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libavcodec/targa.c

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00001 /*
00002  * Targa (.tga) image 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 
00022 #include "libavutil/intreadwrite.h"
00023 #include "avcodec.h"
00024 
00025 enum TargaCompr{
00026     TGA_NODATA = 0, // no image data
00027     TGA_PAL    = 1, // palettized
00028     TGA_RGB    = 2, // true-color
00029     TGA_BW     = 3, // black & white or grayscale
00030     TGA_RLE    = 8, // flag pointing that data is RLE-coded
00031 };
00032 
00033 typedef struct TargaContext {
00034     AVFrame picture;
00035 
00036     int width, height;
00037     int bpp;
00038     int color_type;
00039     int compression_type;
00040 } TargaContext;
00041 
00042 static void targa_decode_rle(AVCodecContext *avctx, TargaContext *s, const uint8_t *src, uint8_t *dst, int w, int h, int stride, int bpp)
00043 {
00044     int i, x, y;
00045     int depth = (bpp + 1) >> 3;
00046     int type, count;
00047     int diff;
00048 
00049     diff = stride - w * depth;
00050     x = y = 0;
00051     while(y < h){
00052         type = *src++;
00053         count = (type & 0x7F) + 1;
00054         type &= 0x80;
00055         if((x + count > w) && (x + count + 1 > (h - y) * w)){
00056             av_log(avctx, AV_LOG_ERROR, "Packet went out of bounds: position (%i,%i) size %i\n", x, y, count);
00057             return;
00058         }
00059         for(i = 0; i < count; i++){
00060             switch(depth){
00061             case 1:
00062                 *dst = *src;
00063                 break;
00064             case 2:
00065                 *((uint16_t*)dst) = AV_RL16(src);
00066                 break;
00067             case 3:
00068                 dst[0] = src[0];
00069                 dst[1] = src[1];
00070                 dst[2] = src[2];
00071                 break;
00072             case 4:
00073                 *((uint32_t*)dst) = AV_RL32(src);
00074                 break;
00075             }
00076             dst += depth;
00077             if(!type)
00078                 src += depth;
00079 
00080             x++;
00081             if(x == w){
00082                 x = 0;
00083                 y++;
00084                 dst += diff;
00085             }
00086         }
00087         if(type)
00088             src += depth;
00089     }
00090 }
00091 
00092 static int decode_frame(AVCodecContext *avctx,
00093                         void *data, int *data_size,
00094                         AVPacket *avpkt)
00095 {
00096     const uint8_t *buf = avpkt->data;
00097     int buf_size = avpkt->size;
00098     TargaContext * const s = avctx->priv_data;
00099     AVFrame *picture = data;
00100     AVFrame * const p= (AVFrame*)&s->picture;
00101     uint8_t *dst;
00102     int stride;
00103     int idlen, pal, compr, x, y, w, h, bpp, flags;
00104     int first_clr, colors, csize;
00105 
00106     /* parse image header */
00107     idlen = *buf++;
00108     pal = *buf++;
00109     compr = *buf++;
00110     first_clr = AV_RL16(buf); buf += 2;
00111     colors = AV_RL16(buf); buf += 2;
00112     csize = *buf++;
00113     x = AV_RL16(buf); buf += 2;
00114     y = AV_RL16(buf); buf += 2;
00115     w = AV_RL16(buf); buf += 2;
00116     h = AV_RL16(buf); buf += 2;
00117     bpp = *buf++;
00118     flags = *buf++;
00119     //skip identifier if any
00120     buf += idlen;
00121     s->bpp = bpp;
00122     s->width = w;
00123     s->height = h;
00124     switch(s->bpp){
00125     case 8:
00126         avctx->pix_fmt = ((compr & (~TGA_RLE)) == TGA_BW) ? PIX_FMT_GRAY8 : PIX_FMT_PAL8;
00127         break;
00128     case 15:
00129         avctx->pix_fmt = PIX_FMT_RGB555;
00130         break;
00131     case 16:
00132         avctx->pix_fmt = PIX_FMT_RGB555;
00133         break;
00134     case 24:
00135         avctx->pix_fmt = PIX_FMT_BGR24;
00136         break;
00137     case 32:
00138         avctx->pix_fmt = PIX_FMT_RGB32;
00139         break;
00140     default:
00141         av_log(avctx, AV_LOG_ERROR, "Bit depth %i is not supported\n", s->bpp);
00142         return -1;
00143     }
00144 
00145     if(s->picture.data[0])
00146         avctx->release_buffer(avctx, &s->picture);
00147 
00148     if(avcodec_check_dimensions(avctx, w, h))
00149         return -1;
00150     if(w != avctx->width || h != avctx->height)
00151         avcodec_set_dimensions(avctx, w, h);
00152     if(avctx->get_buffer(avctx, p) < 0){
00153         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00154         return -1;
00155     }
00156     if(flags & 0x20){
00157         dst = p->data[0];
00158         stride = p->linesize[0];
00159     }else{ //image is upside-down
00160         dst = p->data[0] + p->linesize[0] * (h - 1);
00161         stride = -p->linesize[0];
00162     }
00163 
00164     if(avctx->pix_fmt == PIX_FMT_PAL8 && avctx->palctrl){
00165         memcpy(p->data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
00166         if(avctx->palctrl->palette_changed){
00167             p->palette_has_changed = 1;
00168             avctx->palctrl->palette_changed = 0;
00169         }
00170     }
00171     if(colors){
00172         if((colors + first_clr) > 256){
00173             av_log(avctx, AV_LOG_ERROR, "Incorrect palette: %i colors with offset %i\n", colors, first_clr);
00174             return -1;
00175         }
00176         if(csize != 24){
00177             av_log(avctx, AV_LOG_ERROR, "Palette entry size %i bits is not supported\n", csize);
00178             return -1;
00179         }
00180         if(avctx->pix_fmt != PIX_FMT_PAL8)//should not occur but skip palette anyway
00181             buf += colors * ((csize + 1) >> 3);
00182         else{
00183             int r, g, b, t;
00184             int32_t *pal = ((int32_t*)p->data[1]) + first_clr;
00185             for(t = 0; t < colors; t++){
00186                 r = *buf++;
00187                 g = *buf++;
00188                 b = *buf++;
00189                 *pal++ = (b << 16) | (g << 8) | r;
00190             }
00191             p->palette_has_changed = 1;
00192         }
00193     }
00194     if((compr & (~TGA_RLE)) == TGA_NODATA)
00195         memset(p->data[0], 0, p->linesize[0] * s->height);
00196     else{
00197         if(compr & TGA_RLE)
00198             targa_decode_rle(avctx, s, buf, dst, avctx->width, avctx->height, stride, bpp);
00199         else{
00200             for(y = 0; y < s->height; y++){
00201 #if HAVE_BIGENDIAN
00202                 if((s->bpp + 1) >> 3 == 2){
00203                     uint16_t *dst16 = (uint16_t*)dst;
00204                     for(x = 0; x < s->width; x++)
00205                         dst16[x] = AV_RL16(buf + x * 2);
00206                 }else if((s->bpp + 1) >> 3 == 4){
00207                     uint32_t *dst32 = (uint32_t*)dst;
00208                     for(x = 0; x < s->width; x++)
00209                         dst32[x] = AV_RL32(buf + x * 4);
00210                 }else
00211 #endif
00212                     memcpy(dst, buf, s->width * ((s->bpp + 1) >> 3));
00213 
00214                 dst += stride;
00215                 buf += s->width * ((s->bpp + 1) >> 3);
00216             }
00217         }
00218     }
00219 
00220     *picture= *(AVFrame*)&s->picture;
00221     *data_size = sizeof(AVPicture);
00222 
00223     return buf_size;
00224 }
00225 
00226 static av_cold int targa_init(AVCodecContext *avctx){
00227     TargaContext *s = avctx->priv_data;
00228 
00229     avcodec_get_frame_defaults((AVFrame*)&s->picture);
00230     avctx->coded_frame= (AVFrame*)&s->picture;
00231 
00232     return 0;
00233 }
00234 
00235 static av_cold int targa_end(AVCodecContext *avctx){
00236     TargaContext *s = avctx->priv_data;
00237 
00238     if(s->picture.data[0])
00239         avctx->release_buffer(avctx, &s->picture);
00240 
00241     return 0;
00242 }
00243 
00244 AVCodec targa_decoder = {
00245     "targa",
00246     AVMEDIA_TYPE_VIDEO,
00247     CODEC_ID_TARGA,
00248     sizeof(TargaContext),
00249     targa_init,
00250     NULL,
00251     targa_end,
00252     decode_frame,
00253     CODEC_CAP_DR1,
00254     NULL,
00255     .long_name = NULL_IF_CONFIG_SMALL("Truevision Targa image"),
00256 };

Generated on Fri Sep 16 2011 17:17:43 for FFmpeg by  doxygen 1.7.1