When trying to receive a DAB+ service (64kbit/s) it was found that the generated DAB+ ETI stream does not seem to be standard compliant:
ETSI TS 102 563 Annex D DAB+ specification says:
"The decoder then iterates over the au_start parameters. The first AU starts immediately after the super frame header; the last AU ends at the super frame end."

In the DAB+ Audio WAPP generated stream the AU does NOT end at the super frame end, but earlier. As a result, in the decoder the CRC check on the last AU fails, the AU frame is dropped and this causes one out of every three (3) audio packets to be skipped.

The result for the audio listener is faster audio and gaps in between.

Hi,

The DAB+ encoder fills the last AU with padding bytes to fill the DAB super frame and the CRC is written right after. So, the last AU should ends at the super frame ends, as mentioned in the standard.

I'm currently investigating this issue to find out where the problem is located.

What was your settings:
- Source mode: mono or stereo?
- Target mode: mono or stereo?

Is it specific with 64 kbit/s or also with other target bitrates?

Thank you,

Pascal

The issue is now solved.

The CRC was not updated when the size of the last AU was increased to fill de DAB super frame.

Thanks for reporting this bug.

Pascal