Fri, Dec 06, 2024 at 10:31:06PM +0100, schorpp wrote:
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.
Right, it's H.265 video in Germany. I found somewhere a reference to
something that would transcode H.265 into H.264 on the fly on a
Raspberry Pi 3, so that the Videocore GPU could play it in real time.
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?
At https://git.linuxtv.org/v4l-utils.git I found a reference to the
command dvbv5-scan. An "apt search dvbv5-scan" on my Debian Sid as well
as on Raspbian 12.8 yielded two packages: dvb-tools and w-scan-cpp. I
vaguely remember that I had used the latter one a few years ago. I just
invoked the following on the Raspberry Pi:
w_scan_cpp -c FI
The output during scanning looks convincing, but the program seems to
get stuck waiting for something at the end, for several minutes.
I also tried to invoke dvbv5-scan from dvb-tools, but it seems to
require a file that contains some initial parameters.
Anyway, I was mainly wondering if it is normal that the EPG update in
VDR did not find the new transponder. I guess it is; the search space
would be huge if it had to cover satellite, cable, terrestrial and some
IPTV sources as well.
The HE-AAC support in rpihddevice is experimental,
as it has been in ffmpeg until today and rpihddevive is based on it?
As in:
#ifdef ENABLE_AAC_LATM
#warning "experimental AAC-LATM frame parser enabled, only 2ch/48kHz supported!"
#endif
Have You tried the latest git ffprobe version, does it detect the aac
flavor of Your dvb-t2 DVB channels correctly?
I only have 2-channel recordings or DVB-T2 streams available to me.
Those already play without any problems. But I don't have any recording
with multichannel audio. I would like to implement correct detection and
playback of multichannel HE-AAC audio, so that the AAC audio support
could be enabled by default in rpihddevice.
Have You tried latest git mediainfo?
I was reading the libmediainfo source code a few days ago. I guess I
should just have executed mediainfo on an MPEG-4 TS file inside a
debugger, to find out how and where exactly it detects the audio
parameters.
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.
Right, also according to the NorDig specification, some transcoding of
audio is mandatory for some audio output options.
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.
Sorry, I could not find it. I figured out that AVR here must refer to
Audio Video Receiver. The only HDMI output devices that I have are
displays with 2 built-in speakers. I believe that I am currently using
2-channel PCM audio output.
Are there any sample MPEG TS recordings with 5.1 channel AAC audio?
That would be very helpful. In a 2-channel setup, would it be customary
to pass through only the first 2 channels and ignore the rest?
Marko
