[gst-devel] audio playback shift in time

[franchan]

Hello gstreamer developers,

Nobody knows an answer to my earlier question?


On Fri, Sep 4, 2009 at 5:23 PM, franchan <francis.meyvis at gmail.com> wrote:
> Hello,
>
> I have a custom mpegts demux. It gets data through the appsrc.
> Into the appsrc I push the mpegts coming from an UDP socket.
> This allows to do changing from UDP socket (other mpegts stream).
>
> When this happens I change the playbin2 first from playing to ready,
> Then back to playing again.
>
> The mpegts demux, when it sees the state change,
> removes its pads and waits for the new PAT/PMT information.
> When the mpegts sees the new PAT PMT, it recreates the new pads.
>
> Before the mpegts plugin sends out the PES data,
> I first send a flush-start, flush-stop and the new_segment event downstream.
> with the start and position time corresponding to the first PTS
> detected in the new mpegts data.
>
> For the first socket, when starting playback, all works fine: audio
> and video are in sync.
> When switching the socket the video starts playing fine after 1 to 2 seconds.
>
> However the audio behaves odd: its playback is delayed
> by the amount of time socket 1 has been playing.
>
> I verified the PTS timestamps on the input (in mpegts demux) and
> the output (audio/video decoders). These all seem fine;
> audio/video data is alternately push forward into the sinks.
>
> Still the alsa sink (or something else after the audio decoder)
> introduces this strange delay.
>
> Can somebody tell me what is going on and how to remove this delay for audio
> and still having the video play back as well?

(sorry I forgot to include my question again ...)

Thanks,
francis