Libav
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00001 /* 00002 * KMVC decoder 00003 * Copyright (c) 2006 Konstantin Shishkov 00004 * 00005 * This file is part of FFmpeg. 00006 * 00007 * FFmpeg is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * FFmpeg is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with FFmpeg; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00027 #include <stdio.h> 00028 #include <stdlib.h> 00029 00030 #include "avcodec.h" 00031 #include "bytestream.h" 00032 00033 #define KMVC_KEYFRAME 0x80 00034 #define KMVC_PALETTE 0x40 00035 #define KMVC_METHOD 0x0F 00036 #define MAX_PALSIZE 256 00037 00038 /* 00039 * Decoder context 00040 */ 00041 typedef struct KmvcContext { 00042 AVCodecContext *avctx; 00043 AVFrame pic; 00044 00045 int setpal; 00046 int palsize; 00047 uint32_t pal[MAX_PALSIZE]; 00048 uint8_t *cur, *prev; 00049 uint8_t *frm0, *frm1; 00050 } KmvcContext; 00051 00052 typedef struct BitBuf { 00053 int bits; 00054 int bitbuf; 00055 } BitBuf; 00056 00057 #define BLK(data, x, y) data[(x) + (y) * 320] 00058 00059 #define kmvc_init_getbits(bb, src) bb.bits = 7; bb.bitbuf = *src++; 00060 00061 #define kmvc_getbit(bb, src, res) {\ 00062 res = 0; \ 00063 if (bb.bitbuf & (1 << bb.bits)) res = 1; \ 00064 bb.bits--; \ 00065 if(bb.bits == -1) { \ 00066 bb.bitbuf = *src++; \ 00067 bb.bits = 7; \ 00068 } \ 00069 } 00070 00071 static void kmvc_decode_intra_8x8(KmvcContext * ctx, const uint8_t * src, int w, int h) 00072 { 00073 BitBuf bb; 00074 int res, val; 00075 int i, j; 00076 int bx, by; 00077 int l0x, l1x, l0y, l1y; 00078 int mx, my; 00079 00080 kmvc_init_getbits(bb, src); 00081 00082 for (by = 0; by < h; by += 8) 00083 for (bx = 0; bx < w; bx += 8) { 00084 kmvc_getbit(bb, src, res); 00085 if (!res) { // fill whole 8x8 block 00086 val = *src++; 00087 for (i = 0; i < 64; i++) 00088 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val; 00089 } else { // handle four 4x4 subblocks 00090 for (i = 0; i < 4; i++) { 00091 l0x = bx + (i & 1) * 4; 00092 l0y = by + (i & 2) * 2; 00093 kmvc_getbit(bb, src, res); 00094 if (!res) { 00095 kmvc_getbit(bb, src, res); 00096 if (!res) { // fill whole 4x4 block 00097 val = *src++; 00098 for (j = 0; j < 16; j++) 00099 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val; 00100 } else { // copy block from already decoded place 00101 val = *src++; 00102 mx = val & 0xF; 00103 my = val >> 4; 00104 for (j = 0; j < 16; j++) 00105 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = 00106 BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my); 00107 } 00108 } else { // descend to 2x2 sub-sub-blocks 00109 for (j = 0; j < 4; j++) { 00110 l1x = l0x + (j & 1) * 2; 00111 l1y = l0y + (j & 2); 00112 kmvc_getbit(bb, src, res); 00113 if (!res) { 00114 kmvc_getbit(bb, src, res); 00115 if (!res) { // fill whole 2x2 block 00116 val = *src++; 00117 BLK(ctx->cur, l1x, l1y) = val; 00118 BLK(ctx->cur, l1x + 1, l1y) = val; 00119 BLK(ctx->cur, l1x, l1y + 1) = val; 00120 BLK(ctx->cur, l1x + 1, l1y + 1) = val; 00121 } else { // copy block from already decoded place 00122 val = *src++; 00123 mx = val & 0xF; 00124 my = val >> 4; 00125 BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my); 00126 BLK(ctx->cur, l1x + 1, l1y) = 00127 BLK(ctx->cur, l1x + 1 - mx, l1y - my); 00128 BLK(ctx->cur, l1x, l1y + 1) = 00129 BLK(ctx->cur, l1x - mx, l1y + 1 - my); 00130 BLK(ctx->cur, l1x + 1, l1y + 1) = 00131 BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my); 00132 } 00133 } else { // read values for block 00134 BLK(ctx->cur, l1x, l1y) = *src++; 00135 BLK(ctx->cur, l1x + 1, l1y) = *src++; 00136 BLK(ctx->cur, l1x, l1y + 1) = *src++; 00137 BLK(ctx->cur, l1x + 1, l1y + 1) = *src++; 00138 } 00139 } 00140 } 00141 } 00142 } 00143 } 00144 } 00145 00146 static void kmvc_decode_inter_8x8(KmvcContext * ctx, const uint8_t * src, int w, int h) 00147 { 00148 BitBuf bb; 00149 int res, val; 00150 int i, j; 00151 int bx, by; 00152 int l0x, l1x, l0y, l1y; 00153 int mx, my; 00154 00155 kmvc_init_getbits(bb, src); 00156 00157 for (by = 0; by < h; by += 8) 00158 for (bx = 0; bx < w; bx += 8) { 00159 kmvc_getbit(bb, src, res); 00160 if (!res) { 00161 kmvc_getbit(bb, src, res); 00162 if (!res) { // fill whole 8x8 block 00163 val = *src++; 00164 for (i = 0; i < 64; i++) 00165 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val; 00166 } else { // copy block from previous frame 00167 for (i = 0; i < 64; i++) 00168 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = 00169 BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3)); 00170 } 00171 } else { // handle four 4x4 subblocks 00172 for (i = 0; i < 4; i++) { 00173 l0x = bx + (i & 1) * 4; 00174 l0y = by + (i & 2) * 2; 00175 kmvc_getbit(bb, src, res); 00176 if (!res) { 00177 kmvc_getbit(bb, src, res); 00178 if (!res) { // fill whole 4x4 block 00179 val = *src++; 00180 for (j = 0; j < 16; j++) 00181 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val; 00182 } else { // copy block 00183 val = *src++; 00184 mx = (val & 0xF) - 8; 00185 my = (val >> 4) - 8; 00186 for (j = 0; j < 16; j++) 00187 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = 00188 BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my); 00189 } 00190 } else { // descend to 2x2 sub-sub-blocks 00191 for (j = 0; j < 4; j++) { 00192 l1x = l0x + (j & 1) * 2; 00193 l1y = l0y + (j & 2); 00194 kmvc_getbit(bb, src, res); 00195 if (!res) { 00196 kmvc_getbit(bb, src, res); 00197 if (!res) { // fill whole 2x2 block 00198 val = *src++; 00199 BLK(ctx->cur, l1x, l1y) = val; 00200 BLK(ctx->cur, l1x + 1, l1y) = val; 00201 BLK(ctx->cur, l1x, l1y + 1) = val; 00202 BLK(ctx->cur, l1x + 1, l1y + 1) = val; 00203 } else { // copy block 00204 val = *src++; 00205 mx = (val & 0xF) - 8; 00206 my = (val >> 4) - 8; 00207 BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my); 00208 BLK(ctx->cur, l1x + 1, l1y) = 00209 BLK(ctx->prev, l1x + 1 + mx, l1y + my); 00210 BLK(ctx->cur, l1x, l1y + 1) = 00211 BLK(ctx->prev, l1x + mx, l1y + 1 + my); 00212 BLK(ctx->cur, l1x + 1, l1y + 1) = 00213 BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my); 00214 } 00215 } else { // read values for block 00216 BLK(ctx->cur, l1x, l1y) = *src++; 00217 BLK(ctx->cur, l1x + 1, l1y) = *src++; 00218 BLK(ctx->cur, l1x, l1y + 1) = *src++; 00219 BLK(ctx->cur, l1x + 1, l1y + 1) = *src++; 00220 } 00221 } 00222 } 00223 } 00224 } 00225 } 00226 } 00227 00228 static int decode_frame(AVCodecContext * avctx, void *data, int *data_size, AVPacket *avpkt) 00229 { 00230 const uint8_t *buf = avpkt->data; 00231 int buf_size = avpkt->size; 00232 KmvcContext *const ctx = avctx->priv_data; 00233 uint8_t *out, *src; 00234 int i; 00235 int header; 00236 int blocksize; 00237 00238 if (ctx->pic.data[0]) 00239 avctx->release_buffer(avctx, &ctx->pic); 00240 00241 ctx->pic.reference = 1; 00242 ctx->pic.buffer_hints = FF_BUFFER_HINTS_VALID; 00243 if (avctx->get_buffer(avctx, &ctx->pic) < 0) { 00244 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 00245 return -1; 00246 } 00247 00248 header = *buf++; 00249 00250 /* blocksize 127 is really palette change event */ 00251 if (buf[0] == 127) { 00252 buf += 3; 00253 for (i = 0; i < 127; i++) { 00254 ctx->pal[i + (header & 0x81)] = AV_RB24(buf); 00255 buf += 4; 00256 } 00257 buf -= 127 * 4 + 3; 00258 } 00259 00260 if (header & KMVC_KEYFRAME) { 00261 ctx->pic.key_frame = 1; 00262 ctx->pic.pict_type = FF_I_TYPE; 00263 } else { 00264 ctx->pic.key_frame = 0; 00265 ctx->pic.pict_type = FF_P_TYPE; 00266 } 00267 00268 /* if palette has been changed, copy it from palctrl */ 00269 if (ctx->avctx->palctrl && ctx->avctx->palctrl->palette_changed) { 00270 memcpy(ctx->pal, ctx->avctx->palctrl->palette, AVPALETTE_SIZE); 00271 ctx->setpal = 1; 00272 ctx->avctx->palctrl->palette_changed = 0; 00273 } 00274 00275 if (header & KMVC_PALETTE) { 00276 ctx->pic.palette_has_changed = 1; 00277 // palette starts from index 1 and has 127 entries 00278 for (i = 1; i <= ctx->palsize; i++) { 00279 ctx->pal[i] = bytestream_get_be24(&buf); 00280 } 00281 } 00282 00283 if (ctx->setpal) { 00284 ctx->setpal = 0; 00285 ctx->pic.palette_has_changed = 1; 00286 } 00287 00288 /* make the palette available on the way out */ 00289 memcpy(ctx->pic.data[1], ctx->pal, 1024); 00290 00291 blocksize = *buf++; 00292 00293 if (blocksize != 8 && blocksize != 127) { 00294 av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize); 00295 return -1; 00296 } 00297 memset(ctx->cur, 0, 320 * 200); 00298 switch (header & KMVC_METHOD) { 00299 case 0: 00300 case 1: // used in palette changed event 00301 memcpy(ctx->cur, ctx->prev, 320 * 200); 00302 break; 00303 case 3: 00304 kmvc_decode_intra_8x8(ctx, buf, avctx->width, avctx->height); 00305 break; 00306 case 4: 00307 kmvc_decode_inter_8x8(ctx, buf, avctx->width, avctx->height); 00308 break; 00309 default: 00310 av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD); 00311 return -1; 00312 } 00313 00314 out = ctx->pic.data[0]; 00315 src = ctx->cur; 00316 for (i = 0; i < avctx->height; i++) { 00317 memcpy(out, src, avctx->width); 00318 src += 320; 00319 out += ctx->pic.linesize[0]; 00320 } 00321 00322 /* flip buffers */ 00323 if (ctx->cur == ctx->frm0) { 00324 ctx->cur = ctx->frm1; 00325 ctx->prev = ctx->frm0; 00326 } else { 00327 ctx->cur = ctx->frm0; 00328 ctx->prev = ctx->frm1; 00329 } 00330 00331 *data_size = sizeof(AVFrame); 00332 *(AVFrame *) data = ctx->pic; 00333 00334 /* always report that the buffer was completely consumed */ 00335 return buf_size; 00336 } 00337 00338 00339 00340 /* 00341 * Init kmvc decoder 00342 */ 00343 static av_cold int decode_init(AVCodecContext * avctx) 00344 { 00345 KmvcContext *const c = avctx->priv_data; 00346 int i; 00347 00348 c->avctx = avctx; 00349 00350 if (avctx->width > 320 || avctx->height > 200) { 00351 av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n"); 00352 return -1; 00353 } 00354 00355 c->frm0 = av_mallocz(320 * 200); 00356 c->frm1 = av_mallocz(320 * 200); 00357 c->cur = c->frm0; 00358 c->prev = c->frm1; 00359 00360 for (i = 0; i < 256; i++) { 00361 c->pal[i] = i * 0x10101; 00362 } 00363 00364 if (avctx->extradata_size < 12) { 00365 av_log(NULL, 0, "Extradata missing, decoding may not work properly...\n"); 00366 c->palsize = 127; 00367 } else { 00368 c->palsize = AV_RL16(avctx->extradata + 10); 00369 if (c->palsize >= MAX_PALSIZE) { 00370 av_log(avctx, AV_LOG_ERROR, "KMVC palette too large\n"); 00371 return AVERROR_INVALIDDATA; 00372 } 00373 } 00374 00375 if (avctx->extradata_size == 1036) { // palette in extradata 00376 uint8_t *src = avctx->extradata + 12; 00377 for (i = 0; i < 256; i++) { 00378 c->pal[i] = AV_RL32(src); 00379 src += 4; 00380 } 00381 c->setpal = 1; 00382 if (c->avctx->palctrl) { 00383 c->avctx->palctrl->palette_changed = 0; 00384 } 00385 } 00386 00387 avctx->pix_fmt = PIX_FMT_PAL8; 00388 00389 return 0; 00390 } 00391 00392 00393 00394 /* 00395 * Uninit kmvc decoder 00396 */ 00397 static av_cold int decode_end(AVCodecContext * avctx) 00398 { 00399 KmvcContext *const c = avctx->priv_data; 00400 00401 av_freep(&c->frm0); 00402 av_freep(&c->frm1); 00403 if (c->pic.data[0]) 00404 avctx->release_buffer(avctx, &c->pic); 00405 00406 return 0; 00407 } 00408 00409 AVCodec kmvc_decoder = { 00410 "kmvc", 00411 AVMEDIA_TYPE_VIDEO, 00412 CODEC_ID_KMVC, 00413 sizeof(KmvcContext), 00414 decode_init, 00415 NULL, 00416 decode_end, 00417 decode_frame, 00418 CODEC_CAP_DR1, 00419 .long_name = NULL_IF_CONFIG_SMALL("Karl Morton's video codec"), 00420 };