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1 | /* |
2 | * SGI image decoder | |
3 | * Todd Kirby <doubleshot@pacbell.net> | |
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/imgutils.h" | |
23 | #include "libavutil/avassert.h" | |
24 | #include "avcodec.h" | |
25 | #include "bytestream.h" | |
26 | #include "internal.h" | |
27 | #include "sgi.h" | |
28 | ||
29 | typedef struct SgiState { | |
30 | AVCodecContext *avctx; | |
31 | unsigned int width; | |
32 | unsigned int height; | |
33 | unsigned int depth; | |
34 | unsigned int bytes_per_channel; | |
35 | int linesize; | |
36 | GetByteContext g; | |
37 | } SgiState; | |
38 | ||
39 | /** | |
40 | * Expand an RLE row into a channel. | |
41 | * @param s the current image state | |
42 | * @param out_buf Points to one line after the output buffer. | |
43 | * @param len length of out_buf in bytes | |
44 | * @param pixelstride pixel stride of input buffer | |
45 | * @return size of output in bytes, else return error code. | |
46 | */ | |
47 | static int expand_rle_row8(SgiState *s, uint8_t *out_buf, | |
48 | int len, int pixelstride) | |
49 | { | |
50 | unsigned char pixel, count; | |
51 | unsigned char *orig = out_buf; | |
52 | uint8_t *out_end = out_buf + len; | |
53 | ||
54 | while (out_buf < out_end) { | |
55 | if (bytestream2_get_bytes_left(&s->g) < 1) | |
56 | return AVERROR_INVALIDDATA; | |
57 | pixel = bytestream2_get_byteu(&s->g); | |
58 | if (!(count = (pixel & 0x7f))) { | |
59 | break; | |
60 | } | |
61 | ||
62 | /* Check for buffer overflow. */ | |
63 | if (out_end - out_buf <= pixelstride * (count - 1)) { | |
64 | av_log(s->avctx, AV_LOG_ERROR, "Invalid pixel count.\n"); | |
65 | return AVERROR_INVALIDDATA; | |
66 | } | |
67 | ||
68 | if (pixel & 0x80) { | |
69 | while (count--) { | |
70 | *out_buf = bytestream2_get_byte(&s->g); | |
71 | out_buf += pixelstride; | |
72 | } | |
73 | } else { | |
74 | pixel = bytestream2_get_byte(&s->g); | |
75 | ||
76 | while (count--) { | |
77 | *out_buf = pixel; | |
78 | out_buf += pixelstride; | |
79 | } | |
80 | } | |
81 | } | |
82 | return (out_buf - orig) / pixelstride; | |
83 | } | |
84 | ||
85 | static int expand_rle_row16(SgiState *s, uint16_t *out_buf, | |
86 | int len, int pixelstride) | |
87 | { | |
88 | unsigned short pixel; | |
89 | unsigned char count; | |
90 | unsigned short *orig = out_buf; | |
91 | uint16_t *out_end = out_buf + len; | |
92 | ||
93 | while (out_buf < out_end) { | |
94 | if (bytestream2_get_bytes_left(&s->g) < 2) | |
95 | return AVERROR_INVALIDDATA; | |
96 | pixel = bytestream2_get_be16u(&s->g); | |
97 | if (!(count = (pixel & 0x7f))) | |
98 | break; | |
99 | ||
100 | /* Check for buffer overflow. */ | |
101 | if (out_end - out_buf <= pixelstride * (count - 1)) { | |
102 | av_log(s->avctx, AV_LOG_ERROR, "Invalid pixel count.\n"); | |
103 | return AVERROR_INVALIDDATA; | |
104 | } | |
105 | ||
106 | if (pixel & 0x80) { | |
107 | while (count--) { | |
108 | pixel = bytestream2_get_ne16(&s->g); | |
109 | AV_WN16A(out_buf, pixel); | |
110 | out_buf += pixelstride; | |
111 | } | |
112 | } else { | |
113 | pixel = bytestream2_get_ne16(&s->g); | |
114 | ||
115 | while (count--) { | |
116 | AV_WN16A(out_buf, pixel); | |
117 | out_buf += pixelstride; | |
118 | } | |
119 | } | |
120 | } | |
121 | return (out_buf - orig) / pixelstride; | |
122 | } | |
123 | ||
124 | ||
125 | /** | |
126 | * Read a run length encoded SGI image. | |
127 | * @param out_buf output buffer | |
128 | * @param s the current image state | |
129 | * @return 0 if no error, else return error code. | |
130 | */ | |
131 | static int read_rle_sgi(uint8_t *out_buf, SgiState *s) | |
132 | { | |
133 | uint8_t *dest_row; | |
134 | unsigned int len = s->height * s->depth * 4; | |
135 | GetByteContext g_table = s->g; | |
136 | unsigned int y, z; | |
137 | unsigned int start_offset; | |
138 | int linesize, ret; | |
139 | ||
140 | /* size of RLE offset and length tables */ | |
141 | if (len * 2 > bytestream2_get_bytes_left(&s->g)) { | |
142 | return AVERROR_INVALIDDATA; | |
143 | } | |
144 | ||
145 | for (z = 0; z < s->depth; z++) { | |
146 | dest_row = out_buf; | |
147 | for (y = 0; y < s->height; y++) { | |
148 | linesize = s->width * s->depth; | |
149 | dest_row -= s->linesize; | |
150 | start_offset = bytestream2_get_be32(&g_table); | |
151 | bytestream2_seek(&s->g, start_offset, SEEK_SET); | |
152 | if (s->bytes_per_channel == 1) | |
153 | ret = expand_rle_row8(s, dest_row + z, linesize, s->depth); | |
154 | else | |
155 | ret = expand_rle_row16(s, (uint16_t *)dest_row + z, linesize, s->depth); | |
156 | if (ret != s->width) | |
157 | return AVERROR_INVALIDDATA; | |
158 | } | |
159 | } | |
160 | return 0; | |
161 | } | |
162 | ||
163 | /** | |
164 | * Read an uncompressed SGI image. | |
165 | * @param out_buf output buffer | |
166 | * @param s the current image state | |
167 | * @return 0 if read success, else return error code. | |
168 | */ | |
169 | static int read_uncompressed_sgi(unsigned char *out_buf, SgiState *s) | |
170 | { | |
171 | int x, y, z; | |
172 | unsigned int offset = s->height * s->width * s->bytes_per_channel; | |
173 | GetByteContext gp[4]; | |
174 | uint8_t *out_end; | |
175 | ||
176 | /* Test buffer size. */ | |
177 | if (offset * s->depth > bytestream2_get_bytes_left(&s->g)) | |
178 | return AVERROR_INVALIDDATA; | |
179 | ||
180 | /* Create a reader for each plane */ | |
181 | for (z = 0; z < s->depth; z++) { | |
182 | gp[z] = s->g; | |
183 | bytestream2_skip(&gp[z], z * offset); | |
184 | } | |
185 | ||
186 | for (y = s->height - 1; y >= 0; y--) { | |
187 | out_end = out_buf + (y * s->linesize); | |
188 | if (s->bytes_per_channel == 1) { | |
189 | for (x = s->width; x > 0; x--) | |
190 | for (z = 0; z < s->depth; z++) | |
191 | *out_end++ = bytestream2_get_byteu(&gp[z]); | |
192 | } else { | |
193 | uint16_t *out16 = (uint16_t *)out_end; | |
194 | for (x = s->width; x > 0; x--) | |
195 | for (z = 0; z < s->depth; z++) | |
196 | *out16++ = bytestream2_get_ne16u(&gp[z]); | |
197 | } | |
198 | } | |
199 | return 0; | |
200 | } | |
201 | ||
202 | static int decode_frame(AVCodecContext *avctx, | |
203 | void *data, int *got_frame, | |
204 | AVPacket *avpkt) | |
205 | { | |
206 | SgiState *s = avctx->priv_data; | |
207 | AVFrame *p = data; | |
208 | unsigned int dimension, rle; | |
209 | int ret = 0; | |
210 | uint8_t *out_buf, *out_end; | |
211 | ||
212 | bytestream2_init(&s->g, avpkt->data, avpkt->size); | |
213 | if (bytestream2_get_bytes_left(&s->g) < SGI_HEADER_SIZE) { | |
214 | av_log(avctx, AV_LOG_ERROR, "buf_size too small (%d)\n", avpkt->size); | |
215 | return AVERROR_INVALIDDATA; | |
216 | } | |
217 | ||
218 | /* Test for SGI magic. */ | |
219 | if (bytestream2_get_be16u(&s->g) != SGI_MAGIC) { | |
220 | av_log(avctx, AV_LOG_ERROR, "bad magic number\n"); | |
221 | return AVERROR_INVALIDDATA; | |
222 | } | |
223 | ||
224 | rle = bytestream2_get_byteu(&s->g); | |
225 | s->bytes_per_channel = bytestream2_get_byteu(&s->g); | |
226 | dimension = bytestream2_get_be16u(&s->g); | |
227 | s->width = bytestream2_get_be16u(&s->g); | |
228 | s->height = bytestream2_get_be16u(&s->g); | |
229 | s->depth = bytestream2_get_be16u(&s->g); | |
230 | ||
231 | if (s->bytes_per_channel != 1 && s->bytes_per_channel != 2) { | |
232 | av_log(avctx, AV_LOG_ERROR, "wrong channel number\n"); | |
233 | return AVERROR_INVALIDDATA; | |
234 | } | |
235 | ||
236 | /* Check for supported image dimensions. */ | |
237 | if (dimension != 2 && dimension != 3) { | |
238 | av_log(avctx, AV_LOG_ERROR, "wrong dimension number\n"); | |
239 | return AVERROR_INVALIDDATA; | |
240 | } | |
241 | ||
242 | if (s->depth == SGI_GRAYSCALE) { | |
243 | avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_GRAY16BE : AV_PIX_FMT_GRAY8; | |
244 | } else if (s->depth == SGI_RGB) { | |
245 | avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_RGB48BE : AV_PIX_FMT_RGB24; | |
246 | } else if (s->depth == SGI_RGBA) { | |
247 | avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_RGBA64BE : AV_PIX_FMT_RGBA; | |
248 | } else { | |
249 | av_log(avctx, AV_LOG_ERROR, "wrong picture format\n"); | |
250 | return AVERROR_INVALIDDATA; | |
251 | } | |
252 | ||
253 | ret = ff_set_dimensions(avctx, s->width, s->height); | |
254 | if (ret < 0) | |
255 | return ret; | |
256 | ||
257 | if ((ret = ff_get_buffer(avctx, p, 0)) < 0) | |
258 | return ret; | |
259 | ||
260 | p->pict_type = AV_PICTURE_TYPE_I; | |
261 | p->key_frame = 1; | |
262 | out_buf = p->data[0]; | |
263 | ||
264 | out_end = out_buf + p->linesize[0] * s->height; | |
265 | ||
266 | s->linesize = p->linesize[0]; | |
267 | ||
268 | /* Skip header. */ | |
269 | bytestream2_seek(&s->g, SGI_HEADER_SIZE, SEEK_SET); | |
270 | if (rle) { | |
271 | ret = read_rle_sgi(out_end, s); | |
272 | } else { | |
273 | ret = read_uncompressed_sgi(out_buf, s); | |
274 | } | |
275 | if (ret) | |
276 | return ret; | |
277 | ||
278 | *got_frame = 1; | |
279 | return avpkt->size; | |
280 | } | |
281 | ||
282 | static av_cold int sgi_decode_init(AVCodecContext *avctx) | |
283 | { | |
284 | SgiState *s = avctx->priv_data; | |
285 | ||
286 | s->avctx = avctx; | |
287 | ||
288 | return 0; | |
289 | } | |
290 | ||
291 | AVCodec ff_sgi_decoder = { | |
292 | .name = "sgi", | |
293 | .long_name = NULL_IF_CONFIG_SMALL("SGI image"), | |
294 | .type = AVMEDIA_TYPE_VIDEO, | |
295 | .id = AV_CODEC_ID_SGI, | |
296 | .priv_data_size = sizeof(SgiState), | |
297 | .decode = decode_frame, | |
298 | .init = sgi_decode_init, | |
299 | .capabilities = CODEC_CAP_DR1, | |
300 | }; |