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 "libavutil/imgutils.h"
24#include "avcodec.h"
25#include "bytestream.h"
26#include "internal.h"
27#include "targa.h"
28
29typedef struct TargaContext {
30    GetByteContext gb;
31} TargaContext;
32
33static uint8_t *advance_line(uint8_t *start, uint8_t *line,
34                             int stride, int *y, int h, int interleave)
35{
36    *y += interleave;
37
38    if (*y < h) {
39        return line + interleave * stride;
40    } else {
41        *y = (*y + 1) & (interleave - 1);
42        if (*y && *y < h) {
43            return start + *y * stride;
44        } else {
45            return NULL;
46        }
47    }
48}
49
50static int targa_decode_rle(AVCodecContext *avctx, TargaContext *s,
51                            uint8_t *start, int w, int h, int stride,
52                            int bpp, int interleave)
53{
54    int x, y;
55    int depth = (bpp + 1) >> 3;
56    int type, count;
57    uint8_t *line = start;
58    uint8_t *dst  = line;
59
60    x = y = count = 0;
61    while (dst) {
62        if (bytestream2_get_bytes_left(&s->gb) <= 0) {
63            av_log(avctx, AV_LOG_ERROR,
64                   "Ran ouf of data before end-of-image\n");
65            return AVERROR_INVALIDDATA;
66        }
67        type  = bytestream2_get_byteu(&s->gb);
68        count = (type & 0x7F) + 1;
69        type &= 0x80;
70        if (!type) {
71            do {
72                int n  = FFMIN(count, w - x);
73                bytestream2_get_buffer(&s->gb, dst, n * depth);
74                count -= n;
75                dst   += n * depth;
76                x     += n;
77                if (x == w) {
78                    x    = 0;
79                    dst = line = advance_line(start, line, stride, &y, h, interleave);
80                }
81            } while (dst && count > 0);
82        } else {
83            uint8_t tmp[4];
84            bytestream2_get_buffer(&s->gb, tmp, depth);
85            do {
86                int n  = FFMIN(count, w - x);
87                count -= n;
88                x     += n;
89                do {
90                    memcpy(dst, tmp, depth);
91                    dst += depth;
92                } while (--n);
93                if (x == w) {
94                    x    = 0;
95                    dst = line = advance_line(start, line, stride, &y, h, interleave);
96                }
97            } while (dst && count > 0);
98        }
99    }
100
101    if (count) {
102        av_log(avctx, AV_LOG_ERROR, "Packet went out of bounds\n");
103        return AVERROR_INVALIDDATA;
104    }
105
106    return 0;
107}
108
109static int decode_frame(AVCodecContext *avctx,
110                        void *data, int *got_frame,
111                        AVPacket *avpkt)
112{
113    TargaContext * const s = avctx->priv_data;
114    AVFrame * const p = data;
115    uint8_t *dst;
116    int stride;
117    int idlen, pal, compr, y, w, h, bpp, flags, ret;
118    int first_clr, colors, csize;
119    int interleave;
120
121    bytestream2_init(&s->gb, avpkt->data, avpkt->size);
122
123    /* parse image header */
124    idlen     = bytestream2_get_byte(&s->gb);
125    pal       = bytestream2_get_byte(&s->gb);
126    compr     = bytestream2_get_byte(&s->gb);
127    first_clr = bytestream2_get_le16(&s->gb);
128    colors    = bytestream2_get_le16(&s->gb);
129    csize     = bytestream2_get_byte(&s->gb);
130    bytestream2_skip(&s->gb, 4); /* 2: x, 2: y */
131    w         = bytestream2_get_le16(&s->gb);
132    h         = bytestream2_get_le16(&s->gb);
133    bpp       = bytestream2_get_byte(&s->gb);
134
135    if (bytestream2_get_bytes_left(&s->gb) <= idlen) {
136        av_log(avctx, AV_LOG_ERROR,
137                "Not enough data to read header\n");
138        return AVERROR_INVALIDDATA;
139    }
140
141    flags     = bytestream2_get_byte(&s->gb);
142
143    if (!pal && (first_clr || colors || csize)) {
144        av_log(avctx, AV_LOG_WARNING, "File without colormap has colormap information set.\n");
145        // specification says we should ignore those value in this case
146        first_clr = colors = csize = 0;
147    }
148
149    // skip identifier if any
150    bytestream2_skip(&s->gb, idlen);
151
152    switch (bpp) {
153    case 8:
154        avctx->pix_fmt = ((compr & (~TGA_RLE)) == TGA_BW) ? AV_PIX_FMT_GRAY8 : AV_PIX_FMT_PAL8;
155        break;
156    case 15:
157    case 16:
158        avctx->pix_fmt = AV_PIX_FMT_RGB555LE;
159        break;
160    case 24:
161        avctx->pix_fmt = AV_PIX_FMT_BGR24;
162        break;
163    case 32:
164        avctx->pix_fmt = AV_PIX_FMT_BGRA;
165        break;
166    default:
167        av_log(avctx, AV_LOG_ERROR, "Bit depth %i is not supported\n", bpp);
168        return AVERROR_INVALIDDATA;
169    }
170
171    if (colors && (colors + first_clr) > 256) {
172        av_log(avctx, AV_LOG_ERROR, "Incorrect palette: %i colors with offset %i\n", colors, first_clr);
173        return AVERROR_INVALIDDATA;
174    }
175
176    if ((ret = ff_set_dimensions(avctx, w, h)) < 0)
177        return ret;
178
179    if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
180        return ret;
181    p->pict_type = AV_PICTURE_TYPE_I;
182
183    if (flags & TGA_TOPTOBOTTOM) {
184        dst = p->data[0];
185        stride = p->linesize[0];
186    } else { //image is upside-down
187        dst = p->data[0] + p->linesize[0] * (h - 1);
188        stride = -p->linesize[0];
189    }
190
191    interleave = flags & TGA_INTERLEAVE2 ? 2 :
192                 flags & TGA_INTERLEAVE4 ? 4 : 1;
193
194    if (colors) {
195        int pal_size, pal_sample_size;
196
197        switch (csize) {
198        case 32: pal_sample_size = 4; break;
199        case 24: pal_sample_size = 3; break;
200        case 16:
201        case 15: pal_sample_size = 2; break;
202        default:
203            av_log(avctx, AV_LOG_ERROR, "Palette entry size %i bits is not supported\n", csize);
204            return AVERROR_INVALIDDATA;
205        }
206        pal_size = colors * pal_sample_size;
207        if (avctx->pix_fmt != AV_PIX_FMT_PAL8) //should not occur but skip palette anyway
208            bytestream2_skip(&s->gb, pal_size);
209        else {
210            int t;
211            uint32_t *pal = ((uint32_t *)p->data[1]) + first_clr;
212
213            if (bytestream2_get_bytes_left(&s->gb) < pal_size) {
214                av_log(avctx, AV_LOG_ERROR,
215                       "Not enough data to read palette\n");
216                return AVERROR_INVALIDDATA;
217            }
218            switch (pal_sample_size) {
219            case 4:
220                for (t = 0; t < colors; t++)
221                    *pal++ = bytestream2_get_le32u(&s->gb);
222                break;
223            case 3:
224                /* RGB24 */
225                for (t = 0; t < colors; t++)
226                    *pal++ = (0xffU<<24) | bytestream2_get_le24u(&s->gb);
227                break;
228            case 2:
229                /* RGB555 */
230                for (t = 0; t < colors; t++) {
231                    uint32_t v = bytestream2_get_le16u(&s->gb);
232                    v = ((v & 0x7C00) <<  9) |
233                        ((v & 0x03E0) <<  6) |
234                        ((v & 0x001F) <<  3);
235                    /* left bit replication */
236                    v |= (v & 0xE0E0E0U) >> 5;
237                    *pal++ = (0xffU<<24) | v;
238                }
239                break;
240            }
241            p->palette_has_changed = 1;
242        }
243    }
244
245    if ((compr & (~TGA_RLE)) == TGA_NODATA) {
246        memset(p->data[0], 0, p->linesize[0] * h);
247    } else {
248        if (compr & TGA_RLE) {
249            int res = targa_decode_rle(avctx, s, dst, w, h, stride, bpp, interleave);
250            if (res < 0)
251                return res;
252        } else {
253            size_t img_size = w * ((bpp + 1) >> 3);
254            uint8_t *line;
255            if (bytestream2_get_bytes_left(&s->gb) < img_size * h) {
256                av_log(avctx, AV_LOG_ERROR,
257                       "Not enough data available for image\n");
258                return AVERROR_INVALIDDATA;
259            }
260
261            line = dst;
262            y = 0;
263            do {
264                bytestream2_get_buffer(&s->gb, line, img_size);
265                line = advance_line(dst, line, stride, &y, h, interleave);
266            } while (line);
267        }
268    }
269
270    if (flags & TGA_RIGHTTOLEFT) { // right-to-left, needs horizontal flip
271        int x;
272        for (y = 0; y < h; y++) {
273            void *line = &p->data[0][y * p->linesize[0]];
274            for (x = 0; x < w >> 1; x++) {
275                switch (bpp) {
276                case 32:
277                    FFSWAP(uint32_t, ((uint32_t *)line)[x], ((uint32_t *)line)[w - x - 1]);
278                    break;
279                case 24:
280                    FFSWAP(uint8_t, ((uint8_t *)line)[3 * x    ], ((uint8_t *)line)[3 * w - 3 * x - 3]);
281                    FFSWAP(uint8_t, ((uint8_t *)line)[3 * x + 1], ((uint8_t *)line)[3 * w - 3 * x - 2]);
282                    FFSWAP(uint8_t, ((uint8_t *)line)[3 * x + 2], ((uint8_t *)line)[3 * w - 3 * x - 1]);
283                    break;
284                case 16:
285                    FFSWAP(uint16_t, ((uint16_t *)line)[x], ((uint16_t *)line)[w - x - 1]);
286                    break;
287                case 8:
288                    FFSWAP(uint8_t, ((uint8_t *)line)[x], ((uint8_t *)line)[w - x - 1]);
289                }
290            }
291        }
292    }
293
294    *got_frame = 1;
295
296    return avpkt->size;
297}
298
299AVCodec ff_targa_decoder = {
300    .name           = "targa",
301    .long_name      = NULL_IF_CONFIG_SMALL("Truevision Targa image"),
302    .type           = AVMEDIA_TYPE_VIDEO,
303    .id             = AV_CODEC_ID_TARGA,
304    .priv_data_size = sizeof(TargaContext),
305    .decode         = decode_frame,
306    .capabilities   = CODEC_CAP_DR1,
307};
308