📄 cinepak.c
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/* * Cinepak Video Decoder * Copyright (C) 2003 the ffmpeg project * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA *//** * @file cinepak.c * Cinepak video decoder * by Ewald Snel <ewald@rambo.its.tudelft.nl> * For more information on the Cinepak algorithm, visit: * http://www.csse.monash.edu.au/~timf/ * For more information on the quirky data inside Sega FILM/CPK files, visit: * http://wiki.multimedia.cx/index.php?title=Sega_FILM */#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include "avcodec.h"typedef struct { uint8_t y0, y1, y2, y3; uint8_t u, v;} cvid_codebook_t;#define MAX_STRIPS 32typedef struct { uint16_t id; uint16_t x1, y1; uint16_t x2, y2; cvid_codebook_t v4_codebook[256]; cvid_codebook_t v1_codebook[256];} cvid_strip_t;typedef struct CinepakContext { AVCodecContext *avctx; AVFrame frame; const unsigned char *data; int size; int width, height; int palette_video; cvid_strip_t strips[MAX_STRIPS]; int sega_film_skip_bytes;} CinepakContext;static void cinepak_decode_codebook (cvid_codebook_t *codebook, int chunk_id, int size, const uint8_t *data){ const uint8_t *eod = (data + size); uint32_t flag, mask; int i, n; /* check if this chunk contains 4- or 6-element vectors */ n = (chunk_id & 0x0400) ? 4 : 6; flag = 0; mask = 0; for (i=0; i < 256; i++) { if ((chunk_id & 0x0100) && !(mask >>= 1)) { if ((data + 4) > eod) break; flag = AV_RB32 (data); data += 4; mask = 0x80000000; } if (!(chunk_id & 0x0100) || (flag & mask)) { if ((data + n) > eod) break; if (n == 6) { codebook[i].y0 = *data++; codebook[i].y1 = *data++; codebook[i].y2 = *data++; codebook[i].y3 = *data++; codebook[i].u = 128 + *data++; codebook[i].v = 128 + *data++; } else { /* this codebook type indicates either greyscale or * palettized video; if palettized, U & V components will * not be used so it is safe to set them to 128 for the * benefit of greyscale rendering in YUV420P */ codebook[i].y0 = *data++; codebook[i].y1 = *data++; codebook[i].y2 = *data++; codebook[i].y3 = *data++; codebook[i].u = 128; codebook[i].v = 128; } } }}static int cinepak_decode_vectors (CinepakContext *s, cvid_strip_t *strip, int chunk_id, int size, const uint8_t *data){ const uint8_t *eod = (data + size); uint32_t flag, mask; cvid_codebook_t *codebook; unsigned int x, y; uint32_t iy[4]; uint32_t iu[2]; uint32_t iv[2]; flag = 0; mask = 0; for (y=strip->y1; y < strip->y2; y+=4) { iy[0] = strip->x1 + (y * s->frame.linesize[0]); iy[1] = iy[0] + s->frame.linesize[0]; iy[2] = iy[1] + s->frame.linesize[0]; iy[3] = iy[2] + s->frame.linesize[0]; iu[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[1]); iu[1] = iu[0] + s->frame.linesize[1]; iv[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[2]); iv[1] = iv[0] + s->frame.linesize[2]; for (x=strip->x1; x < strip->x2; x+=4) { if ((chunk_id & 0x0100) && !(mask >>= 1)) { if ((data + 4) > eod) return -1; flag = AV_RB32 (data); data += 4; mask = 0x80000000; } if (!(chunk_id & 0x0100) || (flag & mask)) { if (!(chunk_id & 0x0200) && !(mask >>= 1)) { if ((data + 4) > eod) return -1; flag = AV_RB32 (data); data += 4; mask = 0x80000000; } if ((chunk_id & 0x0200) || (~flag & mask)) { if (data >= eod) return -1; codebook = &strip->v1_codebook[*data++]; s->frame.data[0][iy[0] + 0] = codebook->y0; s->frame.data[0][iy[0] + 1] = codebook->y0; s->frame.data[0][iy[1] + 0] = codebook->y0; s->frame.data[0][iy[1] + 1] = codebook->y0; if (!s->palette_video) { s->frame.data[1][iu[0]] = codebook->u; s->frame.data[2][iv[0]] = codebook->v; } s->frame.data[0][iy[0] + 2] = codebook->y1; s->frame.data[0][iy[0] + 3] = codebook->y1; s->frame.data[0][iy[1] + 2] = codebook->y1; s->frame.data[0][iy[1] + 3] = codebook->y1; if (!s->palette_video) { s->frame.data[1][iu[0] + 1] = codebook->u; s->frame.data[2][iv[0] + 1] = codebook->v; } s->frame.data[0][iy[2] + 0] = codebook->y2; s->frame.data[0][iy[2] + 1] = codebook->y2; s->frame.data[0][iy[3] + 0] = codebook->y2; s->frame.data[0][iy[3] + 1] = codebook->y2; if (!s->palette_video) { s->frame.data[1][iu[1]] = codebook->u; s->frame.data[2][iv[1]] = codebook->v; } s->frame.data[0][iy[2] + 2] = codebook->y3; s->frame.data[0][iy[2] + 3] = codebook->y3; s->frame.data[0][iy[3] + 2] = codebook->y3; s->frame.data[0][iy[3] + 3] = codebook->y3; if (!s->palette_video) { s->frame.data[1][iu[1] + 1] = codebook->u; s->frame.data[2][iv[1] + 1] = codebook->v; } } else if (flag & mask) { if ((data + 4) > eod) return -1; codebook = &strip->v4_codebook[*data++]; s->frame.data[0][iy[0] + 0] = codebook->y0; s->frame.data[0][iy[0] + 1] = codebook->y1; s->frame.data[0][iy[1] + 0] = codebook->y2; s->frame.data[0][iy[1] + 1] = codebook->y3; if (!s->palette_video) { s->frame.data[1][iu[0]] = codebook->u; s->frame.data[2][iv[0]] = codebook->v; } codebook = &strip->v4_codebook[*data++]; s->frame.data[0][iy[0] + 2] = codebook->y0; s->frame.data[0][iy[0] + 3] = codebook->y1; s->frame.data[0][iy[1] + 2] = codebook->y2; s->frame.data[0][iy[1] + 3] = codebook->y3; if (!s->palette_video) { s->frame.data[1][iu[0] + 1] = codebook->u; s->frame.data[2][iv[0] + 1] = codebook->v; } codebook = &strip->v4_codebook[*data++]; s->frame.data[0][iy[2] + 0] = codebook->y0; s->frame.data[0][iy[2] + 1] = codebook->y1; s->frame.data[0][iy[3] + 0] = codebook->y2; s->frame.data[0][iy[3] + 1] = codebook->y3; if (!s->palette_video) { s->frame.data[1][iu[1]] = codebook->u; s->frame.data[2][iv[1]] = codebook->v;
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