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. |
Résultat | 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"); }