Media tools
Sume media tools by API: trim, filter, captions, frames, inspect, speech-to-text, upscaling, background removal, transitions, and Timeline assembly.
Start with Video editing API limits: Sume media tool caps in one table
Hard subtitles vs soft subtitles: what's the difference?
Hard subtitles are burned into the picture and always show; soft subtitles are a separate track viewers can turn off. When to use each, and how.
How to add subtitles to a video from a transcript
Have the words but no timings? Send the transcript as script_text with the video to Sume's captions API, which times it to the speech and burns it.
How to add bilingual subtitles to a video
Burn two languages onto one video with Sume: put both lines in each cue of one caption job, or run two jobs, each language at its own height.
How to add a logo or watermark to a video
Add a logo or watermark to a video by laying the image over every frame. Sume's Timeline compose does it for Sume-hosted files in one MP4.
How to add an image to a video at a specific time
Show a picture only between two timestamps: compose it over that stretch of the clip, or cut to it as a still, then rebuild the video in one render.
How to convert MP3 to MP4 with an image
Turn an MP3 into an MP4 with one picture: a Timeline 1.0 render holds the image for the whole track, up to 30 minutes, at the frame size you set.
How to freeze frame a video: hold the last or any frame
Freeze a video's last frame with one tpad filter call, or hold any frame mid-clip as a still between two parts of the clip in a Timeline render.
How to increase video length by looping a short clip
Loop a short clip until it matches a song or voiceover: put it in one Timeline 1.0 slot as long as the audio and set render.pad_mode to loop.
How to remove silence from a video automatically
Find every pause from a transcript's word timings, keep the speech with a small margin, and render the kept ranges back to back in one Timeline job.
How to fix audio delay in a video by shifting the sound
Fix a video whose sound runs late or early: detach the audio and re-render the clip with the offset set as audio.source_in or the slot's source_in.
How to rotate a video 90 degrees and save it
Rotate a video 90 degrees with ffmpeg's transpose filter: clock turns it clockwise, cclock counterclockwise. Sume's video filter saves a new MP4.
How to make a video square: crop it or fit it in 1:1
Make a video square by cropping a centered 1:1 window, or fit the whole frame in a square with black bars. Both are one FFmpeg filter job on Sume.
How to make a vertical video horizontal (9:16 to 16:9)
To make a vertical video horizontal, put the 9:16 clip in a 16:9 frame and fill the sides with a blurred copy or black bars. How to do it with Sume.
How to remove black bars from a video by cropping
Black bars baked into a video only go away with a crop. Measure them on a full-size still, then crop them off with FFmpeg's crop filter on Sume.
How to make a video black and white (or keep one color)
Make a video black and white by setting its saturation to zero with FFmpeg's hue or eq filter, or keep one color with colorhold. How to do it on Sume.
How to brighten a dark video: exposure, gamma, or levels
Brighten a dark video with FFmpeg's exposure, eq gamma, or colorlevels filter, run as one Sume video filter job. To darken instead, use the dim op.
How to color correct a video: fix a color cast and warmth
Color correct a video with FFmpeg filters on Sume: colorbalance removes a yellow or green cast, colortemperature sets warmth, and eq sets saturation.
How to blur part of a video or black it out
Blur part of a video by cropping the area, blurring it, and overlaying it back in one FFmpeg filtergraph on Sume, or cover it with a solid drawbox.
How to merge two videos of different resolutions
Merge two videos of different resolutions by scaling both into one frame: crop, pad, blur, or stretch each clip, then join them with their sound.
How to add a voiceover to a video and keep its sound
Add a voiceover to a video by mixing narration over its own sound: speak the script with TTS, then render the clip with both tracks in one MP4.
MP4 video has no sound? Find where the audio went
An MP4 with no sound has no audio track, a silent one, or one your player can't decode. Check with a free probe, then fix the step that lost it.
How to convert HEVC (H.265) video to H.264
Convert HEVC (H.265) to H.264 by re-encoding the video stream. On Sume, an exact trim of a whole non-HDR clip returns an H.264 MP4.
How to reduce video file size to fit an upload limit
Reduce video file size with fewer bits: a smaller frame, a lower frame rate, a shorter cut, or no audio. Sume takes no bitrate, so check size_bytes.
How to crop a video without losing quality
A normal crop re-encodes the frames, so lose as little as you can: crop once, from the original, and don't scale back up. How Sume encodes each edit.
How to check a video's bitrate from its size and length
Check a video's average bitrate: size in bytes × 8 ÷ length in seconds. Sume's free probe returns both numbers, size_bytes and duration_seconds.
AI image aspect ratio changer: re-render at 9:16 or 16:9
To change an image's aspect ratio with AI, outpaint the new area or redraw the image at the new ratio. Sume has no uncrop tool; here is the redraw.
How to upscale an image to 3000x3000 (or any exact size)
Divide the target size by the current size to get the upscale factor, then run it: 1000×1000 at 3× is 3000×3000. Sume takes any factor from 1 to 4.
AI image for print: pixel sizes for 300 DPI prints
A 300 DPI print needs 300 pixels per inch of print. Generate an AI image at the largest size a model allows, then upscale it up to 4x with Sume.
AI banner generator for YouTube: a 2560×1440 channel banner
YouTube recommends a 2560 x 1440 px channel banner, 16:9 and 6 MB or less. On Sume, ChatGPT Image 2.5 takes that exact size as a custom image_size.
AI banner generator for LinkedIn: a 1584×396 cover image
LinkedIn recommends a 1584 x 396 px cover image, a 4:1 strip. Generate it at 4:1 with Nano Banana 2 on Sume, then resize it to the exact size.
AI banner generator: wide banner shapes up to 8:1
Choose the banner's shape, then a model that lists it. On Sume, ChatGPT Image 2.5 takes exact sizes up to 3:1 and Nano Banana 2 goes to 8:1.
AI wallpaper generator: 4K desktop and phone wallpapers
Generate a wallpaper at your screen's pixel size. On Sume, ChatGPT Image 2.5 takes an exact 3840 × 2160 for 4K and near-exact phone sizes to crop.
AI thumbnail generator for YouTube: 3840×2160 from a prompt
YouTube recommends 3840×2160 thumbnails at 16:9. ChatGPT Image 2.5 on Sume takes that exact size, from a prompt or with your photo as a reference.
Google Performance Max video specs: sizes and lengths
Performance Max recommends one video each in 16:9, 1:1, and 9:16, 10 seconds or more, at 1920×1080, 1080×1080, and 1080×1920. Make each with Sume.
Demand Gen video specs: sizes, lengths, and the 4:5 cut
Demand Gen takes 1:1, 16:9, 4:5, and optional 9:16 videos of at least 5 seconds, uploaded to YouTube. How to make each, including 4:5, with Sume.
YouTube bumper ad specs: 6 seconds, 16:9, non-skippable
A YouTube bumper ad is a non-skippable video of 5 to 6 seconds, hosted on YouTube, with 16:9 at 1920×1080 listed. How to cut one to 6 s with Sume.
YouTube Shorts ads specs: 9:16, length limits, and sound
Shorts ads must be on YouTube, vertical 9:16 is recommended, and only the first 60 seconds play in the feed. How to make one at 1080×1920 with Sume.
YouTube ad specs: in-stream and in-feed sizes and lengths
Google lists 1920×1080, 1080×1920, and 1080×1080 at a recommended 15 seconds for YouTube in-video ads; non-skippable in-stream runs 15–60 seconds.
Instagram story ad size: 9:16 specs, plus Facebook Stories
Meta recommends 9:16 at 1440×2560 for Instagram and Facebook Stories ads. Lengths that play in full, safe zones, and how to make one with Sume.
Snapchat ad specs: 9:16 video at 720×1280, 3 to 180 seconds
Snapchat video ads are 9:16 at 720×1280, .mp4 or .mov, 3 to 180 seconds; Commercials keep the first 6 seconds unskippable. How to make one with Sume.
Facebook in-stream ads: video specs and the 15-second rule
Facebook in-stream video ads: 16:9 or 1:1, at least 1080×1080, 5–15 s on desktop. Ads of 15 s or less play in full; longer ones stop at 15 s.
Threads ads specs: video ratios, the 4:5 crop, and captions
Threads ads take image, video, and carousel creatives. Video from 1.91:1 to 9:16 is supported, but anything taller than 4:5 is cropped to 4:5.
Prime Video ad specs: Amazon's streaming TV video rules
Prime Video ads need 16:9 at 1920x1080 or more, 15 Mbps or more of video, AAC of 192 kbps or more on 2+ channels, and 15, 30, 45 or 60 s in the US.
Spotify video ad specs: 9:16 or 16:9, up to 30 seconds
Spotify video ads run up to 30 s, 9:16 or 16:9 at about 720x1280 or 1280x720, as MOV or MP4 up to 500 MB, with sound at -14 dBFS RMS.
Translate video subtitles by API: English to Korean captions
Translate an English video's subtitles into Korean with Sume: get timed sentences, translate each line, then burn the lines as cues in a Hangul style.
TikTok video specs for API uploads and ads, mapped to Sume
TikTok's posting API takes MP4, WebM, or MOV at 23–60 fps, 360–4,096 px, and up to 10 minutes. How a Sume clip maps to that, and how to upload it.
Instagram Reels video requirements for API uploads
Instagram's API cURLs a Reel from a public video_url: MP4 or MOV, H.264 or HEVC, 23–60 fps, 3 s to 15 min, 300 MB. How a Sume MP4 maps to each rule.
Meta video ad specs: 4:5 feed, 9:16 Reels, and safe zones
Meta lists 4:5 at 1440×1800 for Facebook Feed video ads and 9:16 for Instagram, with a Reels safe zone. How to make each with Sume and place captions.