diff options
Diffstat (limited to 'filter/dctd.c')
| -rw-r--r-- | filter/dctd.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/filter/dctd.c b/filter/dctd.c new file mode 100644 index 00000000..dd978ac7 --- /dev/null +++ b/filter/dctd.c @@ -0,0 +1,215 @@ +#include <fitz.h> + +#include "dctc.h" + +typedef struct fz_dctd_s fz_dctd; + +struct mysrcmgr +{ + struct jpeg_source_mgr super; + fz_buffer *buf; + int skip; +}; + +struct fz_dctd_s +{ + fz_filter super; + struct jpeg_decompress_struct cinfo; + struct mysrcmgr src; + struct myerrmgr err; + int colortransform; + int stage; +}; + +static void myinitsource(j_decompress_ptr cinfo) { /* empty */ } +static boolean myfillinput(j_decompress_ptr cinfo) { return FALSE; } +static void mytermsource(j_decompress_ptr cinfo) { /* empty */ } + +static void myskipinput(j_decompress_ptr cinfo, long n) +{ + struct mysrcmgr *src = (struct mysrcmgr *)cinfo->src; + fz_buffer *in = src->buf; + + assert(src->skip == 0); + + in->rp = in->wp - src->super.bytes_in_buffer; + + if (in->rp + n > in->wp) { + src->skip = (in->rp + n) - in->wp; + in->rp = in->wp; + } + else { + src->skip = 0; + in->rp += n; + } + + src->super.bytes_in_buffer = in->wp - in->rp; + src->super.next_input_byte = in->rp; +} + +fz_error * +fz_newdctd(fz_filter **fp, fz_obj *params) +{ + fz_error *err; + fz_obj *obj; + int colortransform; + + FZ_NEWFILTER(fz_dctd, d, dctd); + + colortransform = 1; + + if (params) { + obj = fz_dictgets(params, "ColorTransform"); + if (obj) colortransform = fz_toint(obj); + } + + d->colortransform = colortransform; + d->stage = 0; + + /* setup error callback first thing */ + myiniterr(&d->err); + d->cinfo.err = (struct jpeg_error_mgr*) &d->err; + + if (setjmp(d->err.jb)) { + err = fz_throw("ioerror in dctd: %s", d->err.msg); + fz_free(d); + return err; + } + + /* create decompression object. this zeroes cinfo except for err. */ + jpeg_create_decompress(&d->cinfo); + + /* prepare source manager */ + d->cinfo.src = (struct jpeg_source_mgr *)&d->src; + d->src.super.init_source = myinitsource; + d->src.super.fill_input_buffer = myfillinput; + d->src.super.skip_input_data = myskipinput; + d->src.super.resync_to_restart = jpeg_resync_to_restart; + d->src.super.term_source = mytermsource; + + d->src.super.bytes_in_buffer = 0; + d->src.super.next_input_byte = nil; + d->src.skip = 0; + + return nil; +} + +void +fz_freedctd(fz_filter *filter) +{ + fz_dctd *d = (fz_dctd*)filter; + if (setjmp(d->err.jb)) { + fprintf(stderr, "ioerror in dct: jpeg_destroy_decompress: %s", d->err.msg); + return; + } + jpeg_destroy_decompress(&d->cinfo); +} + +fz_error * +fz_processdctd(fz_filter *filter, fz_buffer *in, fz_buffer *out) +{ + fz_dctd *d = (fz_dctd*)filter; + boolean b; + int i; + int stride; + JSAMPROW scanlines[1]; + + d->src.buf = in; + + /* skip any bytes left over from myskipinput() */ + if (d->src.skip > 0) { + if (in->rp + d->src.skip > in->wp) { + d->src.skip = (in->rp + d->src.skip) - in->wp; + in->rp = in->wp; + goto needinput; + } + else { + in->rp += d->src.skip; + d->src.skip = 0; + } + } + + d->src.super.bytes_in_buffer = in->wp - in->rp; + d->src.super.next_input_byte = in->rp; + + if (setjmp(d->err.jb)) { + return fz_throw("ioerror in dctd: %s", d->err.msg); + } + + switch (d->stage) + { + case 0: + i = jpeg_read_header(&d->cinfo, TRUE); + if (i == JPEG_SUSPENDED) + goto needinput; + + /* FIXME: default value if ColorTransform is not set */ + + if (!d->cinfo.saw_Adobe_marker) { + switch (d->cinfo.num_components) { + case 3: + if (d->colortransform) + d->cinfo.jpeg_color_space = JCS_YCbCr; + else + d->cinfo.jpeg_color_space = JCS_RGB; + break; + case 4: + if (d->colortransform) + d->cinfo.jpeg_color_space = JCS_YCCK; + else + d->cinfo.jpeg_color_space = JCS_CMYK; + break; + } + } + + /* fall through */ + d->stage = 1; + + case 1: + b = jpeg_start_decompress(&d->cinfo); + if (b == FALSE) + goto needinput; + + /* fall through */ + d->stage = 2; + + case 2: + stride = d->cinfo.output_width * d->cinfo.output_components; + + while (d->cinfo.output_scanline < d->cinfo.output_height) + { + if (out->wp + stride > out->ep) + goto needoutput; + + scanlines[0] = out->wp; + + i = jpeg_read_scanlines(&d->cinfo, scanlines, 1); + + if (i == 0) + goto needinput; + + out->wp += stride; + } + + /* fall through */ + d->stage = 3; + + case 3: + b = jpeg_finish_decompress(&d->cinfo); + if (b == FALSE) + goto needinput; + d->stage = 4; + out->eof = 1; + in->rp = in->wp - d->src.super.bytes_in_buffer; + return fz_iodone; + } + +needinput: + in->rp = in->wp - d->src.super.bytes_in_buffer; + return fz_ioneedin; + +needoutput: + in->rp = in->wp - d->src.super.bytes_in_buffer; + return fz_ioneedout; +} + |