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ffmpeg / libavcodec / cinepak.c @ 0c3ee78f

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/*
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 * Cinepak Video Decoder
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 * Copyright (C) 2003 the ffmpeg project
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 *
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 * This library is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2 of the License, or (at your option) any later version.
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 *
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 * This library is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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 *
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 */
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/**
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 * @file cinepak.c
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 * Cinepak video decoder
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 * by Ewald Snel <ewald@rambo.its.tudelft.nl>
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 * For more information on the Cinepak algorithm, visit:
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 *   http://www.csse.monash.edu.au/~timf/
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 */
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "common.h"
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#include "avcodec.h"
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#include "dsputil.h"
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typedef struct {
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    uint8_t  y0, y1, y2, y3;
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    uint8_t  u, v;
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} cvid_codebook_t;
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#define MAX_STRIPS      32
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typedef struct {
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    uint16_t          id;
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    uint16_t          x1, y1;
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    uint16_t          x2, y2;
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    cvid_codebook_t   v4_codebook[256];
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    cvid_codebook_t   v1_codebook[256];
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} cvid_strip_t;
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typedef struct CinepakContext {
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    AVCodecContext *avctx;
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    DSPContext dsp;
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    AVFrame frame;
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    unsigned char *data;
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    int size;
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    int width, height;
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    int palette_video;
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    cvid_strip_t strips[MAX_STRIPS];
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} CinepakContext;
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static void cinepak_decode_codebook (cvid_codebook_t *codebook,
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                                     int chunk_id, int size, uint8_t *data)
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{
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    uint8_t *eod = (data + size);
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    uint32_t flag, mask;
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    int      i, n;
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    /* check if this chunk contains 4- or 6-element vectors */
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    n    = (chunk_id & 0x0400) ? 4 : 6;
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    flag = 0;
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    mask = 0;
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    for (i=0; i < 256; i++) {
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        if ((chunk_id & 0x0100) && !(mask >>= 1)) {
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            if ((data + 4) > eod)
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                break;
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            flag  = BE_32 (data);
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            data += 4;
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            mask  = 0x80000000;
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        }
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        if (!(chunk_id & 0x0100) || (flag & mask)) {
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            if ((data + n) > eod)
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                break;
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            if (n == 6) {
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                codebook[i].y0 = *data++;
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                codebook[i].y1 = *data++;
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                codebook[i].y2 = *data++;
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                codebook[i].y3 = *data++;
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                codebook[i].u  = 128 + *data++;
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                codebook[i].v  = 128 + *data++;
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            } else {
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                /* this codebook type indicates either greyscale or 
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                 * palettized video; if palettized, U & V components will
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                 * not be used so it is safe to set them to 128 for the
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                 * benefit of greyscale rendering in YUV420P */
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                codebook[i].y0 = *data++;
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                codebook[i].y1 = *data++;
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                codebook[i].y2 = *data++;
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                codebook[i].y3 = *data++;
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                codebook[i].u  = 128;
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                codebook[i].v  = 128;
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            }
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        }
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    }
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}
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static int cinepak_decode_vectors (CinepakContext *s, cvid_strip_t *strip,
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                                   int chunk_id, int size, uint8_t *data)
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{
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    uint8_t         *eod = (data + size);
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    uint32_t         flag, mask;
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    cvid_codebook_t *codebook;
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    unsigned int     x, y;
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    uint32_t         iy[4];
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    uint32_t         iu[2];
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    uint32_t         iv[2];
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    flag = 0;
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    mask = 0;
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    for (y=strip->y1; y < strip->y2; y+=4) {
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        iy[0] = strip->x1 + (y * s->frame.linesize[0]);
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        iy[1] = iy[0] + s->frame.linesize[0];
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        iy[2] = iy[1] + s->frame.linesize[0];
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        iy[3] = iy[2] + s->frame.linesize[0];
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        iu[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[1]);
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        iu[1] = iu[0] + s->frame.linesize[1];
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        iv[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[2]);
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        iv[1] = iv[0] + s->frame.linesize[2];
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        for (x=strip->x1; x < strip->x2; x+=4) {
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            if ((chunk_id & 0x0100) && !(mask >>= 1)) {
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                if ((data + 4) > eod)
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                    return -1;
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                flag  = BE_32 (data);
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                data += 4;
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                mask  = 0x80000000;
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            }
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            if (!(chunk_id & 0x0100) || (flag & mask)) {
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                if (!(chunk_id & 0x0200) && !(mask >>= 1)) {
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                    if ((data + 4) > eod)
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                        return -1;
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                    flag  = BE_32 (data);
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                    data += 4;
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                    mask  = 0x80000000;
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                }
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                if ((chunk_id & 0x0200) || (~flag & mask)) {
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                    if (data >= eod)
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                        return -1;
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                    codebook = &strip->v1_codebook[*data++];
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                    s->frame.data[0][iy[0] + 0] = codebook->y0;
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                    s->frame.data[0][iy[0] + 1] = codebook->y0;
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                    s->frame.data[0][iy[1] + 0] = codebook->y0;
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                    s->frame.data[0][iy[1] + 1] = codebook->y0;
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                    if (!s->palette_video) {
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                        s->frame.data[1][iu[0]] = codebook->u;
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                        s->frame.data[2][iv[0]] = codebook->v;
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                    }
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                    s->frame.data[0][iy[0] + 2] = codebook->y1;
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                    s->frame.data[0][iy[0] + 3] = codebook->y1;
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                    s->frame.data[0][iy[1] + 2] = codebook->y1;
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                    s->frame.data[0][iy[1] + 3] = codebook->y1;
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                    if (!s->palette_video) {
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                        s->frame.data[1][iu[0] + 1] = codebook->u;
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                        s->frame.data[2][iv[0] + 1] = codebook->v;
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                    }
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                    s->frame.data[0][iy[2] + 0] = codebook->y2;
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                    s->frame.data[0][iy[2] + 1] = codebook->y2;
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                    s->frame.data[0][iy[3] + 0] = codebook->y2;
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                    s->frame.data[0][iy[3] + 1] = codebook->y2;
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                    if (!s->palette_video) {
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                        s->frame.data[1][iu[1]] = codebook->u;
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                        s->frame.data[2][iv[1]] = codebook->v;
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                    }
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                    s->frame.data[0][iy[2] + 2] = codebook->y3;
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                    s->frame.data[0][iy[2] + 3] = codebook->y3;
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                    s->frame.data[0][iy[3] + 2] = codebook->y3;
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                    s->frame.data[0][iy[3] + 3] = codebook->y3;
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                    if (!s->palette_video) {
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                        s->frame.data[1][iu[1] + 1] = codebook->u;
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                        s->frame.data[2][iv[1] + 1] = codebook->v;
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                    }
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                } else if (flag & mask) {
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                    if ((data + 4) > eod)
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                        return -1;
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                    codebook = &strip->v4_codebook[*data++];
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                    s->frame.data[0][iy[0] + 0] = codebook->y0;
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                    s->frame.data[0][iy[0] + 1] = codebook->y1;
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                    s->frame.data[0][iy[1] + 0] = codebook->y2;
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                    s->frame.data[0][iy[1] + 1] = codebook->y3;
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                    if (!s->palette_video) {
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                        s->frame.data[1][iu[0]] = codebook->u;
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                        s->frame.data[2][iv[0]] = codebook->v;
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                    }
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                    codebook = &strip->v4_codebook[*data++];
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                    s->frame.data[0][iy[0] + 2] = codebook->y0;
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                    s->frame.data[0][iy[0] + 3] = codebook->y1;
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                    s->frame.data[0][iy[1] + 2] = codebook->y2;
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                    s->frame.data[0][iy[1] + 3] = codebook->y3;
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                    if (!s->palette_video) {
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                        s->frame.data[1][iu[0] + 1] = codebook->u;
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                        s->frame.data[2][iv[0] + 1] = codebook->v;
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                    }
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                    codebook = &strip->v4_codebook[*data++];
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                    s->frame.data[0][iy[2] + 0] = codebook->y0;
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                    s->frame.data[0][iy[2] + 1] = codebook->y1;
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                    s->frame.data[0][iy[3] + 0] = codebook->y2;
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                    s->frame.data[0][iy[3] + 1] = codebook->y3;
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                    if (!s->palette_video) {
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                        s->frame.data[1][iu[1]] = codebook->u;
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                        s->frame.data[2][iv[1]] = codebook->v;
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                    }
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                    codebook = &strip->v4_codebook[*data++];
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                    s->frame.data[0][iy[2] + 2] = codebook->y0;
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                    s->frame.data[0][iy[2] + 3] = codebook->y1;
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                    s->frame.data[0][iy[3] + 2] = codebook->y2;
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                    s->frame.data[0][iy[3] + 3] = codebook->y3;
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                    if (!s->palette_video) {
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                        s->frame.data[1][iu[1] + 1] = codebook->u;
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                        s->frame.data[2][iv[1] + 1] = codebook->v;
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                    }
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249
                }
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            }
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252
            iy[0] += 4;  iy[1] += 4;
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            iy[2] += 4;  iy[3] += 4;
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            iu[0] += 2;  iu[1] += 2;
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            iv[0] += 2;  iv[1] += 2;
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        }
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    }
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    return 0;
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}
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static int cinepak_decode_strip (CinepakContext *s,
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                                 cvid_strip_t *strip, uint8_t *data, int size)
264
{
265
    uint8_t *eod = (data + size);
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    int      chunk_id, chunk_size;
267

    
268
    /* coordinate sanity checks */
269
    if (strip->x1 >= s->width  || strip->x2 > s->width  ||
270
        strip->y1 >= s->height || strip->y2 > s->height ||
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        strip->x1 >= strip->x2 || strip->y1 >= strip->y2)
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        return -1;
273

    
274
    while ((data + 4) <= eod) {
275
        chunk_id   = BE_16 (&data[0]);
276
        chunk_size = BE_16 (&data[2]) - 4;
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        if(chunk_size < 0)
278
            return -1;
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280
        data      += 4;
281
        chunk_size = ((data + chunk_size) > eod) ? (eod - data) : chunk_size;
282

    
283
        switch (chunk_id) {
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285
        case 0x2000:
286
        case 0x2100:
287
        case 0x2400:
288
        case 0x2500:
289
            cinepak_decode_codebook (strip->v4_codebook, chunk_id, 
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                chunk_size, data);
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            break;
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        case 0x2200:
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        case 0x2300:
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        case 0x2600:
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        case 0x2700:
297
            cinepak_decode_codebook (strip->v1_codebook, chunk_id, 
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                chunk_size, data);
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            break;
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        case 0x3000:
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        case 0x3100:
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        case 0x3200:
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            return cinepak_decode_vectors (s, strip, chunk_id, 
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                chunk_size, data);
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        }
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        data += chunk_size;
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    }
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311
    return -1;
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}
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static int cinepak_decode (CinepakContext *s)
315
{
316
    uint8_t      *eod = (s->data + s->size);
317
    int           i, result, strip_size, frame_flags, num_strips;
318
    int           y0 = 0;
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    int           encoded_buf_size;
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    /* if true, Cinepak data is from a Sega FILM/CPK file */
321
    int           sega_film_data = 0;
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323
    if (s->size < 10)
324
        return -1;
325

    
326
    frame_flags = s->data[0];
327
    num_strips  = BE_16 (&s->data[8]);
328
    encoded_buf_size = ((s->data[1] << 16) | BE_16 (&s->data[2]));
329
    if (encoded_buf_size != s->size)
330
        sega_film_data = 1;
331
    if (sega_film_data)
332
        s->data    += 12;
333
    else
334
        s->data    += 10;
335

    
336
    if (num_strips > MAX_STRIPS)
337
        num_strips = MAX_STRIPS;
338

    
339
    for (i=0; i < num_strips; i++) {
340
        if ((s->data + 12) > eod)
341
            return -1;
342

    
343
        s->strips[i].id = BE_16 (s->data);
344
        s->strips[i].y1 = y0;
345
        s->strips[i].x1 = 0;
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        s->strips[i].y2 = y0 + BE_16 (&s->data[8]);
347
        s->strips[i].x2 = s->avctx->width;
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349
        strip_size = BE_16 (&s->data[2]) - 12;
350
        s->data   += 12;
351
        strip_size = ((s->data + strip_size) > eod) ? (eod - s->data) : strip_size;
352

    
353
        if ((i > 0) && !(frame_flags & 0x01)) {
354
            memcpy (s->strips[i].v4_codebook, s->strips[i-1].v4_codebook,
355
                sizeof(s->strips[i].v4_codebook));
356
            memcpy (s->strips[i].v1_codebook, s->strips[i-1].v1_codebook,
357
                sizeof(s->strips[i].v1_codebook));
358
        }
359

    
360
        result = cinepak_decode_strip (s, &s->strips[i], s->data, strip_size);
361

    
362
        if (result != 0)
363
            return result;
364

    
365
        s->data += strip_size;
366
        y0    = s->strips[i].y2;
367
    }
368
    return 0;
369
}
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371
static int cinepak_decode_init(AVCodecContext *avctx)
372
{
373
    CinepakContext *s = (CinepakContext *)avctx->priv_data;
374

    
375
    s->avctx = avctx;
376
    s->width = (avctx->width + 3) & ~3;
377
    s->height = (avctx->height + 3) & ~3;
378

    
379
    // check for paletted data
380
    if ((avctx->palctrl == NULL) || (avctx->bits_per_sample == 40)) {
381
        s->palette_video = 0;
382
        avctx->pix_fmt = PIX_FMT_YUV420P;
383
    } else {
384
        s->palette_video = 1;
385
        avctx->pix_fmt = PIX_FMT_PAL8;
386
    }
387

    
388
    avctx->has_b_frames = 0;
389
    dsputil_init(&s->dsp, avctx);
390

    
391
    s->frame.data[0] = NULL;
392

    
393
    return 0;
394
}
395

    
396
static int cinepak_decode_frame(AVCodecContext *avctx,
397
                                void *data, int *data_size,
398
                                uint8_t *buf, int buf_size)
399
{
400
    CinepakContext *s = (CinepakContext *)avctx->priv_data;
401

    
402
    s->data = buf;
403
    s->size = buf_size;
404

    
405
    s->frame.reference = 1;
406
    s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
407
                            FF_BUFFER_HINTS_REUSABLE;
408
    if (avctx->reget_buffer(avctx, &s->frame)) {
409
        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
410
        return -1;
411
    }
412

    
413
    cinepak_decode(s);
414

    
415
    if (s->palette_video) {
416
        memcpy (s->frame.data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
417
        if (avctx->palctrl->palette_changed) {
418
            s->frame.palette_has_changed = 1;
419
            avctx->palctrl->palette_changed = 0;
420
        } else
421
            s->frame.palette_has_changed = 0;
422
    }
423

    
424
    *data_size = sizeof(AVFrame);
425
    *(AVFrame*)data = s->frame;
426

    
427
    /* report that the buffer was completely consumed */
428
    return buf_size;
429
}
430

    
431
static int cinepak_decode_end(AVCodecContext *avctx)
432
{
433
    CinepakContext *s = (CinepakContext *)avctx->priv_data;
434

    
435
    if (s->frame.data[0])
436
        avctx->release_buffer(avctx, &s->frame);
437

    
438
    return 0;
439
}
440

    
441
AVCodec cinepak_decoder = {
442
    "cinepak",
443
    CODEC_TYPE_VIDEO,
444
    CODEC_ID_CINEPAK,
445
    sizeof(CinepakContext),
446
    cinepak_decode_init,
447
    NULL,
448
    cinepak_decode_end,
449
    cinepak_decode_frame,
450
    CODEC_CAP_DR1,
451
};