Cinema DTS / Home Video Mixes - Waveform Comparisons

[dvdmike]

Do DTS discs exist for The Game or Avatar?

[borisanddoris]

Do DTS discs exist for The Game or Avatar?

Not sure about The Game but Avatar was quad track (SR-SRD-DTS-SDDS)

[allldu]

So when you convert ac-3 to wav/flac with eac3to, it removes the dialogue normalization, is this the same what drc_scale 0.0000 command does?

So I just did a quick test on 2001 Space Odyssey DVD 5.1, converting it to 5.1 .w64. The first wave is the central channel converted via ffmpeg without drc_scale command aplied. The second one is ffmpeg with drc_scale set to 0. The third one is a straight forward convertion with UsEac3to130, no other commands. Looks like eac3to applies drc to 0 automatically.

   

[dvdmike]

Do DTS discs exist for The Game or Avatar?

Not sure about The Game but Avatar was quad track (SR-SRD-DTS-SDDS)

Was it not all digital distribution? The extended Bd claims to be the full cinema mix just wondered if we had it to compare, same with The Game

[stwd4nder2]

So I just did a quick test on 2001 Space Odyssey DVD 5.1, converting it to 5.1 .w64. The first wave is the central channel converted via ffmpeg without drc_scale command aplied. The second one is ffmpeg with drc_scale set to 0. The third one is a straight forward convertion with UsEac3to130, no other commands. Looks like eac3to applies drc to 0 automatically.

So if importing ac3 into audacity (which uses ffmpeg), would it be better to manually convert the track first with the drc_scale command to better preserver the full dr?

[maksnew]

Do DTS discs exist for The Game or Avatar?

Theatrical DTS kit was released for the Blu Ray Games movie, the comparison is identical

[deleted user]

Tom the problem isn't the codec, it's the implementation

I agree. But I'm just being practical. What use is an okay codec to me if it's just impossible for me to play it back without major distortions or having to transcode the audio every time I want to watch something with it?

So when you convert ac-3 to wav/flac with eac3to, it removes the dialogue normalization, is this the same what drc_scale 0.0000 command does?

So I just did a quick test on 2001 Space Odyssey DVD 5.1, converting it to 5.1 .w64. The first wave is the central channel converted via ffmpeg without drc_scale command aplied. The second one is ffmpeg with drc_scale set to 0. The third one is a straight forward convertion with UsEac3to130, no other commands. Looks like eac3to applies drc to 0 automatically.

Nice job! That mirrors my own experience in terms of how the waveform looks. Makes sense that eac3to can do it properly I guess. I'm just more used to ffmpeg personally.

[dwalkerdon]

It's possible I'm once again missing the context, but... Idk if Dialnorm is the correct term for what I mean, but ac-3 definitely seems to have massive issues with playing back at full dynamic range. I don't think it's necessarily an issue with the format, more with the playback software I've used. It's almost impossible to get a proper playback at full dynamic range in something like VLC or MPC-HC, last I checked.

I distinctly remember being impressed by how loud the gunshots were in Mission Impossible:Fallout in cinema. But then when watching the movie with AC-3 audio, they fell flat. Strange, I thought. I had disabled all dynamic range compression in the input filters and whatnot and in the settings. Still no good.

So I googled around and found that ffmpeg has a "-drc_scale" parameter. If you set it to 0.0000 (maybe a simple 0 is enough, but that's how I saw it), it deactivates any form of dynamic range compression. Lo and behold, the resulting wav file sounded absolutely amazing and just like I had remembered it from cinema.

For the record, I also verified this by recording my system sound with audacity. The base level volume was identical in both playbacks, but with the .ac3 the peaks were significantly lowered, taking all punch out of them.

Maybe this issue wouldn't exist with a properly set up receiver that lets you deactivate DRC. I don't know. But I know that ever since, I haven't trusted AC-3 and the only reason I ever use it is in cases where I can preserve the original ac-3 track without transcoding, simply because I like to preserve the original data. Otherwise I will always transcode to FLAC or WAV using drc_scale 0.0000.

I believe back then I also tested Adobe Audition and it imported it correctly too. But I wouldn't trust that as Adobe seems to sometimes change their import plugins from version to version... for example some of my older Premiere projects are no longer frame accurate when opened with a newer Premiere version.

My 43" Hisense Smart TV doesn't apply DRC to AC-3 tracks when I play files directly from the built in media player and output it via SPDIF to my HT receiver.

[allldu]

So if importing ac3 into audacity (which uses ffmpeg), would it be better to manually convert the track first with the drc_scale command to better preserver the full dr?

I think so, yeah. I am not sure if they fixed this for Audacity.

[titanic]

I just discovered this thread.
I wanted to buy the Matrix 4k, and it sucks now to know that it doesn't include the original audio.
Do we know anything about Matrix revolutions and Matrix reloaded?