Alpha plugin in GStreamer not working

Posted by Miguel Escriva on Super User See other posts from Super User or by Miguel Escriva
Published on 2010-05-03T09:22:13Z Indexed on 2010/05/03 9:28 UTC
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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

© Super User or respective owner

Alpha plugin in GStreamer not working

Posted by Miguel Escriva on Stack Overflow See other posts from Stack Overflow or by Miguel Escriva
Published on 2010-05-03T08:51:20Z Indexed on 2010/05/03 8:58 UTC
Read the original article Hit count: 291

Filed under:
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|

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

© Stack Overflow or respective owner

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