Decoding of interlaced H264 bistreams: interlaced output

Robotics & Edge Computing Jetson & Embedded Systems Jetson Nano
1

Hello!

I have been using the H264 decoder “nvv4l2decoder” with H264 interlaced bitstreams. The decoded output is progressive and seems to use a deinterlacer filter (NVMEDIA: DeinterlaceThread: 782: DeinterlaceThread is created). I have tried to disable it in different ways, but to no avail.

On the other hand, in this forum I have seen several messages that refer to the issue of the deinterlacer filter, but I don’t see how to disable it.

I need the decoder output to be interlaced, since all the systems we use use interlaced format.

Is there a way to disable the deinterlacer filter and have the decoded output be interlaced?

Thank you,
Daniel.

3

Hi,
This is not supported. The output frames are de-interlaced into progressive frames. It is not supported to output top-filed and bottom-filed frames.

4

Hello!

Thank you for answering so quickly.

Do you know if interlaced decoding could be achieved with another decoder?

I have already tried with the Sw decoder “avdec_h264”, but there may be CPU problems. I have also tried the omx plugins, but it uses deinterlacer filter as well (plus they are deprecated). Would there be other Gstreamer plugins that use HW resources that can decode H264 interlaced?

Thank you!
Daniel.

5

Just to add that I don’t care if the top and bottom fields are separated in different output frames, or together in the same output frame.

Thank you!

6

Another question… Could I get H264-interlaced decode without deinterlacing filter by modifying the open source (e.g., by modifying “gst-nvvideo4linux2” plugins), or could I not modify it (because it’s a “black box” for me)?

Thank you so much!

7

Hi,
Since hardware decoder does not support the use-case, please use software decoder. And it may take certain CPU usage.

9

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.