[mythtv-users] trandcoding messes up 6 channel audio slow audio playback

Scott Macdonell genius9976 at yahoo.com
Thu Apr 28 15:40:35 UTC 2011

Thanks for the quick reply

----- Original Message -----
From: Jean-Yves Avenard <jyavenard at gmail.com>
To: Scott Macdonell <genius9976 at yahoo.com>; Discussion about MythTV <mythtv-users at mythtv.org>
Sent: Thursday, April 28, 2011 8:03 AM
Subject: Re: [mythtv-users] trandcoding messes up 6 channel audio slow audio playback

>Can you repost what you did to create that profile (step by step
>instructions) so I can reproduce your setup.

Sure, from the mythfrontend main menu:
Setup->Video->Recording Profiles->Transcoders->(Create new profile)
(though, I just selected one of my old ones that i've been using for years)

Then I created a profile with the following options:
Page 1: 
Profile name: 720p NoResize
No custom filter
The two boxes are not checked (No lossless transcoding 
nor resizing) 

Page 2: 
Codec: MPEG-4 
Bitrate: 5000kb/s 
Max Quality: 2 
Min Quality: 15 
Max quality difference between frames: 3 
Only two boxes are checked: Enable-high quality encoding and Enable 4MV encoding 
Number of Threads: 2 

Page 3: 
Codec: MP3 (When this problem first started I tried "Uncompressed" here, and that didn't help. )
Sampling Rate 48000 
MP3 Quality: 1 
Volume: 100% 

>I never ran mythtranscode personally, so I don't know if those are
>even the right options to use...
The command line options I used worked fine for both SD and HD recordings with only two audio channels (Last night E! HD was broadcasting in High Def, but with only 2 channels), but failed on a recording with 6 channels. As far as the setup of my transcoding profile goes... It worked for years, and I never fiddled with the stuff you're not supposed to change (quality sliders on page 2).

>What audio did you expect in the output file ? the original AC3 audio ?

mp3 stereo audio. I checked the codec info on these recordings in VLC and they all claim to have this (as do recordings I transcoded with this profile before the problems began). As noted above, changing the audio option in my transcoding profile to "uncompressed" didn't seem to fix anything like a month or two ago.

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