libavcodec/targa.c

   1 /*
   2  * Targa (.tga) image decoder
   3  * Copyright (c) 2006 Konstantin Shishkov
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "libavutil/intreadwrite.h"
  23 #include "avcodec.h"
  24
  25 enum TargaCompr{
  26     TGA_NODATA = 0, // no image data
  27     TGA_PAL    = 1, // palettized
  28     TGA_RGB    = 2, // true-color
  29     TGA_BW     = 3, // black & white or grayscale
  30     TGA_RLE    = 8, // flag pointing that data is RLE-coded
  31 };
  32
  33 typedef struct TargaContext {
  34     AVFrame picture;
  35
  36     int width, height;
  37     int bpp;
  38     int color_type;
  39     int compression_type;
  40 } TargaContext;
  41
  42 static void targa_decode_rle(AVCodecContext *avctx, TargaContext *s, const uint8_t *src, uint8_t *dst, int w, int h, int stride, int bpp)
  43 {
  44     int i, x, y;
  45     int depth = (bpp + 1) >> 3;
  46     int type, count;
  47     int diff;
  48
  49     diff = stride - w * depth;
  50     x = y = 0;
  51     while(y < h){
  52         type = *src++;
  53         count = (type & 0x7F) + 1;
  54         type &= 0x80;
  55         if((x + count > w) && (x + count + 1 > (h - y) * w)){
  56             av_log(avctx, AV_LOG_ERROR, "Packet went out of bounds: position (%i,%i) size %i\n", x, y, count);
  57             return;
  58         }
  59         for(i = 0; i < count; i++){
  60             switch(depth){
  61             case 1:
  62                 *dst = *src;
  63                 break;
  64             case 2:
  65                 *((uint16_t*)dst) = AV_RL16(src);
  66                 break;
  67             case 3:
  68                 dst[0] = src[0];
  69                 dst[1] = src[1];
  70                 dst[2] = src[2];
  71                 break;
  72             case 4:
  73                 *((uint32_t*)dst) = AV_RL32(src);
  74                 break;
  75             }
  76             dst += depth;
  77             if(!type)
  78                 src += depth;
  79
  80             x++;
  81             if(x == w){
  82                 x = 0;
  83                 y++;
  84                 dst += diff;
  85             }
  86         }
  87         if(type)
  88             src += depth;
  89     }
  90 }
  91
  92 static int decode_frame(AVCodecContext *avctx,
  93                         void *data, int *data_size,
  94                         AVPacket *avpkt)
  95 {
  96     const uint8_t *buf = avpkt->data;
  97     int buf_size = avpkt->size;
  98     TargaContext * const s = avctx->priv_data;
  99     AVFrame *picture = data;
 100     AVFrame * const p= (AVFrame*)&s->picture;
 101     uint8_t *dst;
 102     int stride;
 103     int idlen, pal, compr, x, y, w, h, bpp, flags;
 104     int first_clr, colors, csize;
 105
 106     /* parse image header */
 107     idlen = *buf++;
 108     pal = *buf++;
 109     compr = *buf++;
 110     first_clr = AV_RL16(buf); buf += 2;
 111     colors = AV_RL16(buf); buf += 2;
 112     csize = *buf++;
 113     x = AV_RL16(buf); buf += 2;
 114     y = AV_RL16(buf); buf += 2;
 115     w = AV_RL16(buf); buf += 2;
 116     h = AV_RL16(buf); buf += 2;
 117     bpp = *buf++;
 118     flags = *buf++;
 119     //skip identifier if any
 120     buf += idlen;
 121     s->bpp = bpp;
 122     s->width = w;
 123     s->height = h;
 124     switch(s->bpp){
 125     case 8:
 126         avctx->pix_fmt = ((compr & (~TGA_RLE)) == TGA_BW) ? PIX_FMT_GRAY8 : PIX_FMT_PAL8;
 127         break;
 128     case 15:
 129         avctx->pix_fmt = PIX_FMT_RGB555;
 130         break;
 131     case 16:
 132         avctx->pix_fmt = PIX_FMT_RGB555;
 133         break;
 134     case 24:
 135         avctx->pix_fmt = PIX_FMT_BGR24;
 136         break;
 137     case 32:
 138         avctx->pix_fmt = PIX_FMT_RGB32;
 139         break;
 140     default:
 141         av_log(avctx, AV_LOG_ERROR, "Bit depth %i is not supported\n", s->bpp);
 142         return -1;
 143     }
 144
 145     if(s->picture.data[0])
 146         avctx->release_buffer(avctx, &s->picture);
 147
 148     if(avcodec_check_dimensions(avctx, w, h))
 149         return -1;
 150     if(w != avctx->width || h != avctx->height)
 151         avcodec_set_dimensions(avctx, w, h);
 152     if(avctx->get_buffer(avctx, p) < 0){
 153         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 154         return -1;
 155     }
 156     if(flags & 0x20){
 157         dst = p->data[0];
 158         stride = p->linesize[0];
 159     }else{ //image is upside-down
 160         dst = p->data[0] + p->linesize[0] * (h - 1);
 161         stride = -p->linesize[0];
 162     }
 163
 164     if(avctx->pix_fmt == PIX_FMT_PAL8 && avctx->palctrl){
 165         memcpy(p->data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
 166         if(avctx->palctrl->palette_changed){
 167             p->palette_has_changed = 1;
 168             avctx->palctrl->palette_changed = 0;
 169         }
 170     }
 171     if(colors){
 172         if((colors + first_clr) > 256){
 173             av_log(avctx, AV_LOG_ERROR, "Incorrect palette: %i colors with offset %i\n", colors, first_clr);
 174             return -1;
 175         }
 176         if(csize != 24){
 177             av_log(avctx, AV_LOG_ERROR, "Palette entry size %i bits is not supported\n", csize);
 178             return -1;
 179         }
 180         if(avctx->pix_fmt != PIX_FMT_PAL8)//should not occur but skip palette anyway
 181             buf += colors * ((csize + 1) >> 3);
 182         else{
 183             int r, g, b, t;
 184             int32_t *pal = ((int32_t*)p->data[1]) + first_clr;
 185             for(t = 0; t < colors; t++){
 186                 r = *buf++;
 187                 g = *buf++;
 188                 b = *buf++;
 189                 *pal++ = (b << 16) | (g << 8) | r;
 190             }
 191             p->palette_has_changed = 1;
 192             avctx->palctrl->palette_changed = 0;
 193         }
 194     }
 195     if((compr & (~TGA_RLE)) == TGA_NODATA)
 196         memset(p->data[0], 0, p->linesize[0] * s->height);
 197     else{
 198         if(compr & TGA_RLE)
 199             targa_decode_rle(avctx, s, buf, dst, avctx->width, avctx->height, stride, bpp);
 200         else{
 201             for(y = 0; y < s->height; y++){
 202 #if HAVE_BIGENDIAN
 203                 if((s->bpp + 1) >> 3 == 2){
 204                     uint16_t *dst16 = (uint16_t*)dst;
 205                     for(x = 0; x < s->width; x++)
 206                         dst16[x] = AV_RL16(buf + x * 2);
 207                 }else if((s->bpp + 1) >> 3 == 4){
 208                     uint32_t *dst32 = (uint32_t*)dst;
 209                     for(x = 0; x < s->width; x++)
 210                         dst32[x] = AV_RL32(buf + x * 4);
 211                 }else
 212 #endif
 213                     memcpy(dst, buf, s->width * ((s->bpp + 1) >> 3));
 214
 215                 dst += stride;
 216                 buf += s->width * ((s->bpp + 1) >> 3);
 217             }
 218         }
 219     }
 220
 221     *picture= *(AVFrame*)&s->picture;
 222     *data_size = sizeof(AVPicture);
 223
 224     return buf_size;
 225 }
 226
 227 static av_cold int targa_init(AVCodecContext *avctx){
 228     TargaContext *s = avctx->priv_data;
 229
 230     avcodec_get_frame_defaults((AVFrame*)&s->picture);
 231     avctx->coded_frame= (AVFrame*)&s->picture;
 232
 233     return 0;
 234 }
 235
 236 static av_cold int targa_end(AVCodecContext *avctx){
 237     TargaContext *s = avctx->priv_data;
 238
 239     if(s->picture.data[0])
 240         avctx->release_buffer(avctx, &s->picture);
 241
 242     return 0;
 243 }
 244
 245 AVCodec targa_decoder = {
 246     "targa",
 247     CODEC_TYPE_VIDEO,
 248     CODEC_ID_TARGA,
 249     sizeof(TargaContext),
 250     targa_init,
 251     NULL,
 252     targa_end,
 253     decode_frame,
 254     CODEC_CAP_DR1,
 255     NULL,
 256     .long_name = NULL_IF_CONFIG_SMALL("Truevision Targa image"),
 257 };