> So "crf 0" already has a meaning different from all other crf values?
No. "crf 0" has the same meanings. It just makes the quality better than "crf 1". I read libaom again, and I apologize for my wrong explanation: I found that if certain conditions are met, "crf 0" also generates lossless videos. If these conditions are not met, "-crf 0" will be lossless: <<FFmpeg options>> "-bit_rate 0" (which means, enccfg.rc_end_usage = AOM_Q) "-aq-mode none" "-enable_restoration 0" <<the libaom settings which can't be configured from FFmpeg yet>> AV1E_SET_ENABLE_CHROMA_DELTAQ must be 0 AV1E_SET_ENABLE_SUPERRES must be 0 Thus, at least, "-lossless" does have a different meaning from "-crf 0", so I think it would be useful to add "-lossless" flags. 2020年4月4日(土) 19:29 Carl Eugen Hoyos <ceffm...@gmail.com>: > Am Sa., 4. Apr. 2020 um 12:16 Uhr schrieb Ryo Hirafuji > <ryo.hiraf...@link-u.co.jp>: > > > > > Is it possible to use "cfr 0" instead? > > > > Unfortunately, crf=0 is not lossless. > > "lossless" flag uses "quantisation matrices", which is different from the > > default quantizer determined by "-crf", to achieve lossless encoding. > > So "crf 0" already has a meaning different from all other crf values? > > Thank you, Carl Eugen > _______________________________________________ > 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". _______________________________________________ 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".
