| 0,0 → 1,221 |
|---|
| #include "fitz.h" |
| |
| #include <jpeglib.h> |
| #include <setjmp.h> |
| |
| typedef struct fz_dctd_s fz_dctd; |
| |
| struct fz_dctd_s |
| { |
| fz_stream *chain; |
| int color_transform; |
| int init; |
| int stride; |
| unsigned char *scanline; |
| unsigned char *rp, *wp; |
| struct jpeg_decompress_struct cinfo; |
| struct jpeg_source_mgr srcmgr; |
| struct jpeg_error_mgr errmgr; |
| jmp_buf jb; |
| char msg[JMSG_LENGTH_MAX]; |
| }; |
| |
| static void error_exit(j_common_ptr cinfo) |
| { |
| fz_dctd *state = cinfo->client_data; |
| cinfo->err->format_message(cinfo, state->msg); |
| longjmp(state->jb, 1); |
| } |
| |
| static void init_source(j_decompress_ptr cinfo) |
| { |
| /* nothing to do */ |
| } |
| |
| static void term_source(j_decompress_ptr cinfo) |
| { |
| /* nothing to do */ |
| } |
| |
| static boolean fill_input_buffer(j_decompress_ptr cinfo) |
| { |
| struct jpeg_source_mgr *src = cinfo->src; |
| fz_dctd *state = cinfo->client_data; |
| fz_stream *chain = state->chain; |
| |
| chain->rp = chain->wp; |
| fz_fill_buffer(chain); |
| src->next_input_byte = chain->rp; |
| src->bytes_in_buffer = chain->wp - chain->rp; |
| |
| if (src->bytes_in_buffer == 0) |
| { |
| static unsigned char eoi[2] = { 0xFF, JPEG_EOI }; |
| fz_warn("premature end of file in jpeg"); |
| src->next_input_byte = eoi; |
| src->bytes_in_buffer = 2; |
| } |
| |
| return 1; |
| } |
| |
| static void skip_input_data(j_decompress_ptr cinfo, long num_bytes) |
| { |
| struct jpeg_source_mgr *src = cinfo->src; |
| if (num_bytes > 0) |
| { |
| while ((size_t)num_bytes > src->bytes_in_buffer) |
| { |
| num_bytes -= src->bytes_in_buffer; |
| (void) src->fill_input_buffer(cinfo); |
| } |
| src->next_input_byte += num_bytes; |
| src->bytes_in_buffer -= num_bytes; |
| } |
| } |
| |
| static int |
| read_dctd(fz_stream *stm, unsigned char *buf, int len) |
| { |
| fz_dctd *state = stm->state; |
| j_decompress_ptr cinfo = &state->cinfo; |
| unsigned char *p = buf; |
| unsigned char *ep = buf + len; |
| |
| if (setjmp(state->jb)) |
| { |
| if (cinfo->src) |
| state->chain->rp = state->chain->wp - cinfo->src->bytes_in_buffer; |
| return fz_throw("jpeg error: %s", state->msg); |
| } |
| |
| if (!state->init) |
| { |
| cinfo->client_data = state; |
| cinfo->err = &state->errmgr; |
| jpeg_std_error(cinfo->err); |
| cinfo->err->error_exit = error_exit; |
| jpeg_create_decompress(cinfo); |
| |
| cinfo->src = &state->srcmgr; |
| cinfo->src->init_source = init_source; |
| cinfo->src->fill_input_buffer = fill_input_buffer; |
| cinfo->src->skip_input_data = skip_input_data; |
| cinfo->src->resync_to_restart = jpeg_resync_to_restart; |
| cinfo->src->term_source = term_source; |
| cinfo->src->next_input_byte = state->chain->rp; |
| cinfo->src->bytes_in_buffer = state->chain->wp - state->chain->rp; |
| |
| jpeg_read_header(cinfo, 1); |
| |
| /* speed up jpeg decoding a bit */ |
| cinfo->dct_method = JDCT_FASTEST; |
| cinfo->do_fancy_upsampling = FALSE; |
| |
| /* default value if ColorTransform is not set */ |
| if (state->color_transform == -1) |
| { |
| if (state->cinfo.num_components == 3) |
| state->color_transform = 1; |
| else |
| state->color_transform = 0; |
| } |
| |
| if (cinfo->saw_Adobe_marker) |
| state->color_transform = cinfo->Adobe_transform; |
| |
| /* Guess the input colorspace, and set output colorspace accordingly */ |
| switch (cinfo->num_components) |
| { |
| case 3: |
| if (state->color_transform) |
| cinfo->jpeg_color_space = JCS_YCbCr; |
| else |
| cinfo->jpeg_color_space = JCS_RGB; |
| break; |
| case 4: |
| if (state->color_transform) |
| cinfo->jpeg_color_space = JCS_YCCK; |
| else |
| cinfo->jpeg_color_space = JCS_CMYK; |
| break; |
| } |
| |
| jpeg_start_decompress(cinfo); |
| |
| state->stride = cinfo->output_width * cinfo->output_components; |
| state->scanline = fz_malloc(state->stride); |
| state->rp = state->scanline; |
| state->wp = state->scanline; |
| |
| state->init = 1; |
| } |
| |
| while (state->rp < state->wp && p < ep) |
| *p++ = *state->rp++; |
| |
| while (p < ep) |
| { |
| if (cinfo->output_scanline == cinfo->output_height) |
| break; |
| |
| if (p + state->stride <= ep) |
| { |
| jpeg_read_scanlines(cinfo, &p, 1); |
| p += state->stride; |
| } |
| else |
| { |
| jpeg_read_scanlines(cinfo, &state->scanline, 1); |
| state->rp = state->scanline; |
| state->wp = state->scanline + state->stride; |
| } |
| |
| while (state->rp < state->wp && p < ep) |
| *p++ = *state->rp++; |
| } |
| |
| return p - buf; |
| } |
| |
| static void |
| close_dctd(fz_stream *stm) |
| { |
| fz_dctd *state = stm->state; |
| |
| if (setjmp(state->jb)) |
| { |
| state->chain->rp = state->chain->wp - state->cinfo.src->bytes_in_buffer; |
| fz_warn("jpeg error: %s", state->msg); |
| goto skip; |
| } |
| |
| if (state->init) |
| jpeg_finish_decompress(&state->cinfo); |
| |
| skip: |
| state->chain->rp = state->chain->wp - state->cinfo.src->bytes_in_buffer; |
| jpeg_destroy_decompress(&state->cinfo); |
| fz_free(state->scanline); |
| fz_close(state->chain); |
| fz_free(state); |
| } |
| |
| fz_stream * |
| fz_open_dctd(fz_stream *chain, fz_obj *params) |
| { |
| fz_dctd *state; |
| fz_obj *obj; |
| |
| state = fz_malloc(sizeof(fz_dctd)); |
| memset(state, 0, sizeof(fz_dctd)); |
| state->chain = chain; |
| state->color_transform = -1; /* unset */ |
| state->init = 0; |
| |
| obj = fz_dict_gets(params, "ColorTransform"); |
| if (obj) |
| state->color_transform = fz_to_int(obj); |
| |
| return fz_new_stream(state, read_dctd, close_dctd); |
| } |