[FFmpeg-user] -preset veryfast produces smallest file, weird

Ulf Zibis Ulf.Zibis at CoSoCo.de
Sun Oct 15 16:12:45 EEST 2023


Hi,

by accident I transcoded a video with -preset veryfast (it took 1 h).
So I had to run it again with -preset veryslow (it took 12 h).
Now I'm wondering about the file sizes. How can that be?

$ ls -l König_it*
-rwxrwxrwx 1 ich ich 1058092584 Okt 13 02:16 König_it_veryfast.mkv
-rwxrwxrwx 1 ich ich 1102865774 Okt 13 14:24 König_it_veryslow.mkv
-rwxrwxrwx 1 ich ich 1238931498 Okt 13 20:21 König_it_medium.mkv

Only for "veryslow" profile High, level 5 was automatically used by libx264, otherwise level 3.1

Visually I can't recognize a quality difference between the 3 videos.

The source video is a screen grab, taken with "-crf 13 -preset ultrafast", so it is 10 times bigger.

=======================================================

Ulf Zischt, [14.10.23 01:01]
$ ffmpeg -ss 4.04 -t 2:06:33.12 -i roh_13-uf_it.mkv -ss 2:06:38.36 -t 91.28 -i roh_13-uf_de+Abspann.mkv -filter_complex "[0:v:0][0:a:0][1:v:0][1:a:0]concat=n=2:v=1:a=1[outv][outa]" -map "[outv]" -map "[outa]" -preset veryfast König_it.mkv
ffmpeg version 5.1.1-1ubuntu2.1 Copyright (c) 2000-2022 the FFmpeg developers
   built with gcc 12 (Ubuntu 12.2.0-3ubuntu1)
   configuration: --prefix=/usr --extra-version=1ubuntu2.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libglslang --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librabbitmq --enable-librist --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid 
--enable-libzimg --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --disable-sndio --enable-pocketsphinx --enable-librsvg --enable-libmfx --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-libplacebo --enable-shared
   libavutil      57. 28.100 / 57. 28.100
   libavcodec     59. 37.100 / 59. 37.100
   libavformat    59. 27.100 / 59. 27.100
   libavdevice    59.  7.100 / 59.  7.100
   libavfilter     8. 44.100 /  8. 44.100
   libswscale      6.  7.100 /  6.  7.100
   libswresample   4.  7.100 /  4.  7.100
   libpostproc    56.  6.100 / 56.  6.100
Guessed Channel Layout for Input Stream #0.1 : stereo
Input #0, matroska,webm, from 'roh_13-uf_it.mkv':
   Metadata:
     ENCODER         : Lavf59.27.100
   Duration: 02:14:57.86, start: 0.000000, bitrate: 13735 kb/s
   Stream #0:0: Video: h264 (Constrained Baseline), yuv420p(tv, bt709, progressive), 1280x688 [SAR 1:1 DAR 80:43], 24.42 fps, 24 tbr, 1k tbn
     Metadata:
       DURATION        : 02:14:57,792000000
   Stream #0:1: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
     Metadata:
       DURATION        : 02:14:57,856000000
Guessed Channel Layout for Input Stream #1.1 : stereo
Input #1, matroska,webm, from 'roh_13-uf_de+Abspann.mkv':
   Metadata:
     ENCODER         : Lavf59.27.100
   Duration: 02:14:57.49, start: 0.000000, bitrate: 13437 kb/s
   Stream #1:0: Video: h264 (Constrained Baseline), yuv420p(tv, bt709, progressive), 1280x688 [SAR 1:1 DAR 80:43], 24.42 fps, 24 tbr, 1k tbn
     Metadata:
       DURATION        : 02:14:57,417000000
   Stream #1:1: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
     Metadata:
       DURATION        : 02:14:57,493000000
Stream mapping:
   Stream #0:0 (h264) -> concat
   Stream #0:1 (pcm_s16le) -> concat
   Stream #1:0 (h264) -> concat
   Stream #1:1 (pcm_s16le) -> concat
   concat -> Stream #0:0 (libx264)
   concat -> Stream #0:1 (libvorbis)
Press [q] to stop, [?] for help
[libx264 @ 0x56346dd4f240] using SAR=1/1
[libx264 @ 0x56346dd4f240] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.1 Cache64
[libx264 @ 0x56346dd4f240] profile High, level 3.1, 4:2:0, 8-bit
[libx264 @ 0x56346dd4f240] 264 - core 164 r3095 baee400 - H.264/MPEG-4 AVC codec - Copyleft 2003-2022 - http://www.videolan.org/x264.html - options: cabac=1 ref=1 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=2 psy=1 psy_rd=1.00:0.00 mixed_ref=0 me_range=16 chroma_me=1 trellis=0 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=0 threads=3 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=1 keyint=250 keyint_min=24 scenecut=40 intra_refresh=0 rc_lookahead=10 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, matroska, to 'König_it.mkv':
   Metadata:
     encoder         : Lavf59.27.100
   Stream #0:0: Video: h264 (H264 / 0x34363248), yuv420p(tv, bt709, progressive), 1280x688 [SAR 1:1 DAR 80:43], q=2-31, 24 fps, 1k tbn
     Metadata:
       encoder         : Lavc59.37.100 libx264
     Side data:
       cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
   Stream #0:1: Audio: vorbis (oV[0][0] / 0x566F), 48000 Hz, stereo, fltp
     Metadata:
       encoder         : Lavc59.37.100 libvorbis
frame=184426 fps= 28 q=-1.0 Lsize= 1033294kB time=02:08:04.38 bitrate=1101.6kbits/s speed=1.18x
video:947784kB audio:81226kB subtitle:0kB other streams:0kB global headers:4kB muxing overhead: 0.416226%
[libx264 @ 0x56346dd4f240] frame I:1824  Avg QP:16.97  size: 51298
[libx264 @ 0x56346dd4f240] frame P:58906 Avg QP:22.31  size: 10003
[libx264 @ 0x56346dd4f240] frame B:123696 Avg QP:24.33  size: 2326
[libx264 @ 0x56346dd4f240] consecutive B-frames:  9.1%  3.0%  4.6% 83.3%
[libx264 @ 0x56346dd4f240] mb I  I16..4: 37.7% 30.4% 32.0%
[libx264 @ 0x56346dd4f240] mb P  I16..4:  6.2%  8.0%  1.2% P16..4: 19.6%  7.1%  3.4%  0.0%  0.0%    skip:54.7%
[libx264 @ 0x56346dd4f240] mb B  I16..4:  1.2%  1.3%  0.1% B16..8:  8.2%  2.1%  0.2%  direct: 3.4%  skip:83.5%  L0:45.5% L1:41.1% BI:13.3%
[libx264 @ 0x56346dd4f240] 8x8 transform intra:49.2% inter:44.6%
[libx264 @ 0x56346dd4f240] coded y,uvDC,uvAC intra: 46.0% 51.1% 16.2% inter: 4.4% 6.5% 0.3%
[libx264 @ 0x56346dd4f240] i16 v,h,dc,p: 48% 27% 16%  9%
[libx264 @ 0x56346dd4f240] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 24% 28% 20%  4%  5%  5%  5%  4%  5%
[libx264 @ 0x56346dd4f240] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 24% 26% 13%  5%  6%  7%  7%  6%  6%
[libx264 @ 0x56346dd4f240] i8c dc,h,v,p: 53% 22% 19%  6%
[libx264 @ 0x56346dd4f240] Weighted P-Frames: Y:3.0% UV:0.9%
[libx264 @ 0x56346dd4f240] kb/s:1010.39


Ulf Zischt, [14.10.23 01:02]
$ ffmpeg -ss 4.04 -t 2:06:33.12 -i roh_13-uf_it.mkv -ss 2:06:38.36 -t 91.28 -i roh_13-uf_de+Abspann.mkv -filter_complex "[0:v:0][0:a:0][1:v:0][1:a:0]concat=n=2:v=1:a=1[outv][outa]" -map "[outv]" -map "[outa]" -preset medium König_it_medium.mkv
ffmpeg version 5.1.1-1ubuntu2.1 Copyright (c) 2000-2022 the FFmpeg developers
   built with gcc 12 (Ubuntu 12.2.0-3ubuntu1)
   configuration: --prefix=/usr --extra-version=1ubuntu2.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libglslang --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librabbitmq --enable-librist --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid 
--enable-libzimg --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --disable-sndio --enable-pocketsphinx --enable-librsvg --enable-libmfx --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-libplacebo --enable-shared
   libavutil      57. 28.100 / 57. 28.100
   libavcodec     59. 37.100 / 59. 37.100
   libavformat    59. 27.100 / 59. 27.100
   libavdevice    59.  7.100 / 59.  7.100
   libavfilter     8. 44.100 /  8. 44.100
   libswscale      6.  7.100 /  6.  7.100
   libswresample   4.  7.100 /  4.  7.100
   libpostproc    56.  6.100 / 56.  6.100
Guessed Channel Layout for Input Stream #0.1 : stereo
Input #0, matroska,webm, from 'roh_13-uf_it.mkv':
   Metadata:
     ENCODER         : Lavf59.27.100
   Duration: 02:14:57.86, start: 0.000000, bitrate: 13735 kb/s
   Stream #0:0: Video: h264 (Constrained Baseline), yuv420p(tv, bt709, progressive), 1280x688 [SAR 1:1 DAR 80:43], 24.42 fps, 24 tbr, 1k tbn
     Metadata:
       DURATION        : 02:14:57,792000000
   Stream #0:1: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
     Metadata:
       DURATION        : 02:14:57,856000000
Guessed Channel Layout for Input Stream #1.1 : stereo
Input #1, matroska,webm, from 'roh_13-uf_de+Abspann.mkv':
   Metadata:
     ENCODER         : Lavf59.27.100
   Duration: 02:14:57.49, start: 0.000000, bitrate: 13437 kb/s
   Stream #1:0: Video: h264 (Constrained Baseline), yuv420p(tv, bt709, progressive), 1280x688 [SAR 1:1 DAR 80:43], 24.42 fps, 24 tbr, 1k tbn
     Metadata:
       DURATION        : 02:14:57,417000000
   Stream #1:1: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
     Metadata:
       DURATION        : 02:14:57,493000000
File 'König_it_medium.mkv' already exists. Overwrite? [y/N] y
Stream mapping:
   Stream #0:0 (h264) -> concat
   Stream #0:1 (pcm_s16le) -> concat
   Stream #1:0 (h264) -> concat
   Stream #1:1 (pcm_s16le) -> concat
   concat -> Stream #0:0 (libx264)
   concat -> Stream #0:1 (libvorbis)
Press [q] to stop, [?] for help
[libx264 @ 0x556457227240] using SAR=1/1
[libx264 @ 0x556457227240] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.1 Cache64
[libx264 @ 0x556457227240] profile High, level 3.1, 4:2:0, 8-bit
[libx264 @ 0x556457227240] 264 - core 164 r3095 baee400 - H.264/MPEG-4 AVC codec - Copyleft 2003-2022 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=3 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=24 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, matroska, to 'König_it_medium.mkv':
   Metadata:
     encoder         : Lavf59.27.100
   Stream #0:0: Video: h264 (H264 / 0x34363248), yuv420p(tv, bt709, progressive), 1280x688 [SAR 1:1 DAR 80:43], q=2-31, 24 fps, 1k tbn
     Metadata:
       encoder         : Lavc59.37.100 libx264
     Side data:
       cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
   Stream #0:1: Audio: vorbis (oV[0][0] / 0x566F), 48000 Hz, stereo, fltp
     Metadata:
       encoder         : Lavc59.37.100 libvorbis
frame=184426 fps= 15 q=-1.0 Lsize= 1209894kB time=02:08:04.38 bitrate=1289.8kbits/s speed=0.646x
video:1124370kB audio:81226kB subtitle:0kB other streams:0kB global headers:4kB muxing overhead: 0.356514%
[libx264 @ 0x556457227240] frame I:1824  Avg QP:18.39  size: 58244
[libx264 @ 0x556457227240] frame P:58915 Avg QP:21.45  size: 11731
[libx264 @ 0x556457227240] frame B:123687 Avg QP:24.96  size: 2862
[libx264 @ 0x556457227240] consecutive B-frames:  9.1%  3.0%  4.6% 83.3%
[libx264 @ 0x556457227240] mb I  I16..4: 26.9% 55.8% 17.3%
[libx264 @ 0x556457227240] mb P  I16..4:  3.1%  6.4%  0.6% P16..4: 27.6%  8.0%  4.6%  0.0%  0.0%    skip:49.7%
[libx264 @ 0x556457227240] mb B  I16..4:  0.6%  0.8%  0.0% B16..8: 23.9%  1.8%  0.3%  direct: 1.6%  skip:71.1%  L0:49.7% L1:46.3% BI: 4.0%
[libx264 @ 0x556457227240] 8x8 transform intra:60.7% inter:80.2%
[libx264 @ 0x556457227240] coded y,uvDC,uvAC intra: 45.0% 57.3% 22.7% inter: 8.2% 10.3% 0.6%
[libx264 @ 0x556457227240] i16 v,h,dc,p: 33% 32% 13% 22%
[libx264 @ 0x556457227240] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 25% 22% 27%  3%  4%  5%  5%  4%  5%
[libx264 @ 0x556457227240] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 28% 26% 15%  4%  6%  6%  6%  5%  4%
[libx264 @ 0x556457227240] i8c dc,h,v,p: 54% 22% 18%  6%
[libx264 @ 0x556457227240] Weighted P-Frames: Y:3.3% UV:1.2%
[libx264 @ 0x556457227240] ref P L0: 61.6% 14.1% 15.4%  8.6%  0.3%
[libx264 @ 0x556457227240] ref B L0: 86.5%  9.8%  3.7%
[libx264 @ 0x556457227240] ref B L1: 94.8%  5.2%
[libx264 @ 0x556457227240] kb/s:1198.64

-Ulf



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