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Use FFmpeg’s concat demuxer to read a text playlist and send the clips to YouTube Live as one continuous encoder session. The simple method works best when the files have matching stream parameters; if they do not, re-encode them to a common output profile. Create the playlist, set the YouTube ingest details, start FFmpeg, then check the preview and stream health before going live.
1. Prepare a playlist of video files
Put the clips in the order you want them to play. Create a UTF-8 or plain-text file named playlist.txt in the same directory as the files:
file 'clip-01.mp4'
file 'clip-02.mp4'
file 'clip-03.mp4'Each file line names one input. Use paths that resolve from the directory where you run FFmpeg. Keep the list local and trusted: the example command uses -safe 0, which permits paths the concat demuxer’s default safe-path policy might reject.
The concat demuxer joins packets in sequence rather than decoding and combining pictures. FFmpeg’s documentation says, “All files must have the same streams (same codecs, same time base, etc.).” See the FFmpeg concat demuxer documentation.
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Check whether stream copy is suitable
If the clips have compatible streams, you can try -c copy to pass their encoded audio and video through without another encode. This avoids extra encoding work, but it is strict: mismatched codecs, time bases, stream layouts, resolutions, or other parameters can cause failure or playback artifacts.
If the files differ, encode them to a shared output format instead. The example below uses H.264 video and AAC audio. Re-encoding takes CPU or GPU capacity and introduces another encode, so test the output and check that the machine can sustain it. FFmpeg explains the distinction between the concat demuxer and filter in its FAQ.
2. Create the YouTube Live stream and copy its ingest details
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Open YouTube Studio and create or select a stream in the Live Control Room.
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Copy the server URL and stream key shown for that stream. Treat the key as a credential: do not publish it in a command example, screenshot, or public repository.
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Use the RTMPS server URL when YouTube provides it; YouTube recommends RTMPS for encrypted ingest. Its encoder setup guide describes the setup flow.
In the command, replace SERVER/STREAM_KEY with the server URL and stream key YouTube provides. Keep the complete destination quoted. Avoid saving a real key in a script or terminal history that other people can access.
3. Start FFmpeg with one command
This illustrative command reads the playlist in real time, encodes a 720p30-style H.264/AAC stream, and sends it to YouTube over RTMP(S):
ffmpeg -re -f concat -safe 0 -i playlist.txt -c:v libx264 -preset veryfast -b:v 8M -maxrate 8M -bufsize 16M -g 60 -c:a aac -b:a 128k -f flv 'rtmps://SERVER/STREAM_KEY'Replace the destination with YouTube’s current server URL and your key. This is a starting template, not a tested command or a universal setting: FFmpeg build capabilities, input streams, account settings, and available upload bandwidth can change what works.
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What the important options do
-rereads the file input at its native rate, pacing it like a live source instead of sending the whole recording as fast as possible.-f concatselects the concat demuxer;-i playlist.txtpoints it at the ordered list.-safe 0relaxes the demuxer’s path checks. Use it only with a playlist you control and local, trusted inputs.-c:v libx264and-c:a aacencode video and audio into formats commonly used for YouTube live ingest.-b:v 8Mand-maxrate 8Mset the example video rate;-bufsize 16Msets the rate-control buffer.-g 60sets the GOP length to 60 frames. That is a two-second interval only at 30 fps.-b:a 128ksets the example audio bitrate;-f flvselects the output container used for this RTMP-style ingest.
Choose a bitrate, frame rate, and keyframe interval
YouTube’s live encoder settings page lists H.264 recommended video bitrates of 8 Mbps for 720p30 and 14 Mbps for 1080p30. Those are recommendations for the specified codec, resolution, and frame rate—not a single rate that fits every stream. Select the output dimensions, frame rate, and bitrate to match the stream settings and ensure your upload connection can sustain the video rate, audio, and network overhead. See YouTube’s live encoder settings for its current supported combinations and rates.
YouTube recommends a two-second keyframe frequency and says it should not exceed four seconds. Set the GOP length to roughly twice the output frame rate: for example, 60 frames at 30 fps or 120 frames at 60 fps. The command’s -g 60 therefore matches the two-second target only if you are outputting 30 fps. YouTube’s settings also list H.264, H.265, and AV1 video; AAC or MP3 audio; CBR; stereo audio at 44.1 kHz; and a recommended 128 kbps for stereo audio. Check the page for the settings relevant to your chosen output.
Use stream copy only when the inputs really match
For compatible clips, a stream-copy command can replace the video and audio encoder options with -c copy, for example:
ffmpeg -re -f concat -safe 0 -i playlist.txt -c copy -f flv 'rtmps://SERVER/STREAM_KEY'This is a compatibility-dependent alternative, not a fix for mismatched files. If it errors, produces artifacts, or behaves badly at a boundary, use a common re-encoded output profile or an appropriate filter-based workflow rather than assuming the clips can be joined unchanged.
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Repeat the playlist instead of ending after the last clip
The basic command plays the listed files once. To ask FFmpeg to loop the concat input, put -stream_loop -1 before that input:
ffmpeg -stream_loop -1 -re -f concat -safe 0 -i playlist.txt -c:v libx264 -preset veryfast -b:v 8M -maxrate 8M -bufsize 16M -g 60 -c:a aac -b:a 128k -f flv 'rtmps://SERVER/STREAM_KEY'Confirm that your installed FFmpeg build accepts this option in this arrangement, and test the transition from the final clip back to the first before relying on it for a long broadcast. Do not assume the repeat will be seamless: file durations, timestamps, and clip compatibility can create a gap or artifact.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.4. Confirm the preview, then go live
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Start the chosen FFmpeg command and watch its console output for errors or a stopped process.
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In YouTube Studio’s Live Control Room, wait for the incoming preview and review stream health.
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When the preview is ready and stream health is acceptable, select Go live in the control room.
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When finished, stop sending from FFmpeg, then end the stream in the control room.
Run a private, unlisted, or otherwise controlled test before a public event. Check audio, picture, clip order, and transitions, and monitor stream health. YouTube says streams under 12 hours are automatically archived; its documentation does not establish that longer streams will be archived. See the YouTube encoder setup guide.
5. Troubleshoot common failures
FFmpeg stops after the first file
- Check that every playlist line begins with
fileand has a correctly quoted path. - Confirm the paths resolve from the working directory used to launch FFmpeg.
- Check for unsupported or mismatched streams. The demuxer requires compatible stream parameters for straightforward concatenation.
- Review duration metadata: FFmpeg advances timestamps using file durations, and incorrect or missing duration information can cause timing problems.
The picture or audio jumps at a clip boundary
Check whether the clips differ in codec, time base, resolution, frame rate, or stream layout, and whether their duration metadata is accurate. Try a common re-encoded output profile if stream copy is unsuitable. Test boundaries before a public broadcast; the concat demuxer does not guarantee a seamless transition for incompatible material.
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YouTube shows no preview
- Verify the destination uses the current server URL and stream key from the selected YouTube stream.
- Check FFmpeg’s console output to confirm that it is sending rather than exiting or reporting an error.
- Inspect the Live Control Room’s stream-health status. Never share the actual key while asking for help.
The stream drops or reports poor health
Check that the upload connection can sustain the selected bitrate, then reduce the output rate or resolution if necessary. Use YouTube’s encoder settings for the selected codec and frame rate rather than choosing a bitrate from resolution alone. Test under the same network conditions you expect during the event.
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