VCU Decoder - 2023.1 English

H.264/H.265 Video Codec Unit v1.2 Solutions LogiCORE IP Product Guide (PG252)

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2023.1 English

An input compressed stream can contain multiple resolutions. The VCU Decoder can decode pictures without re-creating a channel.


  • The maximum resolution must be known.
  • All the streams should belong to same codec either AVC or HEVC.
  • Same chroma-format and bit-depth.
  • Maximum resolution can be set either with the pre-allocation mode or with the first valid SPS. In case the SPS defines a resolution higher than the one provided in pre-allocation, the decoder skips the frames until the next valid SPS.
  • While going from low to high without pre-allocation, resolutions lower than or equal to the first valid resolution that are met are decoded. Pictures and references should always fit in the DPB.


-prealloc-args max-widthxmax-height: video-mode:chroma-mode:bitdepth:profile-idc:level 


resolutionFoundCB is raised each time a new resolution is found.

  • Example command (with pre-allocated arguments)
    ctrlsw_decoder -i input.avc -avc --prealloc-args 3840x2160: progr:420:8:66:51 -o output.yuv
  • Example command (without pre-allocated arguments)
    ctrlsw_decoder -i input.avc -avc -o output.yuv

DRC Decode: To decode a DRC file which is encoded at the control software level using the Gstreamer, use:

gst-launch-1.0 filesrc location=test.avc ! h264parse ! omxh264dec low-latency=0 internal-entropy-buffers=5 ! queue max-size-bytes=0 ! filesink location=test.yuv