diff options
Diffstat (limited to 'rd/read-jpeg.c')
| -rw-r--r-- | rd/read-jpeg.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/rd/read-jpeg.c b/rd/read-jpeg.c new file mode 100644 index 0000000..d12fb40 --- /dev/null +++ b/rd/read-jpeg.c @@ -0,0 +1,187 @@ +#include <stdio.h> +#include <stdlib.h> +#include <stddef.h> +#include <string.h> +#include <errno.h> +#include <jpeglib.h> + +#include <libexif/exif-data.h> + +#include "readers.h" +#include "misc.h" + +/* ---------------------------------------------------------------------- */ +/* load */ + +struct jpeg_state { + FILE * infile; /* source file */ + + struct jpeg_decompress_struct cinfo; + struct jpeg_error_mgr jerr; + JSAMPARRAY buffer; /* Output row buffer */ + int row_stride,linelength; /* physical row width in output buffer */ + unsigned char *image,*ptr; + + /* thumbnail */ + unsigned char *thumbnail; + unsigned int tpos, tsize; +}; + +/* ---------------------------------------------------------------------- */ +/* data source manager for thumbnail images */ + +static void thumbnail_src_init(struct jpeg_decompress_struct *cinfo) +{ + struct jpeg_state *h = container_of(cinfo, struct jpeg_state, cinfo); + cinfo->src->next_input_byte = h->thumbnail; + cinfo->src->bytes_in_buffer = h->tsize; +} + +static int thumbnail_src_fill(struct jpeg_decompress_struct *cinfo) +{ + fprintf(stderr,"jpeg: panic: no more thumbnail input data\n"); + exit(1); +} + +static void thumbnail_src_skip(struct jpeg_decompress_struct *cinfo, + long num_bytes) +{ + cinfo->src->next_input_byte += num_bytes; +} + +static void thumbnail_src_term(struct jpeg_decompress_struct *cinfo) +{ + /* nothing */ +} + +static struct jpeg_source_mgr thumbnail_mgr = { + .init_source = thumbnail_src_init, + .fill_input_buffer = thumbnail_src_fill, + .skip_input_data = thumbnail_src_skip, + .resync_to_restart = jpeg_resync_to_restart, + .term_source = thumbnail_src_term, +}; + +/* ---------------------------------------------------------------------- */ +/* jpeg loader */ + +static void* +jpeg_init(FILE *fp, char *filename, unsigned int page, + struct ida_image_info *i, int thumbnail) +{ + struct jpeg_state *h; + jpeg_saved_marker_ptr mark; + + h = malloc(sizeof(*h)); + memset(h,0,sizeof(*h)); + h->infile = fp; + + h->cinfo.err = jpeg_std_error(&h->jerr); + jpeg_create_decompress(&h->cinfo); + jpeg_save_markers(&h->cinfo, JPEG_COM, 0xffff); /* comment */ + jpeg_save_markers(&h->cinfo, JPEG_APP0+1, 0xffff); /* EXIF */ + jpeg_stdio_src(&h->cinfo, h->infile); + jpeg_read_header(&h->cinfo, TRUE); + + for (mark = h->cinfo.marker_list; NULL != mark; mark = mark->next) { + switch (mark->marker) { + case JPEG_COM: + if (debug) + fprintf(stderr,"jpeg: comment found (COM marker) [%.*s]\n", + (int)mark->data_length, mark->data); + load_add_extra(i,EXTRA_COMMENT,mark->data,mark->data_length); + break; + case JPEG_APP0 +1: + if (debug) + fprintf(stderr,"jpeg: exif data found (APP1 marker)\n"); + load_add_extra(i,EXTRA_COMMENT,mark->data,mark->data_length); + + if (thumbnail) { + ExifData *ed; + + ed = exif_data_new_from_data(mark->data,mark->data_length); + if (ed->data && + ed->data[0] == 0xff && + ed->data[1] == 0xd8) { + if (debug) + fprintf(stderr,"jpeg: exif thumbnail found\n"); + + /* save away thumbnail data */ + h->thumbnail = malloc(ed->size); + h->tsize = ed->size; + memcpy(h->thumbnail,ed->data,ed->size); + } + exif_data_unref(ed); + } + break; + } + } + + if (h->thumbnail) { + /* save image size */ + i->thumbnail = 1; + i->real_width = h->cinfo.image_width; + i->real_height = h->cinfo.image_height; + + /* re-setup jpeg */ + jpeg_destroy_decompress(&h->cinfo); + fclose(h->infile); + h->infile = NULL; + jpeg_create_decompress(&h->cinfo); + h->cinfo.src = &thumbnail_mgr; + jpeg_read_header(&h->cinfo, TRUE); + } + + h->cinfo.out_color_space = JCS_RGB; + jpeg_start_decompress(&h->cinfo); + i->width = h->cinfo.image_width; + i->height = h->cinfo.image_height; + i->npages = 1; + switch (h->cinfo.density_unit) { + case 0: /* unknown */ + break; + case 1: /* dot per inch */ + i->dpi = h->cinfo.X_density; + break; + case 2: /* dot per cm */ + i->dpi = res_cm_to_inch(h->cinfo.X_density); + break; + } + + return h; +} + +static void +jpeg_read(unsigned char *dst, unsigned int line, void *data) +{ + struct jpeg_state *h = data; + JSAMPROW row = dst; + jpeg_read_scanlines(&h->cinfo, &row, 1); +} + +static void +jpeg_done(void *data) +{ + struct jpeg_state *h = data; + jpeg_destroy_decompress(&h->cinfo); + if (h->infile) + fclose(h->infile); + if (h->thumbnail) + free(h->thumbnail); + free(h); +} + +struct ida_loader jpeg_loader = { + magic: "\xff\xd8", + moff: 0, + mlen: 2, + name: "libjpeg", + init: jpeg_init, + read: jpeg_read, + done: jpeg_done, +}; + +static void __init init_rd(void) +{ + load_register(&jpeg_loader); +} |