Hi Boris and Ezequiel, Patch c3adb85745ca6 has removed the ref_pic_list_* members from the v4l2_ctrl_h264_decode_params struct. The MT8183 stateless decoder driver I am working on still relies on these lists and I am trying (a bit late to the game) to remove them from the Chromium OS kernel UAPI in order to match upstream. I have dug into the discussion that resulted in this removal and could not really find how these are supposed to be reconstructed and on the basis on which information. The commit log for the above-mentioned patch mentions that "generic helpers will be provided for drivers that need this list". I could not find any in the kernel so far, do you have any code available at the moment? Or any idea on how these can be reconstructed? The process seems to involve reading the DPB itself as well as reordering information from the slice parameters, and seems to be a bit involved to be done in the kernel, but maybe I am missing something here. Thanks for your help! Alex.