# FFmpeguru
> Plain-language into runnable ffmpeg commands, on a shared community memory.
Public Ghost content for AI and LLM tooling. Use `/llms-full.txt` for consolidated page and post context.
Append `.md` to any post or page URL to get the content in Markdown (for example, `/example-post.md`).

## Pages
- [About this site](https://ffmpeguru.com/about.md) - FFmpeguru is an independent publication launched in October 2026 by Josh Dvir. If you subscribe today, you'll get full access to the website as well as email newsletters about new content when it's available. Your subscription makes this site possible, and allows FFmpeguru to continue to exist. Tha…
- [Generate](https://ffmpeguru.com/ask.md) - The generator below is the same form you get on the home page.
- [One FFmpeg A Day](https://ffmpeguru.com/blog.md) - Notes on FFmpeg, written by and for people who use it every day.
- [HTTP API](https://ffmpeguru.com/docs-api.md) - POST /api/v1/ask The same generator the website uses. No key, no account. curl -X POST https://api.ffmpeguru.com/api/v1/ask \ -H "Content-Type: application/json" \ -d '{"question":"extract the audio as mp3"}' Request FieldTypeNotes questionstringrequired, 8–2000 characters Response { "message_id":…
- [llms.txt](https://ffmpeguru.com/docs-llms-txt.md) - llms.txt is a small convention for telling a language model what a site is and where to read more, so the model does not have to guess at URLs. FFmpeguru serves one: GET /llms.txt # the index GET /ask.md # the longer companion reference What is in it The index names the product in one line, then li…
- [Connect an MCP client](https://ffmpeguru.com/docs-mcp.md) - FFmpeguru speaks Model Context Protocol over Streamable HTTP. Point your client at the endpoint and it will discover a single tool. https://api.ffmpeguru.com/mcp In production this becomes your own hostname, for example https://api.example.com/mcp. The one tool ffmpeguru_generate(question: string)…
- [Docs](https://ffmpeguru.com/docs.md) - Everything FFmpeguru exposes FFmpeguru has four public surfaces. They all do the same thing — turn a plain-language description into a runnable ffmpeg command — and none of them require an account. 1. This website The generator on the home page. No API call needed. 2. HTTP API POST /api/v1/ask — JS…

## Posts
- [Convert AVI to MP4 with H.264 and AAC (the broadly compatible combo)](https://ffmpeguru.com/convert-avi-to-mp4-with-h-264-and-aac-the-broadly-compatible-combo.md) - AVI is still common in legacy workflows, surveillance footage, and some scientific capture pipelines. Converting to MP4 with H.264 video and AAC audio gives you a file that plays everywhere, from phones to browsers to TVs, at reasonable size. The command ffmpeg -i input.avi -c:v libx264 -c:a aac ou…
- [Remux MP4 to MKV without re-encoding (lossless, instant)](https://ffmpeguru.com/remux-mp4-to-mkv-without-re-encoding-lossless-instant.md) - If you only need a different container, do not re-encode. Stream copy moves the encoded audio and video packets from one container into another with no quality loss and finishes in seconds, even on a multi-gigabyte file. The command ffmpeg -i input.mp4 -c copy output.mkv What it does The -c copy fl…
- [How to read any media file's metadata with FFmpeg](https://ffmpeguru.com/how-to-read-any-media-files-metadata-with-ffmpeg.md) - Before you transcode anything, look at what you have. FFmpeg's probe mode is the fastest way to inspect a media file: it reads the container header and stream metadata, prints a full report, and exits. It produces no output file and is read-only, so it is safe to run on anything. The command ffmpeg…
- [Force input file format with -f](https://ffmpeguru.com/force-input-file-format-with-f.md) - FFmpeg usually detects the input format from the file header, but there are cases where the detection fails: raw streams, network captures, or files with a missing extension. The `-f` flag before the input forces the demuxer to use a specific format, bypassing the auto-detection. The command ffmpeg…
- [Set keyframe interval manually with -g](https://ffmpeguru.com/set-keyframe-interval-manually-with-g.md) - The keyframe interval is the distance between I-frames in the encoded video. A smaller interval improves seek performance and recovery from packet loss; a larger interval improves compression efficiency. The default is 250 frames (about 10 seconds at 25 fps), but for web video, a 2-second interval…
- [Generate a thumbnail contact sheet](https://ffmpeguru.com/generate-a-thumbnail-contact-sheet.md) - A contact sheet is a single image with a grid of thumbnails from a video. It is the right tool for a quick visual index of a long file, or for a preview that shows the pacing of the content. The `thumbnail` filter in libavfilter picks the most representative frames and the `tile` filter lays them o…
- [Use the segment muxer to write chunks](https://ffmpeguru.com/use-the-segment-muxer-to-write-chunks.md) - The `segment` muxer writes the output as a sequence of files, each containing a fixed duration of the input. It is the right tool for generating chunks for an HLS or DASH playlist, or for breaking a long recording into manageable pieces for a CDN. The command ffmpeg -i in.mp4 -c:v libx264 -crf 20 -…
- [Use tee to write to multiple outputs at once](https://ffmpeguru.com/use-tee-to-write-to-multiple-outputs-at-once.md) - The `tee` muxer writes the same encoded output to multiple destinations in a single command. It is the right tool for a live stream that needs to go to YouTube and Twitch simultaneously, or a transcoded file that needs to land in two locations. The command ffmpeg -i in.mp4 -c:v libx264 -crf 20 -f t…
- [Use the concat protocol](https://ffmpeguru.com/use-the-concat-protocol.md) - The `concat` protocol is the one-line version of the `concat` demuxer. It uses the `concat:` URL scheme to specify the input files, separated by `|`. It is the right tool for a quick join without a list file. The command ffmpeg -i "concat:a.mp4|b.mp4|c.mp4" -c copy out.mp4 What it does The command…
- [Use the concat demuxer with a list file](https://ffmpeguru.com/use-the-concat-demuxer-with-a-list-file.md) - When the concatenation order is fixed and the input files all share the same codec and parameters, the `concat` demuxer is the fastest way to join them. It runs at I/O speed, requires no re-encoding, and is driven by a plain-text list file. The command ffmpeg -f concat -safe 0 -i list.txt -c copy o…
- [Use -movflags +faststart for web playback](https://ffmpeguru.com/use-movflags-faststart-for-web-playback.md) - When an MP4 is encoded normally, the metadata sits at the end of the file. A web player must download the entire file before it can start playing, which is slow for long videos. The `-movflags +faststart` flag moves the metadata to the front of the file during a second pass, so the player can start…
- [Force a specific output container](https://ffmpeguru.com/force-a-specific-output-container.md) - FFmpeg usually picks the output container from the output filename, but it can be told to use a specific muxer with the `-f` flag. This is the right approach when the output is being piped to another process, or when the container name is not in the filename (e.g., a stream to a network service). T…
- [Cap output file size with -fs](https://ffmpeguru.com/cap-output-file-size-with-fs.md) - When the target is a file size, not a duration, the `-fs` flag stops the encode as soon as the output reaches the cap. It is most useful for fitting a video into a service that limits upload size (email, chat, social) without computing the bitrate manually. The command ffmpeg -i in.mp4 -fs 100M -c:…
- [Limit output duration with -t](https://ffmpeguru.com/limit-output-duration-with-t.md) - The `-t` flag caps the output duration. It works on any input and any output format, and it stops the encode as soon as the limit is reached. The most common use is grabbing the first N seconds of a clip for a preview, a test, or a social-media post. The command ffmpeg -i in.mp4 -t 30 -c copy out.m…
- [Use -ss after -i for accurate seek](https://ffmpeguru.com/use-ss-after-i-for-accurate-seek.md) - When the cut point must be exact, place `-ss` after the input. FFmpeg will decode from the start of the file (or from the nearest keyframe), then seek to the exact time. The cost is a full decode up to the cut point, but the precision is frame-accurate. The command ffmpeg -i long.mp4 -ss 600 -t 30…
- [Use -ss before -i for fast seek](https://ffmpeguru.com/use-ss-before-i-for-fast-seek.md) - When you only need a clip from the middle of a long file, the position of `-ss` on the command line changes the cost by orders of magnitude. `-ss` before `-i` triggers a fast keyframe-aligned seek; `-ss` after `-i` triggers an accurate but slow frame-by-frame seek. The command ffmpeg -ss 600 -i lon…
- [Stream from a USB microphone](https://ffmpeguru.com/stream-from-a-usb-microphone.md) - Capturing a USB microphone is a one-line command on Linux (ALSA), macOS (AVFoundation), or Windows (DirectShow). The output is a raw audio file you can use for a podcast, a voiceover, or a live stream. The command ffmpeg -f alsa -ac 2 -ar 48000 -i hw:0,0 -c:a pcm_s16le out.wav What it does The comm…
- [Stream from a webcam](https://ffmpeguru.com/stream-from-a-webcam.md) - Capturing a webcam in FFmpeg is the first step in any streaming setup. The command depends on the platform: on Linux, the Video4Linux2 API; on macOS, the AVFoundation framework; on Windows, the DirectShow API. Each one has a different device name format, but the principle is the same. The command f…
- [Crossfade between two audio clips](https://ffmpeguru.com/crossfade-between-two-audio-clips.md) - The `acrossfade` filter is the audio version of `xfade`. It blends two audio streams for a specified duration at a specified offset, so a music track can fade into a voiceover, or two songs can be joined without a hard cut. The command ffmpeg -i music.mp3 -i voice.wav -filter_complex "[0:a][1:a]acr…
- [Crossfade between two video clips](https://ffmpeguru.com/crossfade-between-two-video-clips.md) - The `xfade` filter is a one-line dissolve between two videos. It blends the two streams for a specified duration at a specified offset, so a transition can be programmed in the filter graph without an external editor. The filter supports several transition types: fade, wipe, slide, and more. The co…
- [Pad a video with black frames to a target duration](https://ffmpeguru.com/pad-a-video-with-black-frames-to-a-target-duration.md) - Sometimes you have a clip that is too short for the slot it needs to fill — a 2-second title card that needs to run for 10 seconds, a 30-second bumper that needs to be 1 minute. The `tpad` filter pads the start, end, or both of a video with a chosen color (black by default) to a target duration. Th…
- [Loop a short clip to a target duration](https://ffmpeguru.com/loop-a-short-clip-to-a-target-duration.md) - If you have a 30-second bumper and need a 5-minute placeholder, the `stream_loop` flag tells the demuxer to loop the input a fixed number of times. Combined with `-t` to limit the output duration, you get a precise-length file that uses only the source material. The command ffmpeg -stream_loop -1 -…
- [Apply a reverb effect](https://ffmpeguru.com/apply-a-reverb-effect.md) - Reverb simulates a space by adding many delayed copies of the audio to the dry signal. A short reverb makes a vocal sit in a small room; a long reverb makes a snare sound like it was recorded in a cathedral. The `aecho` filter is a simple delay-line reverb; for a more natural sound, use `reverb` (t…
- [Apply a chorus effect](https://ffmpeguru.com/apply-a-chorus-effect.md) - The chorus effect thickens a sound by mixing the dry signal with a slightly delayed and detuned copy. It is the effect that makes a clean electric guitar sound wide, and a clean vocal sound like a choir. The `chorus` filter in libavfilter is a multi-voice chorus with adjustable depth, rate, and del…
- [Add a click track for a metronome](https://ffmpeguru.com/add-a-click-track-for-a-metronome.md) - A click track is a short percussive sound played at a steady tempo. Musicians use it to stay in time, podcasters use it to mark sections, and fitness apps use it to pace a workout. FFmpeg can generate one with a few lines: a sine wave at a fixed frequency, pulsed at the desired BPM. The command ffm…
- [Extract the center channel from stereo](https://ffmpeguru.com/extract-the-center-channel-from-stereo.md) - Karaoke tracks, vocal-removed versions, and isolation mixes all use the same trick: the lead vocal is usually panned to the center of the stereo image, so subtracting the left channel from the right cancels it. The `pan` filter lets you build a custom channel map; for the center extraction, the `pa…
- [Gate quiet audio below a threshold](https://ffmpeguru.com/gate-quiet-audio-below-a-threshold.md) - A noise gate is the audio equivalent of a mute button that engages when the level drops below a threshold. It silences background noise between spoken phrases, removes room tone from a quiet section, and cleans up the gaps in a music track. The `agate` filter in libavfilter is a one-line gate with…
- [Tame harsh high frequencies with lowpass](https://ffmpeguru.com/tame-harsh-high-frequencies-with-lowpass.md) - The mirror of the highpass filter, `lowpass` removes everything above a cutoff frequency. It is the right tool for taming sibilance, hiss, and high-frequency noise that survived the denoiser. It is also a quick way to make a recording sound 'warmer' without changing the overall level. The command f…
- [Remove low-frequency rumble with highpass](https://ffmpeguru.com/remove-low-frequency-rumble-with-highpass.md) - Most recordings have a low-frequency rumble below 80 Hz: HVAC noise, handling noise, mic stand vibrations, wind. The `highpass` filter removes everything below a cutoff frequency, leaving the speech or music intact. It is a one-line fix for the most common audio problem. The command ffmpeg -i in.wa…
- [Denoise audio with afftdn](https://ffmpeguru.com/denoise-audio-with-afftdn.md) - Afftdn is a frequency-domain denoiser for audio. It computes a short-time Fourier transform, identifies the noise floor in each frequency bin, and subtracts it. The result is a clean signal with the speech or music preserved, useful for field recordings, voice memos, and old tapes. The command ffmp…
- [Even out voice levels with acompressor](https://ffmpeguru.com/even-out-voice-levels-with-acompressor.md) - Voice recordings are rarely at a constant level. The speaker leans in, leans back, gets excited, gets quiet — the result is a file that is hard to listen to at a fixed volume. The `acompressor` filter is a one-knob compressor that smooths the dynamic range in real time, lifting quiet sections and s…
- [Add a test-tone sine wave](https://ffmpeguru.com/add-a-test-tone-sine-wave.md) - A pure sine wave at a known frequency is the simplest possible audio test signal. You use it to verify a speaker is wired correctly (left vs right), to calibrate a room's response, or to confirm an audio interface is passing signal at all. FFmpeg can generate one without an input file. The command…
- [Generate a showcqt spectrogram](https://ffmpeguru.com/generate-a-showcqt-spectrogram.md) - Constant-Q transform (CQT) is a variant of the FFT where the frequency bins are spaced logarithmically, matching the way humans perceive pitch. The `showcqt` filter renders a CQT spectrogram as a video, which is the look of audio visualizers and music identification apps. The command ffmpeg -i in.w…
- [Generate a spectrum image from audio](https://ffmpeguru.com/generate-a-spectrum-image-from-audio.md) - A spectrum image shows the frequency content of an audio signal over time, with the low frequencies at the bottom and the high frequencies at the top. It is the visual style of audio editors and music visualizers, and FFmpeg can render it as a still image or a video. The command ffmpeg -i in.wav -f…
- [Generate a waveform image from audio](https://ffmpeguru.com/generate-a-waveform-image-from-audio.md) - A waveform image is a horizontal line graph showing the amplitude of an audio signal over time. Podcasts, DAWs, and audio editors all show one; you can generate one as a static image with FFmpeg, which is useful for embedding in a blog post or a report. The command ffmpeg -i in.wav -filter_complex…
- [Apply a 3D LUT for color](https://ffmpeguru.com/apply-a-3d-lut-for-color.md) - A 3D LUT is a file that maps every RGB color to another RGB color via a three-dimensional lookup table. Colorists use them to apply a specific look (filmic, vintage, brand color) to a flat source. FFmpeg can apply a .cube file directly, so the same LUT used in DaVinci or Premiere can be applied dur…
- [Replace green-screen background with chromakey](https://ffmpeguru.com/replace-green-screen-background-with-chromakey.md) - The chromakey filter makes a color in the source transparent, so you can overlay the foreground on a different background. The classic case is a green or blue screen studio shot; the practical case is anything where you want to replace a flat-colored region with another image or video. The command…
- [Add a vignette](https://ffmpeguru.com/add-a-vignette.md) - A vignette is a soft darkening around the edges of the frame, like an old lens or a portrait photo. It draws the eye to the center and adds a subtle cinematic look. The `vignette` filter in libavfilter is a one-line effect with parameters for angle, aspect, and softness. The command ffmpeg -i in.mp…
- [Convert to grayscale](https://ffmpeguru.com/convert-to-grayscale.md) - Stripping the color from a video is a stylistic choice for music videos, flashbacks, or text overlays, and a technical one for archival footage or color-blind accessibility. The `format=gray` filter does the work in one line, but you have to chain a second format filter to keep the encoder happy. T…
- [Adjust brightness, contrast, saturation with eq](https://ffmpeguru.com/adjust-brightness-contrast-saturation-with-eq.md) - The eq filter is the workhorse for a quick color correction: brightness, contrast, saturation, gamma, and a per-channel red/blue/green balance. It is less precise than curves but faster to type, and the parameters are linear so you can predict the result without rendering. The command ffmpeg -i in.…
- [Color grade with the curves filter](https://ffmpeguru.com/color-grade-with-the-curves-filter.md) - The curves filter is the most precise color tool in libavfilter. It applies a piecewise-linear function to a channel (red, green, blue, luma, or all), letting you lift the shadows, roll off the highlights, or change the contrast at a specific luminance range. The command ffmpeg -i in.mp4 -vf "curve…
- [Stabilize shaky video with vidstab](https://ffmpeguru.com/stabilize-shaky-video-with-vidstab.md) - Handheld phone footage, action-cam clips, and drone passes without a gimbal are rarely stable. The vidstab filter set detects the camera motion in a first pass, then applies a smoothing transform in the encode pass. The result looks like the camera was on a tripod, with a small zoom-in to cover the…
- [Add a vintage film-grain effect](https://ffmpeguru.com/add-a-vintage-film-grain-effect.md) - The `grain` filter adds film-like noise to a video so a clean digital source can read as analog, archival, or hand-processed. It is a stylistic effect — you would not use it for documentary footage you want to look neutral, but it is a one-line effect for moody montage or title sequences. The comma…
- [Blur video with boxblur](https://ffmpeguru.com/blur-video-with-boxblur.md) - Boxblur is the fastest blur in libavfilter and is the right tool when you need to anonymize a face, hide a license plate, or soften a background. It is also the building block of many other effects — a soft vignette, a focus-pull, or a face-blur before a privacy review. The command ffmpeg -i in.mp4…
- [Sharpen video with unsharp](https://ffmpeguru.com/sharpen-video-with-unsharp.md) - If a video looks soft after encoding, scaling, or denoising, a one-pass unsharp sharpen restores perceived detail. The filter builds a blurred copy of the frame and subtracts it, leaving the high-frequency edges that read as 'sharp' to the eye. The command ffmpeg -i in.mp4 -vf "unsharp=5:5:1.0:5:5:…
- [Denoise video with hqdn3d](https://ffmpeguru.com/denoise-video-with-hqdn3d.md) - Old home-video cameras, low-light phone footage, and high-ISO stills converted to video all carry temporal noise — random pixel changes between adjacent frames. hqdn3d is a high-quality 3D denoiser that averages each pixel against its neighbors in space and time, smoothing the noise while preservin…
- [Deinterlace an interlaced video](https://ffmpeguru.com/deinterlace-an-interlaced-video.md) - Interlaced video splits each frame into two fields captured 16ms apart. Modern displays are progressive, so interlaced content shows combing artifacts on motion. The yadif filter deinterlaces by interpolating one field from the other, removing the artifact without re-encoding the static parts of th…
- [Extract a subtitle track to SRT](https://ffmpeguru.com/extract-a-subtitle-track-to-srt.md) - Many video files carry subtitle streams inside the container, often as a `mov_text` track in MP4 or a PGS bitmap track in MKV. If you want to edit them in a text editor, generate transcripts, or burn them back in with custom styling, the first step is to extract the track as a separate SRT file. Th…
- [Embed custom metadata tags](https://ffmpeguru.com/embed-custom-metadata-tags.md) - FFmpeg can attach arbitrary key/value metadata to the container and to individual streams. The most common use is to set the title, artist, year, or comment on a finished audio or video file so media players show it in the info panel. The command ffmpeg -i in.m4a -metadata title="My Podcast Episode…
- [Strip all metadata from a file](https://ffmpeguru.com/strip-all-metadata-from-a-file.md) - Many cameras and editing tools embed a long list of metadata fields: author, location, device serial, encoder settings, edit timestamps. If you are about to publish a file and want to remove that surface, the `map_metadata -1` flag drops every container-level tag in one pass. The command ffmpeg -i…
- [Generate a media file checksum](https://ffmpeguru.com/generate-a-media-file-checksum.md) - If you need a stable identifier for a media file that survives renames and metadata edits, do not hash the file bytes. The header and tags can change without the perceptual content changing. Hash the decoded stream instead, so two encodes of the same source give the same value. The command ffmpeg -…
- [Test decode integrity with the null muxer](https://ffmpeguru.com/test-decode-integrity-with-the-null-muxer.md) - The fastest way to know whether a file decodes without errors from start to end is to run it through the null muxer. FFmpeg decodes every frame, throws the output away, and reports any decode error in real time. It produces no output file, so it costs no disk space. The command ffmpeg -v error -i i…
- [Use ffprobe for JSON metadata](https://ffmpeguru.com/use-ffprobe-for-json-metadata.md) - The human-readable output of `ffmpeg -i` is great for eyes and bad for scripts. ffprobe has a JSON output mode that exposes the same data as a structured document, so a Python, Node, or shell script can read stream count, codec names, duration, and bitrates without parsing free-form text. The comma…

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