audio loss on ISDB-Tb

[sbstian]

Hi, after upgrading to 7.1.1 one channel is suffering from audio loss, in 7.1.2 is the same problem

Normal audio:

 

Audio loss

 

Edited August 19, 2021 by sbstian

[Griga]

Please check which audio type is used by the broadcaster for the working and the non-working channel by opening the DVBViewer Filter property page. Maybe it will also display error messages. Report them here or simply provide screenshots.

 

For a deeper analysis a short recording of the non-working channel in .ts format would be very useful. One minute is sufficient. You can upload it to WeTransfer. Use the menu button with three dots (...) to let WeTransfer provide a download link (instead of sending a mail) and send this link to me in a personal forum message (PM).

 

[sbstian]

14 hours ago, Griga said:

Please check which audio type is used by the broadcaster for the working and the non-working channel by opening the DVBViewer Filter property page. Maybe it will also display error messages. Report them here or simply provide screenshots.

 

For a deeper analysis a short recording of the non-working channel in .ts format would be very useful. One minute is sufficient. You can upload it to WeTransfer. Use the menu button with three dots (...) to let WeTransfer provide a download link (instead of sending a mail) and send this link to me in a personal forum message (PM).

 

audio PTS stopped, this happens only one channel, all use the same LATM AAC codec

Edited August 23, 2021 by sbstian

[Griga]

In your one-minute file there is a 400 ms audio drop-out when I play it with DVBViewer. It does not happen when I play the file with VLC. So far I have no idea why it happens.

 

Which audio decoder do you use for AAC? See Settings -> Filters when DVBViewer is playing.

 

Which DVBViewer version did you use before updating to 7.1.1?

 

[sbstian]

1 hour ago, Griga said:

En su archivo de un minuto hay un 400 ms de audio drop-out cuando lo juego con DVBViewer. No sucede cuando reproduzco el archivo con VLC. Hasta ahora no tengo ni idea de por qué sucede.

 

¿Qué decodificador de audio utilizas para AAC? Consulte Configuración -> filtros cuando DVBViewer se está reproduciendo.

 

¿Qué versión de DVBViewer utilizaste antes de actualizar a 7.1.1?

 

lav audio filter causes audio drop-out, microsoft DTV causes loss audio, only happens with this channel

I used version 7.1.0.0

 

[Griga]

4 hours ago, sbstian said:

I used version 7.1.0.0

 

I've tried with 7.1.0.0, but I get the same audio dropout in your file. No difference to 7.1.2.0.

 

If you want to try: DVBViewer 7.1.0.0 ist still available in the members download area -> older versions section, and maybe also as backup in your C:\Program Files (x86)\DVBViewer\setup folder.

 

[sbstian]

6 hours ago, Griga said:

 

I've tried with 7.1.0.0, but I get the same audio dropout in your file. No difference to 7.1.2.0.

 

If you want to try: DVBViewer 7.1.0.0 ist still available in the members download area -> older versions section, and maybe also as backup in your C:\Program Files (x86)\DVBViewer\setup folder.

 

I downgraded to the 7.1.0.0 and the audio loss returned, is very strange, I suspect it may be a problem with the channel  ?

Edited August 23, 2021 by sbstian

[Griga]

9 hours ago, sbstian said:

I suspect it may be a problem with the channel 

 

The channel seems to broadcast wrong time stamps.

 

Video and audio have presentation time stamps (PTS), so they can be synchronized. You can see the PTS on the DVBViewer Filter property page. If you click DVB, it shows the incoming DVB PTS. If you click Graph, it shows the PTS after conversion to the Windows playback time base. In your screenshot above the audio PTS are more than three hours off the mark. They are completely wrong.

 

I have just found out, that the audio drop-out in your file can be avoided by opening the LAV Audio Decoder property page and switching "Auto A/V Sync Correction" off. If this option is switched on, the decoder looks at the time stamps and pauses audio, if it is ahead of video, so that video and audio stay synchronized. If this option is switched off, it processes audio just as it comes, without considering time stamps. However, video and audio may get out of sync in this case.

 

Obviously there is a time stamp gap in your file. Suddenly the audio time stamps jump 400 ms ahead. The LAV Audio Decoder with Auto A/V Sync Correction tries to compensate it and pauses audio for 400 ms. That causes the short drop-out.

 

[sbstian]

14 hours ago, Griga said:

 

The channel seems to broadcast wrong time stamps.

 

Video and audio have presentation time stamps (PTS), so they can be synchronized. You can see the PTS on the DVBViewer Filter property page. If you click DVB, it shows the incoming DVB PTS. If you click Graph, it shows the PTS after conversion to the Windows playback time base. In your screenshot above the audio PTS are more than three hours off the mark. They are completely wrong.

 

I have just found out, that the audio drop-out in your file can be avoided by opening the LAV Audio Decoder property page and switching "Auto A/V Sync Correction" off. If this option is switched on, the decoder looks at the time stamps and pauses audio, if it is ahead of video, so that video and audio stay synchronized. If this option is switched off, it processes audio just as it comes, without considering time stamps. However, video and audio may get out of sync in this case.

 

Obviously there is a time stamp gap in your file. Suddenly the audio time stamps jump 400 ms ahead. The LAV Audio Decoder with Auto A/V Sync Correction tries to compensate it and pauses audio for 400 ms. That causes the short drop-out.

 

I will be monitoring to see if this is resolved, thank you very much for your help

any news I will leave an update here