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ffmpeg / libavcodec / targa.c @ 63613fe6

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/*
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 * Targa (.tga) image decoder
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 * Copyright (c) 2006 Konstantin Shishkov
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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 Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#include "libavutil/intreadwrite.h"
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#include "avcodec.h"
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enum TargaCompr{
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    TGA_NODATA = 0, // no image data
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    TGA_PAL    = 1, // palettized
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    TGA_RGB    = 2, // true-color
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    TGA_BW     = 3, // black & white or grayscale
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    TGA_RLE    = 8, // flag pointing that data is RLE-coded
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};
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typedef struct TargaContext {
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    AVFrame picture;
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    int width, height;
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    int bpp;
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    int color_type;
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    int compression_type;
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} TargaContext;
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static void targa_decode_rle(AVCodecContext *avctx, TargaContext *s, const uint8_t *src, uint8_t *dst, int w, int h, int stride, int bpp)
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{
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    int i, x, y;
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    int depth = (bpp + 1) >> 3;
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    int type, count;
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    int diff;
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    diff = stride - w * depth;
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    x = y = 0;
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    while(y < h){
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        type = *src++;
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        count = (type & 0x7F) + 1;
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        type &= 0x80;
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        if((x + count > w) && (x + count + 1 > (h - y) * w)){
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            av_log(avctx, AV_LOG_ERROR, "Packet went out of bounds: position (%i,%i) size %i\n", x, y, count);
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            return;
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        }
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        for(i = 0; i < count; i++){
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            switch(depth){
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            case 1:
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                *dst = *src;
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                break;
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            case 2:
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                *((uint16_t*)dst) = AV_RL16(src);
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                break;
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            case 3:
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                dst[0] = src[0];
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                dst[1] = src[1];
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                dst[2] = src[2];
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                break;
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            case 4:
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                *((uint32_t*)dst) = AV_RL32(src);
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                break;
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            }
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            dst += depth;
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            if(!type)
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                src += depth;
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            x++;
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            if(x == w){
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                x = 0;
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                y++;
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                dst += diff;
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            }
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        }
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        if(type)
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            src += depth;
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    }
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}
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static int decode_frame(AVCodecContext *avctx,
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                        void *data, int *data_size,
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                        AVPacket *avpkt)
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{
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    const uint8_t *buf = avpkt->data;
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    int buf_size = avpkt->size;
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    TargaContext * const s = avctx->priv_data;
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    AVFrame *picture = data;
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    AVFrame * const p= (AVFrame*)&s->picture;
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    uint8_t *dst;
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    int stride;
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    int idlen, pal, compr, x, y, w, h, bpp, flags;
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    int first_clr, colors, csize;
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    /* parse image header */
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    idlen = *buf++;
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    pal = *buf++;
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    compr = *buf++;
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    first_clr = AV_RL16(buf); buf += 2;
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    colors = AV_RL16(buf); buf += 2;
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    csize = *buf++;
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    x = AV_RL16(buf); buf += 2;
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    y = AV_RL16(buf); buf += 2;
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    w = AV_RL16(buf); buf += 2;
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    h = AV_RL16(buf); buf += 2;
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    bpp = *buf++;
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    flags = *buf++;
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    //skip identifier if any
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    buf += idlen;
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    s->bpp = bpp;
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    s->width = w;
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    s->height = h;
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    switch(s->bpp){
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    case 8:
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        avctx->pix_fmt = ((compr & (~TGA_RLE)) == TGA_BW) ? PIX_FMT_GRAY8 : PIX_FMT_PAL8;
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        break;
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    case 15:
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        avctx->pix_fmt = PIX_FMT_RGB555;
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        break;
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    case 16:
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        avctx->pix_fmt = PIX_FMT_RGB555;
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        break;
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    case 24:
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        avctx->pix_fmt = PIX_FMT_BGR24;
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        break;
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    case 32:
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        avctx->pix_fmt = PIX_FMT_RGB32;
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        break;
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    default:
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        av_log(avctx, AV_LOG_ERROR, "Bit depth %i is not supported\n", s->bpp);
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        return -1;
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    }
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    if(s->picture.data[0])
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        avctx->release_buffer(avctx, &s->picture);
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    if(avcodec_check_dimensions(avctx, w, h))
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        return -1;
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    if(w != avctx->width || h != avctx->height)
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        avcodec_set_dimensions(avctx, w, h);
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    if(avctx->get_buffer(avctx, p) < 0){
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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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    if(flags & 0x20){
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        dst = p->data[0];
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        stride = p->linesize[0];
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    }else{ //image is upside-down
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        dst = p->data[0] + p->linesize[0] * (h - 1);
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        stride = -p->linesize[0];
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    }
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    if(avctx->pix_fmt == PIX_FMT_PAL8 && avctx->palctrl){
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        memcpy(p->data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
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        if(avctx->palctrl->palette_changed){
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            p->palette_has_changed = 1;
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            avctx->palctrl->palette_changed = 0;
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        }
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    }
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    if(colors){
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        if((colors + first_clr) > 256){
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            av_log(avctx, AV_LOG_ERROR, "Incorrect palette: %i colors with offset %i\n", colors, first_clr);
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            return -1;
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        }
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        if(csize != 24){
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            av_log(avctx, AV_LOG_ERROR, "Palette entry size %i bits is not supported\n", csize);
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            return -1;
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        }
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        if(avctx->pix_fmt != PIX_FMT_PAL8)//should not occur but skip palette anyway
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            buf += colors * ((csize + 1) >> 3);
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        else{
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            int r, g, b, t;
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            int32_t *pal = ((int32_t*)p->data[1]) + first_clr;
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            for(t = 0; t < colors; t++){
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                r = *buf++;
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                g = *buf++;
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                b = *buf++;
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                *pal++ = (b << 16) | (g << 8) | r;
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            }
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            p->palette_has_changed = 1;
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            avctx->palctrl->palette_changed = 0;
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        }
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    }
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    if((compr & (~TGA_RLE)) == TGA_NODATA)
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        memset(p->data[0], 0, p->linesize[0] * s->height);
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    else{
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        if(compr & TGA_RLE)
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            targa_decode_rle(avctx, s, buf, dst, avctx->width, avctx->height, stride, bpp);
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        else{
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            for(y = 0; y < s->height; y++){
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#if HAVE_BIGENDIAN
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                if((s->bpp + 1) >> 3 == 2){
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                    uint16_t *dst16 = (uint16_t*)dst;
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                    for(x = 0; x < s->width; x++)
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                        dst16[x] = AV_RL16(buf + x * 2);
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                }else if((s->bpp + 1) >> 3 == 4){
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                    uint32_t *dst32 = (uint32_t*)dst;
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                    for(x = 0; x < s->width; x++)
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                        dst32[x] = AV_RL32(buf + x * 4);
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                }else
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#endif
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                    memcpy(dst, buf, s->width * ((s->bpp + 1) >> 3));
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                dst += stride;
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                buf += s->width * ((s->bpp + 1) >> 3);
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            }
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        }
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    }
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    *picture= *(AVFrame*)&s->picture;
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    *data_size = sizeof(AVPicture);
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    return buf_size;
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}
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static av_cold int targa_init(AVCodecContext *avctx){
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    TargaContext *s = avctx->priv_data;
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    avcodec_get_frame_defaults((AVFrame*)&s->picture);
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    avctx->coded_frame= (AVFrame*)&s->picture;
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    return 0;
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}
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static av_cold int targa_end(AVCodecContext *avctx){
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    TargaContext *s = avctx->priv_data;
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    if(s->picture.data[0])
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        avctx->release_buffer(avctx, &s->picture);
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    return 0;
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}
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AVCodec targa_decoder = {
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    "targa",
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    CODEC_TYPE_VIDEO,
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    CODEC_ID_TARGA,
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    sizeof(TargaContext),
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    targa_init,
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    NULL,
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    targa_end,
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    decode_frame,
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    CODEC_CAP_DR1,
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    NULL,
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    .long_name = NULL_IF_CONFIG_SMALL("Truevision Targa image"),
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};