Multiple instances of mediamtx #5882

Allasso · 2026-06-18T13:59:35Z

Allasso
Jun 18, 2026

Question

Version v1.19.1
Running on command line

UPDATE - 2026-06-18 20:05 MST (2026-06-19 02:05 UTC): Many additions/clarifications have been made in the preamble of this post.

I am using mediamtx in an application I am building for macos, to capture HEVC streams from surveillance cameras on my local network, and stream over tcp so I can access the stream using WebRTC and play in a

To test this I have been running mediamtx directly from the command line. What I have found is that I can start one instance of mediamtx using a given configuration (simulating some other app's instantiation), and it works fine. However, if I attempt to start another instance of mediamtx using a different configuration (different port numbers, etc, simulating instantiation by my app) the second instance of mediamtx immediately exits with an error relating to port conflict.

So my question is, is it not possible to run 2 instances of mediamtx on the same device?

Here are my configs and the output for each instance started with each config.

First I will give the simpler configuration as I don't think this involves a bug, but is due to my lack of knowledge. I will include output with logLevel set to debug, and dumpPackets set to true further down.

Note, either one of these configs will work as long as there are no other instances of mediamtx running.

Assume that I will not have control over how the first instance is configured. I would need a configuration for the second instance (ie, the configuration I would use in my app) that would be able to launch, regardless (mostly) of how the the first instance is configured.

- First instance - Simulate config and execution of another app, from the command line:

Config:

logLevel: info

api: yes
apiAddress: :9998 

rtsp: yes
rtspAddress: :8555

webrtc: yes
webrtcAddress: :8890

metrics: yes       # ← Metrics enabled on this one.
metricsAddress: :8003 

# NOTE: These addresses must be consecutive.
rtpAddress: :8000
rtcpAddress: :8001 

paths:
  cam2:
    source: rtsp://admin:redacted@192.168.1.181/Preview_01_sub
    rtspTransport: tcp

Output:

./mediamtx mediamtx.yml
2026/06/18 06:16:42 INF MediaMTX v1.19.1, darwin, arm64
2026/06/18 06:16:42 INF configuration loaded from /Users/kevin/Sites/CamMTX.app/Contents/Resources/app.nw/bin/mediamtx.yml
2026/06/18 06:16:42 INF [metrics] started with listener on :8003 (TCP/HTTP)
2026/06/18 06:16:42 INF [path cam2] [RTSP source] started
2026/06/18 06:16:42 INF [RTSP] started with listeners on :8555 (TCP/RTSP), :8000 (UDP/RTP), :8001 (UDP/RTCP)
2026/06/18 06:16:42 INF [RTMP] started with listener on :1935 (TCP/RTMP)
2026/06/18 06:16:42 INF [HLS] started with listener on :8888 (TCP/HTTP)
2026/06/18 06:16:42 INF [WebRTC] started with listeners on :8890 (TCP/HTTP), :8189 (UDP/ICE)
2026/06/18 06:16:42 INF [SRT] started with listener on :8890 (UDP/SRT)
2026/06/18 06:16:42 INF [MoQ] started with listeners on :8892 (TCP/HTTP2), :8892 (UDP/HTTP3)
2026/06/18 06:16:42 INF [API] started with listener on :9998 (TCP/HTTP)
2026/06/18 06:16:42 INF [path cam2] stream is available and online, 2 tracks (H264, MPEG-4 Audio)
2026/06/18 06:16:43 INF [path cam2] RTP packets are too big (1444 > 1440), remuxing them into smaller ones

- Second instance - Simulate config and execution in my app, from the command line:

Config:

logLevel: info

api: yes
apiAddress: :9999        # ← Different from first instantiation config

rtsp: yes
rtspAddress: :8556        # ← Different from first instantiation configed

webrtc: yes
webrtcAddress: :8891      # ← Different from first instantiation configged

metrics: no        # ← Metrics turned off on this one.

# NOTE: These addresses must be consecutive.
rtpAddress: :8020          # ← Different from first instantiation config
rtcpAddress: :8021         # ← Different from first instantiation config

paths:
  cam3:
    source: rtsp://admin:redacted@192.168.1.185/Preview_01_sub
    rtspTransport: tcp

Output:

./mediamtx ./mediamtx2.yml
2026/06/18 07:51:13 INF MediaMTX v1.19.1, darwin, arm64
2026/06/18 07:51:13 INF configuration loaded from /Users/kevin/Sites/CamMTX.app/Contents/Resources/app.nw/bin/mediamtx2.yml
2026/06/18 07:51:13 INF [path cam3] [RTSP source] started
2026/06/18 07:51:13 INF [RTSP] started with listeners on :8556 (TCP/RTSP), :8020 (UDP/RTP), :8021 (UDP/RTCP)
2026/06/18 07:51:13 ERR listen tcp :1935: bind: address already in use
2026/06/18 07:51:13 INF [RTSP] closing
2026/06/18 07:51:13 INF [path cam3] [RTSP source] stopped: path is closing
2026/06/18 07:51:13 INF waiting for running hooks

Here is the output with same configurations, but with logLevel set to debug, and dumpPackets set to true:

First instance:

./mediamtx mediamtx.yml
2026/06/18 07:46:38 INF MediaMTX v1.19.1, darwin, arm64
2026/06/18 07:46:38 INF configuration loaded from /Users/kevin/Sites/CamMTX.app/Contents/Resources/app.nw/bin/mediamtx.yml
2026/06/18 07:46:38 INF [metrics] started with listener on :8003 (TCP/HTTP)
2026/06/18 07:46:38 DEB [path cam2] created
2026/06/18 07:46:38 DEB path manager created
2026/06/18 07:46:38 INF [path cam2] [RTSP source] started
2026/06/18 07:46:38 DEB [path cam2] [RTSP source] connecting
2026/06/18 07:46:38 INF [RTSP] started with listeners on :8555 (TCP/RTSP), :8000 (UDP/RTP), :8001 (UDP/RTCP)
2026/06/18 07:46:38 INF [RTMP] started with listener on :1935 (TCP/RTMP)
2026/06/18 07:46:38 INF [HLS] started with listener on :8888 (TCP/HTTP)
2026/06/18 07:46:38 INF [WebRTC] started with listeners on :8890 (TCP/HTTP), :8189 (UDP/ICE)
2026/06/18 07:46:38 INF [SRT] started with listener on :8890 (UDP/SRT)
2026/06/18 07:46:38 DEB [path cam2] [RTSP source] [c->s] OPTIONS rtsp://192.168.1.181/Preview_01_sub RTSP/1.0
CSeq: 1
User-Agent: gortsplib


2026/06/18 07:46:38 INF [MoQ] started with listeners on :8892 (TCP/HTTP2), :8892 (UDP/HTTP3)
2026/06/18 07:46:38 INF [API] started with listener on :9998 (TCP/HTTP)
2026/06/18 07:46:38 DEB [path cam2] [RTSP source] [s->c] RTSP/1.0 200 OK
CSeq: 1
Date: Thu, Jun 18 2026 13:46:44 GMT
Public: OPTIONS, DESCRIBE, SETUP, TEARDOWN, PLAY, PAUSE, GET_PARAMETER, SET_PARAMETER


2026/06/18 07:46:38 DEB [path cam2] [RTSP source] [c->s] DESCRIBE rtsp://192.168.1.181/Preview_01_sub RTSP/1.0
Accept: application/sdp
CSeq: 2
User-Agent: gortsplib


2026/06/18 07:46:38 DEB [path cam2] [RTSP source] [s->c] RTSP/1.0 401 Unauthorized
CSeq: 2
Date: Thu, Jun 18 2026 13:46:44 GMT
WWW-Authenticate: Digest realm="LIVE555 Streaming Media", nonce="051ea730f0ba92b5071880a6777b9611"


2026/06/18 07:46:38 DEB [path cam2] [RTSP source] [c->s] DESCRIBE rtsp://192.168.1.181/Preview_01_sub RTSP/1.0
Accept: application/sdp
Authorization: Digest username="admin", realm="LIVE555 Streaming Media", nonce="051ea730f0ba92b5071880a6777b9611", uri="rtsp://192.168.1.181/Preview_01_sub", response="54e9e9cde21c013ad9470f5b0c5a56b0"
CSeq: 3
User-Agent: gortsplib


2026/06/18 07:46:38 DEB [path cam2] [RTSP source] [s->c] RTSP/1.0 401 Unauthorized
CSeq: 3
Date: Thu, Jun 18 2026 13:46:44 GMT
WWW-Authenticate: Digest realm="LIVE555 Streaming Media", nonce="6baa9e53f2611d8567e91be5bb6d38ff"


2026/06/18 07:46:38 ERR [path cam2] [RTSP source] bad status code: 401 (Unauthorized)
2026/06/18 07:46:43 DEB [path cam2] [RTSP source] connecting
2026/06/18 07:46:43 DEB [path cam2] [RTSP source] [c->s] OPTIONS rtsp://192.168.1.181/Preview_01_sub RTSP/1.0
CSeq: 1
User-Agent: gortsplib


2026/06/18 07:46:43 DEB [path cam2] [RTSP source] [s->c] RTSP/1.0 200 OK
CSeq: 1
Date: Thu, Jun 18 2026 13:46:49 GMT
Public: OPTIONS, DESCRIBE, SETUP, TEARDOWN, PLAY, PAUSE, GET_PARAMETER, SET_PARAMETER


2026/06/18 07:46:43 DEB [path cam2] [RTSP source] [c->s] DESCRIBE rtsp://192.168.1.181/Preview_01_sub RTSP/1.0
Accept: application/sdp
CSeq: 2
User-Agent: gortsplib


2026/06/18 07:46:43 DEB [path cam2] [RTSP source] [s->c] RTSP/1.0 401 Unauthorized
CSeq: 2
Date: Thu, Jun 18 2026 13:46:49 GMT
WWW-Authenticate: Digest realm="LIVE555 Streaming Media", nonce="4c1e34c7ad827d71019b694b618ddde8"


2026/06/18 07:46:43 DEB [path cam2] [RTSP source] [c->s] DESCRIBE rtsp://192.168.1.181/Preview_01_sub RTSP/1.0
Accept: application/sdp
Authorization: Digest username="admin", realm="LIVE555 Streaming Media", nonce="4c1e34c7ad827d71019b694b618ddde8", uri="rtsp://192.168.1.181/Preview_01_sub", response="f0959844ceb2f55511fb654bd6629c3b"
CSeq: 3
User-Agent: gortsplib


2026/06/18 07:46:43 DEB [path cam2] [RTSP source] [s->c] RTSP/1.0 401 Unauthorized
CSeq: 3
Date: Thu, Jun 18 2026 13:46:49 GMT
WWW-Authenticate: Digest realm="LIVE555 Streaming Media", nonce="4fd8c10d82c1e77ff4943ecf137165cd"


2026/06/18 07:46:43 ERR [path cam2] [RTSP source] bad status code: 401 (Unauthorized)
2026/06/18 07:46:48 DEB [path cam2] [RTSP source] connecting
2026/06/18 07:46:48 DEB [path cam2] [RTSP source] [c->s] OPTIONS rtsp://192.168.1.181/Preview_01_sub RTSP/1.0
CSeq: 1
User-Agent: gortsplib


2026/06/18 07:46:48 DEB [path cam2] [RTSP source] [s->c] RTSP/1.0 200 OK
CSeq: 1
Date: Thu, Jun 18 2026 13:46:54 GMT
Public: OPTIONS, DESCRIBE, SETUP, TEARDOWN, PLAY, PAUSE, GET_PARAMETER, SET_PARAMETER


2026/06/18 07:46:48 DEB [path cam2] [RTSP source] [c->s] DESCRIBE rtsp://192.168.1.181/Preview_01_sub RTSP/1.0
Accept: application/sdp
CSeq: 2
User-Agent: gortsplib


2026/06/18 07:46:48 DEB [path cam2] [RTSP source] [s->c] RTSP/1.0 401 Unauthorized
CSeq: 2
Date: Thu, Jun 18 2026 13:46:54 GMT
WWW-Authenticate: Digest realm="LIVE555 Streaming Media", nonce="9a472845f8785accf8a0bb90f74483a6"


2026/06/18 07:46:48 DEB [path cam2] [RTSP source] [c->s] DESCRIBE rtsp://192.168.1.181/Preview_01_sub RTSP/1.0
Accept: application/sdp
Authorization: Digest username="admin", realm="LIVE555 Streaming Media", nonce="9a472845f8785accf8a0bb90f74483a6", uri="rtsp://192.168.1.181/Preview_01_sub", response="af9d2905fa7f468a9aa3cb81da5a7d07"
CSeq: 3
User-Agent: gortsplib


2026/06/18 07:46:49 DEB [path cam2] [RTSP source] [s->c] RTSP/1.0 401 Unauthorized
CSeq: 3
Date: Thu, Jun 18 2026 13:46:54 GMT
WWW-Authenticate: Digest realm="LIVE555 Streaming Media", nonce="084d2279cde2c1a45054cceb3b17c952"


2026/06/18 07:46:49 ERR [path cam2] [RTSP source] bad status code: 401 (Unauthorized)
2026/06/18 07:46:54 DEB [path cam2] [RTSP source] connecting
2026/06/18 07:46:54 DEB [path cam2] [RTSP source] [c->s] OPTIONS rtsp://192.168.1.181/Preview_01_sub RTSP/1.0
CSeq: 1
User-Agent: gortsplib


2026/06/18 07:46:54 DEB [path cam2] [RTSP source] [s->c] RTSP/1.0 200 OK
CSeq: 1
Date: Thu, Jun 18 2026 13:46:59 GMT
Public: OPTIONS, DESCRIBE, SETUP, TEARDOWN, PLAY, PAUSE, GET_PARAMETER, SET_PARAMETER

#...keeps running...

Second instance:

./mediamtx ./mediamtx2.yml
2026/06/18 07:48:01 INF MediaMTX v1.19.1, darwin, arm64
2026/06/18 07:48:01 INF configuration loaded from /Users/kevin/Sites/CamMTX.app/Contents/Resources/app.nw/bin/mediamtx2.yml
2026/06/18 07:48:01 DEB [path cam3] created
2026/06/18 07:48:01 DEB path manager created
2026/06/18 07:48:01 INF [path cam3] [RTSP source] started
2026/06/18 07:48:01 DEB [path cam3] [RTSP source] connecting
2026/06/18 07:48:01 INF [RTSP] started with listeners on :8556 (TCP/RTSP), :8020 (UDP/RTP), :8021 (UDP/RTCP)
2026/06/18 07:48:01 ERR listen tcp :1935: bind: address already in use
2026/06/18 07:48:01 INF [RTSP] closing
2026/06/18 07:48:01 DEB path manager is shutting down
2026/06/18 07:48:01 INF [path cam3] [RTSP source] stopped: path is closing
2026/06/18 07:48:01 DEB [path cam3] destroyed: terminated
2026/06/18 07:48:01 INF waiting for running hooks

dalamardruid · 2026-06-19T07:29:16Z

dalamardruid
Jun 19, 2026

Port 1935 in the default configuration is used by mediaMTX for RTMP.

rtmpAddress: :1935

Check the rtmp section of the configuration for both instances., if you don't use rtmp try set rtmp: false in both configuration

6 replies

aniolpages Jun 19, 2026

Port 8892 is used by MoQ. If you don't need some of the built-in protocols, you can disable them, for example:

moq: false
rtmp: false
srt: false
hls: false

If you don't specify these settings, MediaMTX will use its default configuration, which enables those servers and binds them to their default ports.

You can check the default configuration file to see which protocols are enabled by default and decide what you want to disable:

https://github.com/bluenviron/mediamtx/blob/main/mediamtx.yml

Allasso Jun 19, 2026
Author

Yes, I have tried with those things turned off. I still get this error then exit:

ERR listen tcp :8892: bind: address already in use

Here is my current config:

api: yes
apiAddress: :30197

rtsp: yes
rtspAddress: :30154
rtpAddress: :30100
rtcpAddress: :30101

hls: no
rtmp: no
srt: no
playback: no
metrics: no
pprof: no
moq: no

webrtc: yes
webrtcAddress: :30189
webrtcLocalUDPAddress: :30190
webrtcLocalTCPAddress: ""

paths:

aniolpages Jun 19, 2026

Since version 1.16.2 (iirc), you need to use “true” / “false” instead of “yes” / “no”.
Can you replace the values and try again?

Allasso Jun 20, 2026
Author

Replaced “yes” / “no” with “true” / “false” -- same result.

aniolpages Jun 20, 2026

Can you provide debug logs again?

Provide feedback

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Multiple instances of mediamtx #5882

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Multiple instances of mediamtx #5882

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Allasso Jun 18, 2026

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Replies: 1 comment · 6 replies

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dalamardruid Jun 19, 2026

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aniolpages Jun 19, 2026

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Allasso Jun 19, 2026 Author

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Allasso Jun 20, 2026 Author

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Allasso
Jun 18, 2026

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dalamardruid
Jun 19, 2026

Allasso Jun 19, 2026
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Allasso Jun 20, 2026
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