[FFmpeg-devel] 回复: [PATCH 1/1] add without_captureblt option for libavdevice/gdigrab.c, when useing the bitblt function with CAPTUREBLT it caused the mouse cursor flicker. most time we dont need this flag to capture window

[Andriy Gelman]

On Wed, 11. Dec 09:01, _ FgoDt wrote:
> did someone review the patch?
> 
> ________________________________
> 发件人: _ FgoDt <fgodtdev at hotmail.com>
> 发送时间: 2019年11月15日 15:03
> 收件人: ffmpeg-devel at ffmpeg.org <ffmpeg-devel at ffmpeg.org>
> 抄送: _ FgoDt <fgodtdev at hotmail.com>
> 主题: [PATCH 1/1] add without_captureblt option for libavdevice/gdigrab.c, when useing the bitblt function with CAPTUREBLT it caused the mouse cursor flicker. most time we dont need this flag to capture window

> 
> From: fgodt <fgodtdev at hotmail.com>

This would be in commit, you should use your name.

> 
> Signed-off-by: fgodt <fgodtdev at hotmail.com>
> ---
>  libavdevice/gdigrab.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/libavdevice/gdigrab.c b/libavdevice/gdigrab.c
> index f4444406fa..0ab0cfed01 100644
> --- a/libavdevice/gdigrab.c
> +++ b/libavdevice/gdigrab.c
> @@ -53,6 +53,8 @@ struct gdigrab {
>      int        offset_x;    /**< Capture x offset (private option) */
>      int        offset_y;    /**< Capture y offset (private option) */
> 
> +    int        without_captureblt; /**< capture without captureblt */
> +
>      HWND       hwnd;        /**< Handle of the window for the grab */
>      HDC        source_hdc;  /**< Source device context */
>      HDC        dest_hdc;    /**< Destination, source-compatible DC */
> @@ -542,6 +544,8 @@ static int gdigrab_read_packet(AVFormatContext *s1, AVPacket *pkt)
> 
>      int64_t curtime, delay;
> 
> +    unsigned long flag;
> +
>      /* Calculate the time of the next frame */
>      time_frame += INT64_C(1000000);
> 
> @@ -570,12 +574,16 @@ static int gdigrab_read_packet(AVFormatContext *s1, AVPacket *pkt)
>          return AVERROR(ENOMEM);
>      pkt->pts = curtime;
> 
> +    flag = SRCCOPY;
> +    if(!gdigrab->without_captureblt)
> +        flag |= CAPTUREBLT;
> +
>      /* Blit screen grab */
>      if (!BitBlt(dest_hdc, 0, 0,
>                  clip_rect.right - clip_rect.left,
>                  clip_rect.bottom - clip_rect.top,
>                  source_hdc,
> -                clip_rect.left, clip_rect.top, SRCCOPY | CAPTUREBLT)) {
> +                clip_rect.left, clip_rect.top, flag)) {
>          WIN32_API_ERROR("Failed to capture image");
>          return AVERROR(EIO);
>      }
> @@ -639,6 +647,7 @@ static const AVOption options[] = {
>      { "video_size", "set video frame size", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, DEC },
>      { "offset_x", "capture area x offset", OFFSET(offset_x), AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, DEC },
>      { "offset_y", "capture area y offset", OFFSET(offset_y), AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, DEC },

> +    { "without_captureblt", "capture without captureblt", OFFSET(without_captureblt), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, DEC },
>      { NULL },
>  };

IMO a not negated option would be better. i.e. use_captureblt that's enabled by
default. 

You also need to update the docs.

I don't have windows so can't test on my machine.

-- 
Andriy