| public jpeg_write_scanlines ( byte scanlines, int num_lines ) : int | ||
| scanlines | byte | The array of scanlines. |
| num_lines | int | The number of scanlines for writing. |
| return | int | |
private static void compress(Stream input, CompressOptions options, Stream output)
{
Debug.Assert(input != null);
Debug.Assert(options != null);
Debug.Assert(output != null);
jpeg_compress_struct cinfo = new jpeg_compress_struct(new cd_jpeg_error_mgr());
/* Initialize JPEG parameters.
* Much of this may be overridden later.
* In particular, we don't yet know the input file's color space,
* but we need to provide some value for jpeg_set_defaults() to work.
*/
cinfo.In_color_space = J_COLOR_SPACE.JCS_RGB; /* arbitrary guess */
cinfo.jpeg_set_defaults();
/* Figure out the input file format, and set up to read it. */
cjpeg_source_struct src_mgr = new bmp_source_struct(cinfo);
src_mgr.input_file = input;
/* Read the input file header to obtain file size & colorspace. */
src_mgr.start_input();
/* Now that we know input colorspace, fix colorspace-dependent defaults */
cinfo.jpeg_default_colorspace();
/* Adjust default compression parameters */
if (!applyOptions(cinfo, options))
return;
/* Specify data destination for compression */
cinfo.jpeg_stdio_dest(output);
/* Start compressor */
cinfo.jpeg_start_compress(true);
/* Process data */
while (cinfo.Next_scanline < cinfo.Image_height)
{
int num_scanlines = src_mgr.get_pixel_rows();
cinfo.jpeg_write_scanlines(src_mgr.buffer, num_scanlines);
}
/* Finish compression and release memory */
src_mgr.finish_input();
cinfo.jpeg_finish_compress();
/* All done. */
if (cinfo.Err.Num_warnings != 0)
Console.WriteLine("Corrupt-data warning count is not zero");
}
public void TestCompressorWithContextRows()
{
using (MemoryStream stream = new MemoryStream())
{
jpeg_compress_struct compressor = new jpeg_compress_struct(new jpeg_error_mgr());
compressor.Image_height = 100;
compressor.Image_width = 100;
compressor.In_color_space = J_COLOR_SPACE.JCS_GRAYSCALE;
compressor.Input_components = 1;
compressor.jpeg_set_defaults();
compressor.Dct_method = J_DCT_METHOD.JDCT_IFAST;
compressor.Smoothing_factor = 94;
compressor.jpeg_set_quality(75, true);
compressor.jpeg_simple_progression();
compressor.Density_unit = DensityUnit.Unknown;
compressor.X_density = (short)96;
compressor.Y_density = (short)96;
compressor.jpeg_stdio_dest(stream);
compressor.jpeg_start_compress(true);
byte[][] rowForDecompressor = new byte[1][];
int bytesPerPixel = 1;
while (compressor.Next_scanline < compressor.Image_height)
{
byte[] row = new byte[100 * bytesPerPixel]; // wasteful, but gets you 0 bytes every time - content is immaterial.
rowForDecompressor[0] = row;
compressor.jpeg_write_scanlines(rowForDecompressor, 1);
}
compressor.jpeg_finish_compress();
byte[] bytes = stream.ToArray();
string filename = "TestCompressorWithContextRows.jpg";
File.WriteAllBytes(Tester.MapOutputPath(filename), bytes);
FileAssert.AreEqual(Tester.MapExpectedPath(filename), Tester.MapOutputPath(filename));
}
}
static string outfilename; /* for -outfile switch */
public static void Main(string[] args)
{
progname = Path.GetFileName(Environment.GetCommandLineArgs()[0]);
cd_jpeg_error_mgr err = new cd_jpeg_error_mgr();
jpeg_compress_struct cinfo = new jpeg_compress_struct(err);
/* Initialize JPEG parameters.
* Much of this may be overridden later.
* In particular, we don't yet know the input file's color space,
* but we need to provide some value for jpeg_set_defaults() to work.
*/
cinfo.In_color_space = J_COLOR_SPACE.JCS_RGB; /* arbitrary guess */
cinfo.jpeg_set_defaults();
/* Scan command line to find file names.
* It is convenient to use just one switch-parsing routine, but the switch
* values read here are ignored; we will rescan the switches after opening
* the input file.
*/
int file_index;
if (!parse_switches(cinfo, args, false, out file_index))
{
usage();
return;
}
/* Must have either -outfile switch or explicit output file name */
if (outfilename == null)
{
// file_index should point to input file
if (file_index != args.Length - 2)
{
Console.WriteLine(string.Format("{0}: must name one input and one output file.", progname));
usage();
return;
}
// output file comes right after input one
outfilename = args[file_index + 1];
}
else
{
// file_index should point to input file
if (file_index != args.Length - 1)
{
Console.WriteLine(string.Format("{0}: must name one input and one output file.", progname));
usage();
return;
}
}
/* Open the input file. */
FileStream input_file = null;
if (file_index < args.Length)
{
try
{
input_file = new FileStream(args[file_index], FileMode.Open);
}
catch (Exception e)
{
Console.WriteLine(string.Format("{0}: can't open {1}", progname, args[file_index]));
Console.WriteLine(e.Message);
return;
}
}
else
{
Console.WriteLine(string.Format("{0}: sorry, can't read file from console"));
return;
}
/* Open the output file. */
FileStream output_file = null;
if (outfilename != null)
{
try
{
output_file = new FileStream(outfilename, FileMode.Create);
}
catch (Exception e)
{
Console.WriteLine(string.Format("{0}: can't open {1}", progname, args[file_index]));
Console.WriteLine(e.Message);
return;
}
}
else
{
Console.WriteLine(string.Format("{0}: sorry, can't write file to console"));
return;
}
/* Figure out the input file format, and set up to read it. */
cjpeg_source_struct src_mgr = new bmp_source_struct(cinfo);
src_mgr.input_file = input_file;
/* Read the input file header to obtain file size & colorspace. */
src_mgr.start_input();
/* Now that we know input colorspace, fix colorspace-dependent defaults */
cinfo.jpeg_default_colorspace();
/* Adjust default compression parameters by re-parsing the options */
parse_switches(cinfo, args, true, out file_index);
/* Specify data destination for compression */
cinfo.jpeg_stdio_dest(output_file);
/* Start compressor */
cinfo.jpeg_start_compress(true);
/* Process data */
while (cinfo.Next_scanline < cinfo.Image_height)
{
int num_scanlines = src_mgr.get_pixel_rows();
cinfo.jpeg_write_scanlines(src_mgr.buffer, num_scanlines);
}
/* Finish compression and release memory */
src_mgr.finish_input();
cinfo.jpeg_finish_compress();
/* Close files, if we opened them */
input_file.Close();
input_file.Dispose();
output_file.Close();
output_file.Dispose();
/* All done. */
if (cinfo.Err.Num_warnings != 0)
Console.WriteLine("Corrupt-data warning count is not zero");
}