96 lines
2.8 KiB
Plaintext
96 lines
2.8 KiB
Plaintext
|
unit imjcinit;
|
||
|
|
|
||
|
|
{ Original: jcinit.c ; Copyright (C) 1991-1997, Thomas G. Lane. }
|
||
|
|
|
||
|
|
{ This file contains initialization logic for the JPEG compressor.
|
||
|
|
This routine is in charge of selecting the modules to be executed and
|
||
|
|
making an initialization call to each one.
|
||
|
|
|
||
|
|
Logically, this code belongs in jcmaster.c. It's split out because
|
||
|
|
linking this routine implies linking the entire compression library.
|
||
|
|
For a transcoding-only application, we want to be able to use jcmaster.c
|
||
|
|
without linking in the whole library. }
|
||
|
|
|
||
|
|
interface
|
||
|
|
|
||
|
|
{$I imjconfig.inc}
|
||
|
|
|
||
|
|
uses
|
||
|
|
imjinclude,
|
||
|
|
imjdeferr,
|
||
|
|
imjerror,
|
||
|
|
imjpeglib,
|
||
|
|
{$ifdef C_PROGRESSIVE_SUPPORTED}
|
||
|
|
imjcphuff,
|
||
|
|
{$endif}
|
||
|
|
imjchuff, imjcmaster, imjccolor, imjcsample, imjcprepct,
|
||
|
|
imjcdctmgr, imjccoefct, imjcmainct, imjcmarker;
|
||
|
|
|
||
|
|
{ Master selection of compression modules.
|
||
|
|
This is done once at the start of processing an image. We determine
|
||
|
|
which modules will be used and give them appropriate initialization calls. }
|
||
|
|
|
||
|
|
{GLOBAL}
|
||
|
|
procedure jinit_compress_master (cinfo : j_compress_ptr);
|
||
|
|
|
||
|
|
implementation
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
{ Master selection of compression modules.
|
||
|
|
This is done once at the start of processing an image. We determine
|
||
|
|
which modules will be used and give them appropriate initialization calls. }
|
||
|
|
|
||
|
|
{GLOBAL}
|
||
|
|
procedure jinit_compress_master (cinfo : j_compress_ptr);
|
||
|
|
begin
|
||
|
|
{ Initialize master control (includes parameter checking/processing) }
|
||
|
|
jinit_c_master_control(cinfo, FALSE { full compression });
|
||
|
|
|
||
|
|
{ Preprocessing }
|
||
|
|
if (not cinfo^.raw_data_in) then
|
||
|
|
begin
|
||
|
|
jinit_color_converter(cinfo);
|
||
|
|
jinit_downsampler(cinfo);
|
||
|
|
jinit_c_prep_controller(cinfo, FALSE { never need full buffer here });
|
||
|
|
end;
|
||
|
|
{ Forward DCT }
|
||
|
|
jinit_forward_dct(cinfo);
|
||
|
|
{ Entropy encoding: either Huffman or arithmetic coding. }
|
||
|
|
if (cinfo^.arith_code) then
|
||
|
|
begin
|
||
|
|
ERREXIT(j_common_ptr(cinfo), JERR_ARITH_NOTIMPL);
|
||
|
|
end
|
||
|
|
else
|
||
|
|
begin
|
||
|
|
if (cinfo^.progressive_mode) then
|
||
|
|
begin
|
||
|
|
{$ifdef C_PROGRESSIVE_SUPPORTED}
|
||
|
|
jinit_phuff_encoder(cinfo);
|
||
|
|
{$else}
|
||
|
|
ERREXIT(j_common_ptr(cinfo), JERR_NOT_COMPILED);
|
||
|
|
{$endif}
|
||
|
|
end
|
||
|
|
else
|
||
|
|
jinit_huff_encoder(cinfo);
|
||
|
|
end;
|
||
|
|
|
||
|
|
{ Need a full-image coefficient buffer in any multi-pass mode. }
|
||
|
|
jinit_c_coef_controller(cinfo,
|
||
|
|
(cinfo^.num_scans > 1) or (cinfo^.optimize_coding));
|
||
|
|
jinit_c_main_controller(cinfo, FALSE { never need full buffer here });
|
||
|
|
|
||
|
|
jinit_marker_writer(cinfo);
|
||
|
|
|
||
|
|
{ We can now tell the memory manager to allocate virtual arrays. }
|
||
|
|
cinfo^.mem^.realize_virt_arrays (j_common_ptr(cinfo));
|
||
|
|
|
||
|
|
{ Write the datastream header (SOI) immediately.
|
||
|
|
Frame and scan headers are postponed till later.
|
||
|
|
This lets application insert special markers after the SOI. }
|
||
|
|
|
||
|
|
cinfo^.marker^.write_file_header (cinfo);
|
||
|
|
end;
|
||
|
|
|
||
|
|
end.
|