diff options
Diffstat (limited to 'rd/read-gif.c')
| -rw-r--r-- | rd/read-gif.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/rd/read-gif.c b/rd/read-gif.c new file mode 100644 index 0000000..b841dc7 --- /dev/null +++ b/rd/read-gif.c @@ -0,0 +1,220 @@ +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <gif_lib.h> + +#include "readers.h" + +struct gif_state { + FILE *infile; + GifFileType *gif; + GifPixelType *row; + GifPixelType *il; + int w,h; +}; + +static GifRecordType +gif_fileread(struct gif_state *h) +{ + GifRecordType RecordType; + GifByteType *Extension; + int ExtCode, rc; + char *type; + + for (;;) { + if (GIF_ERROR == DGifGetRecordType(h->gif,&RecordType)) { + if (debug) + fprintf(stderr,"gif: DGifGetRecordType failed\n"); + PrintGifError(); + return -1; + } + switch (RecordType) { + case IMAGE_DESC_RECORD_TYPE: + if (debug) + fprintf(stderr,"gif: IMAGE_DESC_RECORD_TYPE found\n"); + return RecordType; + case EXTENSION_RECORD_TYPE: + if (debug) + fprintf(stderr,"gif: EXTENSION_RECORD_TYPE found\n"); + for (rc = DGifGetExtension(h->gif,&ExtCode,&Extension); + NULL != Extension; + rc = DGifGetExtensionNext(h->gif,&Extension)) { + if (rc == GIF_ERROR) { + if (debug) + fprintf(stderr,"gif: DGifGetExtension failed\n"); + PrintGifError(); + return -1; + } + if (debug) { + switch (ExtCode) { + case COMMENT_EXT_FUNC_CODE: type="comment"; break; + case GRAPHICS_EXT_FUNC_CODE: type="graphics"; break; + case PLAINTEXT_EXT_FUNC_CODE: type="plaintext"; break; + case APPLICATION_EXT_FUNC_CODE: type="appl"; break; + default: type="???"; break; + } + fprintf(stderr,"gif: extcode=0x%x [%s]\n",ExtCode,type); + } + } + break; + case TERMINATE_RECORD_TYPE: + if (debug) + fprintf(stderr,"gif: TERMINATE_RECORD_TYPE found\n"); + return RecordType; + default: + if (debug) + fprintf(stderr,"gif: unknown record type [%d]\n",RecordType); + return -1; + } + } +} + +#if 0 +static void +gif_skipimage(struct gif_state *h) +{ + unsigned char *line; + int i; + + if (debug) + fprintf(stderr,"gif: skipping image record ...\n"); + DGifGetImageDesc(h->gif); + line = malloc(h->gif->SWidth); + for (i = 0; i < h->gif->SHeight; i++) + DGifGetLine(h->gif, line, h->gif->SWidth); + free(line); +} +#endif + +static void* +gif_init(FILE *fp, char *filename, unsigned int page, + struct ida_image_info *info, int thumbnail) +{ + struct gif_state *h; + GifRecordType RecordType; + int i, image = 0; + + h = malloc(sizeof(*h)); + memset(h,0,sizeof(*h)); + + h->infile = fp; + h->gif = DGifOpenFileHandle(fileno(fp)); + h->row = malloc(h->gif->SWidth * sizeof(GifPixelType)); + + while (0 == image) { + RecordType = gif_fileread(h); + switch (RecordType) { + case IMAGE_DESC_RECORD_TYPE: + if (GIF_ERROR == DGifGetImageDesc(h->gif)) { + if (debug) + fprintf(stderr,"gif: DGifGetImageDesc failed\n"); + PrintGifError(); + } + if (NULL == h->gif->SColorMap && + NULL == h->gif->Image.ColorMap) { + if (debug) + fprintf(stderr,"gif: oops: no colormap found\n"); + goto oops; + } +#if 0 + info->width = h->w = h->gif->SWidth; + info->height = h->h = h->gif->SHeight; +#else + info->width = h->w = h->gif->Image.Width; + info->height = h->h = h->gif->Image.Height; +#endif + info->npages = 1; + image = 1; + if (debug) + fprintf(stderr,"gif: reading image record ...\n"); + if (h->gif->Image.Interlace) { + if (debug) + fprintf(stderr,"gif: interlaced\n"); + h->il = malloc(h->w * h->h * sizeof(GifPixelType)); + for (i = 0; i < h->h; i += 8) + DGifGetLine(h->gif, h->il + h->w*i,h->w); + for (i = 4; i < h->gif->SHeight; i += 8) + DGifGetLine(h->gif, h->il + h->w*i,h->w); + for (i = 2; i < h->gif->SHeight; i += 4) + DGifGetLine(h->gif, h->il + h->w*i,h->w); + } + break; + case TERMINATE_RECORD_TYPE: + default: + goto oops; + } + } + if (0 == info->width || 0 == info->height) + goto oops; + + if (debug) + fprintf(stderr,"gif: s=%dx%d i=%dx%d\n", + h->gif->SWidth,h->gif->SHeight, + h->gif->Image.Width,h->gif->Image.Height); + return h; + + oops: + if (debug) + fprintf(stderr,"gif: fatal error, aborting\n"); + DGifCloseFile(h->gif); + fclose(h->infile); + free(h->row); + free(h); + return NULL; +} + +static void +gif_read(unsigned char *dst, unsigned int line, void *data) +{ + struct gif_state *h = data; + GifColorType *cmap; + int x; + + if (h->gif->Image.Interlace) { + if (line % 2) { + DGifGetLine(h->gif, h->row, h->w); + } else { + memcpy(h->row, h->il + h->w * line, h->w); + } + } else { + DGifGetLine(h->gif, h->row, h->w); + } + cmap = h->gif->Image.ColorMap ? + h->gif->Image.ColorMap->Colors : h->gif->SColorMap->Colors; + for (x = 0; x < h->w; x++) { + dst[0] = cmap[h->row[x]].Red; + dst[1] = cmap[h->row[x]].Green; + dst[2] = cmap[h->row[x]].Blue; + dst += 3; + } +} + +static void +gif_done(void *data) +{ + struct gif_state *h = data; + + if (debug) + fprintf(stderr,"gif: done, cleaning up\n"); + DGifCloseFile(h->gif); + fclose(h->infile); + if (h->il) + free(h->il); + free(h->row); + free(h); +} + +static struct ida_loader gif_loader = { + magic: "GIF", + moff: 0, + mlen: 3, + name: "libungif", + init: gif_init, + read: gif_read, + done: gif_done, +}; + +static void __init init_rd(void) +{ + load_register(&gif_loader); +} |