Opening MPEG-TS files - audio is offset in timeline

Audacity 3 Help Forum Windows
1

I’m using Audacity 2.1.3 to edit MPEG-TS files which have come from recording radio programmes on a DVB-S2 satellite receiver. Operating system is Windows 10.

I find that although the files open, the audio does not begin at 0 in the timeline, but is offset so that it starts at approximately 1 or 2 hours along. If I immediately save the file to another format, I get an hour or so of silence followed by the expected audio. The actual offset seems to vary from file to file.

Obviously I can edit the silence out but it is a bit of a nuisance.

At first I thought it must be something wrong with my installation but I’ve tried a fresh install on a different machine and get exactly the same effect.

I’ve never had this problem with other file formats, only these transport streams. I’m wondering whether Audacity is being confused by some internal timestamps within the file. Is there any way to force the audio to start at time zero?

2

You didn’t mention the special FFMpeg software add-on. Do you have the latest one compatible with Audacity 2.1.3?

Native Audacity will only open a relatively small list of files, but if you install FFMpeg, the list grows a lot. Audacity may have trouble knowing what a Transport Stream is, but is guessing at it anyway.

http://www.audacityteam.org/download/windows/

Scroll down.

Koz

3

Oh yes, I have the FFMpeg library installed. Audacity is not much use to me without it. It is definitely needed to open MPEG-TS.

I just follow the installation instructions from the “Library” section of “Preferences”. It currently reports the version as

F(55.33.100),C(55.52.102),U(52.66.100)

I also have LAME 3.99.3 but I don’t believe that is relevant to the current issue.

4

I have given up on this problem. I have switched to using the raw command line version of ffmpeg to transcode my MPEG-TS files. It turns out to be orders of magnitude faster anyway.

5

What is the command that you are using?
Do you have an example file that we could try so that we can take a look at what may be going wrong?