I know that it is possible to apply slow motion to a section of video using a combination of splitting the video into the relevant sections, using setpts to adjust the rate and then concat'ing them back together. E.g: ffmpeg -i input.mp4 -filter_complex "[0:v]trim=0:2,setpts=expr=PTS-STARTPTS[v0];[0:v]trim=2:3,setpts=expr=PTS-STARTPTS[v1];[0:v]trim=3:5,setpts=expr=PTS-STARTPTS[v2];[v1]setpts=PTS/0.5[v1_slowmo];[v0][v1_slowmo][v2]concat=n=3:v=1:a=0[out]" -map [out] output.mp4 I wondered if it is also possible to do this with an equation in setpts (and might be easier to read)? E.g: ffmpeg -i input.mp4 -filter_complex "[0:v]setpts=if(between(T\, 2\, 3)\, 0.5\, 1)*PTS[out]" -map [out] output.mp4 This command doesn't adjust the times correctly though, I guess because each segment of time doesn't account for the previous shifts. Therefore t=0--2 and t=2-3 (with slowmo) actually end up overlapping in PTS. Is the equation I am going to have to write going to end up more complicated that my first example? / Just impossible. Full output: $ ffmpeg -y -i input.mp4 -filter_complex "[0:v]setpts=if(between(T\, 2\, 3)\, 0.5\, 1)*PTS[out]" -map [out] output.mp4 ffmpeg version 3.3 Copyright (c) 2000-2017 the FFmpeg developers built with gcc 4.9.2 (Debian 4.9.2-10) configuration: --prefix=/usr/local --extra-cflags=-I/usr/local/include --extra-ldflags=-L/usr/local/lib --bindir=/usr/local/bin --disable-doc --disable-static --enable-shared --disable-ffplay --extra-libs=-ldl --enable-version3 --enable-libfreetype --enable-libx264 --enable-gpl --enable-openssl --enable-nonfree --disable-debug libavutil 55. 58.100 / 55. 58.100 libavcodec 57. 89.100 / 57. 89.100 libavformat 57. 71.100 / 57. 71.100 libavdevice 57. 6.100 / 57. 6.100 libavfilter 6. 82.100 / 6. 82.100 libswscale 4. 6.100 / 4. 6.100 libswresample 2. 7.100 / 2. 7.100 libpostproc 54. 5.100 / 54. 5.100 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4': Metadata: major_brand : isom minor_version : 512 compatible_brands: isomiso2avc1mp41 encoder : Lavf57.19.100 Duration: 00:00:11.05, start: 0.000000, bitrate: 5584 kb/s Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 5473 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default) Metadata: handler_name : VideoHandler Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 128 kb/s (default) Metadata: handler_name : SoundHandler Stream mapping: Stream #0:0 (h264) -> setpts setpts -> Stream #0:0 (libx264) Press [q] to stop, [?] for help [libx264 @ 0xd89820] using SAR=1/1 [libx264 @ 0xd89820] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 AVX2 LZCNT BMI2 [libx264 @ 0xd89820] profile High, level 3.1 [libx264 @ 0xd89820] 264 - core 148 - H.264/MPEG-4 AVC codec - Copyleft 2003-2016 - 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=12 lookahead_threads=2 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=25 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, mp4, to 'output.mp4': Metadata: major_brand : isom minor_version : 512 compatible_brands: isomiso2avc1mp41 encoder : Lavf57.71.100 Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], q=-1--1, 25 fps, 12800 tbn, 25 tbc (default) Metadata: encoder : Lavc57.89.100 libx264 Side data: cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1 frame= 78 fps=0.0 q=28.0 size= 403kB time=00:00:00.76 bitrate=4346.3kbits/s dup=25 drop=25 speed= 1frame= 122 fps=112 q=28.0 size= 1085kB time=00:00:02.52 bitrate=3525.7kbits/s dup=25 drop=25 speed=2.frame= 158 fps= 99 q=28.0 size= 1568kB time=00:00:03.96 bitrate=3243.6kbits/s dup=25 drop=25 speed=2.frame= 191 fps= 91 q=28.0 size= 2210kB time=00:00:05.28 bitrate=3428.1kbits/s dup=25 drop=25 speed=2.frame= 224 fps= 86 q=28.0 size= 2859kB time=00:00:06.60 bitrate=3549.2kbits/s dup=25 drop=25 speed=2.frame= 254 fps= 81 q=28.0 size= 3402kB time=00:00:07.80 bitrate=3572.8kbits/s dup=25 drop=25 speed= 2frame= 275 fps= 68 q=-1.0 Lsize= 4877kB time=00:00:10.88 bitrate=3672.0kbits/s dup=25 drop=25 speed=2.68x video:4875kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.046016% [libx264 @ 0xd89820] frame I:4 Avg QP:18.22 size: 89324 [libx264 @ 0xd89820] frame P:250 Avg QP:23.73 size: 18427 [libx264 @ 0xd89820] frame B:21 Avg QP:27.84 size: 1288 [libx264 @ 0xd89820] consecutive B-frames: 89.1% 2.2% 0.0% 8.7% [libx264 @ 0xd89820] mb I I16..4: 45.8% 20.2% 34.1% [libx264 @ 0xd89820] mb P I16..4: 6.4% 1.2% 1.2% P16..4: 53.7% 8.4% 4.7% 0.0% 0.0% skip:24.4% [libx264 @ 0xd89820] mb B I16..4: 0.5% 0.1% 0.0% B16..8: 5.0% 0.7% 0.1% direct: 0.3% skip:93.2% L0:53.8% L1:32.6% BI:13.5% [libx264 @ 0xd89820] 8x8 transform intra:14.6% inter:37.3% [libx264 @ 0xd89820] coded y,uvDC,uvAC intra: 53.2% 65.0% 12.8% inter: 27.7% 19.0% 0.1% [libx264 @ 0xd89820] i16 v,h,dc,p: 10% 46% 34% 9% [libx264 @ 0xd89820] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 8% 55% 24% 2% 1% 1% 3% 1% 6% [libx264 @ 0xd89820] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 13% 51% 22% 2% 2% 1% 3% 1% 5% [libx264 @ 0xd89820] i8c dc,h,v,p: 43% 40% 9% 8% [libx264 @ 0xd89820] Weighted P-Frames: Y:0.4% UV:0.4% [libx264 @ 0xd89820] ref P L0: 83.6% 14.8% 1.3% 0.2% 0.0% [libx264 @ 0xd89820] ref B L0: 84.2% 15.6% 0.2% [libx264 @ 0xd89820] ref B L1: 99.9% 0.1% [libx264 @ 0xd89820] kb/s:3629.85