# Table of Contents - [Table of Contents](#table-of-contents) - [About ffmpeg](#about-ffmpeg) - [Get Video Info with `mediainfo`](#get-video-info-with-mediainfo) - [Get Test Image with ffmpeg](#get-test-image-with-ffmpeg) - [Batch-ify ffmpeg Command](#batch-ify-ffmpeg-command) - [Transcode Profiles](#transcode-profiles) - [Original [40.3 Mb/s]](#original-403-mbs) - [Mediainfo](#mediainfo) - [Test Image](#test-image) - [CRF 21 [19.9 Mb/s]](#crf-21-199-mbs) - [Mediainfo](#mediainfo-1) - [Test Image](#test-image-1) - [CRF 27 [10.3 Mb/s]](#crf-27-103-mbs) - [Mediainfo](#mediainfo-2) - [Test Image](#test-image-2) - [1080p CRF 21 [11.9 Mb/s]](#1080p-crf-21-119-mbs) - [Mediainfo](#mediainfo-3) - [Test Image](#test-image-3) - [1080p CRF 27 [6,232 kb/s]](#1080p-crf-27-6232-kbs) - [Mediainfo](#mediainfo-4) - [Test Image](#test-image-4) - [720p CRF 21 [6,314 kb/s]](#720p-crf-21-6314-kbs) - [Mediainfo](#mediainfo-5) - [Test Image](#test-image-5) - [720p CRF 27 [3,305 kb/s]](#720p-crf-27-3305-kbs) - [Mediainfo](#mediainfo-6) - [Test Image](#test-image-6) - [Test a New Profile](#test-a-new-profile) # About ffmpeg FFmpeg is a free and open-source software project consisting of a suite of libraries and programs for handling video, audio, and other multimedia files and streams. At its core is the command-line ffmpeg tool itself, designed for processing of video and audio files. [Wikipedia](https://en.wikipedia.org/wiki/FFmpeg). [ffmpeg.org](https://ffmpeg.org/). # Get Video Info with `mediainfo` MediaInfo is a free, cross-platform and open-source program that displays technical information about media files, as well as tag information for many audio and video files. [Wikipedia](https://en.wikipedia.org/wiki/MediaInfo). To install on Debian, run `sudo apt install mediainfo`. To get comprehensive media information about a file, simply use `mediainfo `. # Get Test Image with ffmpeg To get the test image, we extract frame of timestamp 15:20.01 from the test video with `ffmpeg -ss 00:15:20.01 -i "$input" -frames:v 1 "$output"`. # Batch-ify ffmpeg Command For a given `ffmpeg -i $video `, apply the command to all `.mp4` videos in a directory and send all outputs to `./Transcodes/` with the following structure: ```bash for video in ./*.mp4 do ffmpeg -i "$video" "Transcodes/${video%.*}.mp4" done ``` # Transcode Profiles ## Original [40.3 Mb/s] The pre-transcode data for the sample video. It was recorded using OBS with the following encoder settings at 1440p60: | Parameter | Value | |:---------:|:-----:| | Rate Control | CBR | | Bitrate | 40000 Kbps | | Keyframe interval | 0s (auto) | | Preset | Quality | | Profile | high | | Look-ahead | Yes | | Psycho Visual Tuning | Yes | | GPU | Nvidia RTX 3060 Ti | | Max B-Frames | 2 | ### Mediainfo ``` General Complete name : ffmpeg test file.mp4 Format : MPEG-4 Format profile : Base Media Codec ID : isom (isom/iso2/avc1/mp41) File size : 4.57 GiB Duration : 16 min 12 s Overall bit rate mode : Constant Overall bit rate : 40.3 Mb/s Writing application : Lavf59.16.100 Video ID : 1 Format : AVC Format/Info : Advanced Video Codec Format profile : High@L5.1 Format settings : CABAC / 4 Ref Frames Format settings, CABAC : Yes Format settings, Reference frames : 4 frames Codec ID : avc1 Codec ID/Info : Advanced Video Coding Duration : 16 min 12 s Source duration : 16 min 12 s Bit rate mode : Constant Bit rate : 40.0 Mb/s Width : 2 560 pixels Height : 1 440 pixels Display aspect ratio : 16:9 Frame rate mode : Variable Frame rate : 60.000 FPS Minimum frame rate : 58.824 FPS Maximum frame rate : 62.500 FPS Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.181 Stream size : 4.53 GiB (99%) Source stream size : 4.53 GiB (99%) Color range : Limited Color primaries : BT.709 Transfer characteristics : BT.709 Matrix coefficients : BT.709 mdhd_Duration : 972666 Codec configuration box : avcC Audio ID : 2 Format : AAC LC Format/Info : Advanced Audio Codec Low Complexity Codec ID : mp4a-40-2 Duration : 16 min 12 s Bit rate mode : Constant Bit rate : 318 kb/s Channel(s) : 2 channels Channel layout : L R Sampling rate : 48.0 kHz Frame rate : 46.875 FPS (1024 SPF) Compression mode : Lossy Stream size : 36.9 MiB (1%) Title : Track1 Default : Yes Alternate group : 1 ``` ### Test Image ![Test Image - Original](img/ffmpeg/original.png) ## CRF 21 [19.9 Mb/s] `ffmpeg -i "$input" -movflags +faststart -c:v libx264 -preset slower -crf 21 "$output"` ### Mediainfo ``` General Complete name : CRF 21.mp4 Format : MPEG-4 Format profile : Base Media Codec ID : isom (isom/iso2/avc1/mp41) File size : 2.25 GiB Duration : 16 min 12 s Overall bit rate : 19.9 Mb/s Writing application : Lavf58.45.100 Video ID : 1 Format : AVC Format/Info : Advanced Video Codec Format profile : High@L5.1 Format settings : CABAC / 8 Ref Frames Format settings, CABAC : Yes Format settings, Reference frames : 8 frames Codec ID : avc1 Codec ID/Info : Advanced Video Coding Duration : 16 min 12 s Bit rate : 19.8 Mb/s Width : 2 560 pixels Height : 1 440 pixels Display aspect ratio : 16:9 Frame rate mode : Constant Frame rate : 60.000 FPS Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.089 Stream size : 2.24 GiB (99%) Writing library : x264 core 160 r3011 cde9a93 Encoding settings : cabac=1 / ref=8 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=9 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=24 / 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=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=crf / mbtree=1 / crf=21.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00 Codec configuration box : avcC Audio ID : 2 Format : AAC LC Format/Info : Advanced Audio Codec Low Complexity Codec ID : mp4a-40-2 Duration : 16 min 12 s Bit rate mode : Constant Bit rate : 129 kb/s Channel(s) : 2 channels Channel layout : L R Sampling rate : 48.0 kHz Frame rate : 46.875 FPS (1024 SPF) Compression mode : Lossy Stream size : 14.9 MiB (1%) Default : Yes Alternate group : 1 ``` ### Test Image ![Test Image - CRF 21](img/ffmpeg/CRF%2021.png) ## CRF 27 [10.3 Mb/s] `ffmpeg -i "$input" -movflags +faststart -c:v libx264 -preset slower -crf 27 "$output"` ### Mediainfo ``` General Complete name : CRF 27.mp4 Format : MPEG-4 Format profile : Base Media Codec ID : isom (isom/iso2/avc1/mp41) File size : 1.17 GiB Duration : 16 min 12 s Overall bit rate : 10.3 Mb/s Writing application : Lavf59.9.102 Video ID : 1 Format : AVC Format/Info : Advanced Video Codec Format profile : High@L5.1 Format settings : CABAC / 8 Ref Frames Format settings, CABAC : Yes Format settings, Reference frames : 8 frames Codec ID : avc1 Codec ID/Info : Advanced Video Coding Duration : 16 min 12 s Bit rate : 10.2 Mb/s Width : 2 560 pixels Height : 1 440 pixels Display aspect ratio : 16:9 Frame rate mode : Constant Frame rate : 60.000 FPS Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.046 Stream size : 1.15 GiB (99%) Writing library : x264 core 164 r3075 66a5bc1 Encoding settings : cabac=1 / ref=8 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=9 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=24 / 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=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=crf / mbtree=1 / crf=27.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00 Color range : Limited Color primaries : BT.709 Transfer characteristics : BT.709 Matrix coefficients : BT.709 Codec configuration box : avcC Audio ID : 2 Format : AAC LC Format/Info : Advanced Audio Codec Low Complexity Codec ID : mp4a-40-2 Duration : 16 min 12 s Source duration : 16 min 12 s Bit rate mode : Constant Bit rate : 132 kb/s Channel(s) : 2 channels Channel layout : L R Sampling rate : 48.0 kHz Frame rate : 46.875 FPS (1024 SPF) Compression mode : Lossy Stream size : 15.2 MiB (1%) Source stream size : 15.2 MiB (1%) Default : Yes Alternate group : 1 mdhd_Duration : 972629 ``` ### Test Image ![Test Image - CRF 27](img/ffmpeg/CRF%2027.png) ## 1080p CRF 21 [11.9 Mb/s] `ffmpeg -i "$input" -movflags +faststart -vf scale=1920:1080 -c:v libx264 -preset slower -crf 21 "$output"` ### Mediainfo ``` General Complete name : 1080p CRF 21.mp4 Format : MPEG-4 Format profile : Base Media Codec ID : isom (isom/iso2/avc1/mp41) File size : 1.35 GiB Duration : 16 min 12 s Overall bit rate : 11.9 Mb/s Writing application : Lavf58.45.100 Video ID : 1 Format : AVC Format/Info : Advanced Video Codec Format profile : High@L5 Format settings : CABAC / 8 Ref Frames Format settings, CABAC : Yes Format settings, Reference frames : 8 frames Codec ID : avc1 Codec ID/Info : Advanced Video Coding Duration : 16 min 12 s Bit rate : 11.8 Mb/s Width : 1 920 pixels Height : 1 080 pixels Display aspect ratio : 16:9 Frame rate mode : Constant Frame rate : 60.000 FPS Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.095 Stream size : 1.33 GiB (99%) Writing library : x264 core 160 r3011 cde9a93 Encoding settings : cabac=1 / ref=8 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=9 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=24 / 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=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=crf / mbtree=1 / crf=21.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00 Codec configuration box : avcC Audio ID : 2 Format : AAC LC Format/Info : Advanced Audio Codec Low Complexity Codec ID : mp4a-40-2 Duration : 16 min 12 s Bit rate mode : Constant Bit rate : 129 kb/s Channel(s) : 2 channels Channel layout : L R Sampling rate : 48.0 kHz Frame rate : 46.875 FPS (1024 SPF) Compression mode : Lossy Stream size : 14.9 MiB (1%) Default : Yes Alternate group : 1 ``` ### Test Image ![Test Image - 1080p CRF 21](img/ffmpeg/1080p%20CRF%2021.png) ## 1080p CRF 27 [6,232 kb/s] `ffmpeg -i "$input" -movflags +faststart -vf scale=1920:1080 -c:v libx264 -preset slower -crf 27 "$output"` Our test file described in the [Get Video Info](#get-video-info-with-mediainfo) section was compressed from 40.5 Mbps (over 16m12s) to ### Mediainfo ``` General Complete name : ffmpeg test file - 1080p crf 27.mp4 Format : MPEG-4 Format profile : Base Media Codec ID : isom (isom/iso2/avc1/mp41) File size : 723 MiB Duration : 16 min 12 s Overall bit rate : 6 232 kb/s Writing application : Lavf58.45.100 Video ID : 1 Format : AVC Format/Info : Advanced Video Codec Format profile : High@L5 Format settings : CABAC / 8 Ref Frames Format settings, CABAC : Yes Format settings, Reference frames : 8 frames Codec ID : avc1 Codec ID/Info : Advanced Video Coding Duration : 16 min 12 s Bit rate : 6 089 kb/s Width : 1 920 pixels Height : 1 080 pixels Display aspect ratio : 16:9 Frame rate mode : Constant Frame rate : 60.000 FPS Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.049 Stream size : 706 MiB (98%) Writing library : x264 core 160 r3011 cde9a93 Encoding settings : cabac=1 / ref=8 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=9 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=24 / 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=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=crf / mbtree=1 / crf=27.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00 Codec configuration box : avcC Audio ID : 2 Format : AAC LC Format/Info : Advanced Audio Codec Low Complexity Codec ID : mp4a-40-2 Duration : 16 min 12 s Bit rate mode : Constant Bit rate : 129 kb/s Channel(s) : 2 channels Channel layout : L R Sampling rate : 48.0 kHz Frame rate : 46.875 FPS (1024 SPF) Compression mode : Lossy Stream size : 14.9 MiB (2%) Default : Yes Alternate group : 1 ``` ### Test Image ![Test Image - 1080p CRF 27](img/ffmpeg/1080p%20crf%2027.png) ## 720p CRF 21 [6,314 kb/s] `ffmpeg -i "$input" -movflags +faststart -vf scale=1280:720 -c:v libx264 -preset slower -crf 21 "$output"` ### Mediainfo ``` General Complete name : 720p CRF 21.mp4 Format : MPEG-4 Format profile : Base Media Codec ID : isom (isom/iso2/avc1/mp41) File size : 732 MiB Duration : 16 min 12 s Overall bit rate : 6 314 kb/s Writing application : Lavf59.9.102 Video ID : 1 Format : AVC Format/Info : Advanced Video Codec Format profile : High@L4 Format settings : CABAC / 8 Ref Frames Format settings, CABAC : Yes Format settings, Reference frames : 8 frames Codec ID : avc1 Codec ID/Info : Advanced Video Coding Duration : 16 min 12 s Bit rate : 6 169 kb/s Width : 1 280 pixels Height : 720 pixels Display aspect ratio : 16:9 Frame rate mode : Constant Frame rate : 60.000 FPS Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.112 Stream size : 715 MiB (98%) Writing library : x264 core 164 r3075 66a5bc1 Encoding settings : cabac=1 / ref=8 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=9 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=22 / 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=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=crf / mbtree=1 / crf=21.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00 Color range : Limited Color primaries : BT.709 Transfer characteristics : BT.709 Matrix coefficients : BT.709 Codec configuration box : avcC Audio ID : 2 Format : AAC LC Format/Info : Advanced Audio Codec Low Complexity Codec ID : mp4a-40-2 Duration : 16 min 12 s Source duration : 16 min 12 s Bit rate mode : Constant Bit rate : 132 kb/s Channel(s) : 2 channels Channel layout : L R Sampling rate : 48.0 kHz Frame rate : 46.875 FPS (1024 SPF) Compression mode : Lossy Stream size : 15.2 MiB (2%) Source stream size : 15.2 MiB (2%) Default : Yes Alternate group : 1 mdhd_Duration : 972629 ``` ### Test Image ![Test Image - 720p CRF 21](img/ffmpeg/720p%20CRF%2021.png) ## 720p CRF 27 [3,305 kb/s] `ffmpeg -i "$input" -movflags +faststart -vf scale=1280:720 -c:v libx264 -preset slower -crf 27 "$output"` ### Mediainfo ``` General Complete name : 720p CRF 27.mp4 Format : MPEG-4 Format profile : Base Media Codec ID : isom (isom/iso2/avc1/mp41) File size : 383 MiB Duration : 16 min 12 s Overall bit rate : 3 305 kb/s Writing application : Lavf58.45.100 Video ID : 1 Format : AVC Format/Info : Advanced Video Codec Format profile : High@L4 Format settings : CABAC / 8 Ref Frames Format settings, CABAC : Yes Format settings, Reference frames : 8 frames Codec ID : avc1 Codec ID/Info : Advanced Video Coding Duration : 16 min 12 s Bit rate : 3 162 kb/s Width : 1 280 pixels Height : 720 pixels Display aspect ratio : 16:9 Frame rate mode : Constant Frame rate : 60.000 FPS Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.057 Stream size : 367 MiB (96%) Writing library : x264 core 160 r3011 cde9a93 Encoding settings : cabac=1 / ref=8 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=9 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=22 / 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=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=crf / mbtree=1 / crf=27.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00 Codec configuration box : avcC Audio ID : 2 Format : AAC LC Format/Info : Advanced Audio Codec Low Complexity Codec ID : mp4a-40-2 Duration : 16 min 12 s Bit rate mode : Constant Bit rate : 129 kb/s Channel(s) : 2 channels Channel layout : L R Sampling rate : 48.0 kHz Frame rate : 46.875 FPS (1024 SPF) Compression mode : Lossy Stream size : 14.9 MiB (4%) Default : Yes Alternate group : 1 ``` ### Test Image ![Test Image - 720p CRF 27](img/ffmpeg/720p%20CRF%2027.png) # Test a New Profile 0. Name the profile. `profile=""` (E.g. "720p CRF 21") 1. Transcode the file. `ffmpeg -i "original.mp4" "$profile.mp4"` 2. Extract sample frame from transcoded file. `ffmpeg -ss 00:15:20.01 -i "$profile.mp4" -frames:v 1 "$profile.png"` 3. Print media info for the new file. `mediainfo "$profile.mp4"` 4. Update this doc!