'A OVER B' compositing is explained at
http://en.wikipedia.org/wiki/Alpha_compositing.
Previously, overlaying text on a transparent background image left the
text overlay also transparent. This pipeline shows such an example:
gst-launch videotestsrc pattern=white ! video/x-raw-yuv,format=\(fourcc\)AYUV ! alpha alpha=0.0 ! textoverlay text=Testing auto-resize=False font-desc=60px ! videomixer ! ffmpegcolorspace ! autovideosink
With this patch, text is composited "OVER" the background image and
thus is visible regardless of the alpha of the background image. The
overlay in the above pipeline works after applying this patch.
Pango is not reentrant. Use a class wide mutex to protect pange use in
gst_text_overlay_render_pangocairo(). This works reliable in contrast to the
hack in my previous commit.
Fixes Bug #412678
In case of odd values for xpos or ypos, the division by two in CbCr
plane would result in an off-by-one error, which in the case of NV12,
NV21, or UYVY would cause inversion of blue and red colors. (And
would be not so easily noticed for I420 as it would just cause the
chroma to be offset slightly from the luma.)
This patch also fixes a silly typo from the earlier patch which
added NV12 support that broke UYVY support.
Rather than only left, right, top, etc, allow for horizontal and vertical
positioning on a scale from 0 to 1.
Also cater for configuring rendered text color.
Fixes#624920.
API: GstTextOverlay:xpos
API: GstTextOverlay:ypos
API: GstTextOverlay:color
This reverts commit 60aa09d28c.
First drawing the real text and then the outline produces ugly
text in lower resolutions. The outline line width needs to be somehow
changed relative to the resolution. Fixes bug #602924.
Original commit message from CVS:
* ext/pango/Makefile.am:
* ext/pango/gsttextoverlay.c: (gst_text_overlay_shade_y),
(gst_text_overlay_blit_yuv420), (gst_text_overlay_push_frame):
Use gstvideo functions to calculate strides and plane offsets. Fixes
rendering issue ('ghost' images of the text on the chroma planes)
with widths or heights that are not multiples of 8 (#506659 and
probably also #485729).
* tests/icles/test-textoverlay.c: (show_text), (test_textoverlay),
(main):
Test with odd height/width too.
Original commit message from CVS:
* ext/pango/gsttextoverlay.c: (gst_text_overlay_class_init),
(gst_text_overlay_init):
Fix textoverlay unit test again by making the supposed default
value for the wait-text property the actual default value.
Also fix Since: tag for new property.
Original commit message from CVS:
* ext/pango/gsttextoverlay.c: (gst_text_overlay_class_init),
(gst_text_overlay_init), (gst_text_overlay_set_property),
(gst_text_overlay_get_property), (gst_text_overlay_src_event),
(gst_text_overlay_text_event), (gst_text_overlay_video_event),
(gst_text_overlay_text_chain), (gst_text_overlay_video_chain),
(gst_text_overlay_change_state):
* ext/pango/gsttextoverlay.h:
Add property to configure waiting for text on the textpad or not, with
the default behaviour being the old one (always wait for text before
rendering the video). This default behaviour is usually not the best one
because the text stream can very sparse and could require queueing a lot
of video.
Fix the flushing and EOS handing so that we don't mix up their meaning.
Original commit message from CVS:
* ext/pango/gsttextoverlay.c: (gst_text_overlay_class_init):
* gst/playback/gstplaybasebin.c: (set_subtitles_visible),
(set_active_source):
* gst/playback/gstplaybasebin.h:
* gst/playback/gstplaybin.c: (gst_play_bin_class_init),
(setup_sinks), (playbin_set_subtitles_visible):
Make switching off of subtitles work. To avoid all kind of
problems with unlinking of the subtitle input, we just keep
the subtitle inputs linked as they are and tell textoverlay
not to render them. Fixes#373011.
Other subtitle switching issues (esp. when there are both
external and in-stream subtitles) remain. They'll be solved
in playbin2.
Original commit message from CVS:
* ext/pango/gsttextoverlay.c: (gst_text_overlay_init),
(gst_text_overlay_set_property):
* ext/vorbis/vorbisdec.c: (vorbis_handle_data_packet):
* gst-libs/gst/audio/gstbaseaudiosink.c:
(gst_base_audio_sink_render):
* gst-libs/gst/rtp/gstrtcpbuffer.c: (gst_rtcp_ntp_to_unix),
(gst_rtcp_unix_to_ntp):
* gst-libs/gst/rtsp/gstrtspmessage.c: (gst_rtsp_message_get_type):
* gst/playback/gstqueue2.c:
* tests/examples/seek/seek.c: (set_scale):
Fix a bunch of compile warnings shown with Forte.
* gst/audiorate/gstaudiorate.c:
Always pull in config.h before including any system headers.
Original commit message from CVS:
Patch by: Dan Williams <dcbw redhat com>
* ext/pango/gsttextoverlay.c:
* ext/pango/gsttextoverlay.h:
API: add "line-alignment" property (#459334). Add gtk-doc blurb for
"silent" property so there's a Since tag in the API reference.
