412709cfd9f86a8d9272e59e828b18a6ba06d9bb
[libav.git] / libavcodec / sgidec.c
1 /*
2 * SGI image decoder
3 * Todd Kirby <doubleshot@pacbell.net>
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/imgutils.h"
23 #include "avcodec.h"
24 #include "bytestream.h"
25 #include "sgi.h"
26
27 typedef struct SgiState {
28 AVFrame picture;
29 unsigned int width;
30 unsigned int height;
31 unsigned int depth;
32 unsigned int bytes_per_channel;
33 int linesize;
34 GetByteContext g;
35 } SgiState;
36
37 /**
38 * Expand an RLE row into a channel.
39 * @param s the current image state
40 * @param out_buf Points to one line after the output buffer.
41 * @param out_end end of line in output buffer
42 * @param pixelstride pixel stride of input buffer
43 * @return size of output in bytes, -1 if buffer overflows
44 */
45 static int expand_rle_row(SgiState *s, uint8_t *out_buf,
46 uint8_t *out_end, int pixelstride)
47 {
48 unsigned char pixel, count;
49 unsigned char *orig = out_buf;
50
51 while (1) {
52 if (bytestream2_get_bytes_left(&s->g) < 1)
53 return AVERROR_INVALIDDATA;
54 pixel = bytestream2_get_byteu(&s->g);
55 if (!(count = (pixel & 0x7f))) {
56 return (out_buf - orig) / pixelstride;
57 }
58
59 /* Check for buffer overflow. */
60 if(out_buf + pixelstride * count >= out_end) return -1;
61
62 if (pixel & 0x80) {
63 while (count--) {
64 *out_buf = bytestream2_get_byte(&s->g);
65 out_buf += pixelstride;
66 }
67 } else {
68 pixel = bytestream2_get_byte(&s->g);
69
70 while (count--) {
71 *out_buf = pixel;
72 out_buf += pixelstride;
73 }
74 }
75 }
76 }
77
78 /**
79 * Read a run length encoded SGI image.
80 * @param out_buf output buffer
81 * @param s the current image state
82 * @return 0 if no error, else return error number.
83 */
84 static int read_rle_sgi(uint8_t *out_buf, SgiState *s)
85 {
86 uint8_t *dest_row;
87 unsigned int len = s->height * s->depth * 4;
88 GetByteContext g_table = s->g;
89 unsigned int y, z;
90 unsigned int start_offset;
91
92 /* size of RLE offset and length tables */
93 if (len * 2 > bytestream2_get_bytes_left(&s->g)) {
94 return AVERROR_INVALIDDATA;
95 }
96
97 for (z = 0; z < s->depth; z++) {
98 dest_row = out_buf;
99 for (y = 0; y < s->height; y++) {
100 dest_row -= s->linesize;
101 start_offset = bytestream2_get_be32(&g_table);
102 bytestream2_seek(&s->g, start_offset, SEEK_SET);
103 if (expand_rle_row(s, dest_row + z, dest_row + FFABS(s->linesize),
104 s->depth) != s->width) {
105 return AVERROR_INVALIDDATA;
106 }
107 }
108 }
109 return 0;
110 }
111
112 /**
113 * Read an uncompressed SGI image.
114 * @param out_buf output buffer
115 * @param out_end end ofoutput buffer
116 * @param s the current image state
117 * @return 0 if read success, otherwise return -1.
118 */
119 static int read_uncompressed_sgi(unsigned char* out_buf, uint8_t* out_end,
120 SgiState *s)
121 {
122 int x, y, z;
123 unsigned int offset = s->height * s->width * s->bytes_per_channel;
124 GetByteContext gp[4];
125
126 /* Test buffer size. */
127 if (offset * s->depth > bytestream2_get_bytes_left(&s->g))
128 return AVERROR_INVALIDDATA;
129
130 /* Create a reader for each plane */
131 for (z = 0; z < s->depth; z++) {
132 gp[z] = s->g;
133 bytestream2_skip(&gp[z], z * offset);
134 }
135
136 for (y = s->height - 1; y >= 0; y--) {
137 out_end = out_buf + (y * s->linesize);
138 if (s->bytes_per_channel == 1) {
139 for (x = s->width; x > 0; x--)
140 for (z = 0; z < s->depth; z++)
141 *out_end++ = bytestream2_get_byteu(&gp[z]);
142 } else {
143 uint16_t *out16 = (uint16_t *)out_end;
144 for (x = s->width; x > 0; x--)
145 for (z = 0; z < s->depth; z++)
146 *out16++ = bytestream2_get_ne16u(&gp[z]);
147 }
148 }
149 return 0;
150 }
151
152 static int decode_frame(AVCodecContext *avctx,
153 void *data, int *data_size,
154 AVPacket *avpkt)
155 {
156 SgiState *s = avctx->priv_data;
157 AVFrame *picture = data;
158 AVFrame *p = &s->picture;
159 unsigned int dimension, rle;
160 int ret = 0;
161 uint8_t *out_buf, *out_end;
162
163 bytestream2_init(&s->g, avpkt->data, avpkt->size);
164 if (bytestream2_get_bytes_left(&s->g) < SGI_HEADER_SIZE) {
165 av_log(avctx, AV_LOG_ERROR, "buf_size too small (%d)\n", avpkt->size);
166 return AVERROR_INVALIDDATA;
167 }
168
169 /* Test for SGI magic. */
170 if (bytestream2_get_be16(&s->g) != SGI_MAGIC) {
171 av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
172 return AVERROR_INVALIDDATA;
173 }
174
175 rle = bytestream2_get_byte(&s->g);
176 s->bytes_per_channel = bytestream2_get_byte(&s->g);
177 dimension = bytestream2_get_be16(&s->g);
178 s->width = bytestream2_get_be16(&s->g);
179 s->height = bytestream2_get_be16(&s->g);
180 s->depth = bytestream2_get_be16(&s->g);
181
182 if (s->bytes_per_channel != 1 && (s->bytes_per_channel != 2 || rle)) {
183 av_log(avctx, AV_LOG_ERROR, "wrong channel number\n");
184 return -1;
185 }
186
187 /* Check for supported image dimensions. */
188 if (dimension != 2 && dimension != 3) {
189 av_log(avctx, AV_LOG_ERROR, "wrong dimension number\n");
190 return -1;
191 }
192
193 if (s->depth == SGI_GRAYSCALE) {
194 avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_GRAY16BE : AV_PIX_FMT_GRAY8;
195 } else if (s->depth == SGI_RGB) {
196 avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_RGB48BE : AV_PIX_FMT_RGB24;
197 } else if (s->depth == SGI_RGBA && s->bytes_per_channel == 1) {
198 avctx->pix_fmt = AV_PIX_FMT_RGBA;
199 } else {
200 av_log(avctx, AV_LOG_ERROR, "wrong picture format\n");
201 return -1;
202 }
203
204 if (av_image_check_size(s->width, s->height, 0, avctx))
205 return -1;
206 avcodec_set_dimensions(avctx, s->width, s->height);
207
208 if (p->data[0])
209 avctx->release_buffer(avctx, p);
210
211 p->reference = 0;
212 if (avctx->get_buffer(avctx, p) < 0) {
213 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed.\n");
214 return -1;
215 }
216
217 p->pict_type = AV_PICTURE_TYPE_I;
218 p->key_frame = 1;
219 out_buf = p->data[0];
220
221 out_end = out_buf + p->linesize[0] * s->height;
222
223 s->linesize = p->linesize[0];
224
225 /* Skip header. */
226 bytestream2_seek(&s->g, SGI_HEADER_SIZE, SEEK_SET);
227 if (rle) {
228 ret = read_rle_sgi(out_end, s);
229 } else {
230 ret = read_uncompressed_sgi(out_buf, out_end, s);
231 }
232
233 if (ret == 0) {
234 *picture = s->picture;
235 *data_size = sizeof(AVPicture);
236 return avpkt->size;
237 } else {
238 return ret;
239 }
240 }
241
242 static av_cold int sgi_init(AVCodecContext *avctx){
243 SgiState *s = avctx->priv_data;
244
245 avcodec_get_frame_defaults(&s->picture);
246 avctx->coded_frame = &s->picture;
247
248 return 0;
249 }
250
251 static av_cold int sgi_end(AVCodecContext *avctx)
252 {
253 SgiState * const s = avctx->priv_data;
254
255 if (s->picture.data[0])
256 avctx->release_buffer(avctx, &s->picture);
257
258 return 0;
259 }
260
261 AVCodec ff_sgi_decoder = {
262 .name = "sgi",
263 .type = AVMEDIA_TYPE_VIDEO,
264 .id = AV_CODEC_ID_SGI,
265 .priv_data_size = sizeof(SgiState),
266 .init = sgi_init,
267 .close = sgi_end,
268 .decode = decode_frame,
269 .long_name = NULL_IF_CONFIG_SMALL("SGI image"),
270 .capabilities = CODEC_CAP_DR1,
271 };