AC3 to AC3 transcoding (because volume)

  • I prefer to use the built-in volume options of Kodi to change the volume of all media. This way I only have to use 1 remote and it also works with the Kore app on my phone.


    This always works except when I watch media with Dolby Digital AC3 as the audio stream. Then the Pi4 does pass through and the audio is out or reach for volume manipulation. When its AAC or DTS or any other multi channel format transcoding kicks in and the volume can be changed from within Kodi.


    As a workaround I would like to see an option to always transcode all formats to AC3 even when the original is already AC3. Then I won't ever again have to grab the receiver's remote when I'm too lazy and comfortable on the couch. 😎

  • Yes but the effect is that the audio is then downmixed to a stereo signal.

    What kind of audio interface you're using? You should be able to send multichannel PCM over HDMI as long as the receiver supports it:

    Quote

    For digital audio, if an HDMI device has audio, it is required to implement the baseline format: stereo (uncompressed) PCM. Other formats are optional, with HDMI allowing up to 8 channels of uncompressed audio at sample sizes of 16 bits, 20 bits, or 24 bits, with sample rates of 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, or 192 kHz

    HDMI - Wikipedia
    en.wikipedia.org

  • What kind of audio interface you're using? You should be able to send multichannel PCM over HDMI as long as the receiver supports it:

    https://en.wikipedia.org/wiki/HDMI#Audio/video

    Unfortunately the receiver only has optical and digital spdif ports. So no HDMI and thus no multi channel PCM. Therefor the standard HDMI output to the TV is set to 2.0 stereo. The TV passes the audio on to the receiver via optical spdif. The receiver supports AC3 and DTS but since the TV for some reason won't pass DTS through I only selected AC3 support in the audio settings in Kodi. AC3 is the only way to feed multi channel audio into this setup.

    When enabling Sync Playback To Display audio is always re-coded. Keep passthrough and AC3 Transcoding enabled.

    Doesn't that conflict with the function to change the Hz of the display to the media framerate? I always have the Pi4 match the video output with the media for fluent playback.