1/* 2 * Copyright (C) 2005 Ole Andr� Vadla Ravn�s <oleavr@gmail.com> 3 * Copyright (C) 2008 Ramiro Polla <ramiro@lisha.ufsc.br> 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#include <stdlib.h> 23#include <string.h> 24#include <stdint.h> 25 26#include "avcodec.h" 27#include "get_bits.h" 28#include "bytestream.h" 29#include "dsputil.h" 30 31#define MIMIC_HEADER_SIZE 20 32 33typedef struct { 34 AVCodecContext *avctx; 35 36 int num_vblocks[3]; 37 int num_hblocks[3]; 38 39 void *swap_buf; 40 int swap_buf_size; 41 42 int cur_index; 43 int prev_index; 44 45 AVFrame buf_ptrs [16]; 46 AVPicture flipped_ptrs[16]; 47 48 DECLARE_ALIGNED(16, DCTELEM, dct_block)[64]; 49 50 GetBitContext gb; 51 ScanTable scantable; 52 DSPContext dsp; 53 VLC vlc; 54} MimicContext; 55 56static const uint32_t huffcodes[] = { 57 0x0000000a, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 58 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 59 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x0000000b, 60 0x0000001b, 0x00000038, 0x00000078, 0x00000079, 0x0000007a, 0x000000f9, 61 0x000000fa, 0x000003fb, 0x000007f8, 0x000007f9, 0x000007fa, 0x000007fb, 62 0x00000ff8, 0x00000ff9, 0x00000001, 0x00000039, 0x0000007b, 0x000000fb, 63 0x000001f8, 0x000001f9, 0x00000ffa, 0x00000ffb, 0x00001ff8, 0x00001ff9, 64 0x00001ffa, 0x00001ffb, 0x00003ff8, 0x00003ff9, 0x00003ffa, 0x00000000, 65 0x00000004, 0x0000003a, 0x000001fa, 0x00003ffb, 0x00007ff8, 0x00007ff9, 66 0x00007ffa, 0x00007ffb, 0x0000fff8, 0x0000fff9, 0x0000fffa, 0x0000fffb, 67 0x0001fff8, 0x0001fff9, 0x0001fffa, 0x00000000, 0x0000000c, 0x000000f8, 68 0x000001fb, 0x0001fffb, 0x0003fff8, 0x0003fff9, 0x0003fffa, 0x0003fffb, 69 0x0007fff8, 0x0007fff9, 0x0007fffa, 0x0007fffb, 0x000ffff8, 0x000ffff9, 70 0x000ffffa, 0x00000000, 0x0000001a, 0x000003f8, 0x000ffffb, 0x001ffff8, 71 0x001ffff9, 0x001ffffa, 0x001ffffb, 0x003ffff8, 0x003ffff9, 0x003ffffa, 72 0x003ffffb, 0x007ffff8, 0x007ffff9, 0x007ffffa, 0x007ffffb, 0x00000000, 73 0x0000003b, 0x000003f9, 0x00fffff8, 0x00fffff9, 0x00fffffa, 0x00fffffb, 74 0x01fffff8, 0x01fffff9, 0x01fffffa, 0x01fffffb, 0x03fffff8, 0x03fffff9, 75 0x03fffffa, 0x03fffffb, 0x07fffff8, 0x00000000, 0x000003fa, 0x07fffff9, 76 0x07fffffa, 0x07fffffb, 0x0ffffff8, 0x0ffffff9, 0x0ffffffa, 0x0ffffffb, 77 0x1ffffff8, 0x1ffffff9, 0x1ffffffa, 0x1ffffffb, 0x3ffffff8, 0x3ffffff9, 78 0x3ffffffa, 79}; 80 81static const uint8_t huffbits[] = { 82 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 83 0, 0, 0, 0, 2, 4, 5, 6, 7, 7, 7, 8, 84 8, 10, 11, 11, 11, 11, 12, 12, 2, 6, 7, 8, 85 9, 9, 12, 12, 13, 13, 13, 13, 14, 14, 14, 0, 86 3, 6, 9, 14, 15, 15, 15, 15, 16, 16, 16, 16, 87 17, 17, 17, 0, 4, 8, 9, 17, 18, 18, 18, 18, 88 19, 19, 19, 19, 20, 20, 20, 0, 5, 10, 20, 21, 89 21, 21, 21, 22, 22, 22, 22, 23, 23, 23, 23, 0, 90 6, 10, 24, 24, 24, 24, 25, 25, 25, 25, 26, 26, 91 26, 26, 27, 0, 10, 27, 27, 27, 28, 28, 28, 28, 92 29, 29, 29, 29, 30, 30, 30, 93}; 94 95static const uint8_t col_zag[64] = { 96 0, 8, 1, 2, 9, 16, 24, 17, 97 10, 3, 4, 11, 18, 25, 32, 40, 98 33, 26, 19, 12, 5, 6, 13, 20, 99 27, 34, 41, 48, 56, 49, 42, 35, 100 28, 21, 14, 7, 15, 22, 29, 36, 101 43, 50, 57, 58, 51, 44, 37, 30, 102 23, 31, 38, 45, 52, 59, 39, 46, 103 53, 60, 61, 54, 47, 55, 62, 63, 104}; 105 106static av_cold int mimic_decode_init(AVCodecContext *avctx) 107{ 108 MimicContext *ctx = avctx->priv_data; 109 110 ctx->prev_index = 0; 111 ctx->cur_index = 15; 112 113 if(init_vlc(&ctx->vlc, 11, FF_ARRAY_ELEMS(huffbits), 114 huffbits, 1, 1, huffcodes, 4, 4, 0)) { 115 av_log(avctx, AV_LOG_ERROR, "error initializing vlc table\n"); 116 return -1; 117 } 118 dsputil_init(&ctx->dsp, avctx); 119 ff_init_scantable(ctx->dsp.idct_permutation, &ctx->scantable, col_zag); 120 121 return 0; 122} 123 124static const int8_t vlcdec_lookup[9][64] = { 125 { 0, }, 126 { -1, 1, }, 127 { -3, 3, -2, 2, }, 128 { -7, 7, -6, 6, -5, 5, -4, 4, }, 129 { -15, 15, -14, 14, -13, 13, -12, 12, 130 -11, 11, -10, 10, -9, 9, -8, 8, }, 131 { -31, 31, -30, 30, -29, 29, -28, 28, 132 -27, 27, -26, 26, -25, 25, -24, 24, 133 -23, 23, -22, 22, -21, 21, -20, 20, 134 -19, 19, -18, 18, -17, 17, -16, 16, }, 135 { -63, 63, -62, 62, -61, 61, -60, 60, 136 -59, 59, -58, 58, -57, 57, -56, 56, 137 -55, 55, -54, 54, -53, 53, -52, 52, 138 -51, 51, -50, 50, -49, 49, -48, 48, 139 -47, 47, -46, 46, -45, 45, -44, 44, 140 -43, 43, -42, 42, -41, 41, -40, 40, 141 -39, 39, -38, 38, -37, 37, -36, 36, 142 -35, 35, -34, 34, -33, 33, -32, 32, }, 143 { -127, 127, -126, 126, -125, 125, -124, 124, 144 -123, 123, -122, 122, -121, 121, -120, 120, 145 -119, 119, -118, 118, -117, 117, -116, 116, 146 -115, 115, -114, 114, -113, 113, -112, 112, 147 -111, 111, -110, 110, -109, 109, -108, 108, 148 -107, 107, -106, 106, -105, 105, -104, 104, 149 -103, 103, -102, 102, -101, 101, -100, 100, 150 -99, 99, -98, 98, -97, 97, -96, 96, }, 151 { -95, 95, -94, 94, -93, 93, -92, 92, 152 -91, 91, -90, 90, -89, 89, -88, 88, 153 -87, 87, -86, 86, -85, 85, -84, 84, 154 -83, 83, -82, 82, -81, 81, -80, 80, 155 -79, 79, -78, 78, -77, 77, -76, 76, 156 -75, 75, -74, 74, -73, 73, -72, 72, 157 -71, 71, -70, 70, -69, 69, -68, 68, 158 -67, 67, -66, 66, -65, 65, -64, 64, }, 159}; 160 161static int vlc_decode_block(MimicContext *ctx, int num_coeffs, int qscale) 162{ 163 DCTELEM *block = ctx->dct_block; 164 unsigned int pos; 165 166 ctx->dsp.clear_block(block); 167 168 block[0] = get_bits(&ctx->gb, 8) << 3; 169 170 for(pos = 1; pos < num_coeffs; pos++) { 171 uint32_t vlc, num_bits; 172 int value; 173 int coeff; 174 175 vlc = get_vlc2(&ctx->gb, ctx->vlc.table, ctx->vlc.bits, 3); 176 if(!vlc) /* end-of-block code */ 177 return 1; 178 if(vlc == -1) 179 return 0; 180 181 /* pos_add and num_bits are coded in the vlc code */ 182 pos += vlc&15; // pos_add 183 num_bits = vlc>>4; // num_bits 184 185 if(pos >= 64) 186 return 0; 187 188 value = get_bits(&ctx->gb, num_bits); 189 190 /* FFmpeg's IDCT behaves somewhat different from the original code, so 191 * a factor of 4 was added to the input */ 192 193 coeff = vlcdec_lookup[num_bits][value]; 194 if(pos<3) 195 coeff <<= 4; 196 else /* TODO Use >> 10 instead of / 1001 */ 197 coeff = (coeff * qscale) / 1001; 198 199 block[ctx->scantable.permutated[pos]] = coeff; 200 } 201 202 return 1; 203} 204 205static int decode(MimicContext *ctx, int quality, int num_coeffs, 206 int is_iframe) 207{ 208 int y, x, plane; 209 210 for(plane = 0; plane < 3; plane++) { 211 const int is_chroma = !!plane; 212 const int qscale = av_clip(10000-quality,is_chroma?1000:2000,10000)<<2; 213 const int stride = ctx->flipped_ptrs[ctx->cur_index].linesize[plane]; 214 const uint8_t *src = ctx->flipped_ptrs[ctx->prev_index].data[plane]; 215 uint8_t *dst = ctx->flipped_ptrs[ctx->cur_index ].data[plane]; 216 217 for(y = 0; y < ctx->num_vblocks[plane]; y++) { 218 for(x = 0; x < ctx->num_hblocks[plane]; x++) { 219 220 /* Check for a change condition in the current block. 221 * - iframes always change. 222 * - Luma plane changes on get_bits1 == 0 223 * - Chroma planes change on get_bits1 == 1 */ 224 if(is_iframe || get_bits1(&ctx->gb) == is_chroma) { 225 226 /* Luma planes may use a backreference from the 15 last 227 * frames preceding the previous. (get_bits1 == 1) 228 * Chroma planes don't use backreferences. */ 229 if(is_chroma || is_iframe || !get_bits1(&ctx->gb)) { 230 231 if(!vlc_decode_block(ctx, num_coeffs, qscale)) 232 return 0; 233 ctx->dsp.idct_put(dst, stride, ctx->dct_block); 234 } else { 235 unsigned int backref = get_bits(&ctx->gb, 4); 236 int index = (ctx->cur_index+backref)&15; 237 uint8_t *p = ctx->flipped_ptrs[index].data[0]; 238 239 if(p) { 240 p += src - 241 ctx->flipped_ptrs[ctx->prev_index].data[plane]; 242 ctx->dsp.put_pixels_tab[1][0](dst, p, stride, 8); 243 } else { 244 av_log(ctx->avctx, AV_LOG_ERROR, 245 "No such backreference! Buggy sample.\n"); 246 } 247 } 248 } else { 249 ctx->dsp.put_pixels_tab[1][0](dst, src, stride, 8); 250 } 251 src += 8; 252 dst += 8; 253 } 254 src += (stride - ctx->num_hblocks[plane])<<3; 255 dst += (stride - ctx->num_hblocks[plane])<<3; 256 } 257 } 258 259 return 1; 260} 261 262/** 263 * Flip the buffer upside-down and put it in the YVU order to match the 264 * way Mimic encodes frames. 265 */ 266static void prepare_avpic(MimicContext *ctx, AVPicture *dst, AVPicture *src) 267{ 268 int i; 269 dst->data[0] = src->data[0]+( ctx->avctx->height -1)*src->linesize[0]; 270 dst->data[1] = src->data[2]+((ctx->avctx->height>>1)-1)*src->linesize[2]; 271 dst->data[2] = src->data[1]+((ctx->avctx->height>>1)-1)*src->linesize[1]; 272 for(i = 0; i < 3; i++) 273 dst->linesize[i] = -src->linesize[i]; 274} 275 276static int mimic_decode_frame(AVCodecContext *avctx, void *data, 277 int *data_size, AVPacket *avpkt) 278{ 279 const uint8_t *buf = avpkt->data; 280 int buf_size = avpkt->size; 281 MimicContext *ctx = avctx->priv_data; 282 int is_pframe; 283 int width, height; 284 int quality, num_coeffs; 285 int swap_buf_size = buf_size - MIMIC_HEADER_SIZE; 286 287 if(buf_size < MIMIC_HEADER_SIZE) { 288 av_log(avctx, AV_LOG_ERROR, "insufficient data\n"); 289 return -1; 290 } 291 292 buf += 2; /* some constant (always 256) */ 293 quality = bytestream_get_le16(&buf); 294 width = bytestream_get_le16(&buf); 295 height = bytestream_get_le16(&buf); 296 buf += 4; /* some constant */ 297 is_pframe = bytestream_get_le32(&buf); 298 num_coeffs = bytestream_get_byte(&buf); 299 buf += 3; /* some constant */ 300 301 if(!ctx->avctx) { 302 int i; 303 304 if(!(width == 160 && height == 120) && 305 !(width == 320 && height == 240)) { 306 av_log(avctx, AV_LOG_ERROR, "invalid width/height!\n"); 307 return -1; 308 } 309 310 ctx->avctx = avctx; 311 avctx->width = width; 312 avctx->height = height; 313 avctx->pix_fmt = PIX_FMT_YUV420P; 314 for(i = 0; i < 3; i++) { 315 ctx->num_vblocks[i] = -((-height) >> (3 + !!i)); 316 ctx->num_hblocks[i] = width >> (3 + !!i) ; 317 } 318 } else if(width != ctx->avctx->width || height != ctx->avctx->height) { 319 av_log(avctx, AV_LOG_ERROR, "resolution changing is not supported\n"); 320 return -1; 321 } 322 323 if(is_pframe && !ctx->buf_ptrs[ctx->prev_index].data[0]) { 324 av_log(avctx, AV_LOG_ERROR, "decoding must start with keyframe\n"); 325 return -1; 326 } 327 328 ctx->buf_ptrs[ctx->cur_index].reference = 1; 329 if(avctx->get_buffer(avctx, &ctx->buf_ptrs[ctx->cur_index])) { 330 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 331 return -1; 332 } 333 334 prepare_avpic(ctx, &ctx->flipped_ptrs[ctx->cur_index], 335 (AVPicture*) &ctx->buf_ptrs[ctx->cur_index]); 336 337 av_fast_malloc(&ctx->swap_buf, &ctx->swap_buf_size, 338 swap_buf_size + FF_INPUT_BUFFER_PADDING_SIZE); 339 if(!ctx->swap_buf) 340 return AVERROR(ENOMEM); 341 342 ctx->dsp.bswap_buf(ctx->swap_buf, 343 (const uint32_t*) buf, 344 swap_buf_size>>2); 345 init_get_bits(&ctx->gb, ctx->swap_buf, swap_buf_size << 3); 346 347 if(!decode(ctx, quality, num_coeffs, !is_pframe)) { 348 avctx->release_buffer(avctx, &ctx->buf_ptrs[ctx->cur_index]); 349 return -1; 350 } 351 352 ctx->buf_ptrs[ctx->cur_index].pict_type = is_pframe ? FF_P_TYPE:FF_I_TYPE; 353 *(AVFrame*)data = ctx->buf_ptrs[ctx->cur_index]; 354 *data_size = sizeof(AVFrame); 355 356 ctx->prev_index = ctx->cur_index; 357 ctx->cur_index--; 358 ctx->cur_index &= 15; 359 360 /* Only release frames that aren't used for backreferences anymore */ 361 if(ctx->buf_ptrs[ctx->cur_index].data[0]) 362 avctx->release_buffer(avctx, &ctx->buf_ptrs[ctx->cur_index]); 363 364 return buf_size; 365} 366 367static av_cold int mimic_decode_end(AVCodecContext *avctx) 368{ 369 MimicContext *ctx = avctx->priv_data; 370 int i; 371 372 av_free(ctx->swap_buf); 373 for(i = 0; i < 16; i++) 374 if(ctx->buf_ptrs[i].data[0]) 375 avctx->release_buffer(avctx, &ctx->buf_ptrs[i]); 376 free_vlc(&ctx->vlc); 377 378 return 0; 379} 380 381AVCodec mimic_decoder = { 382 "mimic", 383 AVMEDIA_TYPE_VIDEO, 384 CODEC_ID_MIMIC, 385 sizeof(MimicContext), 386 mimic_decode_init, 387 NULL, 388 mimic_decode_end, 389 mimic_decode_frame, 390 CODEC_CAP_DR1, 391 .long_name = NULL_IF_CONFIG_SMALL("Mimic"), 392}; 393