I'm trying to write a program in C which replicates the pipeline:
gst-launch -v filesrc location="bbb.mp4" ! decodebin2 ! ffmpegcolorspace ! autovideosink
DecodeBin2 has a dynamic pad and I've attached a callback to handle its creation. I am unable to link it to ffmpegcolorspace however because the pad capability is always video/quicktime. I would like it to be video/x-raw-yuv or something else which is compatible with ffmpegcolorspace.
Is this possible to force/select the output type of decodebin2?
Thanks.
EDIT: Please do not recommend playbin. I'm trying to learn how how to make pipelines.
Is this possible to force/select the output type of decodebin2?
No you can not force or select the type of its source pad.
decoderbin2 select appropriate demuxer element and that demuxer element parse that media file and depending upon the codec of elementry stream in that media file it creates the caps/type of the output/Source pad.so that type of decoder can link with it and pipeline works.
this all happen in gstremer-plugin code
so if you want such then you need to write plugin by your self..!!
You can try the playbin plugin instead of generating your pipeline by hand.
Take a look on https://code.google.com/p/gstmultimedialib/source/browse/trunk/gstmultimedialib/Multimedia/Multimedia/FilterGraph/PlaybinFilterGraph.h from my gstmultimedialib project.
Good Luck!!!
来源：https://stackoverflow.com/questions/8049801/gstreamer-force-decodebin2-output-type