===== versions ===== ffmpeg version 6.1.1-3ubuntu5 Copyright (c) 2000-2023 the FFmpeg developers ffprobe version 6.1.1-3ubuntu5 Copyright (c) 2007-2023 the FFmpeg developers Python 3.12.3 ===== input titmouse.webm (container tags included) ===== codec_name=vp8 width=1920 height=1080 pix_fmt=yuv420p r_frame_rate=30/1 avg_frame_rate=30/1 format_name=matroska,webm duration=37.133000 size=4315773 TAG:COM.ANDROID.VERSION=12 TAG:MAJOR_BRAND=mp42 TAG:MINOR_VERSION=0 TAG:COMPATIBLE_BRANDS=isommp42 TAG:COM.ANDROID.CAPTURE.FPS=240.000000 TAG:LOCATION=+41.0133-081.5179/ TAG:LOCATION-eng=+41.0133-081.5179/ TAG:ENCODER=Lavf58.76.100 ===== input salad.webm (container tags included) ===== codec_name=vp9 width=1280 height=720 pix_fmt=yuv420p r_frame_rate=24000/1001 avg_frame_rate=24000/1001 format_name=matroska,webm duration=68.277000 size=14403354 TAG:COMPATIBLE_BRANDS=iso6mp41 TAG:MAJOR_BRAND=iso5 TAG:MINOR_VERSION=512 TAG:ENCODER=Lavf58.29.100 ===== CONTROL 1: excerpt at its native rate, no retime (expected: 0 identical frames) ===== Input #0, matroska,webm, from 'titmouse.webm': Metadata: COM.ANDROID.VERSION: 12 MAJOR_BRAND : mp42 MINOR_VERSION : 0 COMPATIBLE_BRANDS: isommp42 COM.ANDROID.CAPTURE.FPS: 240.000000 LOCATION : +41.0133-081.5179/ LOCATION-eng : +41.0133-081.5179/ ENCODER : Lavf58.76.100 Duration: 00:00:37.13, start: 0.000000, bitrate: 929 kb/s Stream #0:0(eng): Video: vp8, yuv420p(tv, smpte170m/bt470bg/smpte170m, progressive), 1920x1080, SAR 1:1 DAR 16:9, 30 fps, 30 tbr, 1k tbn (default) Metadata: HANDLER_NAME : VideoHandle VENDOR_ID : [0][0][0][0] ENCODER : Lavc58.134.100 libvpx DURATION : 00:00:37.133000000 Stream mapping: Stream #0:0 -> #0:0 (vp8 (native) -> ffv1 (native)) Output #0, matroska, to 'ctrl_1x.mkv': Metadata: COM.ANDROID.VERSION: 12 MAJOR_BRAND : mp42 MINOR_VERSION : 0 COMPATIBLE_BRANDS: isommp42 COM.ANDROID.CAPTURE.FPS: 240.000000 LOCATION : +41.0133-081.5179/ LOCATION-eng : +41.0133-081.5179/ encoder : Lavf60.16.100 Stream #0:0(eng): Video: ffv1 (FFV1 / 0x31564646), yuv420p(tv, bt470bg/bt470bg/smpte170m, progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 30 fps, 1k tbn (default) Metadata: HANDLER_NAME : VideoHandle VENDOR_ID : [0][0][0][0] DURATION : 00:00:37.133000000 encoder : Lavc60.31.102 ffv1 frame= 0 fps=0.0 q=-0.0 size= 0kB time=00:00:00.00 bitrate=N/A speed= 0x frame= 21 fps=0.0 q=-0.0 size= 14080kB time=00:00:00.70 bitrate=164776.2kbits/s speed=1.27x frame= 59 fps= 55 q=-0.0 size= 42752kB time=00:00:01.96 bitrate=178080.2kbits/s speed=1.85x [out#0/matroska @ 0x6420dc10ee00] video:71645kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.002849% frame= 90 fps= 61 q=-0.0 Lsize= 71647kB time=00:00:02.96 bitrate=197843.5kbits/s speed=2.01x duration=3.000000 size=73366975 ctrl_1x.mkv: frames=90 identical_to_previous=0 (0.00% of frames) distinct=90 ===== SLOW 2x: 30 fps file slowed 2x and exported at 30 fps (expected: about 50% identical frames) ===== Input #0, matroska,webm, from 'titmouse.webm': Metadata: COM.ANDROID.VERSION: 12 MAJOR_BRAND : mp42 MINOR_VERSION : 0 COMPATIBLE_BRANDS: isommp42 COM.ANDROID.CAPTURE.FPS: 240.000000 LOCATION : +41.0133-081.5179/ LOCATION-eng : +41.0133-081.5179/ ENCODER : Lavf58.76.100 Duration: 00:00:37.13, start: 0.000000, bitrate: 929 kb/s Stream #0:0(eng): Video: vp8, yuv420p(tv, smpte170m/bt470bg/smpte170m, progressive), 1920x1080, SAR 1:1 DAR 16:9, 30 fps, 30 tbr, 1k tbn (default) Metadata: HANDLER_NAME : VideoHandle VENDOR_ID : [0][0][0][0] ENCODER : Lavc58.134.100 libvpx DURATION : 00:00:37.133000000 Stream mapping: Stream #0:0 -> #0:0 (vp8 (native) -> ffv1 (native)) Output #0, matroska, to 'slow_2x_30fps.mkv': Metadata: COM.ANDROID.VERSION: 12 MAJOR_BRAND : mp42 MINOR_VERSION : 0 COMPATIBLE_BRANDS: isommp42 COM.ANDROID.CAPTURE.FPS: 240.000000 LOCATION : +41.0133-081.5179/ LOCATION-eng : +41.0133-081.5179/ encoder : Lavf60.16.100 Stream #0:0(eng): Video: ffv1 (FFV1 / 0x31564646), yuv420p(tv, bt470bg/bt470bg/smpte170m, progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 30 fps, 1k tbn (default) Metadata: HANDLER_NAME : VideoHandle VENDOR_ID : [0][0][0][0] DURATION : 00:00:37.133000000 encoder : Lavc60.31.102 ffv1 frame= 0 fps=0.0 q=-0.0 size= 0kB time=00:00:00.00 bitrate=N/A speed= 0x frame= 22 fps=0.0 q=-0.0 size= 13824kB time=00:00:00.73 bitrate=154426.7kbits/s dup=11 drop=0 speed=1.26x frame= 58 fps= 53 q=-0.0 size= 41472kB time=00:00:01.93 bitrate=175726.9kbits/s dup=29 drop=0 speed=1.78x frame= 94 fps= 58 q=-0.0 size= 70144kB time=00:00:03.13 bitrate=183389.3kbits/s dup=47 drop=0 speed=1.94x frame= 130 fps= 61 q=-0.0 size= 99584kB time=00:00:04.33 bitrate=188259.7kbits/s dup=65 drop=0 speed=2.05x frame= 168 fps= 64 q=-0.0 size= 129280kB time=00:00:05.60 bitrate=189118.2kbits/s dup=84 drop=0 speed=2.13x [out#0/matroska @ 0x5f35aa57be00] video:142559kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.002200% frame= 179 fps= 64 q=-0.0 Lsize= 142562kB time=00:00:05.93 bitrate=196831.6kbits/s dup=89 drop=0 speed=2.12x duration=5.966000 size=145983427 slow_2x_30fps.mkv: frames=179 identical_to_previous=89 (49.72% of frames) distinct=90 ===== SLOW 4x: 30 fps file slowed 4x and exported at 30 fps (expected: about 75% identical frames) ===== Input #0, matroska,webm, from 'titmouse.webm': Metadata: COM.ANDROID.VERSION: 12 MAJOR_BRAND : mp42 MINOR_VERSION : 0 COMPATIBLE_BRANDS: isommp42 COM.ANDROID.CAPTURE.FPS: 240.000000 LOCATION : +41.0133-081.5179/ LOCATION-eng : +41.0133-081.5179/ ENCODER : Lavf58.76.100 Duration: 00:00:37.13, start: 0.000000, bitrate: 929 kb/s Stream #0:0(eng): Video: vp8, yuv420p(tv, smpte170m/bt470bg/smpte170m, progressive), 1920x1080, SAR 1:1 DAR 16:9, 30 fps, 30 tbr, 1k tbn (default) Metadata: HANDLER_NAME : VideoHandle VENDOR_ID : [0][0][0][0] ENCODER : Lavc58.134.100 libvpx DURATION : 00:00:37.133000000 Stream mapping: Stream #0:0 -> #0:0 (vp8 (native) -> ffv1 (native)) Output #0, matroska, to 'slow_4x_30fps.mkv': Metadata: COM.ANDROID.VERSION: 12 MAJOR_BRAND : mp42 MINOR_VERSION : 0 COMPATIBLE_BRANDS: isommp42 COM.ANDROID.CAPTURE.FPS: 240.000000 LOCATION : +41.0133-081.5179/ LOCATION-eng : +41.0133-081.5179/ encoder : Lavf60.16.100 Stream #0:0(eng): Video: ffv1 (FFV1 / 0x31564646), yuv420p(tv, bt470bg/bt470bg/smpte170m, progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 30 fps, 1k tbn (default) Metadata: HANDLER_NAME : VideoHandle VENDOR_ID : [0][0][0][0] DURATION : 00:00:37.133000000 encoder : Lavc60.31.102 ffv1 frame= 0 fps=0.0 q=-0.0 size= 0kB time=00:00:00.00 bitrate=N/A speed= 0x frame= 28 fps=0.0 q=-0.0 size= 17408kB time=00:00:00.93 bitrate=152792.6kbits/s dup=21 drop=0 speed=1.63x frame= 68 fps= 62 q=-0.0 size= 44288kB time=00:00:02.26 bitrate=160062.0kbits/s dup=51 drop=0 speed=2.07x frame= 108 fps= 67 q=-0.0 size= 77568kB time=00:00:03.60 bitrate=176510.3kbits/s dup=81 drop=0 speed=2.23x frame= 148 fps= 70 q=-0.0 size= 110080kB time=00:00:04.93 bitrate=182792.3kbits/s dup=111 drop=0 speed=2.32x frame= 188 fps= 71 q=-0.0 size= 139008kB time=00:00:06.26 bitrate=181716.0kbits/s dup=141 drop=0 speed=2.36x frame= 228 fps= 71 q=-0.0 size= 173824kB time=00:00:07.60 bitrate=187364.0kbits/s dup=171 drop=0 speed=2.37x frame= 264 fps= 71 q=-0.0 size= 203264kB time=00:00:08.80 bitrate=189220.3kbits/s dup=198 drop=0 speed=2.36x frame= 304 fps= 72 q=-0.0 size= 237056kB time=00:00:10.13 bitrate=191641.1kbits/s dup=228 drop=0 speed=2.39x frame= 344 fps= 72 q=-0.0 size= 266752kB time=00:00:11.46 bitrate=190572.6kbits/s dup=258 drop=0 speed= 2.4x [out#0/matroska @ 0x61804a7d4e00] video:285823kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.001876% frame= 359 fps= 72 q=-0.0 Lsize= 285829kB time=00:00:11.93 bitrate=196215.8kbits/s dup=269 drop=0 speed=2.38x duration=11.966000 size=292688521 slow_4x_30fps.mkv: frames=359 identical_to_previous=269 (74.93% of frames) distinct=90 ===== CONTROL 2: salad.webm (23.976 fps) slowed 2x and exported at 23.976 fps (expected: about 50% identical frames) ===== Input #0, matroska,webm, from 'salad.webm': Metadata: COMPATIBLE_BRANDS: iso6mp41 MAJOR_BRAND : iso5 MINOR_VERSION : 512 ENCODER : Lavf58.29.100 Duration: 00:01:08.28, start: 0.000000, bitrate: 1687 kb/s Stream #0:0: Video: vp9 (Profile 0), yuv420p(tv), 1280x720, SAR 1:1 DAR 16:9, 23.98 fps, 23.98 tbr, 1k tbn (default) Metadata: HANDLER_NAME : VideoHandler ENCODER : Lavc58.54.100 libvpx-vp9 DURATION : 00:01:08.277000000 Stream mapping: Stream #0:0 -> #0:0 (vp9 (native) -> ffv1 (native)) Output #0, matroska, to 'salad_2x.mkv': Metadata: COMPATIBLE_BRANDS: iso6mp41 MAJOR_BRAND : iso5 MINOR_VERSION : 512 encoder : Lavf60.16.100 Stream #0:0: Video: ffv1 (FFV1 / 0x31564646), yuv420p(tv, progressive), 1280x720 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 23.98 fps, 1k tbn (default) Metadata: HANDLER_NAME : VideoHandler DURATION : 00:01:08.277000000 encoder : Lavc60.31.102 ffv1 frame= 0 fps=0.0 q=-0.0 size= 0kB time=00:00:00.00 bitrate=N/A speed= 0x frame= 58 fps=0.0 q=-0.0 size= 10240kB time=00:00:02.41 bitrate=34676.8kbits/s dup=29 drop=0 speed=3.76x [out#0/matroska @ 0x5cfbcfbbb840] video:28064kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.008184% frame= 144 fps=130 q=-0.0 Lsize= 28066kB time=00:00:05.96 bitrate=38549.2kbits/s dup=72 drop=0 speed=5.38x duration=6.006000 size=28739815 salad_2x.mkv: frames=144 identical_to_previous=72 (50.00% of frames) distinct=72 ===== INTERPOLATION: the same 4x slowdown with in-between frames synthesized ===== Input #0, matroska,webm, from 'titmouse.webm': Metadata: COM.ANDROID.VERSION: 12 MAJOR_BRAND : mp42 MINOR_VERSION : 0 COMPATIBLE_BRANDS: isommp42 COM.ANDROID.CAPTURE.FPS: 240.000000 LOCATION : +41.0133-081.5179/ LOCATION-eng : +41.0133-081.5179/ ENCODER : Lavf58.76.100 Duration: 00:00:37.13, start: 0.000000, bitrate: 929 kb/s Stream #0:0(eng): Video: vp8, yuv420p(tv, smpte170m/bt470bg/smpte170m, progressive), 1920x1080, SAR 1:1 DAR 16:9, 30 fps, 30 tbr, 1k tbn (default) Metadata: HANDLER_NAME : VideoHandle VENDOR_ID : [0][0][0][0] ENCODER : Lavc58.134.100 libvpx DURATION : 00:00:37.133000000 Stream mapping: Stream #0:0 -> #0:0 (vp8 (native) -> ffv1 (native)) Output #0, matroska, to 'interp_smooth.mkv': Metadata: COM.ANDROID.VERSION: 12 MAJOR_BRAND : mp42 MINOR_VERSION : 0 COMPATIBLE_BRANDS: isommp42 COM.ANDROID.CAPTURE.FPS: 240.000000 LOCATION : +41.0133-081.5179/ LOCATION-eng : +41.0133-081.5179/ encoder : Lavf60.16.100 Stream #0:0(eng): Video: ffv1 (FFV1 / 0x31564646), yuv420p(tv, bt470bg/bt470bg/smpte170m, progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 30 fps, 1k tbn (default) Metadata: HANDLER_NAME : VideoHandle VENDOR_ID : [0][0][0][0] DURATION : 00:00:37.133000000 encoder : Lavc60.31.102 ffv1 frame= 3 fps=0.0 q=-0.0 size= 1kB time=00:00:00.10 bitrate= 74.6kbits/s speed=0.263x frame= 8 fps=4.4 q=-0.0 size= 1kB time=00:00:00.26 bitrate= 28.0kbits/s speed=0.145x frame= 12 fps=3.2 q=-0.0 size= 5632kB time=00:00:00.40 bitrate=115343.4kbits/s speed=0.105x frame= 15 fps=2.9 q=-0.0 size= 8448kB time=00:00:00.50 bitrate=138412.0kbits/s speed=0.0983x frame= 20 fps=3.2 q=-0.0 size= 8448kB time=00:00:00.66 bitrate=103809.0kbits/s speed=0.106x frame= 24 fps=2.9 q=-0.0 size= 14336kB time=00:00:00.80 bitrate=146800.6kbits/s speed=0.0973x frame= 27 fps=2.8 q=-0.0 size= 17152kB time=00:00:00.90 bitrate=156121.3kbits/s speed=0.0946x frame= 32 fps=3.0 q=-0.0 size= 17152kB time=00:00:01.06 bitrate=131727.3kbits/s speed=0.0993x frame= 36 fps=2.8 q=-0.0 size= 22272kB time=00:00:01.20 bitrate=152043.5kbits/s speed=0.0944x frame= 39 fps=2.8 q=-0.0 size= 26112kB time=00:00:01.30 bitrate=164545.8kbits/s speed=0.0928x frame= 44 fps=2.9 q=-0.0 size= 26112kB time=00:00:01.46 bitrate=145847.4kbits/s speed=0.0961x frame= 48 fps=2.8 q=-0.0 size= 31232kB time=00:00:01.60 bitrate=159907.8kbits/s speed=0.0928x frame= 51 fps=2.8 q=-0.0 size= 35072kB time=00:00:01.70 bitrate=169005.8kbits/s speed=0.0918x frame= 56 fps=2.8 q=-0.0 size= 35072kB time=00:00:01.86 bitrate=153915.9kbits/s speed=0.0947x frame= 60 fps=2.8 q=-0.0 size= 40192kB time=00:00:02.00 bitrate=164626.4kbits/s speed=0.0924x frame= 63 fps=2.7 q=-0.0 size= 43776kB time=00:00:02.10 bitrate=170768.1kbits/s speed=0.0916x frame= 68 fps=2.8 q=-0.0 size= 43776kB time=00:00:02.26 bitrate=158211.6kbits/s speed=0.0938x frame= 72 fps=2.8 q=-0.0 size= 49152kB time=00:00:02.40 bitrate=167772.2kbits/s speed=0.0925x frame= 75 fps=2.8 q=-0.0 size= 52992kB time=00:00:02.50 bitrate=173644.2kbits/s speed=0.0921x frame= 80 fps=2.8 q=-0.0 size= 52992kB time=00:00:02.66 bitrate=162791.4kbits/s speed=0.094x frame= 84 fps=2.8 q=-0.0 size= 58112kB time=00:00:02.80 bitrate=170019.1kbits/s speed=0.0928x frame= 87 fps=2.8 q=-0.0 size= 61952kB time=00:00:02.90 bitrate=175003.7kbits/s speed=0.0925x frame= 92 fps=2.8 q=-0.0 size= 61952kB time=00:00:03.06 bitrate=165492.6kbits/s speed=0.094x frame= 96 fps=2.8 q=-0.0 size= 67328kB time=00:00:03.20 bitrate=172359.7kbits/s speed=0.0924x frame= 99 fps=2.8 q=-0.0 size= 71168kB time=00:00:03.30 bitrate=176669.2kbits/s speed=0.092x frame= 104 fps=2.8 q=-0.0 size= 71168kB time=00:00:03.46 bitrate=168175.4kbits/s speed=0.0933x frame= 108 fps=2.8 q=-0.0 size= 76800kB time=00:00:03.60 bitrate=174762.7kbits/s speed=0.0919x frame= 111 fps=2.7 q=-0.0 size= 80640kB time=00:00:03.70 bitrate=178541.3kbits/s speed=0.0914x frame= 116 fps=2.8 q=-0.0 size= 80640kB time=00:00:03.86 bitrate=170845.6kbits/s speed=0.0929x frame= 120 fps=2.8 q=-0.0 size= 86016kB time=00:00:04.00 bitrate=176160.8kbits/s speed=0.092x frame= 123 fps=2.7 q=-0.0 size= 89856kB time=00:00:04.10 bitrate=179536.7kbits/s speed=0.0916x frame= 128 fps=2.8 q=-0.0 size= 89856kB time=00:00:04.26 bitrate=172523.5kbits/s speed=0.0927x frame= 132 fps=2.8 q=-0.0 size= 95488kB time=00:00:04.40 bitrate=177781.3kbits/s speed=0.0917x frame= 135 fps=2.7 q=-0.0 size= 99328kB time=00:00:04.50 bitrate=180821.1kbits/s speed=0.0915x frame= 140 fps=2.8 q=-0.0 size= 99328kB time=00:00:04.66 bitrate=174363.2kbits/s speed=0.0927x frame= 144 fps=2.8 q=-0.0 size= 104960kB time=00:00:04.80 bitrate=179131.7kbits/s speed=0.092x frame= 147 fps=2.8 q=-0.0 size= 108800kB time=00:00:04.90 bitrate=181895.8kbits/s speed=0.0918x frame= 152 fps=2.8 q=-0.0 size= 108800kB time=00:00:05.06 bitrate=175912.4kbits/s speed=0.0927x frame= 156 fps=2.8 q=-0.0 size= 114432kB time=00:00:05.20 bitrate=180274.4kbits/s speed=0.0919x frame= 159 fps=2.8 q=-0.0 size= 118528kB time=00:00:05.30 bitrate=183204.0kbits/s speed=0.0918x frame= 164 fps=2.8 q=-0.0 size= 118528kB time=00:00:05.46 bitrate=177618.5kbits/s speed=0.0926x frame= 168 fps=2.8 q=-0.0 size= 124160kB time=00:00:05.60 bitrate=181628.3kbits/s speed=0.0919x frame= 171 fps=2.7 q=-0.0 size= 128000kB time=00:00:05.70 bitrate=183960.7kbits/s speed=0.0916x frame= 176 fps=2.8 q=-0.0 size= 128000kB time=00:00:05.86 bitrate=178734.5kbits/s speed=0.0924x frame= 180 fps=2.8 q=-0.0 size= 133632kB time=00:00:06.00 bitrate=182452.2kbits/s speed=0.0918x frame= 183 fps=2.8 q=-0.0 size= 137728kB time=00:00:06.10 bitrate=184961.9kbits/s speed=0.0917x frame= 188 fps=2.8 q=-0.0 size= 137728kB time=00:00:06.26 bitrate=180042.7kbits/s speed=0.0925x frame= 192 fps=2.8 q=-0.0 size= 143360kB time=00:00:06.40 bitrate=183500.8kbits/s speed=0.0919x frame= 195 fps=2.8 q=-0.0 size= 147456kB time=00:00:06.50 bitrate=185839.9kbits/s speed=0.0918x frame= 200 fps=2.8 q=-0.0 size= 147456kB time=00:00:06.66 bitrate=181193.9kbits/s speed=0.0925x frame= 204 fps=2.8 q=-0.0 size= 153088kB time=00:00:06.80 bitrate=184426.0kbits/s speed=0.0917x frame= 207 fps=2.7 q=-0.0 size= 157184kB time=00:00:06.90 bitrate=186616.1kbits/s speed=0.0915x frame= 212 fps=2.8 q=-0.0 size= 157184kB time=00:00:07.06 bitrate=182214.8kbits/s speed=0.0923x frame= 216 fps=2.8 q=-0.0 size= 162816kB time=00:00:07.20 bitrate=185248.4kbits/s speed=0.0917x frame= 219 fps=2.7 q=-0.0 size= 166912kB time=00:00:07.30 bitrate=187307.3kbits/s speed=0.0915x frame= 224 fps=2.8 q=-0.0 size= 166912kB time=00:00:07.46 bitrate=183126.3kbits/s speed=0.0921x frame= 228 fps=2.7 q=-0.0 size= 172544kB time=00:00:07.60 bitrate=185984.3kbits/s speed=0.0915x frame= 231 fps=2.7 q=-0.0 size= 176640kB time=00:00:07.70 bitrate=187926.6kbits/s speed=0.0913x frame= 236 fps=2.8 q=-0.0 size= 176640kB time=00:00:07.86 bitrate=183945.1kbits/s speed=0.092x frame= 240 fps=2.7 q=-0.0 size= 182272kB time=00:00:08.00 bitrate=186646.5kbits/s speed=0.0914x frame= 243 fps=2.7 q=-0.0 size= 186112kB time=00:00:08.10 bitrate=188225.9kbits/s speed=0.0913x frame= 248 fps=2.8 q=-0.0 size= 186112kB time=00:00:08.26 bitrate=184431.0kbits/s speed=0.0919x frame= 252 fps=2.7 q=-0.0 size= 192000kB time=00:00:08.40 bitrate=187245.7kbits/s speed=0.0914x frame= 255 fps=2.7 q=-0.0 size= 195840kB time=00:00:08.50 bitrate=188743.7kbits/s speed=0.0912x frame= 260 fps=2.8 q=-0.0 size= 195840kB time=00:00:08.66 bitrate=185114.0kbits/s speed=0.0918x frame= 264 fps=2.7 q=-0.0 size= 201728kB time=00:00:08.80 bitrate=187790.4kbits/s speed=0.0913x frame= 267 fps=2.7 q=-0.0 size= 205824kB time=00:00:08.90 bitrate=189450.6kbits/s speed=0.0911x frame= 272 fps=2.7 q=-0.0 size= 205824kB time=00:00:09.06 bitrate=185968.0kbits/s speed=0.0916x frame= 276 fps=2.7 q=-0.0 size= 211456kB time=00:00:09.20 bitrate=188287.8kbits/s speed=0.0912x frame= 279 fps=2.7 q=-0.0 size= 215552kB time=00:00:09.30 bitrate=189871.2kbits/s speed=0.091x frame= 284 fps=2.7 q=-0.0 size= 215552kB time=00:00:09.46 bitrate=186528.4kbits/s speed=0.0916x frame= 288 fps=2.7 q=-0.0 size= 221184kB time=00:00:09.60 bitrate=188743.7kbits/s speed=0.0913x frame= 291 fps=2.7 q=-0.0 size= 225280kB time=00:00:09.70 bitrate=190257.1kbits/s speed=0.0911x frame= 296 fps=2.7 q=-0.0 size= 225280kB time=00:00:09.86 bitrate=187043.3kbits/s speed=0.0917x frame= 300 fps=2.7 q=-0.0 size= 230912kB time=00:00:10.00 bitrate=189163.1kbits/s speed=0.0913x frame= 303 fps=2.7 q=-0.0 size= 235008kB time=00:00:10.10 bitrate=190612.4kbits/s speed=0.0912x frame= 308 fps=2.7 q=-0.0 size= 235008kB time=00:00:10.26 bitrate=187518.1kbits/s speed=0.0916x frame= 312 fps=2.7 q=-0.0 size= 240896kB time=00:00:10.40 bitrate=189751.9kbits/s speed=0.0913x frame= 315 fps=2.7 q=-0.0 size= 244992kB time=00:00:10.50 bitrate=191140.4kbits/s speed=0.0912x frame= 320 fps=2.8 q=-0.0 size= 244992kB time=00:00:10.66 bitrate=188153.9kbits/s speed=0.0917x frame= 324 fps=2.7 q=-0.0 size= 250880kB time=00:00:10.80 bitrate=190297.1kbits/s speed=0.0914x frame= 327 fps=2.7 q=-0.0 size= 254976kB time=00:00:10.90 bitrate=191629.7kbits/s speed=0.0913x frame= 332 fps=2.8 q=-0.0 size= 254976kB time=00:00:11.06 bitrate=188743.7kbits/s speed=0.0917x frame= 336 fps=2.7 q=-0.0 size= 260608kB time=00:00:11.20 bitrate=190616.1kbits/s speed=0.0914x frame= 339 fps=2.7 q=-0.0 size= 264704kB time=00:00:11.30 bitrate=191898.7kbits/s speed=0.0912x frame= 344 fps=2.8 q=-0.0 size= 264704kB time=00:00:11.46 bitrate=189109.5kbits/s speed=0.0917x frame= 348 fps=2.7 q=-0.0 size= 270592kB time=00:00:11.60 bitrate=191093.9kbits/s speed=0.0913x frame= 351 fps=2.7 q=-0.0 size= 274688kB time=00:00:11.70 bitrate=192328.6kbits/s speed=0.0913x frame= 352 fps=2.7 q=-0.0 size= 274688kB time=00:00:11.70 bitrate=192328.6kbits/s speed=0.0904x [out#0/matroska @ 0x62a95e41ce00] video:278069kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.001903% frame= 352 fps=2.7 q=-0.0 Lsize= 278074kB time=00:00:11.70 bitrate=194699.6kbits/s speed=0.0904x interpolation encode wall time = 129.60 s for the 3 s excerpt duration=11.733000 size=284748133 interp_smooth.mkv: frames=352 identical_to_previous=0 (0.00% of frames) distinct=352 -rw-rw-r-- 1 ubuntu ubuntu 284748133 Oct 27 04:19 interp_smooth.mkv -rw-rw-r-- 1 ubuntu ubuntu 292688521 Oct 27 04:17 slow_4x_30fps.mkv ===== FRAME MATH: captured frames per second of output, for each capture rate and slowdown ===== capture rate slowdown captured frames per output second if exported at 30 fps 30 fps phone video (measured on titmouse.webm) 1x 30.000 0.00% 30 fps phone video (measured on titmouse.webm) 1.5x 20.000 33.33% 30 fps phone video (measured on titmouse.webm) 2x 15.000 50.00% 30 fps phone video (measured on titmouse.webm) 4x 7.500 75.00% 30 fps phone video (measured on titmouse.webm) 8x 3.750 87.50% 23.976 fps camera file (measured on salad.webm) 1x 23.976 20.08% 23.976 fps camera file (measured on salad.webm) 1.5x 15.984 46.72% 23.976 fps camera file (measured on salad.webm) 2x 11.988 60.04% 23.976 fps camera file (measured on salad.webm) 4x 5.994 80.02% 23.976 fps camera file (measured on salad.webm) 8x 2.997 90.01% 120 fps (Apple Slo-mo front camera, published) 1x 120.000 0.00% 120 fps (Apple Slo-mo front camera, published) 1.5x 80.000 0.00% 120 fps (Apple Slo-mo front camera, published) 2x 60.000 0.00% 120 fps (Apple Slo-mo front camera, published) 4x 30.000 0.00% 120 fps (Apple Slo-mo front camera, published) 8x 15.000 50.00% 240 fps (Apple Slo-mo back camera, published) 1x 240.000 0.00% 240 fps (Apple Slo-mo back camera, published) 1.5x 160.000 0.00% 240 fps (Apple Slo-mo back camera, published) 2x 120.000 0.00% 240 fps (Apple Slo-mo back camera, published) 4x 60.000 0.00% 240 fps (Apple Slo-mo back camera, published) 8x 30.000 0.00% ===== done ===== === editor review addition, October 27, 2026: export rate alone versus a retime (ffmpeg 6.1.1) input: synthetic ffmpeg testsrc2, 640x360, 240 fps, 2 s (no third-party footage) file r_frame_rate,frames duration src240 240/1,480 2.000000 s only-r30 30/1,62 2.066000 s (export rate changed, timing left alone: same length, 418 of 480 frames dropped) retimed8 30/1,480 16.000000 s (setpts=8*PTS, then 30 fps: 8x longer, all 480 frames kept) retimed8 frames identical to the one before: 0