[FFmpeg-devel] [PATCH] lavd/xv: handle delete window message

[Nicolas George]

Good idea, thanks.

L'octidi 8 prairial, an CCXXII, Lukasz Marek a écrit :
> User may close X11 window by close button on tray.
> FFmpeg leaves in graceless way.

Bogus window manager, it should not be destroying a window if it can not
delete it, unless the user really request it.

> This commit detects it and return IO error.

Seems reasonable. EPIPE could make sense too.

> 
> Signed-off-by: Lukasz Marek <lukasz.m.luki2 at gmail.com>
> ---
>  libavdevice/xv.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/libavdevice/xv.c b/libavdevice/xv.c
> index d1f8907..cc362a7 100644
> --- a/libavdevice/xv.c
> +++ b/libavdevice/xv.c
> @@ -58,6 +58,7 @@ typedef struct {
>      int image_width, image_height;
>      XShmSegmentInfo yuv_shminfo;
>      int xv_port;
> +    Atom wm_delete_message;
>  } XVContext;
>  
>  typedef struct XVTagFormatMap
> @@ -156,6 +157,8 @@ static int xv_write_header(AVFormatContext *s)
>              }
>          }
>          XStoreName(xv->display, xv->window, xv->window_title);
> +        xv->wm_delete_message = XInternAtom(xv->display, "WM_DELETE_WINDOW", False);
> +        XSetWMProtocols(xv->display, xv->window, &xv->wm_delete_message, 1);
>          XMapWindow(xv->display, xv->window);
>      } else
>          xv->window = xv->window_id;
> @@ -297,6 +300,18 @@ static int write_picture(AVFormatContext *s, AVPicture *pict)
>          img->data + img->offsets[1],
>          img->data + img->offsets[2]
>      };

> +
> +    /* Check messages. Window might get closed. */
> +    if (!xv->window_id) {
> +        XEvent event;
> +        if (XCheckTypedEvent(xv->display, ClientMessage, &event)) {
> +            if (event.xclient.data.l[0] == xv->wm_delete_message) {
> +                av_log(xv, AV_LOG_DEBUG, "Window close event.\n");
> +                return AVERROR(EIO);
> +            }
> +        }
> +    }
> +

I must say I do not like XCheckTypedEvent() much: what happens to the other
events? They stay and clobber the queue. I suggest to loop over XPending and
XNextEvent. That would also make life easier to someone who wants to
implement other kind of events.

>      av_image_copy(data, img->pitches, (const uint8_t **)pict->data, pict->linesize,
>                    xv->image_format, img->width, img->height);
>      return xv_repaint(s);

Regards,

-- 
  Nicolas George