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00022 #include "libavutil/imgutils.h"
00023 #include "avcodec.h"
00024 #include "bytestream.h"
00025 #include "sgi.h"
00026
00027 typedef struct SgiState {
00028 AVFrame picture;
00029 unsigned int width;
00030 unsigned int height;
00031 unsigned int depth;
00032 unsigned int bytes_per_channel;
00033 int linesize;
00034 GetByteContext g;
00035 } SgiState;
00036
00045 static int expand_rle_row(SgiState *s, uint8_t *out_buf,
00046 uint8_t *out_end, int pixelstride)
00047 {
00048 unsigned char pixel, count;
00049 unsigned char *orig = out_buf;
00050
00051 while (1) {
00052 if (bytestream2_get_bytes_left(&s->g) < 1)
00053 return AVERROR_INVALIDDATA;
00054 pixel = bytestream2_get_byteu(&s->g);
00055 if (!(count = (pixel & 0x7f))) {
00056 return (out_buf - orig) / pixelstride;
00057 }
00058
00059
00060 if(out_buf + pixelstride * count >= out_end) return -1;
00061
00062 if (pixel & 0x80) {
00063 while (count--) {
00064 *out_buf = bytestream2_get_byte(&s->g);
00065 out_buf += pixelstride;
00066 }
00067 } else {
00068 pixel = bytestream2_get_byte(&s->g);
00069
00070 while (count--) {
00071 *out_buf = pixel;
00072 out_buf += pixelstride;
00073 }
00074 }
00075 }
00076 }
00077
00084 static int read_rle_sgi(uint8_t *out_buf, SgiState *s)
00085 {
00086 uint8_t *dest_row;
00087 unsigned int len = s->height * s->depth * 4;
00088 GetByteContext g_table = s->g;
00089 unsigned int y, z;
00090 unsigned int start_offset;
00091
00092
00093 if (len * 2 > bytestream2_get_bytes_left(&s->g)) {
00094 return AVERROR_INVALIDDATA;
00095 }
00096
00097 for (z = 0; z < s->depth; z++) {
00098 dest_row = out_buf;
00099 for (y = 0; y < s->height; y++) {
00100 dest_row -= s->linesize;
00101 start_offset = bytestream2_get_be32(&g_table);
00102 bytestream2_seek(&s->g, start_offset, SEEK_SET);
00103 if (expand_rle_row(s, dest_row + z, dest_row + FFABS(s->linesize),
00104 s->depth) != s->width) {
00105 return AVERROR_INVALIDDATA;
00106 }
00107 }
00108 }
00109 return 0;
00110 }
00111
00119 static int read_uncompressed_sgi(unsigned char* out_buf, uint8_t* out_end,
00120 SgiState *s)
00121 {
00122 int x, y, z;
00123 unsigned int offset = s->height * s->width * s->bytes_per_channel;
00124 GetByteContext gp[4];
00125
00126
00127 if (offset * s->depth > bytestream2_get_bytes_left(&s->g))
00128 return AVERROR_INVALIDDATA;
00129
00130
00131 for (z = 0; z < s->depth; z++) {
00132 gp[z] = s->g;
00133 bytestream2_skip(&gp[z], z * offset);
00134 }
00135
00136 for (y = s->height - 1; y >= 0; y--) {
00137 out_end = out_buf + (y * s->linesize);
00138 if (s->bytes_per_channel == 1) {
00139 for (x = s->width; x > 0; x--)
00140 for (z = 0; z < s->depth; z++)
00141 *out_end++ = bytestream2_get_byteu(&gp[z]);
00142 } else {
00143 uint16_t *out16 = (uint16_t *)out_end;
00144 for (x = s->width; x > 0; x--)
00145 for (z = 0; z < s->depth; z++)
00146 *out16++ = bytestream2_get_ne16u(&gp[z]);
00147 }
00148 }
00149 return 0;
00150 }
00151
00152 static int decode_frame(AVCodecContext *avctx,
00153 void *data, int *data_size,
00154 AVPacket *avpkt)
00155 {
00156 SgiState *s = avctx->priv_data;
00157 AVFrame *picture = data;
00158 AVFrame *p = &s->picture;
00159 unsigned int dimension, rle;
00160 int ret = 0;
00161 uint8_t *out_buf, *out_end;
00162
00163 bytestream2_init(&s->g, avpkt->data, avpkt->size);
00164 if (bytestream2_get_bytes_left(&s->g) < SGI_HEADER_SIZE) {
00165 av_log(avctx, AV_LOG_ERROR, "buf_size too small (%d)\n", avpkt->size);
00166 return AVERROR_INVALIDDATA;
00167 }
00168
00169
00170 if (bytestream2_get_be16(&s->g) != SGI_MAGIC) {
00171 av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
00172 return AVERROR_INVALIDDATA;
00173 }
00174
00175 rle = bytestream2_get_byte(&s->g);
00176 s->bytes_per_channel = bytestream2_get_byte(&s->g);
00177 dimension = bytestream2_get_be16(&s->g);
00178 s->width = bytestream2_get_be16(&s->g);
00179 s->height = bytestream2_get_be16(&s->g);
00180 s->depth = bytestream2_get_be16(&s->g);
00181
00182 if (s->bytes_per_channel != 1 && (s->bytes_per_channel != 2 || rle)) {
00183 av_log(avctx, AV_LOG_ERROR, "wrong channel number\n");
00184 return -1;
00185 }
00186
00187
00188 if (dimension != 2 && dimension != 3) {
00189 av_log(avctx, AV_LOG_ERROR, "wrong dimension number\n");
00190 return -1;
00191 }
00192
00193 if (s->depth == SGI_GRAYSCALE) {
00194 avctx->pix_fmt = s->bytes_per_channel == 2 ? PIX_FMT_GRAY16BE : PIX_FMT_GRAY8;
00195 } else if (s->depth == SGI_RGB) {
00196 avctx->pix_fmt = s->bytes_per_channel == 2 ? PIX_FMT_RGB48BE : PIX_FMT_RGB24;
00197 } else if (s->depth == SGI_RGBA && s->bytes_per_channel == 1) {
00198 avctx->pix_fmt = PIX_FMT_RGBA;
00199 } else {
00200 av_log(avctx, AV_LOG_ERROR, "wrong picture format\n");
00201 return -1;
00202 }
00203
00204 if (av_image_check_size(s->width, s->height, 0, avctx))
00205 return -1;
00206 avcodec_set_dimensions(avctx, s->width, s->height);
00207
00208 if (p->data[0])
00209 avctx->release_buffer(avctx, p);
00210
00211 p->reference = 0;
00212 if (avctx->get_buffer(avctx, p) < 0) {
00213 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed.\n");
00214 return -1;
00215 }
00216
00217 p->pict_type = AV_PICTURE_TYPE_I;
00218 p->key_frame = 1;
00219 out_buf = p->data[0];
00220
00221 out_end = out_buf + p->linesize[0] * s->height;
00222
00223 s->linesize = p->linesize[0];
00224
00225
00226 bytestream2_seek(&s->g, SGI_HEADER_SIZE, SEEK_SET);
00227 if (rle) {
00228 ret = read_rle_sgi(out_end, s);
00229 } else {
00230 ret = read_uncompressed_sgi(out_buf, out_end, s);
00231 }
00232
00233 if (ret == 0) {
00234 *picture = s->picture;
00235 *data_size = sizeof(AVPicture);
00236 return avpkt->size;
00237 } else {
00238 return ret;
00239 }
00240 }
00241
00242 static av_cold int sgi_init(AVCodecContext *avctx){
00243 SgiState *s = avctx->priv_data;
00244
00245 avcodec_get_frame_defaults(&s->picture);
00246 avctx->coded_frame = &s->picture;
00247
00248 return 0;
00249 }
00250
00251 static av_cold int sgi_end(AVCodecContext *avctx)
00252 {
00253 SgiState * const s = avctx->priv_data;
00254
00255 if (s->picture.data[0])
00256 avctx->release_buffer(avctx, &s->picture);
00257
00258 return 0;
00259 }
00260
00261 AVCodec ff_sgi_decoder = {
00262 .name = "sgi",
00263 .type = AVMEDIA_TYPE_VIDEO,
00264 .id = CODEC_ID_SGI,
00265 .priv_data_size = sizeof(SgiState),
00266 .init = sgi_init,
00267 .close = sgi_end,
00268 .decode = decode_frame,
00269 .long_name = NULL_IF_CONFIG_SMALL("SGI image"),
00270 };
00271