FFmpeg: libavcodec/kmvc.c Source File

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, src_end, res) {\
00062     res = 0; \
00063     if (bb.bitbuf & (1 << bb.bits)) res = 1; \
00064     bb.bits--; \
00065     if(bb.bits == -1) { \
00066         if (src >= src_end) { \
00067             av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n"); \
00068             return AVERROR_INVALIDDATA; \
00069         } \
00070         bb.bitbuf = *src++; \
00071         bb.bits = 7; \
00072     } \
00073 }
00074 
00075 static int kmvc_decode_intra_8x8(KmvcContext * ctx, const uint8_t * src, int src_size, int w, int h)
00076 {
00077     BitBuf bb;
00078     int res, val;
00079     int i, j;
00080     int bx, by;
00081     int l0x, l1x, l0y, l1y;
00082     int mx, my;
00083     const uint8_t *src_end = src + src_size;
00084 
00085     kmvc_init_getbits(bb, src);
00086 
00087     for (by = 0; by < h; by += 8)
00088         for (bx = 0; bx < w; bx += 8) {
00089             kmvc_getbit(bb, src, src_end, res);
00090             if (!res) {         // fill whole 8x8 block
00091                 if (src >= src_end) {
00092                     av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
00093                     return AVERROR_INVALIDDATA;
00094                 }
00095                 val = *src++;
00096                 for (i = 0; i < 64; i++)
00097                     BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
00098             } else {            // handle four 4x4 subblocks
00099                 for (i = 0; i < 4; i++) {
00100                     l0x = bx + (i & 1) * 4;
00101                     l0y = by + (i & 2) * 2;
00102                     kmvc_getbit(bb, src, src_end, res);
00103                     if (!res) {
00104                         kmvc_getbit(bb, src, src_end, res);
00105                         if (!res) {     // fill whole 4x4 block
00106                             if (src >= src_end) {
00107                                 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
00108                                 return AVERROR_INVALIDDATA;
00109                             }
00110                             val = *src++;
00111                             for (j = 0; j < 16; j++)
00112                                 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
00113                         } else {        // copy block from already decoded place
00114                             if (src >= src_end) {
00115                                 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
00116                                 return AVERROR_INVALIDDATA;
00117                             }
00118                             val = *src++;
00119                             mx = val & 0xF;
00120                             my = val >> 4;
00121                             for (j = 0; j < 16; j++)
00122                                 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
00123                                     BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my);
00124                         }
00125                     } else {    // descend to 2x2 sub-sub-blocks
00126                         for (j = 0; j < 4; j++) {
00127                             l1x = l0x + (j & 1) * 2;
00128                             l1y = l0y + (j & 2);
00129                             kmvc_getbit(bb, src, src_end, res);
00130                             if (!res) {
00131                                 kmvc_getbit(bb, src, src_end, res);
00132                                 if (!res) {     // fill whole 2x2 block
00133                                     if (src >= src_end) {
00134                                         av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
00135                                         return AVERROR_INVALIDDATA;
00136                                     }
00137                                     val = *src++;
00138                                     BLK(ctx->cur, l1x, l1y) = val;
00139                                     BLK(ctx->cur, l1x + 1, l1y) = val;
00140                                     BLK(ctx->cur, l1x, l1y + 1) = val;
00141                                     BLK(ctx->cur, l1x + 1, l1y + 1) = val;
00142                                 } else {        // copy block from already decoded place
00143                                     if (src >= src_end) {
00144                                         av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
00145                                         return AVERROR_INVALIDDATA;
00146                                     }
00147                                     val = *src++;
00148                                     mx = val & 0xF;
00149                                     my = val >> 4;
00150                                     BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my);
00151                                     BLK(ctx->cur, l1x + 1, l1y) =
00152                                         BLK(ctx->cur, l1x + 1 - mx, l1y - my);
00153                                     BLK(ctx->cur, l1x, l1y + 1) =
00154                                         BLK(ctx->cur, l1x - mx, l1y + 1 - my);
00155                                     BLK(ctx->cur, l1x + 1, l1y + 1) =
00156                                         BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my);
00157                                 }
00158                             } else {    // read values for block
00159                                 BLK(ctx->cur, l1x, l1y) = *src++;
00160                                 BLK(ctx->cur, l1x + 1, l1y) = *src++;
00161                                 BLK(ctx->cur, l1x, l1y + 1) = *src++;
00162                                 BLK(ctx->cur, l1x + 1, l1y + 1) = *src++;
00163                             }
00164                         }
00165                     }
00166                 }
00167             }
00168         }
00169 
00170     return 0;
00171 }
00172 
00173 static int kmvc_decode_inter_8x8(KmvcContext * ctx, const uint8_t * src, int src_size, int w, int h)
00174 {
00175     BitBuf bb;
00176     int res, val;
00177     int i, j;
00178     int bx, by;
00179     int l0x, l1x, l0y, l1y;
00180     int mx, my;
00181     const uint8_t *src_end = src + src_size;
00182 
00183     kmvc_init_getbits(bb, src);
00184 
00185     for (by = 0; by < h; by += 8)
00186         for (bx = 0; bx < w; bx += 8) {
00187             kmvc_getbit(bb, src, src_end, res);
00188             if (!res) {
00189                 kmvc_getbit(bb, src, src_end, res);
00190                 if (!res) {     // fill whole 8x8 block
00191                     if (src >= src_end) {
00192                         av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
00193                         return AVERROR_INVALIDDATA;
00194                     }
00195                     val = *src++;
00196                     for (i = 0; i < 64; i++)
00197                         BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
00198                 } else {        // copy block from previous frame
00199                     for (i = 0; i < 64; i++)
00200                         BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) =
00201                             BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3));
00202                 }
00203             } else {            // handle four 4x4 subblocks
00204                 for (i = 0; i < 4; i++) {
00205                     l0x = bx + (i & 1) * 4;
00206                     l0y = by + (i & 2) * 2;
00207                     kmvc_getbit(bb, src, src_end, res);
00208                     if (!res) {
00209                         kmvc_getbit(bb, src, src_end, res);
00210                         if (!res) {     // fill whole 4x4 block
00211                             if (src >= src_end) {
00212                                 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
00213                                 return AVERROR_INVALIDDATA;
00214                             }
00215                             val = *src++;
00216                             for (j = 0; j < 16; j++)
00217                                 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
00218                         } else {        // copy block
00219                             if (src >= src_end) {
00220                                 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
00221                                 return AVERROR_INVALIDDATA;
00222                             }
00223                             val = *src++;
00224                             mx = (val & 0xF) - 8;
00225                             my = (val >> 4) - 8;
00226                             for (j = 0; j < 16; j++)
00227                                 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
00228                                     BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my);
00229                         }
00230                     } else {    // descend to 2x2 sub-sub-blocks
00231                         for (j = 0; j < 4; j++) {
00232                             l1x = l0x + (j & 1) * 2;
00233                             l1y = l0y + (j & 2);
00234                             kmvc_getbit(bb, src, src_end, res);
00235                             if (!res) {
00236                                 kmvc_getbit(bb, src, src_end, res);
00237                                 if (!res) {     // fill whole 2x2 block
00238                                     if (src >= src_end) {
00239                                         av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
00240                                         return AVERROR_INVALIDDATA;
00241                                     }
00242                                     val = *src++;
00243                                     BLK(ctx->cur, l1x, l1y) = val;
00244                                     BLK(ctx->cur, l1x + 1, l1y) = val;
00245                                     BLK(ctx->cur, l1x, l1y + 1) = val;
00246                                     BLK(ctx->cur, l1x + 1, l1y + 1) = val;
00247                                 } else {        // copy block
00248                                     if (src >= src_end) {
00249                                         av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
00250                                         return AVERROR_INVALIDDATA;
00251                                     }
00252                                     val = *src++;
00253                                     mx = (val & 0xF) - 8;
00254                                     my = (val >> 4) - 8;
00255                                     BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my);
00256                                     BLK(ctx->cur, l1x + 1, l1y) =
00257                                         BLK(ctx->prev, l1x + 1 + mx, l1y + my);
00258                                     BLK(ctx->cur, l1x, l1y + 1) =
00259                                         BLK(ctx->prev, l1x + mx, l1y + 1 + my);
00260                                     BLK(ctx->cur, l1x + 1, l1y + 1) =
00261                                         BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my);
00262                                 }
00263                             } else {    // read values for block
00264                                 BLK(ctx->cur, l1x, l1y) = *src++;
00265                                 BLK(ctx->cur, l1x + 1, l1y) = *src++;
00266                                 BLK(ctx->cur, l1x, l1y + 1) = *src++;
00267                                 BLK(ctx->cur, l1x + 1, l1y + 1) = *src++;
00268                             }
00269                         }
00270                     }
00271                 }
00272             }
00273         }
00274 
00275     return 0;
00276 }
00277 
00278 static int decode_frame(AVCodecContext * avctx, void *data, int *data_size, AVPacket *avpkt)
00279 {
00280     const uint8_t *buf = avpkt->data;
00281     int buf_size = avpkt->size;
00282     KmvcContext *const ctx = avctx->priv_data;
00283     uint8_t *out, *src;
00284     int i;
00285     int header;
00286     int blocksize;
00287 
00288     if (ctx->pic.data[0])
00289         avctx->release_buffer(avctx, &ctx->pic);
00290 
00291     ctx->pic.reference = 1;
00292     ctx->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
00293     if (avctx->get_buffer(avctx, &ctx->pic) < 0) {
00294         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00295         return -1;
00296     }
00297 
00298     header = *buf++;
00299 
00300     /* blocksize 127 is really palette change event */
00301     if (buf[0] == 127) {
00302         buf += 3;
00303         for (i = 0; i < 127; i++) {
00304             ctx->pal[i + (header & 0x81)] = AV_RB24(buf);
00305             buf += 4;
00306         }
00307         buf -= 127 * 4 + 3;
00308     }
00309 
00310     if (header & KMVC_KEYFRAME) {
00311         ctx->pic.key_frame = 1;
00312         ctx->pic.pict_type = AV_PICTURE_TYPE_I;
00313     } else {
00314         ctx->pic.key_frame = 0;
00315         ctx->pic.pict_type = AV_PICTURE_TYPE_P;
00316     }
00317 
00318     /* if palette has been changed, copy it from palctrl */
00319     if (ctx->avctx->palctrl && ctx->avctx->palctrl->palette_changed) {
00320         memcpy(ctx->pal, ctx->avctx->palctrl->palette, AVPALETTE_SIZE);
00321         ctx->setpal = 1;
00322         ctx->avctx->palctrl->palette_changed = 0;
00323     }
00324 
00325     if (header & KMVC_PALETTE) {
00326         ctx->pic.palette_has_changed = 1;
00327         // palette starts from index 1 and has 127 entries
00328         for (i = 1; i <= ctx->palsize; i++) {
00329             ctx->pal[i] = bytestream_get_be24(&buf);
00330         }
00331     }
00332 
00333     if (ctx->setpal) {
00334         ctx->setpal = 0;
00335         ctx->pic.palette_has_changed = 1;
00336     }
00337 
00338     /* make the palette available on the way out */
00339     memcpy(ctx->pic.data[1], ctx->pal, 1024);
00340 
00341     blocksize = *buf++;
00342 
00343     if (blocksize != 8 && blocksize != 127) {
00344         av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize);
00345         return -1;
00346     }
00347     memset(ctx->cur, 0, 320 * 200);
00348     switch (header & KMVC_METHOD) {
00349     case 0:
00350     case 1: // used in palette changed event
00351         memcpy(ctx->cur, ctx->prev, 320 * 200);
00352         break;
00353     case 3:
00354         kmvc_decode_intra_8x8(ctx, buf, buf_size, avctx->width, avctx->height);
00355         break;
00356     case 4:
00357         kmvc_decode_inter_8x8(ctx, buf, buf_size, avctx->width, avctx->height);
00358         break;
00359     default:
00360         av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD);
00361         return -1;
00362     }
00363 
00364     out = ctx->pic.data[0];
00365     src = ctx->cur;
00366     for (i = 0; i < avctx->height; i++) {
00367         memcpy(out, src, avctx->width);
00368         src += 320;
00369         out += ctx->pic.linesize[0];
00370     }
00371 
00372     /* flip buffers */
00373     if (ctx->cur == ctx->frm0) {
00374         ctx->cur = ctx->frm1;
00375         ctx->prev = ctx->frm0;
00376     } else {
00377         ctx->cur = ctx->frm0;
00378         ctx->prev = ctx->frm1;
00379     }
00380 
00381     *data_size = sizeof(AVFrame);
00382     *(AVFrame *) data = ctx->pic;
00383 
00384     /* always report that the buffer was completely consumed */
00385     return buf_size;
00386 }
00387 
00388 
00389 
00390 /*
00391  * Init kmvc decoder
00392  */
00393 static av_cold int decode_init(AVCodecContext * avctx)
00394 {
00395     KmvcContext *const c = avctx->priv_data;
00396     int i;
00397 
00398     c->avctx = avctx;
00399 
00400     if (avctx->width > 320 || avctx->height > 200) {
00401         av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n");
00402         return -1;
00403     }
00404 
00405     c->frm0 = av_mallocz(320 * 200);
00406     c->frm1 = av_mallocz(320 * 200);
00407     c->cur = c->frm0;
00408     c->prev = c->frm1;
00409 
00410     for (i = 0; i < 256; i++) {
00411         c->pal[i] = i * 0x10101;
00412     }
00413 
00414     if (avctx->extradata_size < 12) {
00415         av_log(NULL, 0, "Extradata missing, decoding may not work properly...\n");
00416         c->palsize = 127;
00417     } else {
00418         c->palsize = AV_RL16(avctx->extradata + 10);
00419         if (c->palsize >= MAX_PALSIZE) {
00420             av_log(avctx, AV_LOG_ERROR, "KMVC palette too large\n");
00421             return AVERROR_INVALIDDATA;
00422         }
00423     }
00424 
00425     if (avctx->extradata_size == 1036) {        // palette in extradata
00426         uint8_t *src = avctx->extradata + 12;
00427         for (i = 0; i < 256; i++) {
00428             c->pal[i] = AV_RL32(src);
00429             src += 4;
00430         }
00431         c->setpal = 1;
00432         if (c->avctx->palctrl) {
00433             c->avctx->palctrl->palette_changed = 0;
00434         }
00435     }
00436 
00437     avcodec_get_frame_defaults(&c->pic);
00438     avctx->pix_fmt = PIX_FMT_PAL8;
00439 
00440     return 0;
00441 }
00442 
00443 
00444 
00445 /*
00446  * Uninit kmvc decoder
00447  */
00448 static av_cold int decode_end(AVCodecContext * avctx)
00449 {
00450     KmvcContext *const c = avctx->priv_data;
00451 
00452     av_freep(&c->frm0);
00453     av_freep(&c->frm1);
00454     if (c->pic.data[0])
00455         avctx->release_buffer(avctx, &c->pic);
00456 
00457     return 0;
00458 }
00459 
00460 AVCodec ff_kmvc_decoder = {
00461     "kmvc",
00462     AVMEDIA_TYPE_VIDEO,
00463     CODEC_ID_KMVC,
00464     sizeof(KmvcContext),
00465     decode_init,
00466     NULL,
00467     decode_end,
00468     decode_frame,
00469     CODEC_CAP_DR1,
00470     .long_name = NULL_IF_CONFIG_SMALL("Karl Morton's video codec"),
00471 };