Support uncompressed 16 bit sgi image format, as e.g. used by the files at
[libav.git] / libavcodec / sgidec.c
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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 "avcodec.h"
23#include "bytestream.h"
24#include "sgi.h"
25
26typedef struct SgiState {
27 AVFrame picture;
28 unsigned int width;
29 unsigned int height;
30 unsigned int depth;
fbc03004 31 unsigned int bytes_per_channel;
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32 int linesize;
33} SgiState;
34
35/**
36 * Expand an RLE row into a channel.
37 * @param in_buf input buffer
38 * @param in_end end of input buffer
39 * @param out_buf Points to one line after the output buffer.
40 * @param out_end end of line in output buffer
41 * @param pixelstride pixel stride of input buffer
42 * @return size of output in bytes, -1 if buffer overflows
43 */
7993df65 44static int expand_rle_row(const uint8_t *in_buf, const uint8_t* in_end,
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45 unsigned char *out_buf, uint8_t* out_end, int pixelstride)
46{
47 unsigned char pixel, count;
48 unsigned char *orig = out_buf;
49
50 while (1) {
51 if(in_buf + 1 > in_end) return -1;
52 pixel = bytestream_get_byte(&in_buf);
53 if (!(count = (pixel & 0x7f))) {
54 return (out_buf - orig) / pixelstride;
55 }
56
57 /* Check for buffer overflow. */
58 if(out_buf + pixelstride * count >= out_end) return -1;
59
60 if (pixel & 0x80) {
61 while (count--) {
62 *out_buf = bytestream_get_byte(&in_buf);
63 out_buf += pixelstride;
64 }
65 } else {
66 pixel = bytestream_get_byte(&in_buf);
67
68 while (count--) {
69 *out_buf = pixel;
70 out_buf += pixelstride;
71 }
72 }
73 }
74}
75
76/**
77 * Read a run length encoded SGI image.
78 * @param out_buf output buffer
79 * @param in_buf input buffer
80 * @param in_end end of input buffer
81 * @param s the current image state
82 * @return 0 if no error, else return error number.
83 */
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84static int read_rle_sgi(unsigned char* out_buf, const uint8_t *in_buf,
85 const uint8_t *in_end, SgiState* s)
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86{
87 uint8_t *dest_row;
88 unsigned int len = s->height * s->depth * 4;
7993df65 89 const uint8_t *start_table = in_buf;
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90 unsigned int y, z;
91 unsigned int start_offset;
92
93 /* size of RLE offset and length tables */
94 if(len * 2 > in_end - in_buf) {
95 return AVERROR_INVALIDDATA;
96 }
97
98 in_buf -= SGI_HEADER_SIZE;
99 for (z = 0; z < s->depth; z++) {
100 dest_row = out_buf;
101 for (y = 0; y < s->height; y++) {
102 dest_row -= s->linesize;
103 start_offset = bytestream_get_be32(&start_table);
104 if(start_offset > in_end - in_buf) {
105 return AVERROR_INVALIDDATA;
106 }
107 if (expand_rle_row(in_buf + start_offset, in_end, dest_row + z,
108 dest_row + FFABS(s->linesize), s->depth) != s->width)
109 return AVERROR_INVALIDDATA;
110 }
111 }
112 return 0;
113}
114
115/**
116 * Read an uncompressed SGI image.
117 * @param out_buf output buffer
118 * @param out_end end ofoutput buffer
119 * @param in_buf input buffer
120 * @param in_end end of input buffer
121 * @param s the current image state
122 * @return 0 if read success, otherwise return -1.
123 */
124static int read_uncompressed_sgi(unsigned char* out_buf, uint8_t* out_end,
7993df65 125 const uint8_t *in_buf, const uint8_t *in_end, SgiState* s)
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126{
127 int x, y, z;
7993df65 128 const uint8_t *ptr;
fbc03004 129 unsigned int offset = s->height * s->width * s->bytes_per_channel;
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130
131 /* Test buffer size. */
132 if (offset * s->depth > in_end - in_buf) {
133 return -1;
134 }
135
136 for (y = s->height - 1; y >= 0; y--) {
137 out_end = out_buf + (y * s->linesize);
138 for (x = s->width; x > 0; x--) {
fbc03004 139 ptr = in_buf += s->bytes_per_channel;
2d99eed1 140 for(z = 0; z < s->depth; z ++) {
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141 memcpy(out_end, ptr, s->bytes_per_channel);
142 out_end += s->bytes_per_channel;
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143 ptr += offset;
144 }
145 }
146 }
147 return 0;
148}
149
150static int decode_frame(AVCodecContext *avctx,
151 void *data, int *data_size,
7a00bbad 152 AVPacket *avpkt)
2d99eed1 153{
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154 const uint8_t *in_buf = avpkt->data;
155 int buf_size = avpkt->size;
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156 SgiState *s = avctx->priv_data;
157 AVFrame *picture = data;
158 AVFrame *p = &s->picture;
7993df65 159 const uint8_t *in_end = in_buf + buf_size;
fbc03004 160 unsigned int dimension, rle;
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161 int ret = 0;
162 uint8_t *out_buf, *out_end;
163
164 if (buf_size < SGI_HEADER_SIZE){
165 av_log(avctx, AV_LOG_ERROR, "buf_size too small (%d)\n", buf_size);
166 return -1;
167 }
168
169 /* Test for SGI magic. */
170 if (bytestream_get_be16(&in_buf) != SGI_MAGIC) {
171 av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
172 return -1;
173 }
174
175 rle = bytestream_get_byte(&in_buf);
fbc03004 176 s->bytes_per_channel = bytestream_get_byte(&in_buf);
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177 dimension = bytestream_get_be16(&in_buf);
178 s->width = bytestream_get_be16(&in_buf);
179 s->height = bytestream_get_be16(&in_buf);
180 s->depth = bytestream_get_be16(&in_buf);
181
fbc03004 182 if (s->bytes_per_channel != 1 && (s->bytes_per_channel != 2 || rle)) {
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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) {
fbc03004 194 avctx->pix_fmt = s->bytes_per_channel == 2 ? PIX_FMT_GRAY16BE : PIX_FMT_GRAY8;
2d99eed1 195 } else if (s->depth == SGI_RGB) {
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196 avctx->pix_fmt = s->bytes_per_channel == 2 ? PIX_FMT_RGB48BE : PIX_FMT_RGB24;
197 } else if (s->depth == SGI_RGBA && s->bytes_per_channel == 1) {
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198 avctx->pix_fmt = PIX_FMT_RGBA;
199 } else {
200 av_log(avctx, AV_LOG_ERROR, "wrong picture format\n");
201 return -1;
202 }
203
204 if (avcodec_check_dimensions(avctx, s->width, s->height))
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 = FF_I_TYPE;
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 in_buf += SGI_HEADER_SIZE - 12;
227 if (rle) {
228 ret = read_rle_sgi(out_end, in_buf, in_end, s);
229 } else {
230 ret = read_uncompressed_sgi(out_buf, out_end, in_buf, in_end, s);
231 }
232
233 if (ret == 0) {
234 *picture = s->picture;
235 *data_size = sizeof(AVPicture);
236 return buf_size;
237 } else {
238 return -1;
239 }
240}
241
98a6fff9 242static av_cold int sgi_init(AVCodecContext *avctx){
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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
98a6fff9 251static av_cold int sgi_end(AVCodecContext *avctx)
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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
261AVCodec sgi_decoder = {
262 "sgi",
263 CODEC_TYPE_VIDEO,
264 CODEC_ID_SGI,
265 sizeof(SgiState),
266 sgi_init,
267 NULL,
268 sgi_end,
269 decode_frame,
fe4bf374 270 .long_name = NULL_IF_CONFIG_SMALL("SGI image"),
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271};
272