Transcode fails after a few hours

[niels2000]

Hello community,

I am running a setup where I use VLC to transcode a number of web-radio channels to multicast using VLC. However, these transcodes start to fail after a number of hours (typically 3-5 but sometimes much less) with the following error types:

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main warning: late buffer for mux input (14678) main warning: late buffer for mux input (4865) main warning: late buffer for mux input (976)

The error is logged many, many times in the log (of course the number in paranthesis changes). The only way to recover from the problem appears to be to completely restart the VLC process.

Here is an example of the configuration used to encode the stream:

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#!/bin/sh # export SUDO_UID=105 KANAL=radiotest exec /usr/bin/vlc-wrapper -I dummy --rtsp-wmserver --rtsp-tcp --ttl 32 --vlm-conf /etc/vlc/$KANAL.conf --loop --http-reconnect --verbose 2 --extraintf logger --logfile /var/log/vlc/$KANAL.log

/etc/vlc/radiotest.conf

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new radiotest broadcast enabled setup radiotest input http://netradio.radioskive.dk/ setup radiotest output #transcode{acodec=mp2a,ab=128,channels=2,samplerate=48000,alang=dan}:duplicate{dst=std{access=udp,mux=ts,dst=239.101.102.253:5501}} control radiotest play

The channel in question is publicly available as linked above, in case anyone feels like testing.

The VLC version used is this (I have removed the debian-multimedia repository as described on these forums):

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vlc@media-transcoder2:~$ vlc --version VLC media player 1.1.3 The Luggage (revision exported) VLC version 1.1.3 The Luggage (exported) Compiled by pbuilder on deep-thought (Feb 9 2011 20:15:21) Compiler: gcc version 4.4.5 (Debian 4.4.5-8) This program comes with NO WARRANTY, to the extent permitted by law. You may redistribute it under the terms of the GNU General Public License; see the file named COPYING for details. Written by the VideoLAN team; see the AUTHORS file.

Here is a log of the VLC starting up, and failing after a while:

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-- logger module started -- inhibit error: Failed to connect to the D-Bus session daemon: /usr/bin/dbus-launch terminated abnormally with the following error: Autolaunch error: X11 initialization failed. main error: no suitable interface module main error: no suitable interface module main error: interface "globalhotkeys,none" initialization failed dummy: using the dummy interface module... main warning: option file-caching is unknown access_http warning: ICY metaint=16000 access_http: Raw-audio server found, mp3 demuxer selected main error: ES_OUT_SET_(GROUP_)PCR is called too late (pts_delay increased to 1200 ms) main warning: late buffer for mux input (1695116) main warning: late buffer for mux input (1672654) main warning: late buffer for mux input (1649932) main warning: late buffer for mux input (1627101) main warning: late buffer for mux input (1604404)

I currently have a hack in place that scans the recent log files for "late buffer for mux input" and restarts the player when it happens. But obviously that is an ugly non-solution, so hopefully someone can help me understand what is going wrong and what I might change to fix it.

I will be happy to provide any information I have neglected.

[Rémi Denis-Courmont]

I guess the buffering code in the multiplexer code is not sufficiently robust.

[niels2000]

Thank you for the reply. From my reading the forums, it is my understanding that your expert opinion is to be trusted.

However, does this leave me without options? Does anyone have suggestions as to what I could try? Is there a work-around that would allow me to not have interruptions in the stream?

Here's one horrible hack I have been considering: what if I do two simultaneous transcodes of each channel and forward them to a single other VLC instance that then selects the working one and fails over to the other if one is down for a few seconds?

[niels2000]

In a different vein, if there's a bug in the software causing this behavior, is it possible to hire a developer to work on a patch that would fix our problem? We would be willing to allow the work to go into open source with the rest of VLC.

[Rémi Denis-Courmont]

This was just an educated guess. I don't know what the problem is; I only suspect buffering and synchronization lack robustness in the muxer plugins. If I am right, fixing may be quite involved.

[niels2000]

Any suggestions on things I could try?

Would upgrading to the latest git-release help?

Could I increase the buffer size to make the problem occur less frequently?

Is there anything I could do to try and improve the resilience of my setup?

Here's examples of what is logged that is NOT the "late mux" error. Any hints on how to clean up these errors to isolate the real problem?

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-- logger module started -- main warning: option file-caching is unknown inhibit error: Failed to connect to the D-Bus session daemon: /usr/bin/dbus-launch terminated abnormally with the following error: Autolaunch error: X11 initialization failed. main error: no suitable interface module main error: no suitable interface module main error: interface "globalhotkeys,none" initialization failed dummy: using the dummy interface module... access_http warning: ICY metaint=16000 access_http: Raw-audio server found, mp3 demuxer selected main error: ES_OUT_SET_(GROUP_)PCR is called too late (pts_delay increased to 1200 ms) main error: ES_OUT_SET_(GROUP_)PCR is called too late (pts_delay increased to 1404 ms) -- logger module started -- main warning: option file-caching is unknown inhibit error: Failed to connect to the D-Bus session daemon: /usr/bin/dbus-launch terminated abnormally with the following error: Autolaunch error: X11 initialization failed. main error: no suitable interface module main error: no suitable interface module main error: interface "globalhotkeys,none" initialization failed dummy: using the dummy interface module... access_http warning: ICY metaint=16000 access_http: Raw-audio server found, mp3 demuxer selected