xref: /third_party/ffmpeg/libavcodec/targa.c (revision cabdff1a) 
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 "codec_internal.h"
27#include "internal.h"
28#include "targa.h"
29
30typedef struct TargaContext {
31    GetByteContext gb;
32} TargaContext;
33
34static uint8_t *advance_line(uint8_t *start, uint8_t *line,
35                             int stride, int *y, int h, int interleave)
36{
37    *y += interleave;
38
39    if (*y < h) {
40        return line + interleave * stride;
41    } else {
42        *y = (*y + 1) & (interleave - 1);
43        if (*y && *y < h) {
44            return start + *y * stride;
45        } else {
46            return NULL;
47        }
48    }
49}
50
51static int targa_decode_rle(AVCodecContext *avctx, TargaContext *s,
52                            uint8_t *start, int w, int h, int stride,
53                            int bpp, int interleave)
54{
55    int x, y;
56    int depth = (bpp + 1) >> 3;
57    int type, count;
58    uint8_t *line = start;
59    uint8_t *dst  = line;
60
61    x = y = count = 0;
62    while (dst) {
63        if (bytestream2_get_bytes_left(&s->gb) <= 0) {
64            av_log(avctx, AV_LOG_ERROR,
65                   "Ran ouf of data before end-of-image\n");
66            return AVERROR_INVALIDDATA;
67        }
68        type  = bytestream2_get_byteu(&s->gb);
69        count = (type & 0x7F) + 1;
70        type &= 0x80;
71        if (!type) {
72            do {
73                int n  = FFMIN(count, w - x);
74                bytestream2_get_buffer(&s->gb, dst, n * depth);
75                count -= n;
76                dst   += n * depth;
77                x     += n;
78                if (x == w) {
79                    x    = 0;
80                    dst = line = advance_line(start, line, stride, &y, h, interleave);
81                }
82            } while (dst && count > 0);
83        } else {
84            uint8_t tmp[4];
85            bytestream2_get_buffer(&s->gb, tmp, depth);
86            do {
87                int n  = FFMIN(count, w - x);
88                count -= n;
89                x     += n;
90                do {
91                    memcpy(dst, tmp, depth);
92                    dst += depth;
93                } while (--n);
94                if (x == w) {
95                    x    = 0;
96                    dst = line = advance_line(start, line, stride, &y, h, interleave);
97                }
98            } while (dst && count > 0);
99        }
100    }
101
102    if (count) {
103        av_log(avctx, AV_LOG_ERROR, "Packet went out of bounds\n");
104        return AVERROR_INVALIDDATA;
105    }
106
107    return 0;
108}
109
110static int decode_frame(AVCodecContext *avctx, AVFrame *p,
111                        int *got_frame, AVPacket *avpkt)
112{
113    TargaContext * const s = avctx->priv_data;
114    uint8_t *dst;
115    int stride;
116    int idlen, pal, compr, y, w, h, bpp, flags, ret;
117    int first_clr, colors, csize;
118    int interleave;
119    size_t img_size;
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    flags     = bytestream2_get_byte(&s->gb);
136
137    if (!pal && (first_clr || colors || csize)) {
138        av_log(avctx, AV_LOG_WARNING, "File without colormap has colormap information set.\n");
139        // specification says we should ignore those value in this case
140        first_clr = colors = csize = 0;
141    }
142
143    if (bytestream2_get_bytes_left(&s->gb) < idlen + 2*colors) {
144        av_log(avctx, AV_LOG_ERROR,
145                "Not enough data to read header\n");
146        return AVERROR_INVALIDDATA;
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 ((compr & (~TGA_RLE)) == TGA_NODATA) {
180        return avpkt->size;
181    }
182
183    if (!(compr & TGA_RLE)) {
184        img_size = w * ((bpp + 1) >> 3);
185        if (bytestream2_get_bytes_left(&s->gb) < img_size * h) {
186            av_log(avctx, AV_LOG_ERROR,
187                    "Not enough data available for image\n");
188            return AVERROR_INVALIDDATA;
189        }
190    }
191
192    if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
193        return ret;
194    p->pict_type = AV_PICTURE_TYPE_I;
195
196    if (flags & TGA_TOPTOBOTTOM) {
197        dst = p->data[0];
198        stride = p->linesize[0];
199    } else { //image is upside-down
200        dst = p->data[0] + p->linesize[0] * (h - 1);
201        stride = -p->linesize[0];
202    }
203
204    interleave = flags & TGA_INTERLEAVE2 ? 2 :
205                 flags & TGA_INTERLEAVE4 ? 4 : 1;
206
207    if (colors) {
208        int pal_size, pal_sample_size;
209
210        switch (csize) {
211        case 32: pal_sample_size = 4; break;
212        case 24: pal_sample_size = 3; break;
213        case 16:
214        case 15: pal_sample_size = 2; break;
215        default:
216            av_log(avctx, AV_LOG_ERROR, "Palette entry size %i bits is not supported\n", csize);
217            return AVERROR_INVALIDDATA;
218        }
219        pal_size = colors * pal_sample_size;
220        if (avctx->pix_fmt != AV_PIX_FMT_PAL8) //should not occur but skip palette anyway
221            bytestream2_skip(&s->gb, pal_size);
222        else {
223            int t;
224            uint32_t *pal = ((uint32_t *)p->data[1]) + first_clr;
225
226            if (bytestream2_get_bytes_left(&s->gb) < pal_size) {
227                av_log(avctx, AV_LOG_ERROR,
228                       "Not enough data to read palette\n");
229                return AVERROR_INVALIDDATA;
230            }
231            switch (pal_sample_size) {
232            case 4:
233                for (t = 0; t < colors; t++)
234                    *pal++ = bytestream2_get_le32u(&s->gb);
235                break;
236            case 3:
237                /* RGB24 */
238                for (t = 0; t < colors; t++)
239                    *pal++ = (0xffU<<24) | bytestream2_get_le24u(&s->gb);
240                break;
241            case 2:
242                /* RGB555 */
243                for (t = 0; t < colors; t++) {
244                    uint32_t v = bytestream2_get_le16u(&s->gb);
245                    v = ((v & 0x7C00) <<  9) |
246                        ((v & 0x03E0) <<  6) |
247                        ((v & 0x001F) <<  3);
248                    /* left bit replication */
249                    v |= (v & 0xE0E0E0U) >> 5;
250                    *pal++ = (0xffU<<24) | v;
251                }
252                break;
253            }
254            p->palette_has_changed = 1;
255        }
256    }
257
258        if (compr & TGA_RLE) {
259            int res = targa_decode_rle(avctx, s, dst, w, h, stride, bpp, interleave);
260            if (res < 0)
261                return res;
262        } else {
263            uint8_t *line;
264            if (bytestream2_get_bytes_left(&s->gb) < img_size * h) {
265                av_log(avctx, AV_LOG_ERROR,
266                       "Not enough data available for image\n");
267                return AVERROR_INVALIDDATA;
268            }
269
270            line = dst;
271            y = 0;
272            do {
273                bytestream2_get_buffer(&s->gb, line, img_size);
274                line = advance_line(dst, line, stride, &y, h, interleave);
275            } while (line);
276        }
277
278        if (flags & TGA_RIGHTTOLEFT) { // right-to-left, needs horizontal flip
279            int x;
280            for (y = 0; y < h; y++) {
281                void *line = &p->data[0][y * p->linesize[0]];
282                for (x = 0; x < w >> 1; x++) {
283                    switch (bpp) {
284                    case 32:
285                        FFSWAP(uint32_t, ((uint32_t *)line)[x], ((uint32_t *)line)[w - x - 1]);
286                        break;
287                    case 24:
288                        FFSWAP(uint8_t, ((uint8_t *)line)[3 * x    ], ((uint8_t *)line)[3 * w - 3 * x - 3]);
289                        FFSWAP(uint8_t, ((uint8_t *)line)[3 * x + 1], ((uint8_t *)line)[3 * w - 3 * x - 2]);
290                        FFSWAP(uint8_t, ((uint8_t *)line)[3 * x + 2], ((uint8_t *)line)[3 * w - 3 * x - 1]);
291                        break;
292                    case 16:
293                        FFSWAP(uint16_t, ((uint16_t *)line)[x], ((uint16_t *)line)[w - x - 1]);
294                        break;
295                    case 8:
296                        FFSWAP(uint8_t, ((uint8_t *)line)[x], ((uint8_t *)line)[w - x - 1]);
297                    }
298                }
299            }
300        }
301
302
303    *got_frame = 1;
304
305    return avpkt->size;
306}
307
308const FFCodec ff_targa_decoder = {
309    .p.name         = "targa",
310    .p.long_name    = NULL_IF_CONFIG_SMALL("Truevision Targa image"),
311    .p.type         = AVMEDIA_TYPE_VIDEO,
312    .p.id           = AV_CODEC_ID_TARGA,
313    .p.capabilities = AV_CODEC_CAP_DR1,
314    .priv_data_size = sizeof(TargaContext),
315    FF_CODEC_DECODE_CB(decode_frame),
316};
317