Video File Processing

Maurice Ackel maurice.ackel at
Sat Oct 30 00:34:25 UTC 2021

Hi there,

I’m currently trying to set up a pipeline for a simple dummy task that should be the basis of a more complex pipeline. For now, I want to open a video file (also containing audio), flipping the image vertically and then storing everything again in the same file format as the input.

From my research I found out, that I can use „decodebin“ to demux the input file and „encodebin“ to combine it back to a file. Based on this I tried the following pipeline:

gst-launch-1.0 \
> filesrc location=„in.mp4" ! decodebin name=demux \
> encodebin name=mux ! filesink location="out.mp4" \
> .demux ! video/x-raw ! queue ! videoflip method=vertical-flip ! .mux \
> .demux ! audio/x-raw ! queue ! .mux

Which already fails on construction probably because of the caps.

My questions would be
1) How can I make the encodebin use the same output codec as decodebin detected on the input file
2) How do I properly split up the audio and video channels so that I can only process the video channel and let the audio bypass while keeping everything in the correct timing


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