+/*****************************************************************************
+ * Dump an Image to a Portable Network Graphics (PNG) file
+ ****************************************************************************
+ Copyright (C) 2004 VideoLAN
+ Author: Rocky Bernstein
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
+ *****************************************************************************/
+
+#include "config.h"
+#ifdef HAVE_LIBPNG
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "write_png.h"
+#include <setjmp.h>
+
+typedef void (*snapshot_messenger_t)(char *message);
+
+#define _(x) x
+
+/*
+ * Error functions for use as callbacks by the png libraries
+ */
+
+void error_msg(char *message)
+{
+ printf("error: %s\n", message);
+}
+
+void warning_msg(char *message)
+{
+ printf("warning: %s\n", message);
+}
+
+static snapshot_messenger_t error_msg_cb = error_msg;
+static snapshot_messenger_t warning_msg_cb = warning_msg;
+
+static void
+user_error_fn(png_structp png_ptr, png_const_charp error_msg)
+{
+
+ if(error_msg_cb) {
+ char uerror[4096];
+
+ memset(&uerror, 0, sizeof(uerror));
+ sprintf(uerror, _("Error: %s\n"), error_msg);
+ error_msg_cb(uerror);
+ }
+}
+
+static void
+user_warning_fn(png_structp png_ptr, png_const_charp warning_msg)
+{
+ if(error_msg_cb) {
+ char uerror[4096];
+
+ memset(&uerror, 0, sizeof(uerror));
+ sprintf(uerror, _("Error: %s\n"), warning_msg);
+ warning_msg_cb(uerror);
+ }
+}
+
+/*
+ Dump an image to a Portable Network Graphics (PNG) file. File_name
+ is where the file goes, i_height and i_width are the height and
+ width in pixels of the image. The data for the image is stored as a
+ linear array of one byte for each of red, green, and blue
+ components of an RGB pixel. Thus row[i] will begin at rgb_image +
+ i*(i_width*3) and the blue pixel at image[i][0] would be rgb_image +
+ i*(i_width*3) + 1.
+
+ */
+void
+write_png(const char *file_name, png_uint_32 i_height, png_uint_32 i_width,
+ void *rgb_image, /*in*/ png_text *text_ptr, int i_text_count )
+{
+ FILE *fp;
+ png_structp png_ptr;
+ png_infop info_ptr;
+ png_color_8 sig_bit;
+ png_bytep *row_pointers;
+
+ unsigned int i,j;
+
+ /* open the file */
+ fp = fopen(file_name, "wb");
+ if (fp == NULL)
+ return;
+
+ /* Create and initialize the png_struct with the desired error handler
+ * functions. If you want to use the default stderr and longjump method,
+ * you can supply NULL for the last three parameters. We also check that
+ * the library version is compatible with the one used at compile time,
+ * in case we are using dynamically linked libraries. REQUIRED.
+ */
+ png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, (png_voidp) NULL,
+ user_error_fn, user_warning_fn);
+
+ if (png_ptr == NULL)
+ {
+ fclose(fp);
+ return;
+ }
+
+ /* Allocate/initialize the image information data. REQUIRED */
+ info_ptr = png_create_info_struct(png_ptr);
+ if (info_ptr == NULL)
+ {
+ fclose(fp);
+ png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
+ return;
+ }
+
+ /* Set error handling. REQUIRED if you aren't supplying your own
+ * error handling functions in the png_create_write_struct() call.
+ */
+ if (setjmp(png_ptr->jmpbuf))
+ {
+ /* If we get here, we had a problem writing the file */
+ fclose(fp);
+ png_destroy_write_struct(&png_ptr, (png_infopp) &info_ptr);
+ return;
+ }
+
+ /* Set up the output control using standard C streams. This
+ is required. */
+ png_init_io(png_ptr, fp);
+
+ /* Set the image information here. i_width and i_height are up to 2^31,
+ * bit_depth is one of 1, 2, 4, 8, or 16, but valid values also depend on
+ * the color_type selected. color_type is one of PNG_COLOR_TYPE_GRAY,
+ * PNG_COLOR_TYPE_GRAY_ALPHA, PNG_COLOR_TYPE_PALETTE, PNG_COLOR_TYPE_RGB,
+ * or PNG_COLOR_TYPE_RGB_ALPHA. interlace is either PNG_INTERLACE_NONE or
+ * PNG_INTERLACE_ADAM7, and the compression_type and filter_type MUST
+ * currently be PNG_COMPRESSION_TYPE_BASE and PNG_FILTER_TYPE_BASE. REQUIRED
+ */
+ png_set_IHDR(png_ptr, info_ptr, i_width, i_height, 8, PNG_COLOR_TYPE_RGB,
+ PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
+ PNG_FILTER_TYPE_BASE);
+
+ /* For color images: */
+ sig_bit.red = 8;
+ sig_bit.green = 8;
+ sig_bit.blue = 8;
+
+ if (text_ptr)
+ png_set_text(png_ptr, info_ptr, text_ptr, i_text_count);
+
+ /* Write the file header information. REQUIRED */
+ png_write_info(png_ptr, info_ptr);
+
+ /* Once we write out the header, the compression type on the text
+ * chunks gets changed to PNG_TEXT_COMPRESSION_NONE_WR or
+ * PNG_TEXT_COMPRESSION_zTXt_WR, so it doesn't get written out again
+ * at the end.
+ */
+
+ /* Shift the pixels up to a legal bit depth and fill in
+ * as appropriate to correctly scale the image.
+ */
+ png_set_shift(png_ptr, &sig_bit);
+
+ /* pack pixels into bytes */
+ png_set_packing(png_ptr);
+
+ row_pointers = png_malloc(png_ptr, i_height*sizeof(png_bytep *));
+ for (i=0, j=0; i<i_height; i++, j+=i_width*3) {
+ row_pointers[i] = rgb_image + j;
+ }
+
+ png_set_rows (png_ptr, info_ptr, row_pointers);
+ png_write_image(png_ptr, row_pointers);
+
+ /* You can write optional chunks like tEXt, zTXt, and tIME at the end
+ * as well.
+ */
+
+ /* It is REQUIRED to call this to finish writing the rest of the file */
+ png_write_end(png_ptr, info_ptr);
+
+ /* if you allocated any text comments, free them here */
+ /* free image data if allocated. */
+
+ /* clean up after the write, and free any memory allocated */
+ png_destroy_info_struct(png_ptr, &info_ptr);
+
+ /* clean up after the write, and free any memory allocated */
+ png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
+
+ fclose(fp);
+
+ return;
+}
+
+#ifdef STANDALONE
+int
+main(int argc, char **argv)
+{
+ char image_data[3*16 * 3*16 * 3];
+ int i,j,k,l,m;
+ char r,g,b,t, or,og,ob;
+
+ or=0x00; og=0xFF; ob=0x0;
+ m=0;
+ for (i=0; i<3; i++) {
+ t=or; or=og; og=ob; ob=t;
+ for (j=0; j<16; j++) {
+ r=or; g=og; b=ob;
+ for (k=0; k<3; k++) {
+ for (l=0; l<16; l++) {
+ image_data[m++]=r;
+ image_data[m++]=g;
+ image_data[m++]=b;
+ }
+ t=r; r=g; g=b; b=t;
+ }
+ }
+ }
+
+ write_png("/tmp/pngtest.png", 3*16, 3*16, (void *) image_data) ;
+ return 0;
+}
+#endif /*STANDALONE*/
+
+#endif /*HAVE_LIBPNG*/
projects / vlc / commitdiff