928806f1bbf25d7a14c4b416c419b605cdb3f4ea
[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 "internal.h"
26 #include "sgi.h"
27
28 typedef struct SgiState {
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 *got_frame,
154 AVPacket *avpkt)
155 {
156 SgiState *s = avctx->priv_data;
157 AVFrame *p = data;
158 unsigned int dimension, rle;
159 int ret = 0;
160 uint8_t *out_buf, *out_end;
161
162 bytestream2_init(&s->g, avpkt->data, avpkt->size);
163 if (bytestream2_get_bytes_left(&s->g) < SGI_HEADER_SIZE) {
164 av_log(avctx, AV_LOG_ERROR, "buf_size too small (%d)\n", avpkt->size);
165 return AVERROR_INVALIDDATA;
166 }
167
168 /* Test for SGI magic. */
169 if (bytestream2_get_be16(&s->g) != SGI_MAGIC) {
170 av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
171 return AVERROR_INVALIDDATA;
172 }
173
174 rle = bytestream2_get_byte(&s->g);
175 s->bytes_per_channel = bytestream2_get_byte(&s->g);
176 dimension = bytestream2_get_be16(&s->g);
177 s->width = bytestream2_get_be16(&s->g);
178 s->height = bytestream2_get_be16(&s->g);
179 s->depth = bytestream2_get_be16(&s->g);
180
181 if (s->bytes_per_channel != 1 && (s->bytes_per_channel != 2 || rle)) {
182 av_log(avctx, AV_LOG_ERROR, "wrong channel number\n");
183 return -1;
184 }
185
186 /* Check for supported image dimensions. */
187 if (dimension != 2 && dimension != 3) {
188 av_log(avctx, AV_LOG_ERROR, "wrong dimension number\n");
189 return -1;
190 }
191
192 if (s->depth == SGI_GRAYSCALE) {
193 avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_GRAY16BE : AV_PIX_FMT_GRAY8;
194 } else if (s->depth == SGI_RGB) {
195 avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_RGB48BE : AV_PIX_FMT_RGB24;
196 } else if (s->depth == SGI_RGBA && s->bytes_per_channel == 1) {
197 avctx->pix_fmt = AV_PIX_FMT_RGBA;
198 } else {
199 av_log(avctx, AV_LOG_ERROR, "wrong picture format\n");
200 return -1;
201 }
202
203 ret = ff_set_dimensions(avctx, s->width, s->height);
204 if (ret < 0)
205 return ret;
206
207 if (ff_get_buffer(avctx, p, 0) < 0) {
208 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed.\n");
209 return -1;
210 }
211
212 p->pict_type = AV_PICTURE_TYPE_I;
213 p->key_frame = 1;
214 out_buf = p->data[0];
215
216 out_end = out_buf + p->linesize[0] * s->height;
217
218 s->linesize = p->linesize[0];
219
220 /* Skip header. */
221 bytestream2_seek(&s->g, SGI_HEADER_SIZE, SEEK_SET);
222 if (rle) {
223 ret = read_rle_sgi(out_end, s);
224 } else {
225 ret = read_uncompressed_sgi(out_buf, out_end, s);
226 }
227
228 if (ret == 0) {
229 *got_frame = 1;
230 return avpkt->size;
231 } else {
232 return ret;
233 }
234 }
235
236 AVCodec ff_sgi_decoder = {
237 .name = "sgi",
238 .long_name = NULL_IF_CONFIG_SMALL("SGI image"),
239 .type = AVMEDIA_TYPE_VIDEO,
240 .id = AV_CODEC_ID_SGI,
241 .priv_data_size = sizeof(SgiState),
242 .decode = decode_frame,
243 .capabilities = CODEC_CAP_DR1,
244 };