[mythtv-users] Why do MythTV recordings have no sound when played outside MythTV?

[James Linder]

> On Jul 30, 2025, at 06:27, Nick Morrott <knowledgejunkie at gmail.com> wrote:
> 
> On Tue, 29 Jul 2025 at 22:46, A. F. Cano via mythtv-users
> <mythtv-users at mythtv.org> wrote:
>> 
>> 
>> I would like to extract some video clips from MythTV recordings.  I've done
>> this with Kdenlive with other non-MythTV video files and it works fine.  If
>> I try to play the MythTV recordings with smplayer, mplayer, etc...  There
>> is no sound.
>> 
>> What is different about MythTV recordings (*.ts) that make them incompatible
>> with every other video player I've tried?  I have tried to transcode video
>> clips and put them on my bepasty server and they work fine, ie: a regular
>> browser can play them, but not those that come from MythTV recordings.
> 
> I was not aware AC-3 was supported in an MP4 container, but times may
> have likely changed (especially in software players).
> 
> A couple of quick tests:
> 
> i) in your ffmpeg command, keep audio/video handing the same, but
> output to an mkv container (instead of mp4)
> ii) in your ffmpeg command, transcode the AC-3 audio to AAC, whilst
> outputting to an mp4 container
> 
> Questions:
> 
> i) What do the smplayer/mpv logs say if you start them from the
> command when playing one of the problematic files? Do they see any
> audio tracks?
> ii) Do you have any AC-3 pass through enabled which might be affecting
> which audio device is used for output?
> iii) Do you see the same behaviour in e.g. vlc?

Nick
I’m flat out at the moment. You are welcome to have and fiddle, but I have to appologise and pass
James