->data[0]);

287 break;

288 default:

289 av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", compr);

290 return AVERROR_INVALIDDATA;

291 }

292

293 av_frame_unref(c->prev);

294 if ((ret = av_frame_ref(c->prev, frame)) < 0)

295 return ret;

296

297 *got_frame = 1;

298

299 /* always report that the buffer was completely consumed */

300 return avpkt->size;

301 }

302

303 static av_cold int decode_init(AVCodecContext *avctx)

304 {

305 DxaDecContext * const c = avctx->priv_data;

306

307 avctx->pix_fmt = AV_PIX_FMT_PAL8;

308

309 c->prev = av_frame_alloc();

310 if (!c->prev)

311 return AVERROR(ENOMEM);

312

313 c->dsize = avctx->width * avctx->height * 2;

314 c->decomp_buf = av_malloc(c->dsize);

315 if (!c->decomp_buf) {

316 av_frame_free(&c->prev);

317 av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");

318 return AVERROR(ENOMEM);

319 }

320

321 return 0;

322 }

323

324 static av_cold int decode_end(AVCodecContext *avctx)

325 {

326 DxaDecContext * const c = avctx->priv_data;

327

328 av_freep(&c->decomp_buf);

329 av_frame_free(&c->prev);

330

331 return 0;

332 }

333

334 AVCodec ff_dxa_decoder = {

335 .name = "dxa",

336 .type = AVMEDIA_TYPE_VIDEO,

337 .id = AV_CODEC_ID_DXA,

338 .priv_data_size = sizeof(DxaDecContext),

339 .init = decode_init,

340 .close = decode_end,

341 .decode = decode_frame,

342 .capabilities = CODEC_CAP_DR1,

343 .long_name = NULL_IF_CONFIG_SMALL("Feeble Files/ScummVM DXA"),

344 };

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