ffmpeg not 100% compliant with DVB

[PE5PVB]

It strikes me that ffmpeg's TS as we use it is not completely compatible with the DVB standard. For example, if I watch the stream with VLC player, it often takes a while before I have audio and video. I also have a Tandberg MPEG encoder and it gives an almost instant image. I also see that, for example, a professional Tandberg receiver has some difficulty with demodulating the ffmpeg signal, while it works fine with the signal from the Tandberg encoder. I assume this has to do with frame composition and timing. Has anyone ever analyzed this?

In my case I tested this with a symbol rate of 1000ks/s

[g0mjw]

I suspect this is true, but I can't imagine how to take the ffmpeg source code and modify it to be compliant. We have to use what is available.

Mike

[PE5PVB]

Mike,

I'm on the quest to find the differences. If anyone have info on this, please let me know. In that case I can send the info to the ffmpeg team.

[VK3EHT]

Hello Mike,
Did you work through ffmpeg's issues?
I believe the issue is to do with the stream PCR inconsistencies and possibly injection of PMT and PAT at regular intervals.

need to TS Analyse the difference between the Tandberg stream and ffmpeg generated stream?
Would be great to include a ffmpeg option to force dvb-compliance?

Regards

Rob VK3EHT

[g0mjw]

I didn't Rob - but the main thing is it works, compliant or not.

Mike

[VK3EHT]

Thanks for the reply Mike.
I thought ffmpeg development team may have devoted some resources to fix the mpegtsmux in the later releases?

[g0mjw]

Thanks for the reply Mike.
I thought ffmpeg development team may have devoted some resources to fix the mpegtsmux in the later releases?

Only if they know. Perhaps raise a bug report?