videomixer: Add transparent background option for alpha channel formats

This commit is contained in:
Lane Brooks 2011-01-19 18:06:45 -07:00 committed by Sebastian Dröge
parent 69b5aedc58
commit ef5ac986f1
2 changed files with 39 additions and 3 deletions

View file

@ -533,6 +533,8 @@ gst_video_mixer_background_get_type (void)
{VIDEO_MIXER_BACKGROUND_CHECKER, "Checker pattern", "checker"},
{VIDEO_MIXER_BACKGROUND_BLACK, "Black", "black"},
{VIDEO_MIXER_BACKGROUND_WHITE, "White", "white"},
{VIDEO_MIXER_BACKGROUND_TRANSPARENT,
"Transparent Background to enable further mixing", "transparent"},
{0, NULL, NULL},
};
@ -1025,6 +1027,7 @@ gst_videomixer_setcaps (GstPad * pad, GstCaps * caps)
GST_INFO_OBJECT (mixer, "set src caps: %" GST_PTR_FORMAT, caps);
mixer->blend = NULL;
mixer->overlay = NULL;
mixer->fill_checker = NULL;
mixer->fill_color = NULL;
@ -1034,114 +1037,133 @@ gst_videomixer_setcaps (GstPad * pad, GstCaps * caps)
switch (mixer->fmt) {
case GST_VIDEO_FORMAT_AYUV:
mixer->blend = gst_video_mixer_blend_ayuv;
mixer->overlay = gst_video_mixer_overlay_ayuv;
mixer->fill_checker = gst_video_mixer_fill_checker_ayuv;
mixer->fill_color = gst_video_mixer_fill_color_ayuv;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_ARGB:
mixer->blend = gst_video_mixer_blend_argb;
mixer->overlay = gst_video_mixer_overlay_argb;
mixer->fill_checker = gst_video_mixer_fill_checker_argb;
mixer->fill_color = gst_video_mixer_fill_color_argb;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_BGRA:
mixer->blend = gst_video_mixer_blend_bgra;
mixer->overlay = gst_video_mixer_overlay_bgra;
mixer->fill_checker = gst_video_mixer_fill_checker_bgra;
mixer->fill_color = gst_video_mixer_fill_color_bgra;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_ABGR:
mixer->blend = gst_video_mixer_blend_abgr;
mixer->overlay = gst_video_mixer_overlay_abgr;
mixer->fill_checker = gst_video_mixer_fill_checker_abgr;
mixer->fill_color = gst_video_mixer_fill_color_abgr;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_RGBA:
mixer->blend = gst_video_mixer_blend_rgba;
mixer->overlay = gst_video_mixer_overlay_rgba;
mixer->fill_checker = gst_video_mixer_fill_checker_rgba;
mixer->fill_color = gst_video_mixer_fill_color_rgba;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_Y444:
mixer->blend = gst_video_mixer_blend_y444;
mixer->overlay = mixer->blend;
mixer->fill_checker = gst_video_mixer_fill_checker_y444;
mixer->fill_color = gst_video_mixer_fill_color_y444;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_Y42B:
mixer->blend = gst_video_mixer_blend_y42b;
mixer->overlay = mixer->blend;
mixer->fill_checker = gst_video_mixer_fill_checker_y42b;
mixer->fill_color = gst_video_mixer_fill_color_y42b;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_YUY2:
mixer->blend = gst_video_mixer_blend_yuy2;
mixer->overlay = mixer->blend;
mixer->fill_checker = gst_video_mixer_fill_checker_yuy2;
mixer->fill_color = gst_video_mixer_fill_color_yuy2;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_UYVY:
mixer->blend = gst_video_mixer_blend_uyvy;
mixer->overlay = mixer->blend;
mixer->fill_checker = gst_video_mixer_fill_checker_uyvy;
mixer->fill_color = gst_video_mixer_fill_color_uyvy;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_YVYU:
mixer->blend = gst_video_mixer_blend_yvyu;
mixer->overlay = mixer->blend;
mixer->fill_checker = gst_video_mixer_fill_checker_yvyu;
mixer->fill_color = gst_video_mixer_fill_color_yvyu;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_I420:
mixer->blend = gst_video_mixer_blend_i420;
mixer->overlay = mixer->blend;
mixer->fill_checker = gst_video_mixer_fill_checker_i420;
mixer->fill_color = gst_video_mixer_fill_color_i420;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_YV12:
mixer->blend = gst_video_mixer_blend_yv12;
mixer->overlay = mixer->blend;
mixer->fill_checker = gst_video_mixer_fill_checker_yv12;
mixer->fill_color = gst_video_mixer_fill_color_yv12;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_Y41B:
mixer->blend = gst_video_mixer_blend_y41b;
mixer->overlay = mixer->blend;
mixer->fill_checker = gst_video_mixer_fill_checker_y41b;
mixer->fill_color = gst_video_mixer_fill_color_y41b;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_RGB:
mixer->blend = gst_video_mixer_blend_rgb;
mixer->overlay = mixer->blend;
mixer->fill_checker = gst_video_mixer_fill_checker_rgb;
mixer->fill_color = gst_video_mixer_fill_color_rgb;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_BGR:
mixer->blend = gst_video_mixer_blend_bgr;
mixer->overlay = mixer->blend;
mixer->fill_checker = gst_video_mixer_fill_checker_bgr;
mixer->fill_color = gst_video_mixer_fill_color_bgr;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_xRGB:
mixer->blend = gst_video_mixer_blend_xrgb;
mixer->overlay = mixer->blend;
mixer->fill_checker = gst_video_mixer_fill_checker_xrgb;
mixer->fill_color = gst_video_mixer_fill_color_xrgb;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_xBGR:
mixer->blend = gst_video_mixer_blend_xbgr;
mixer->overlay = mixer->blend;
mixer->fill_checker = gst_video_mixer_fill_checker_xbgr;
mixer->fill_color = gst_video_mixer_fill_color_xbgr;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_RGBx:
mixer->blend = gst_video_mixer_blend_rgbx;
mixer->overlay = mixer->blend;
mixer->fill_checker = gst_video_mixer_fill_checker_rgbx;
mixer->fill_color = gst_video_mixer_fill_color_rgbx;
ret = TRUE;
break;
case GST_VIDEO_FORMAT_BGRx:
mixer->blend = gst_video_mixer_blend_bgrx;
mixer->overlay = mixer->blend;
mixer->fill_checker = gst_video_mixer_fill_checker_bgrx;
mixer->fill_color = gst_video_mixer_fill_color_bgrx;
ret = TRUE;
@ -1387,6 +1409,13 @@ static void
gst_videomixer_blend_buffers (GstVideoMixer * mix, GstBuffer * outbuf)
{
GSList *walk;
BlendFunction blend;
if (mix->background == VIDEO_MIXER_BACKGROUND_TRANSPARENT) {
blend = mix->overlay;
} else {
blend = mix->blend;
}
walk = mix->sinkpads;
while (walk) { /* We walk with this list because it's ordered */
@ -1411,7 +1440,7 @@ gst_videomixer_blend_buffers (GstVideoMixer * mix, GstBuffer * outbuf)
if (GST_CLOCK_TIME_IS_VALID (stream_time))
gst_object_sync_values (G_OBJECT (pad), stream_time);
mix->blend (GST_BUFFER_DATA (mixcol->buffer),
blend (GST_BUFFER_DATA (mixcol->buffer),
pad->xpos, pad->ypos, pad->in_width, pad->in_height, pad->alpha,
GST_BUFFER_DATA (outbuf), mix->out_width, mix->out_height);
}
@ -1580,6 +1609,11 @@ gst_videomixer_collected (GstCollectPads * pads, GstVideoMixer * mix)
mix->fill_color (GST_BUFFER_DATA (outbuf), mix->out_width,
mix->out_height, 240, 128, 128);
break;
case VIDEO_MIXER_BACKGROUND_TRANSPARENT:
memset (GST_BUFFER_DATA (outbuf), 0,
gst_video_format_get_row_stride (mix->fmt, 0,
mix->out_width) * mix->out_height);
break;
}
gst_videomixer_blend_buffers (mix, outbuf);

View file

@ -45,6 +45,7 @@ typedef struct _GstVideoMixerClass GstVideoMixerClass;
* @VIDEO_MIXER_BACKGROUND_CHECKER: checker pattern background
* @VIDEO_MIXER_BACKGROUND_BLACK: solid color black background
* @VIDEO_MIXER_BACKGROUND_WHITE: solid color white background
* @VIDEO_MIXER_BACKGROUND_TRANSPARENT: background is left transparent and layers are composited using "A OVER B" composition rules. This is only applicable to AYUV and ARGB (and variants) as it preserves the alpha channel and allows for further mixing.
*
* The different backgrounds videomixer can blend over.
*/
@ -52,7 +53,8 @@ typedef enum
{
VIDEO_MIXER_BACKGROUND_CHECKER,
VIDEO_MIXER_BACKGROUND_BLACK,
VIDEO_MIXER_BACKGROUND_WHITE
VIDEO_MIXER_BACKGROUND_WHITE,
VIDEO_MIXER_BACKGROUND_TRANSPARENT,
}
GstVideoMixerBackground;
@ -112,7 +114,7 @@ struct _GstVideoMixer
gdouble proportion;
GstClockTime earliest_time;
BlendFunction blend;
BlendFunction blend, overlay;
FillCheckerFunction fill_checker;
FillColorFunction fill_color;