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
25enum 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
33typedef struct TargaContext {
34    AVFrame picture;
35
36    int width, height;
37    int bpp;
38    int color_type;
39    int compression_type;
40} TargaContext;
41
42static 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
92static 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
225static 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
235static 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
244AVCodec 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};
257