SRT, VTT and video delivery tools

Subtitles and Video Files

These tools work on the video itself. Extract subtitle tracks from an MP4 or MKV, check an SRT on your video and copy the ffmpeg command, open the SRT a DJI drone saves, and relate video bitrate to file size and duration.

Tools in this group

  • 1080p Bitrate: Recommended Video Bitrate by Frame Rate — Pick a resolution and frame rate to see the bitrates YouTube publishes for uploads and live streams, with the file size per minute and hour and our own estimate.
  • 1080p vs 4K: Compare Pixels, Bitrate and File Size — Pick any two video sizes, from SD to 8K, to see the pixel ratio, YouTube's published bitrate, video size per hour and pixel density. Quick buttons cover FHD vs QHD, 1080p vs 2K, 4K vs UHD and SD vs HD.
  • Adding SRT Subtitles to Video (MP4) — Open your video and your SRT to check the timing on the picture, then copy the exact ffmpeg command, HandBrake steps or sidecar file name. The video never leaves your device.
  • DJI SRT File Viewer: Read the Telemetry, Export GPX, KML, CSV — Open the .SRT file your DJI drone saved next to the video to see every GPS and camera record, then download a GPX track, KML path, GeoJSON or CSV.
  • Extract SRT From MKV (and MKS) — Open an .mkv, .mks or .webm file and save its subtitle tracks as SRT, WebVTT or the original ASS. The video is read locally and never uploaded.
  • Extract Subtitle From MP4 — Open an .mp4, .m4v or .mov file and save its subtitle tracks as SRT or WebVTT. Only the track data is read; the video never leaves your device.
  • H264 vs H265: Compare File Size, Bitrate and Compatibility — Enter a resolution, frame rate and length to estimate how big the same video is in H.264 and in H.265 (HEVC), with a bitrate saving you can adjust. Copy the ffmpeg commands for both and compare support and licensing.
  • M4A vs MP3: Compare File Size and Format — Enter the length, channels, sample rate and bit depth of a recording and the bitrate you would use, to see the file size of MP3, AAC in M4A, Ogg Vorbis, FLAC, WAV and AIFF side by side.
  • Video Bitrate Calculator — Turn a target file size and a duration into the video bitrate to encode with, copy the ffmpeg two-pass command, or measure the bitrate of a file you have.
  • Video File Size Calculator — Enter the length, the video bitrate and the audio bitrate to get the file size in MB, GB, MiB and GiB, plus how long a 32, 64, 128 or 256 GB card lasts.