1/*
2 * Targa (.tga) image decoder
3 * Copyright (c) 2006 Konstantin Shishkov
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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 "libavutil/imgutils.h"
24#include "avcodec.h"
25#include "bytestream.h"
26#include "targa.h"
27
28typedef struct TargaContext {
29    AVFrame picture;
30
31    int width, height;
32    int bpp;
33    int color_type;
34    int compression_type;
35} TargaContext;
36
37#define CHECK_BUFFER_SIZE(buf, buf_end, needed, where) \
38    if(needed > buf_end - buf){ \
39        av_log(avctx, AV_LOG_ERROR, "Problem: unexpected end of data while reading " where "\n"); \
40        return -1; \
41    } \
42
43static int targa_decode_rle(AVCodecContext *avctx, TargaContext *s, const uint8_t *src, int src_size, uint8_t *dst, int w, int h, int stride, int bpp)
44{
45    int i, x, y;
46    int depth = (bpp + 1) >> 3;
47    int type, count;
48    int diff;
49    const uint8_t *src_end = src + src_size;
50
51    diff = stride - w * depth;
52    x = y = 0;
53    while(y < h){
54        CHECK_BUFFER_SIZE(src, src_end, 1, "image type");
55        type = *src++;
56        count = (type & 0x7F) + 1;
57        type &= 0x80;
58        if((x + count > w) && (x + count + 1 > (h - y) * w)){
59            av_log(avctx, AV_LOG_ERROR, "Packet went out of bounds: position (%i,%i) size %i\n", x, y, count);
60            return -1;
61        }
62        if(type){
63            CHECK_BUFFER_SIZE(src, src_end, depth, "image data");
64        }else{
65            CHECK_BUFFER_SIZE(src, src_end, count * depth, "image data");
66        }
67        for(i = 0; i < count; i++){
68            switch(depth){
69            case 1:
70                *dst = *src;
71                break;
72            case 2:
73                *((uint16_t*)dst) = AV_RL16(src);
74                break;
75            case 3:
76                dst[0] = src[0];
77                dst[1] = src[1];
78                dst[2] = src[2];
79                break;
80            case 4:
81                *((uint32_t*)dst) = AV_RL32(src);
82                break;
83            }
84            dst += depth;
85            if(!type)
86                src += depth;
87
88            x++;
89            if(x == w){
90                x = 0;
91                y++;
92                dst += diff;
93            }
94        }
95        if(type)
96            src += depth;
97    }
98    return src_size;
99}
100
101static int decode_frame(AVCodecContext *avctx,
102                        void *data, int *data_size,
103                        AVPacket *avpkt)
104{
105    const uint8_t *buf = avpkt->data;
106    const uint8_t *buf_end = avpkt->data + avpkt->size;
107    TargaContext * const s = avctx->priv_data;
108    AVFrame *picture = data;
109    AVFrame * const p= (AVFrame*)&s->picture;
110    uint8_t *dst;
111    int stride;
112    int idlen, compr, y, w, h, bpp, flags;
113    int first_clr, colors, csize;
114
115    /* parse image header */
116    CHECK_BUFFER_SIZE(buf, buf_end, 18, "header");
117    idlen = *buf++;
118    buf++; /* pal */
119    compr = *buf++;
120    first_clr = AV_RL16(buf); buf += 2;
121    colors = AV_RL16(buf); buf += 2;
122    csize = *buf++;
123    buf += 2; /* x */
124    y = AV_RL16(buf); buf += 2;
125    w = AV_RL16(buf); buf += 2;
126    h = AV_RL16(buf); buf += 2;
127    bpp = *buf++;
128    flags = *buf++;
129    //skip identifier if any
130    CHECK_BUFFER_SIZE(buf, buf_end, idlen, "identifiers");
131    buf += idlen;
132    s->bpp = bpp;
133    s->width = w;
134    s->height = h;
135    switch(s->bpp){
136    case 8:
137        avctx->pix_fmt = ((compr & (~TGA_RLE)) == TGA_BW) ? PIX_FMT_GRAY8 : PIX_FMT_PAL8;
138        break;
139    case 15:
140        avctx->pix_fmt = PIX_FMT_RGB555;
141        break;
142    case 16:
143        avctx->pix_fmt = PIX_FMT_RGB555;
144        break;
145    case 24:
146        avctx->pix_fmt = PIX_FMT_BGR24;
147        break;
148    case 32:
149        avctx->pix_fmt = PIX_FMT_RGB32;
150        break;
151    default:
152        av_log(avctx, AV_LOG_ERROR, "Bit depth %i is not supported\n", s->bpp);
153        return -1;
154    }
155
156    if(s->picture.data[0])
157        avctx->release_buffer(avctx, &s->picture);
158
159    if(av_image_check_size(w, h, 0, avctx))
160        return -1;
161    if(w != avctx->width || h != avctx->height)
162        avcodec_set_dimensions(avctx, w, h);
163    if(avctx->get_buffer(avctx, p) < 0){
164        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
165        return -1;
166    }
167    if(flags & 0x20){
168        dst = p->data[0];
169        stride = p->linesize[0];
170    }else{ //image is upside-down
171        dst = p->data[0] + p->linesize[0] * (h - 1);
172        stride = -p->linesize[0];
173    }
174
175    if(colors){
176        int pal_size, pal_sample_size;
177        if((colors + first_clr) > 256){
178            av_log(avctx, AV_LOG_ERROR, "Incorrect palette: %i colors with offset %i\n", colors, first_clr);
179            return -1;
180        }
181        switch (csize) {
182        case 24: pal_sample_size = 3; break;
183        case 16:
184        case 15: pal_sample_size = 2; break;
185        default:
186            av_log(avctx, AV_LOG_ERROR, "Palette entry size %i bits is not supported\n", csize);
187            return -1;
188        }
189        pal_size = colors * pal_sample_size;
190        CHECK_BUFFER_SIZE(buf, buf_end, pal_size, "color table");
191        if(avctx->pix_fmt != PIX_FMT_PAL8)//should not occur but skip palette anyway
192            buf += pal_size;
193        else{
194            int t;
195            uint32_t *pal = ((uint32_t *)p->data[1]) + first_clr;
196
197            switch (pal_sample_size) {
198            case 3:
199                /* RGB24 */
200                for (t = 0; t < colors; t++)
201                    *pal++ = bytestream_get_le24(&buf);
202                break;
203            case 2:
204                /* RGB555 */
205                for (t = 0; t < colors; t++) {
206                    uint32_t v = bytestream_get_le16(&buf);
207                    v = ((v & 0x7C00) <<  9) |
208                        ((v & 0x03E0) <<  6) |
209                        ((v & 0x001F) <<  3);
210                    /* left bit replication */
211                    v |= (v & 0xE0E0E0U) >> 5;
212                    *pal++ = v;
213                }
214                break;
215            }
216            p->palette_has_changed = 1;
217        }
218    }
219    if((compr & (~TGA_RLE)) == TGA_NODATA)
220        memset(p->data[0], 0, p->linesize[0] * s->height);
221    else{
222        if(compr & TGA_RLE){
223            int res = targa_decode_rle(avctx, s, buf, buf_end - buf, dst, avctx->width, avctx->height, stride, bpp);
224            if (res < 0)
225                return -1;
226            buf += res;
227        }else{
228            size_t img_size = s->width * ((s->bpp + 1) >> 3);
229            CHECK_BUFFER_SIZE(buf, buf_end, img_size, "image data");
230            for(y = 0; y < s->height; y++){
231#if HAVE_BIGENDIAN
232                int x;
233                if((s->bpp + 1) >> 3 == 2){
234                    uint16_t *dst16 = (uint16_t*)dst;
235                    for(x = 0; x < s->width; x++)
236                        dst16[x] = AV_RL16(buf + x * 2);
237                }else if((s->bpp + 1) >> 3 == 4){
238                    uint32_t *dst32 = (uint32_t*)dst;
239                    for(x = 0; x < s->width; x++)
240                        dst32[x] = AV_RL32(buf + x * 4);
241                }else
242#endif
243                    memcpy(dst, buf, img_size);
244
245                dst += stride;
246                buf += img_size;
247            }
248        }
249    }
250
251    *picture= *(AVFrame*)&s->picture;
252    *data_size = sizeof(AVPicture);
253
254    return avpkt->size;
255}
256
257static av_cold int targa_init(AVCodecContext *avctx){
258    TargaContext *s = avctx->priv_data;
259
260    avcodec_get_frame_defaults((AVFrame*)&s->picture);
261    avctx->coded_frame= (AVFrame*)&s->picture;
262
263    return 0;
264}
265
266static av_cold int targa_end(AVCodecContext *avctx){
267    TargaContext *s = avctx->priv_data;
268
269    if(s->picture.data[0])
270        avctx->release_buffer(avctx, &s->picture);
271
272    return 0;
273}
274
275AVCodec ff_targa_decoder = {
276    .name           = "targa",
277    .type           = AVMEDIA_TYPE_VIDEO,
278    .id             = CODEC_ID_TARGA,
279    .priv_data_size = sizeof(TargaContext),
280    .init           = targa_init,
281    .close          = targa_end,
282    .decode         = decode_frame,
283    .capabilities   = CODEC_CAP_DR1,
284    .long_name = NULL_IF_CONFIG_SMALL("Truevision Targa image"),
285};
286