Since TVNZ insist on still using AAC-HE LATM audio (thank you TV3 for providing a AC3 alternative audio track) and Syabas not making any commitments when they will release a firmware fix to play those files I set to finding a way (not in real time to be sure) of playing those files on the PCH.
Note this is still in experimentation stage (and though he is unlikely to read this, many thanks to Donald Graft, author of dgindex and now dgavcindex for taking some sample captures I uploaded, and changing his program to read this audio file format). Those who are game to try I would welcome feedback on their experiences.
Note also this is not a complete guide - much is left to the reader to work out!
1. Get dgavcindex from dgavcindex You will need the Alpha 30 release that supports LATM audio
2. Open the ts file captured from your DVB-T card. Go to Audio, select the AAC-HC LATM/LOAS stream
3. Save the project and demux video. You should get 3 files xxx.dga xxx.avc (the video) and xxx.aac (the audio demuxed)
4. Fire up Winamp and open this aac file. You should get audio. I am using Winamp v5.54
5. Get hold of the Winamp File Output plugin (go to the winamp site and look for plugins)
6. In Winamp Options/Preferences/Output choose the File Output plugin
7. Play the file again. It will output the file as a wav file
8. Use besweet or the gui belight to convert this wav file to ac3 (make sure you retain the sampling rate of 48Khz)
9 Get hold of tsmuxer Get the gui if you can
10 Open the avc and ac3 files you have now. This part I am not sure you have to do and I doing further experimentation on it. In the audio delay area insert a delay of 1000ms (it seems to be constant)
11 Mux the files back as a ts file
And you're done - you have a ts file that now has ac3 audio rather than aac and the PCH plays it fine