MediaMTX HLS fMP4 incompatibility with FFmpeg (mpv/ffplay)

[wbtcpip2]

Which version are you using?

1.19.2

Which operating system are you using?

Windows amd64 standard

Describe the issue

Summary

HLS fMP4 streams generated by MediaMTX often stall after startup in all FFmpeg‑based players (mpv, ffplay, OBS, GStreamer).
Playback stalls after startup and sometimes during streaming.
VLC works correctly because it uses a different HLS demuxer.

This indicates a compatibility issue between MediaMTX’s HLS fMP4 output and FFmpeg’s HLS demuxer.

Issues observed

1. TLS connections closed immediately
   FFmpeg logs show repeated premature connection closures:
   tls: Server closed the connection
   tls: Server closed the connection
   This happens during playlist fetch and segment fetch.

2. Duplicate init.mp4 files
   MediaMTX sends audio/video init segments more than once:
   Opening audio2_init.mp4
   Opening audio2_init.mp4

3. MOOV atoms duplicated inside segments
   Segments contain unexpected MOOV atoms:
   Found duplicated MOOV Atom. Skipped it

4. Audio and video segments arrive in inconsistent order
   FFmpeg receives:

   audio init
   audio segments
   video init
   video segments

The order varies at each startup, causing FFmpeg to wait for both tracks → stall.
MediaMTX closes some of these connections prematurely → playback cannot start.

Expected behavior
No premature TLS connection closures
No duplicate init segments
No MOOV atoms inside fMP4 segments
Stable ordering of audio/video segments
Compatibility with FFmpeg’s multi‑connection HLS behavior

Actual behavior
mpv and ffplay stall at startup
repeated reconnections
duplicated init/mp4
duplicated MOOV atoms
inconsistent segment ordering
VLC works (single persistent connection)

How to reproduce
ffplay -loglevel verbose https://mbsoft.net:8888/mbradio/index.m3u8

most of times playback stalls immediately after start.
VLC plays without issues.

Describe how to replicate the issue

1. start the MediaMTX
2. publish with ...
3. read with ...

MediaMTX configuration

MediaMTX logs

No response

Packet dump

No response

[di33y-clear44]

Currently, I want iPhone 16 a I broke the Chromebook with a with the 64 inch charm. I have tablets in front of me and it’s real time cemetery so just trying to locate and run a score process after a security API key.

…

On Tue, Jul 7, 2026 at 3:55 PM Maurizio ***@***.***> wrote: *wbtcpip2* created an issue (bluenviron/mediamtx#5931) <#5931> Which version are you using? 1.19.2 Which operating system are you using? Windows amd64 standard Describe the issue Summary HLS fMP4 streams generated by MediaMTX often stall after startup in all FFmpeg‑based players (mpv, ffplay, OBS, GStreamer). Playback stalls after startup and sometimes during streaming. VLC works correctly because it uses a different HLS demuxer. This indicates a compatibility issue between MediaMTX’s HLS fMP4 output and FFmpeg’s HLS demuxer. Issues observed 1. TLS connections closed immediately FFmpeg logs show repeated premature connection closures: tls: Server closed the connection tls: Server closed the connection This happens during playlist fetch and segment fetch. 2. Duplicate init.mp4 files MediaMTX sends audio/video init segments more than once: Opening audio2_init.mp4 Opening audio2_init.mp4 3. MOOV atoms duplicated inside segments Segments contain unexpected MOOV atoms: Found duplicated MOOV Atom. Skipped it 4. Audio and video segments arrive in inconsistent order FFmpeg receives: audio init audio segments video init video segments The order varies at each startup, causing FFmpeg to wait for both tracks → stall. MediaMTX closes some of these connections prematurely → playback cannot start. Expected behavior No premature TLS connection closures No duplicate init segments No MOOV atoms inside fMP4 segments Stable ordering of audio/video segments Compatibility with FFmpeg’s multi‑connection HLS behavior Actual behavior mpv and ffplay stall at startup repeated reconnections duplicated init/mp4 duplicated MOOV atoms inconsistent segment ordering VLC works (single persistent connection) How to reproduce ffplay -loglevel verbose https://mbsoft.net:8888/mbradio/index.m3u8 most of times playback stalls immediately after start. VLC plays without issues. Describe how to replicate the issue 1. start the MediaMTX 2. publish with ... 3. read with ... MediaMTX configuration MediaMTX logs *No response* Packet dump *No response* — Reply to this email directly, view it on GitHub <#5931?email_source=notifications&email_token=BZHSCLCYN5LQYGCCIMHP2JT5DVIRZA5CNFSL4Z3JMQ5C6L3HNF2C22DVMIXUS43TOVSS6NBYGMYTONRVHEYTHJTSMVQXG33OVJZXKYTTMNZGSYTFMSSWK5TFNZ2KYZTPN52GK4S7MNWGSY3L>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BZHSCLFNOPOBMKIT5YTKNOL5DVIRZAVCNFSNUABFKJSXA33TNF2G64TZHMZDGMBWGYYDMNRZHNEXG43VMU5TIOBTGE3TMNJZGEZ2C5QC> . Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS <https://github.com/notifications/mobile/ios/BZHSCLB37PNNGWNHG5TUFKL5DVIRZA5CNFSL4Z3JMQ5C6L3HNF2C22DVMIXUS43TOVSS6NBYGMYTONRVHEYTHJTSMVQXG33OVJZXKYTTMNZGSYTFMSSWK5TFNZ2KUZTPN52GK4S7NFXXG> and Android <https://github.com/notifications/mobile/android/BZHSCLB5DPRIBGPE6UWE5OL5DVIRZA5CNFSL4Z3JMQ5C6L3HNF2C22DVMIXUS43TOVSS6NBYGMYTONRVHEYTHJTSMVQXG33OVJZXKYTTMNZGSYTFMSSWK5TFNZ2K4ZTPN52GK4S7MFXGI4TPNFSA>. Download it today! You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[di33y-clear44]

I believe I left the open egg. I don’t believe I left an open API key to get her repository lost the phone had one stolen it had in point with a specific UUID.

…

On Tue, Jul 7, 2026 at 3:55 PM Maurizio ***@***.***> wrote: *wbtcpip2* created an issue (bluenviron/mediamtx#5931) <#5931> Which version are you using? 1.19.2 Which operating system are you using? Windows amd64 standard Describe the issue Summary HLS fMP4 streams generated by MediaMTX often stall after startup in all FFmpeg‑based players (mpv, ffplay, OBS, GStreamer). Playback stalls after startup and sometimes during streaming. VLC works correctly because it uses a different HLS demuxer. This indicates a compatibility issue between MediaMTX’s HLS fMP4 output and FFmpeg’s HLS demuxer. Issues observed 1. TLS connections closed immediately FFmpeg logs show repeated premature connection closures: tls: Server closed the connection tls: Server closed the connection This happens during playlist fetch and segment fetch. 2. Duplicate init.mp4 files MediaMTX sends audio/video init segments more than once: Opening audio2_init.mp4 Opening audio2_init.mp4 3. MOOV atoms duplicated inside segments Segments contain unexpected MOOV atoms: Found duplicated MOOV Atom. Skipped it 4. Audio and video segments arrive in inconsistent order FFmpeg receives: audio init audio segments video init video segments The order varies at each startup, causing FFmpeg to wait for both tracks → stall. MediaMTX closes some of these connections prematurely → playback cannot start. Expected behavior No premature TLS connection closures No duplicate init segments No MOOV atoms inside fMP4 segments Stable ordering of audio/video segments Compatibility with FFmpeg’s multi‑connection HLS behavior Actual behavior mpv and ffplay stall at startup repeated reconnections duplicated init/mp4 duplicated MOOV atoms inconsistent segment ordering VLC works (single persistent connection) How to reproduce ffplay -loglevel verbose https://mbsoft.net:8888/mbradio/index.m3u8 most of times playback stalls immediately after start. VLC plays without issues. Describe how to replicate the issue 1. start the MediaMTX 2. publish with ... 3. read with ... MediaMTX configuration MediaMTX logs *No response* Packet dump *No response* — Reply to this email directly, view it on GitHub <#5931?email_source=notifications&email_token=BZHSCLCYN5LQYGCCIMHP2JT5DVIRZA5CNFSL4Z3JMQ5C6L3HNF2C22DVMIXUS43TOVSS6NBYGMYTONRVHEYTHJTSMVQXG33OVJZXKYTTMNZGSYTFMSSWK5TFNZ2KYZTPN52GK4S7MNWGSY3L>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BZHSCLFNOPOBMKIT5YTKNOL5DVIRZAVCNFSNUABFKJSXA33TNF2G64TZHMZDGMBWGYYDMNRZHNEXG43VMU5TIOBTGE3TMNJZGEZ2C5QC> . Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS <https://github.com/notifications/mobile/ios/BZHSCLB37PNNGWNHG5TUFKL5DVIRZA5CNFSL4Z3JMQ5C6L3HNF2C22DVMIXUS43TOVSS6NBYGMYTONRVHEYTHJTSMVQXG33OVJZXKYTTMNZGSYTFMSSWK5TFNZ2KUZTPN52GK4S7NFXXG> and Android <https://github.com/notifications/mobile/android/BZHSCLB5DPRIBGPE6UWE5OL5DVIRZA5CNFSL4Z3JMQ5C6L3HNF2C22DVMIXUS43TOVSS6NBYGMYTONRVHEYTHJTSMVQXG33OVJZXKYTTMNZGSYTFMSSWK5TFNZ2K4ZTPN52GK4S7MFXGI4TPNFSA>. Download it today! You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>