On Fri, Feb 25, 2022 at 11:58:30AM +0000, Kshitij Suri wrote:
Currently screendump only supports PPM format, which is un-compressed and not
standard. Added a "format" parameter to qemu monitor screendump capabilites
to support PNG image capture using libpng. The param was added in QAPI schema
of screendump present in ui.json along with png_save() function which converts
pixman_image to PNG. HMP command equivalent was also modified to support the
feature.
Example usage:
{ "execute": "screendump", "arguments": { "filename": "/tmp/image",
"format":"png" } }
Resolves:
https://urldefense.proofpoint.com/v2/url?u=https-3A__gitlab.com_qemu-2Dproject_qemu_-2D_issues_718&d=DwIBAg&c=s883GpUCOChKOHiocYtGcg&r=utjv19Ej9Fb0TB7_DX0o3faQ-OAm2ypPniPyqVSoj_w&m=N58ni_R8AQHe3XV2MX9aeKN2mCiEkpdyiqhV71sHDUEIuIk3P1HcXc-QfepnNaIE&s=CM400Sor3Oiio6iq3V_F9jFMCrn8UdbeKKXDnIh2QRw&e=
Signed-off-by: Kshitij Suri <kshitij.s...@nutanix.com>
---
+ .args_type = "filename:F,device:s?,head:i?,format:f?",
+ .params = "filename [device [head]] [format]",
+ .help = "save screen from head 'head' of display device 'device'"
+ "in specified format 'format' as image 'filename'."
+ "Currently only 'png' and 'ppm' formats are supported.",
.cmd = hmp_screendump,
.coroutine = true,
},
SRST
``screendump`` *filename*
- Save screen into PPM image *filename*.
+ Save screen as an image *filename*.
Maybe:
as an image *filename*, with default format of PPM.
ERST
{
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index 8c384dc1b2..c300545f34 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -1677,9 +1677,15 @@ hmp_screendump(Monitor *mon, const QDict *qdict)
const char *filename = qdict_get_str(qdict, "filename");
const char *id = qdict_get_try_str(qdict, "device");
int64_t head = qdict_get_try_int(qdict, "head", 0);
+ const char *input_format = qdict_get_str(qdict, "format");
Error *err = NULL;
+ ImageFormat format = IMAGE_FORMAT_PPM;
+ if (input_format != NULL && strcmp(input_format, "png") == 0) {
+ format = IMAGE_FORMAT_PNG;
+ }
Instead of open-coding the string-to-enum translation (which will be
hard to located if we expand to a third format down the road), you
should use qapi_enum_parse(&ImageFormat_lookup, ...).
+++ b/ui/console.c
@@ -37,6 +37,9 @@
#include "exec/memory.h"
#include "io/channel-file.h"
#include "qom/object.h"
+#ifdef CONFIG_PNG
+#include <png.h>
+#endif
#define DEFAULT_BACKSCROLL 512
#define CONSOLE_CURSOR_PERIOD 500
@@ -289,6 +292,87 @@ void graphic_hw_invalidate(QemuConsole *con)
}
}
+#ifdef CONFIG_PNG
+/**
+ * png_save: Take a screenshot as PNG
+ *
+ * Saves screendump as a PNG file
+ *
+ * Returns true for success or false for error.
+ *
+ * @fd: File descriptor for PNG file.
+ * @image: Image data in pixman format.
+ * @errp: Pointer to an error.
+ */
+static bool png_save(int fd, pixman_image_t *image, Error **errp)
+{
+ int width = pixman_image_get_width(image);
+ int height = pixman_image_get_height(image);
+ g_autofree png_struct *png_ptr = NULL;
+ g_autofree png_info *info_ptr = NULL;
+ g_autoptr(pixman_image_t) linebuf =
+ qemu_pixman_linebuf_create(PIXMAN_a8r8g8b8, width);
+ uint8_t *buf = (uint8_t *)pixman_image_get_data(linebuf);
+ FILE *f = fdopen(fd, "wb");
+ int y;
+ if (!f) {
+ error_setg(errp, "Failed to create file from file descriptor");
error_setg_errno() might be nicer to use here, since fdopen() failure sets
errno.
+ return false;
+ }
+
+ png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL,
+ NULL, NULL);
Indentation looks off.
+ if (!png_ptr) {
+ error_setg(errp, "PNG creation failed. Unable to write struct");
+ free(f);
free() is the wrong function to call on FILE*. You meant fclose().
+ return false;
+ }
+
+ info_ptr = png_create_info_struct(png_ptr);
+
+ if (!info_ptr) {
+ error_setg(errp, "PNG creation failed. Unable to write info");
+ free(f);
and again
+ png_destroy_write_struct(&png_ptr, &info_ptr);
+ return false;
+ }
+
+ png_init_io(png_ptr, f);
+
+ png_set_IHDR(png_ptr, info_ptr, width, height, 8,
+ PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,
+ PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+ png_write_info(png_ptr, info_ptr);
+
+ for (y = 0; y < height; ++y) {
+ qemu_pixman_linebuf_fill(linebuf, image, width, 0, y);
+ png_write_row(png_ptr, buf);
+ }
+ qemu_pixman_image_unref(linebuf);
+
+ png_write_end(png_ptr, NULL);
+
+ png_destroy_write_struct(&png_ptr, &info_ptr);
+
+ if (fclose(f) != 0) {
+ error_setg(errp, "PNG creation failed. Unable to close file");
Another spot for error_setg_errno
