[Qemu-devel] [PATCH/RFC 7/7] Add PNG screendump

["Marc-André Lureau" <marcandre.lureau@gmail.com>]

Dump an image in PNG format if the URI ends with ".png" and PNG
support is enabled.
---
 hw/vga.c |   75 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 74 insertions(+), 1 deletions(-)

diff --git a/hw/vga.c b/hw/vga.c
index 9f7ca89..0210cde 100644
--- a/hw/vga.c
+++ b/hw/vga.c
@@ -32,6 +32,13 @@
 #include "xen.h"
 #include "qemu_socket.h"
 
+#ifdef CONFIG_PNG
+/* The following define is needed by pngconf.h. Otherwise it won't compile,
+   because setjmp.h was already included by qemu-common.h. */
+#define PNG_SKIP_SETJMP_CHECK
+#include <png.h>
+#endif
+
 //#define DEBUG_VGA
 //#define DEBUG_VGA_MEM
 //#define DEBUG_VGA_REG
@@ -2422,6 +2429,39 @@ QEMUFile *qemu_fopen_uri(const char *uri, const char *mode)
     return f;
 }
 
+#ifdef CONFIG_PNG
+static void *vga_png_malloc(png_structp png_ptr, png_size_t size)
+{
+    return g_malloc(size);
+}
+
+static void vga_png_free(png_structp png_ptr, png_voidp ptr)
+{
+    g_free(ptr);
+}
+
+static void vga_png_write_data(png_structp png_ptr, png_bytep data,
+                               png_size_t length)
+{
+    QEMUFile *f = png_get_io_ptr(png_ptr);
+
+    qemu_put_buffer(f, (uint8_t*)data, length);
+}
+
+static void vga_png_flush_data(png_structp png_ptr)
+{
+}
+
+static int png_line_handler(void *opaque, uint8_t *line, size_t length)
+{
+    png_structp png_ptr = opaque;
+
+    png_write_row(png_ptr, line);
+
+    return length;
+}
+#endif
+
 static int ppm_line_handler(void *opaque, uint8_t *line, size_t length)
 {
     QEMUFile *f = opaque;
@@ -2482,7 +2522,39 @@ int ppm_save(const char *uri, struct DisplaySurface *ds)
     f = qemu_fopen_uri(uri, "wb");
     g_return_val_if_fail(f != NULL, -1);
 
-    {
+    if (g_str_has_suffix(uri, ".png")) {
+#ifdef CONFIG_PNG
+        png_structp png_ptr;
+        png_infop info_ptr;
+
+        png_ptr = png_create_write_struct_2(PNG_LIBPNG_VER_STRING,
+                                            NULL, NULL, NULL,
+                                            NULL, vga_png_malloc,
+                                            vga_png_free);
+        if (png_ptr == NULL) {
+            goto out;
+        }
+
+        info_ptr = png_create_info_struct(png_ptr);
+        if (info_ptr == NULL) {
+            png_destroy_write_struct(&png_ptr, NULL);
+            goto out;
+        }
+
+        png_set_write_fn(png_ptr, (void *)f,
+                         vga_png_write_data, vga_png_flush_data);
+        png_set_IHDR(png_ptr, info_ptr, ds->width, ds->height,
+                     8, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE,
+                     PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+        png_write_info(png_ptr, info_ptr);
+        screen_dump_lines(ds, png_line_handler, png_ptr);
+        png_write_end(png_ptr, NULL);
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+#else
+        DPRINTF("PNG support is disabled");
+        goto out;
+#endif
+    } else {
         gchar *header;
         header = g_strdup_printf("P6\n%d %d\n%d\n", ds->width, ds->height, 255);
         qemu_put_buffer(f, (uint8_t*)header, strlen(header));
@@ -2491,6 +2563,7 @@ int ppm_save(const char *uri, struct DisplaySurface *ds)
     }
 
     ret = 0;
+out:
     qemu_fclose(f);
     return ret;
 }
-- 
1.7.7.6