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                         const uint8_t *buf, int buf_size)
  95 {
  96     TargaContext * const s = avctx->priv_data;
  97     AVFrame *picture = data;
  98     AVFrame * const p= (AVFrame*)&s->picture;
  99     uint8_t *dst;
 100     int stride;
 101     int idlen, pal, compr, x, y, w, h, bpp, flags;
 102     int first_clr, colors, csize;
 103
 104     /* parse image header */
 105     idlen = *buf++;
 106     pal = *buf++;
 107     compr = *buf++;
 108     first_clr = AV_RL16(buf); buf += 2;
 109     colors = AV_RL16(buf); buf += 2;
 110     csize = *buf++;
 111     x = AV_RL16(buf); buf += 2;
 112     y = AV_RL16(buf); buf += 2;
 113     w = AV_RL16(buf); buf += 2;
 114     h = AV_RL16(buf); buf += 2;
 115     bpp = *buf++;
 116     flags = *buf++;
 117     //skip identifier if any
 118     buf += idlen;
 119     s->bpp = bpp;
 120     s->width = w;
 121     s->height = h;
 122     switch(s->bpp){
 123     case 8:
 124         avctx->pix_fmt = ((compr & (~TGA_RLE)) == TGA_BW) ? PIX_FMT_GRAY8 : PIX_FMT_PAL8;
 125         break;
 126     case 15:
 127         avctx->pix_fmt = PIX_FMT_RGB555;
 128         break;
 129     case 16:
 130         avctx->pix_fmt = PIX_FMT_RGB555;
 131         break;
 132     case 24:
 133         avctx->pix_fmt = PIX_FMT_BGR24;
 134         break;
 135     case 32:
 136         avctx->pix_fmt = PIX_FMT_RGB32;
 137         break;
 138     default:
 139         av_log(avctx, AV_LOG_ERROR, "Bit depth %i is not supported\n", s->bpp);
 140         return -1;
 141     }
 142
 143     if(s->picture.data[0])
 144         avctx->release_buffer(avctx, &s->picture);
 145
 146     if(avcodec_check_dimensions(avctx, w, h))
 147         return -1;
 148     if(w != avctx->width || h != avctx->height)
 149         avcodec_set_dimensions(avctx, w, h);
 150     if(avctx->get_buffer(avctx, p) < 0){
 151         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 152         return -1;
 153     }
 154     if(flags & 0x20){
 155         dst = p->data[0];
 156         stride = p->linesize[0];
 157     }else{ //image is upside-down
 158         dst = p->data[0] + p->linesize[0] * (h - 1);
 159         stride = -p->linesize[0];
 160     }
 161
 162     if(avctx->pix_fmt == PIX_FMT_PAL8 && avctx->palctrl){
 163         memcpy(p->data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
 164         if(avctx->palctrl->palette_changed){
 165             p->palette_has_changed = 1;
 166             avctx->palctrl->palette_changed = 0;
 167         }
 168     }
 169     if(colors){
 170         if((colors + first_clr) > 256){
 171             av_log(avctx, AV_LOG_ERROR, "Incorrect palette: %i colors with offset %i\n", colors, first_clr);
 172             return -1;
 173         }
 174         if(csize != 24){
 175             av_log(avctx, AV_LOG_ERROR, "Palette entry size %i bits is not supported\n", csize);
 176             return -1;
 177         }
 178         if(avctx->pix_fmt != PIX_FMT_PAL8)//should not occur but skip palette anyway
 179             buf += colors * ((csize + 1) >> 3);
 180         else{
 181             int r, g, b, t;
 182             int32_t *pal = ((int32_t*)p->data[1]) + first_clr;
 183             for(t = 0; t < colors; t++){
 184                 r = *buf++;
 185                 g = *buf++;
 186                 b = *buf++;
 187                 *pal++ = (b << 16) | (g << 8) | r;
 188             }
 189             p->palette_has_changed = 1;
 190             avctx->palctrl->palette_changed = 0;
 191         }
 192     }
 193     if((compr & (~TGA_RLE)) == TGA_NODATA)
 194         memset(p->data[0], 0, p->linesize[0] * s->height);
 195     else{
 196         if(compr & TGA_RLE)
 197             targa_decode_rle(avctx, s, buf, dst, avctx->width, avctx->height, stride, bpp);
 198         else{
 199             for(y = 0; y < s->height; y++){
 200 #ifdef WORDS_BIGENDIAN
 201                 if((s->bpp + 1) >> 3 == 2){
 202                     uint16_t *dst16 = (uint16_t*)dst;
 203                     for(x = 0; x < s->width; x++)
 204                         dst16[x] = AV_RL16(buf + x * 2);
 205                 }else if((s->bpp + 1) >> 3 == 4){
 206                     uint32_t *dst32 = (uint32_t*)dst;
 207                     for(x = 0; x < s->width; x++)
 208                         dst32[x] = AV_RL32(buf + x * 4);
 209                 }else
 210 #endif
 211                     memcpy(dst, buf, s->width * ((s->bpp + 1) >> 3));
 212
 213                 dst += stride;
 214                 buf += s->width * ((s->bpp + 1) >> 3);
 215             }
 216         }
 217     }
 218
 219     *picture= *(AVFrame*)&s->picture;
 220     *data_size = sizeof(AVPicture);
 221
 222     return buf_size;
 223 }
 224
 225 static av_cold int targa_init(AVCodecContext *avctx){
 226     TargaContext *s = avctx->priv_data;
 227
 228     avcodec_get_frame_defaults((AVFrame*)&s->picture);
 229     avctx->coded_frame= (AVFrame*)&s->picture;
 230     s->picture.data[0] = NULL;
 231
 232     return 0;
 233 }
 234
 235 static av_cold int targa_end(AVCodecContext *avctx){
 236     TargaContext *s = avctx->priv_data;
 237
 238     if(s->picture.data[0])
 239         avctx->release_buffer(avctx, &s->picture);
 240
 241     return 0;
 242 }
 243
 244 AVCodec targa_decoder = {
 245     "targa",
 246     CODEC_TYPE_VIDEO,
 247     CODEC_ID_TARGA,
 248     sizeof(TargaContext),
 249     targa_init,
 250     NULL,
 251     targa_end,
 252     decode_frame,
 253     0,
 254     NULL,
 255     .long_name = NULL_IF_CONFIG_SMALL("Truevision Targa image"),
 256 };