Alpha plugin in GStreamer not working
- by Miguel Escriva
Hi!
I'm trying to compose two videos, and I'm using the alpha plug-in to make the white color transparent.
To test the alpha plug-in I'm creating the pipeline with gst-launch.
The first test I done was:
gst-launch videotestsrc pattern=smpte75 \
! alpha method=custom target-r=255 target-g=255 target-b=255 angle=10 \
! videomixer name=mixer ! ffmpegcolorspace ! autovideosink \
videotestsrc pattern=snow ! mixer.
and it works great! Then I created two videos with those lines:
gst-launch videotestsrc pattern=snow ! ffmpegcolorspace ! theoraenc ! oggmux ! filesink location=snow.ogv
gst-launch videotestsrc pattern=smpte75 ! ffmpegcolorspace ! theoraenc ! oggmux ! filesink location=bars75.ogv
And changed the videotestsrc to a filesrc and it continues working
gst-launch filesrc location=bars75.ogv ! decodebin2 \
! alpha method=custom target-r=255 target-g=255 target-b=255 angle=10 \
! videomixer name=mixer ! ffmpegcolorspace ! autovideosink \
filesrc location=snow.ogv ! decodebin2 ! alpha ! mixer.
But, when I use the ideo I want to compose, I'm not able to make the white color transparent
gst-launch filesrc location=video.ogv ! decodebin2 \
! alpha method=custom target-r=255 target-g=255 target-b=255 angle=10 \
! videomixer name=mixer ! ffmpegcolorspace ! autovideosink \
filesrc location=snow.ogv ! decodebin2 ! alpha ! mixer.
Can you help me? Any idea what is happening?
I'm using GStreamer 0.10.28
You can download the test videos from here: http://polimedia.upv.es/pub/gst/gst.zip
Thanks in advance,
Miguel Escriva
