00001
00002
00003
00004
00005
00006
00007
00008
00009
00010
00011
00012
00013
00014
00015
00016
00017
00018
00019
00020
00021
00022 #include "avcodec.h"
00023 #include "bytestream.h"
00024 #include "sgi.h"
00025
00026 typedef struct SgiState {
00027 AVFrame picture;
00028 unsigned int width;
00029 unsigned int height;
00030 unsigned int depth;
00031 unsigned int bytes_per_channel;
00032 int linesize;
00033 } SgiState;
00034
00044 static int expand_rle_row(const uint8_t *in_buf, const uint8_t* in_end,
00045 unsigned char *out_buf, uint8_t* out_end, int pixelstride)
00046 {
00047 unsigned char pixel, count;
00048 unsigned char *orig = out_buf;
00049
00050 while (1) {
00051 if(in_buf + 1 > in_end) return -1;
00052 pixel = bytestream_get_byte(&in_buf);
00053 if (!(count = (pixel & 0x7f))) {
00054 return (out_buf - orig) / pixelstride;
00055 }
00056
00057
00058 if(out_buf + pixelstride * count >= out_end) return -1;
00059
00060 if (pixel & 0x80) {
00061 while (count--) {
00062 *out_buf = bytestream_get_byte(&in_buf);
00063 out_buf += pixelstride;
00064 }
00065 } else {
00066 pixel = bytestream_get_byte(&in_buf);
00067
00068 while (count--) {
00069 *out_buf = pixel;
00070 out_buf += pixelstride;
00071 }
00072 }
00073 }
00074 }
00075
00084 static int read_rle_sgi(unsigned char* out_buf, const uint8_t *in_buf,
00085 const uint8_t *in_end, SgiState* s)
00086 {
00087 uint8_t *dest_row;
00088 unsigned int len = s->height * s->depth * 4;
00089 const uint8_t *start_table = in_buf;
00090 unsigned int y, z;
00091 unsigned int start_offset;
00092
00093
00094 if(len * 2 > in_end - in_buf) {
00095 return AVERROR_INVALIDDATA;
00096 }
00097
00098 in_buf -= SGI_HEADER_SIZE;
00099 for (z = 0; z < s->depth; z++) {
00100 dest_row = out_buf;
00101 for (y = 0; y < s->height; y++) {
00102 dest_row -= s->linesize;
00103 start_offset = bytestream_get_be32(&start_table);
00104 if(start_offset > in_end - in_buf) {
00105 return AVERROR_INVALIDDATA;
00106 }
00107 if (expand_rle_row(in_buf + start_offset, in_end, dest_row + z,
00108 dest_row + FFABS(s->linesize), s->depth) != s->width)
00109 return AVERROR_INVALIDDATA;
00110 }
00111 }
00112 return 0;
00113 }
00114
00124 static int read_uncompressed_sgi(unsigned char* out_buf, uint8_t* out_end,
00125 const uint8_t *in_buf, const uint8_t *in_end, SgiState* s)
00126 {
00127 int x, y, z;
00128 const uint8_t *ptr;
00129 unsigned int offset = s->height * s->width * s->bytes_per_channel;
00130
00131
00132 if (offset * s->depth > in_end - in_buf) {
00133 return -1;
00134 }
00135
00136 for (y = s->height - 1; y >= 0; y--) {
00137 out_end = out_buf + (y * s->linesize);
00138 for (x = s->width; x > 0; x--) {
00139 ptr = in_buf += s->bytes_per_channel;
00140 for(z = 0; z < s->depth; z ++) {
00141 memcpy(out_end, ptr, s->bytes_per_channel);
00142 out_end += s->bytes_per_channel;
00143 ptr += offset;
00144 }
00145 }
00146 }
00147 return 0;
00148 }
00149
00150 static int decode_frame(AVCodecContext *avctx,
00151 void *data, int *data_size,
00152 AVPacket *avpkt)
00153 {
00154 const uint8_t *in_buf = avpkt->data;
00155 int buf_size = avpkt->size;
00156 SgiState *s = avctx->priv_data;
00157 AVFrame *picture = data;
00158 AVFrame *p = &s->picture;
00159 const uint8_t *in_end = in_buf + buf_size;
00160 unsigned int dimension, rle;
00161 int ret = 0;
00162 uint8_t *out_buf, *out_end;
00163
00164 if (buf_size < SGI_HEADER_SIZE){
00165 av_log(avctx, AV_LOG_ERROR, "buf_size too small (%d)\n", buf_size);
00166 return -1;
00167 }
00168
00169
00170 if (bytestream_get_be16(&in_buf) != SGI_MAGIC) {
00171 av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
00172 return -1;
00173 }
00174
00175 rle = bytestream_get_byte(&in_buf);
00176 s->bytes_per_channel = bytestream_get_byte(&in_buf);
00177 dimension = bytestream_get_be16(&in_buf);
00178 s->width = bytestream_get_be16(&in_buf);
00179 s->height = bytestream_get_be16(&in_buf);
00180 s->depth = bytestream_get_be16(&in_buf);
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 (avcodec_check_dimensions(avctx, s->width, s->height))
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 = FF_I_TYPE;
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 in_buf += SGI_HEADER_SIZE - 12;
00227 if (rle) {
00228 ret = read_rle_sgi(out_end, in_buf, in_end, s);
00229 } else {
00230 ret = read_uncompressed_sgi(out_buf, out_end, in_buf, in_end, s);
00231 }
00232
00233 if (ret == 0) {
00234 *picture = s->picture;
00235 *data_size = sizeof(AVPicture);
00236 return buf_size;
00237 } else {
00238 return -1;
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 sgi_decoder = {
00262 "sgi",
00263 AVMEDIA_TYPE_VIDEO,
00264 CODEC_ID_SGI,
00265 sizeof(SgiState),
00266 sgi_init,
00267 NULL,
00268 sgi_end,
00269 decode_frame,
00270 .long_name = NULL_IF_CONFIG_SMALL("SGI image"),
00271 };
00272