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ffmpeg / libavcodec / eatgq.c @ 72415b2a

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/*
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 * Electronic Arts TGQ Video Decoder
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 * Copyright (c) 2007-2008 Peter Ross <pross@xvid.org>
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg 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 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg 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 FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
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 */
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/**
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 * @file libavcodec/eatgq.c
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 * Electronic Arts TGQ Video Decoder
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 * @author Peter Ross <pross@xvid.org>
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 *
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 * Technical details here:
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 * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_TGQ
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 */
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#include "avcodec.h"
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#define ALT_BITSTREAM_READER_LE
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#include "get_bits.h"
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#include "bytestream.h"
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#include "dsputil.h"
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#include "aandcttab.h"
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typedef struct TgqContext {
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    AVCodecContext *avctx;
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    DSPContext dsp;
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    AVFrame frame;
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    int width,height;
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    ScanTable scantable;
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    int qtable[64];
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    DECLARE_ALIGNED(16, DCTELEM, block)[6][64];
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} TgqContext;
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static av_cold int tgq_decode_init(AVCodecContext *avctx){
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    TgqContext *s = avctx->priv_data;
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    s->avctx = avctx;
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    if(avctx->idct_algo==FF_IDCT_AUTO)
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        avctx->idct_algo=FF_IDCT_EA;
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    dsputil_init(&s->dsp, avctx);
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    ff_init_scantable(s->dsp.idct_permutation, &s->scantable, ff_zigzag_direct);
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    avctx->time_base = (AVRational){1, 15};
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    avctx->pix_fmt = PIX_FMT_YUV420P;
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    return 0;
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}
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static void tgq_decode_block(TgqContext *s, DCTELEM block[64], GetBitContext *gb){
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    uint8_t *perm = s->scantable.permutated;
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    int i,j,value;
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    block[0] = get_sbits(gb,8) * s->qtable[0];
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    for(i=1; i<64; ) {
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        switch(show_bits(gb,3)) {
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        case 4:
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            block[perm[i++]] = 0;
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        case 0:
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            block[perm[i++]] = 0;
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            skip_bits(gb,3);
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            break;
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        case 5:
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        case 1:
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            skip_bits(gb,2);
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            value = get_bits(gb,6);
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            for(j=0; j<value; j++)
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                block[perm[i++]] = 0;
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            break;
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        case 6:
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            skip_bits(gb,3);
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            block[perm[i]] = -s->qtable[perm[i]];
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            i++;
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            break;
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        case 2:
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            skip_bits(gb,3);
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            block[perm[i]] = s->qtable[perm[i]];
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            i++;
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            break;
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        case 7: // 111b
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        case 3: // 011b
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            skip_bits(gb,2);
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            if (show_bits(gb,6)==0x3F) {
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                skip_bits(gb, 6);
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                block[perm[i]] = get_sbits(gb,8)*s->qtable[perm[i]];
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            }else{
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                block[perm[i]] = get_sbits(gb,6)*s->qtable[perm[i]];
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            }
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            i++;
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            break;
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        }
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    }
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    block[0] += 128<<4;
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}
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static void tgq_idct_put_mb(TgqContext *s, DCTELEM (*block)[64], int mb_x, int mb_y){
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    int linesize= s->frame.linesize[0];
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    uint8_t *dest_y  = s->frame.data[0] + (mb_y * 16* linesize            ) + mb_x * 16;
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    uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
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    uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
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    s->dsp.idct_put(dest_y                 , linesize, block[0]);
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    s->dsp.idct_put(dest_y              + 8, linesize, block[1]);
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    s->dsp.idct_put(dest_y + 8*linesize    , linesize, block[2]);
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    s->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]);
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    if(!(s->avctx->flags&CODEC_FLAG_GRAY)){
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         s->dsp.idct_put(dest_cb, s->frame.linesize[1], block[4]);
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         s->dsp.idct_put(dest_cr, s->frame.linesize[2], block[5]);
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    }
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}
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static inline void tgq_dconly(TgqContext *s, unsigned char *dst, int dst_stride, int dc){
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    int level = av_clip_uint8((dc*s->qtable[0] + 2056)>>4);
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    int j;
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    for(j=0;j<8;j++)
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        memset(dst+j*dst_stride, level, 8);
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}
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static void tgq_idct_put_mb_dconly(TgqContext *s, int mb_x, int mb_y, const int8_t *dc)
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{
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    int linesize= s->frame.linesize[0];
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    uint8_t *dest_y  = s->frame.data[0] + (mb_y * 16* linesize            ) + mb_x * 16;
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    uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
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    uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
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    tgq_dconly(s,dest_y                 , linesize, dc[0]);
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    tgq_dconly(s,dest_y              + 8, linesize, dc[1]);
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    tgq_dconly(s,dest_y + 8*linesize    , linesize, dc[2]);
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    tgq_dconly(s,dest_y + 8*linesize + 8, linesize, dc[3]);
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    if(!(s->avctx->flags&CODEC_FLAG_GRAY)) {
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        tgq_dconly(s,dest_cb, s->frame.linesize[1], dc[4]);
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        tgq_dconly(s,dest_cr, s->frame.linesize[2], dc[5]);
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    }
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}
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static void tgq_decode_mb(TgqContext *s, int mb_y, int mb_x, const uint8_t **bs, const uint8_t *buf_end){
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    int mode;
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    int i;
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    int8_t dc[6];
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    mode = bytestream_get_byte(bs);
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    if (mode>buf_end-*bs) {
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        av_log(s->avctx, AV_LOG_ERROR, "truncated macroblock\n");
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        return;
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    }
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    if (mode>12) {
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        GetBitContext gb;
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        init_get_bits(&gb, *bs, mode*8);
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        for(i=0; i<6; i++)
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            tgq_decode_block(s, s->block[i], &gb);
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        tgq_idct_put_mb(s, s->block, mb_x, mb_y);
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    }else{
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        if (mode==3) {
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            memset(dc, (*bs)[0], 4);
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            dc[4] = (*bs)[1];
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            dc[5] = (*bs)[2];
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        }else if (mode==6) {
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            memcpy(dc, *bs, 6);
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        }else if (mode==12) {
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            for(i=0; i<6; i++)
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                dc[i] = (*bs)[i*2];
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        }else{
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            av_log(s->avctx, AV_LOG_ERROR, "unsupported mb mode %i\n", mode);
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        }
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        tgq_idct_put_mb_dconly(s, mb_x, mb_y, dc);
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    }
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    *bs += mode;
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}
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static void tgq_calculate_qtable(TgqContext *s, int quant){
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    int i,j;
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    const int a = (14*(100-quant))/100 + 1;
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    const int b = (11*(100-quant))/100 + 4;
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    for(j=0;j<8;j++)
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    for(i=0;i<8;i++)
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        if (s->avctx->idct_algo==FF_IDCT_EA)
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            s->qtable[j*8+i] = ((a*(j+i)/(7+7) + b)*ff_inv_aanscales[j*8+i])>>(14-4);
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        else
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            s->qtable[j*8+i] = (a*(j+i)/(7+7) + b)<<3;
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}
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static int tgq_decode_frame(AVCodecContext *avctx,
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                            void *data, int *data_size,
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                            AVPacket *avpkt){
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    const uint8_t *buf = avpkt->data;
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    int buf_size = avpkt->size;
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    const uint8_t *buf_start = buf;
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    const uint8_t *buf_end = buf + buf_size;
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    TgqContext *s = avctx->priv_data;
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    int x,y;
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    int big_endian = AV_RL32(&buf[4]) > 0x000FFFFF;
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    buf += 8;
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    if(8>buf_end-buf) {
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        av_log(avctx, AV_LOG_WARNING, "truncated header\n");
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        return -1;
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    }
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    s->width  = big_endian ? AV_RB16(&buf[0]) : AV_RL16(&buf[0]);
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    s->height = big_endian ? AV_RB16(&buf[2]) : AV_RL16(&buf[2]);
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    if (s->avctx->width!=s->width || s->avctx->height!=s->height) {
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        avcodec_set_dimensions(s->avctx, s->width, s->height);
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        if (s->frame.data[0])
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            avctx->release_buffer(avctx, &s->frame);
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    }
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    tgq_calculate_qtable(s, buf[4]);
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    buf += 8;
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    if (!s->frame.data[0]) {
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        s->frame.key_frame = 1;
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        s->frame.pict_type = FF_I_TYPE;
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        s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
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        if (avctx->get_buffer(avctx, &s->frame)) {
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            av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
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            return -1;
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        }
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    }
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    for (y=0; y<(avctx->height+15)/16; y++)
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    for (x=0; x<(avctx->width+15)/16; x++)
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        tgq_decode_mb(s, y, x, &buf, buf_end);
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    *data_size = sizeof(AVFrame);
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    *(AVFrame*)data = s->frame;
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    return buf-buf_start;
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}
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static av_cold int tgq_decode_end(AVCodecContext *avctx){
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    TgqContext *s = avctx->priv_data;
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    if (s->frame.data[0])
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        s->avctx->release_buffer(avctx, &s->frame);
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    return 0;
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}
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AVCodec eatgq_decoder = {
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    "eatgq",
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    AVMEDIA_TYPE_VIDEO,
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    CODEC_ID_TGQ,
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    sizeof(TgqContext),
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    tgq_decode_init,
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    NULL,
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    tgq_decode_end,
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    tgq_decode_frame,
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    CODEC_CAP_DR1,
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    .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts TGQ video"),
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};