> From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> On Behalf Of > Mark Thompson > Sent: Sunday, March 8, 2020 00:31 > To: ffmpeg-devel@ffmpeg.org > Subject: Re: [FFmpeg-devel] [PATCH 3/4] vaapi_encode_h265: Query > encoding block sizes and features > > On 05/03/2020 05:13, Fu, Linjie wrote: > >> -----Original Message----- > >> From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> On Behalf Of > >> Mark Thompson > >> Sent: Thursday, March 5, 2020 08:25 > >> To: ffmpeg-devel@ffmpeg.org > >> Subject: [FFmpeg-devel] [PATCH 3/4] vaapi_encode_h265: Query > encoding > >> block sizes and features > >> > >> --- > >> Requires <https://github.com/intel/libva/pull/385>. That isn't upstream, > so > >> this will need to wait for that and then get at least a fix to the version > >> numbering before applying. > > > > The query looks good to me since I'm suffering from the differences of > default > > parameters allowed for VDENC and VMEPAK in media-driver while adding > support > > for low power encoding [1] for VAAPI. > > > > However got several questions: > > > > 1. Why not include PPS parameters as well? There are some differences in > > cu_qp_delta_enabled_flag and diff_cu_qp_delta_depth supported for > VAEntrypointEncSliceLP. > > Support for cu_qp_delta_enabled_flag is implied by the presence of non- > CQP RC modes (maybe I should add a comment saying that explicitly?). > > The possible range of diff_cu_qp_delta_depth is set by > min_cu_qp_delta_block_size_minus3, since the variable you actually want to > define is Log2MinCuQpDeltaSize. (So for example that would be 1 if the > smallest block supporting a qp_delta is 16x16 (Log2MinCuQpDeltaSize = 4), > and then depth could be up to 2 on 64x64 CTBs or 1 on 32x32 CTBs.)
Yes you are right, this should be not related with LP, setting the depth would make sense. Log2MinCuQpDeltaSize = CtbLog2SizeY − diff_cu_qp_delta_depth; > > 2. Would it be better to only involve the variable parameters for > > sps/pps... ? > This is > > what PR 379 [2] (unfinished) intended to do. > > I'm not sure what you mean by this question - all of these are variable > parameters in SPS/PPS. > > > 3. The suggested value of SAO enable flag could also be 1 in corresponding > code in > > media-driver, which would provide 3% BD-Rate improvement with no fps > penalty > > based on previous experiment with FFmpeg VAAPI. > > Huh, nice. That never worked in Gen 9, so I guess that's another difference > which needs the query information to express. > > > 4. There is separate media_libva_caps for gen11 and gen12, maybe need > further update > > or centralization for the code in driver. (not tested yet, will do later) > > Since the documentation has not been released this needs someone from > Intel to define what the capabilities actually are. As I wrote in the PR > against > iHD, all I have are guesses based on what I can observe working (or not). > I'll sync with media-driver and try to get capabilities for each platform. Thanks for the PRs in libva and iHD. - Linjie _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
