Am 06.12.24 um 21:32 schrieb Marko Mäkelä:
A couple of weeks ago, Finland took the penultimate step to get rid of DVB-T. Since years, we had DVB-T and DVB-T2 running in parallel. The DVB-T transponders should be shut down in 2025.
same here but h.265 video and aac audio.
The step was to introduce a second free-to-air DVB-T2 bouquet to carry some channels that were previously only available with DVB-T and MPEG-2. The VDR channel search failed to find this transponder; I ran a patched version of https://github.com/mighty-p/t2scan/pull/15/ to generate a new channels.conf. (Is this a bug of VDR, or a feature? I remember that when I originally set up VDR, I had to get a channels.conf from tscan or t2scan.)
have You tried the latest git version of scan in dvb-utils @linuxtx.org repo?
Unlike our first free-to-air DVB-T2 bouquet, which uses MPEG-4 H.264 video with AC3 audio, the second one uses H.264 video and HE-AAC audio, also known as LATM or LOAS. This had to be explicitly enabled for my output device: https://github.com/reufer/rpihddevice/issues/20
The HE-AAC support in rpihddevice is experimental,
as it has been in ffmpeg until today and rpihddevive is based on it?
maybe because the sampling rate is hard-coded as 48 kHz and the number of channels as 2. Unlike AC3, it does not look like these parameters would be available in any audio frame header. As far I understood from a NorDig.org specification, the sampling rate would always be 48 kHz, but the number of channels could be identified by something in the container, specifically, Table 12.28 and Table 12.29 at page 164 of https://nordig.org/wp-content/uploads/2016/03/NorDig-Unified- Requirements-ver.-3.2.1.pdf
Have You tried the latest git ffprobe version, does it detect the aac flavor of Your dvb-t2 DVB channels correctly?
Have You tried latest git mediainfo?
What would have to be changed in VDR or rpihddevice or both to correctly switch between 2-channel and 5.1-channel HE-AAC audio? This is mostly an academic question and exercise, because I only have stereo audio hardware and don't know if any programming is actually available with multichannel audio.
Not at all academic. Since AVRs do not implement Fraunhofer codecs we need a HDNI PCM Multichannel driver for the raspberry pi to playback 5.1 channel aac without transcoding it to ac3 which can be done with mplayer on the fly.
I've made a HDMI PCM Multichannel output to AVR driver patch for the Allwinner SoC alsa audio driver, look for it on the alsa-dev list archives.
Best regards, Marko
y tom
