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authorMattias Andrée <maandree@member.fsf.org>2015-12-11 11:25:02 +0100
committerMattias Andrée <maandree@member.fsf.org>2015-12-11 11:25:02 +0100
commit6d2d5307a6b358f3528f53cc6a8c9b2acd50f397 (patch)
tree72bbada59c7c2188e7bdfbe7e7b372097cc9ef38 /src
parentsoon, convert will not be used (diff)
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use libpng, ... now we just have to make it faster
Signed-off-by: Mattias Andrée <maandree@member.fsf.org>
Diffstat (limited to 'src')
-rw-r--r--src/png.c130
-rw-r--r--src/png.h29
-rw-r--r--src/scrotty.c23
3 files changed, 172 insertions, 10 deletions
diff --git a/src/png.c b/src/png.c
new file mode 100644
index 0000000..0944f18
--- /dev/null
+++ b/src/png.c
@@ -0,0 +1,130 @@
+/**
+ * scrotty — Screenshot program for Linux's TTY
+ *
+ * Copyright © 2014, 2015 Mattias Andrée (maandree@member.fsf.org)
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+#include "common.h"
+#include "png.h"
+
+#ifdef __GNUC__
+# pragma GCC diagnostic ignored "-Wpadded"
+#endif
+#include <png.h>
+
+
+/*
+ * Rationale:
+ *
+ * Users want their files in PNG (most often), not PNM.
+ * Calling an external program for conversion poses
+ * potential security risks, and is slower.
+ */
+
+
+/**
+ * Convert an image from PNM to PNG.
+ *
+ * This is a very limited conversion implementation.
+ * It is not generally reusable. It makes assumptions
+ * that are true only necessarily for this program.
+ *
+ * @param fdin The file descriptor for the image to convert (PNM).
+ * @param fdout The file descriptor for the output image (PNG).
+ * @return Zero on success, -1 on error.
+ */
+int
+convert (int fdin, int fdout)
+{
+#define SCAN(...) do { if (fscanf(in, __VA_ARGS__) != 1) goto fail; } while (0)
+
+ FILE *in = NULL;
+ FILE *out = NULL;
+ long height, width, width3;
+ long y, x, r, g, b;
+ png_byte *pixbuf = 0;
+ png_struct *pngbuf = NULL;
+ png_info *pnginfo = NULL;
+ int saved_errno = 0, rc, c;
+
+ /* Get a FILE * for the input, we want to use fscanf, there is no dscanf. */
+ in = fdopen (fdin, "r");
+ if (in == NULL)
+ goto fail;
+ /* Get a FILE * for the output, libpng wants a FILE *, not a file descriptor. */
+ out = fdopen (fdout, "w");
+ if (out == NULL)
+ goto fail;
+
+ /* Read head. */
+ do c = fgetc(in); while ((c != '\n') && (c != EOF));
+ SCAN ("%li ", &width);
+ SCAN ("%li\n", &height);
+ do c = fgetc(in); while ((c != '\n') && (c != EOF));
+
+ /* Allocte structures for the PNG. */
+ width3 = width * 3;
+ pixbuf = malloc ((size_t)width3 * sizeof (png_byte));
+ if (pixbuf == NULL)
+ goto fail;
+ pngbuf = png_create_write_struct (png_get_libpng_ver (NULL), NULL, NULL, NULL);
+ if (pngbuf == NULL)
+ goto fail;
+ pnginfo = png_create_info_struct (pngbuf);
+ if (pnginfo == NULL)
+ goto fail;
+
+ /* Initialise PNG write, and write head. */
+ if (setjmp (png_jmpbuf(pngbuf))) /* Failing libpng calls jump here. */
+ goto fail;
+ png_init_io (pngbuf, out);
+ png_set_IHDR (pngbuf, pnginfo, (png_uint_32)width, (png_uint_32)height,
+ 8 /* bit depth */, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE,
+ PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+ png_write_info (pngbuf, pnginfo);
+
+ /* Read and convert body. */
+ for (y = 0; y < height; y++)
+ {
+ for (x = 0; x < width3; x += 3)
+ {
+ SCAN ("%li\n", &r);
+ SCAN ("%li\n", &g);
+ SCAN ("%li\n", &b);
+ pixbuf[x + 0] = (png_byte)r;
+ pixbuf[x + 1] = (png_byte)g;
+ pixbuf[x + 2] = (png_byte)b;
+ }
+ png_write_row (pngbuf, pixbuf);
+ }
+ png_write_end (pngbuf, pnginfo);
+
+ rc = 0;
+ goto cleanup;
+ fail:
+ saved_errno = errno;
+ rc = -1;
+ goto cleanup;
+
+ cleanup:
+ png_destroy_write_struct (&pngbuf, (pnginfo ? &pnginfo : NULL));
+ if (in != NULL)
+ fclose (in);
+ if (out != NULL)
+ fclose (out);
+ free (pixbuf);
+ return errno = saved_errno, rc;
+}
+
diff --git a/src/png.h b/src/png.h
new file mode 100644
index 0000000..02a6223
--- /dev/null
+++ b/src/png.h
@@ -0,0 +1,29 @@
+/**
+ * scrotty — Screenshot program for Linux's TTY
+ *
+ * Copyright © 2014, 2015 Mattias Andrée (maandree@member.fsf.org)
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+
+
+/**
+ * Convert an image from PNM to PNG.
+ *
+ * @param fdin The file descriptor for the image to convert (PNM).
+ * @param fdout The file descriptor for the output image (PNG).
+ * @return Zero on success, -1 on error.
+ */
+int convert (int fdin, int fdout);
+
diff --git a/src/scrotty.c b/src/scrotty.c
index da69cc9..9837a26 100644
--- a/src/scrotty.c
+++ b/src/scrotty.c
@@ -21,6 +21,7 @@
#include "kern.h"
#include "info.h"
#include "pnm.h"
+#include "png.h"
#include "pattern.h"
#include <getopt.h>
@@ -188,6 +189,7 @@ save (const char *fbpath, const char *imgpath, long width, long height, int raw)
if (raw)
goto no_convert;
+
/* Create a pipe that for sending data into the conversion process program. */
if (pipe (pipe_rw) < 0)
goto fail;
@@ -203,17 +205,18 @@ save (const char *fbpath, const char *imgpath, long width, long height, int raw)
{
/* Close the write-end of the pipe. */
close (pipe_rw[1]);
- /* Turn the read-end of the pipe into stdin. */
- if (pipe_rw[0] != STDIN_FILENO)
- {
- close (STDIN_FILENO);
- if (dup2 (pipe_rw[0], STDIN_FILENO) == -1)
- goto child_fail;
- close (pipe_rw[0]);
- }
- /* Exec. `convert` to convert the PNM-image we create to a compressed image. */
- execlp ("convert", "convert", DEVDIR "/stdin", imgpath, NULL);
+ /* Open file descriptor for the output image. */
+ fd = open(imgpath, O_WRONLY | O_CREAT | O_TRUNC,
+ S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
+ if (fd == -1)
+ goto child_fail;
+
+ /* Convert the PNM-image we create to a compressed image, namely in PNG. */
+ if (convert (pipe_rw[0], fd) < 0)
+ goto child_fail;
+
+ _exit(0);
child_fail:
perror(execname);
_exit(1);