Hi,
I did some more testing with Flac audio. For some movies after converting trueHD/dts-hd to Flac (i think it applies to lpcm too) the resulting audio track is significantly lower volume. Probably because dts contains metadata that instructs the receiver by how much it should boost the signal and flac/lpcm is just raw audio information. For example Gladiator is a movie for which flac/lpcm is 4,5 dB lower than it could be.
I found a good way to safely increase the signal with ffmpeg. First you have to find by how many dB you can losslessly increase volume with this command:
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ffmpeg -i video.avi -af "volumedetect" -vn -sn -dn -f null /dev/null
This outputs information about how much dB you can increse the volume without going into clipping. For example:
[Parsed_volumedetect_0 @ 0x7f8ba1c121a0] mean_volume: -16.0 dB
[Parsed_volumedetect_0 @ 0x7f8ba1c121a0] max_volume: -5.0 dB
[Parsed_volumedetect_0 @ 0x7f8ba1c121a0] histogram_0db: 87861
Important is only the max_volume
Then use the command to increase the volume by max_volume amount:
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ffmpeg -i input.wav -af "volume=5dB" output.wav
This command only boosts the overall signal, there is no normalization happening, so it's still a lossless process.
Is it possible to incorporate this process into dovi_scripts @RESET_9999
You can find more information about it under this link (Option 3)
https://superuser.com/questions/323119/ ... ing-ffmpeg