Re: [PATCH v2 2/2] Added parameter to take screenshot with screendump as PNG.

[Kshitij Suri]

On 11/03/22 5:50 pm, Markus Armbruster wrote:
> Kshitij Suri <kshitij.suri@nutanix.com> writes:
>
> > 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=SxmcA4FlCCy9O9eUaDUiSY37bauF6iJbDRVL--VUyTG5Vze_GFjmJuxgwAVYRjad&s=OIKnm9xXYjeat7TyIJ_-z9EvG2XYXMULNbHe0Bjzyjo&e=
> >
> > Signed-off-by: Kshitij Suri <kshitij.suri@nutanix.com>
> > ---
> [...]
>
> > diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
> > index 8c384dc1b2..9a640146eb 100644
> > --- a/monitor/hmp-cmds.c
> > +++ b/monitor/hmp-cmds.c
> > @@ -1677,9 +1677,26 @@ 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;
> >   
> > -    qmp_screendump(filename, id != NULL, id, id != NULL, head, &err);
> > +    int val = qapi_enum_parse(&ImageFormat_lookup, input_format, -1, &err);
> > +    if (val < 0) {
> > +        goto end;
> > +    }
> > +
> > +    switch (val) {
> > +    case IMAGE_FORMAT_PNG:
> > +        format = IMAGE_FORMAT_PNG;
> > +        break;
> > +    default:
> > +        format = IMAGE_FORMAT_PPM;
> > +    }
> > +
> > +    qmp_screendump(filename, id != NULL, id, id != NULL, head,
> > +                   input_format != NULL, format, &err);
> > +end:
> >       hmp_handle_error(mon, err);
> >   }
> >   
> > diff --git a/qapi/ui.json b/qapi/ui.json
> > index 9354f4c467..6aa0dd7c1b 100644
> > --- a/qapi/ui.json
> > +++ b/qapi/ui.json
> > @@ -73,12 +73,27 @@
> >   ##
> >   { 'command': 'expire_password', 'data': {'protocol': 'str', 'time': 'str'} }
> >   
> > +##
> > +# @ImageFormat:
> > +#
> > +# Available list of supported types.
> This is just a hair better than "Lorem ipsum" :)
>
> Suggest: Supported image format types.
Will add in the updated patch
> > +#
> > +# @png: PNG format
> > +#
> > +# @ppm: PPM format
> > +#
> > +# Since: 7.0
> > +#
> > +##
> > +{ 'enum': 'ImageFormat',
> > +  'data': ['ppm', 'png'] }
> > +
> >   ##
> >   # @screendump:
> >   #
> > -# Write a PPM of the VGA screen to a file.
> > +# Write a screenshot of the VGA screen to a file.
> Is "VGA screen" accurate?  Or does this work for other displays, too?

The patch didn't modify any display changes and VGA screen was

previously supported display type.

> >   #
> > -# @filename: the path of a new PPM file to store the image
> > +# @filename: the path of a new file to store the image
> >   #
> >   # @device: ID of the display device that should be dumped. If this parameter
> >   #          is missing, the primary display will be used. (Since 2.12)
> > @@ -87,6 +102,9 @@
> >   #        parameter is missing, head #0 will be used. Also note that the head
> >   #        can only be specified in conjunction with the device ID. (Since 2.12)
> >   #
> > +# @format: image format for screendump is specified. ppm is the set as the
> > +#          default format. (Since 7.0)
> I figure you mean "is set as the default".  Suggest to replace the
> sentence by "(default: ppm)".
Will add in the updated patch.
> > +#
> >   # Returns: Nothing on success
> >   #
> >   # Since: 0.14
> > @@ -99,7 +117,8 @@
> >   #
> >   ##
> >   { 'command': 'screendump',
> > -  'data': {'filename': 'str', '*device': 'str', '*head': 'int'},
> > +  'data': {'filename': 'str', '*device': 'str', '*head': 'int',
> > +           '*format': 'ImageFormat'},
> >     'coroutine': true }
> >   
> >   ##
> [...]
Thank you for your review!

Regards,
Kshitij Suri
>