| 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 | }; |