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ittiam-systems / libmpegh

MPEG-H 3D Audio Low Complexity Profile Decoder. Encoder: https://github.com/ittiam-systems/libmpeghe
http://www.ittiam.com/
BSD 3-Clause Clear License
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What are valid drc effect types? #35

Closed sclsj closed 1 year ago

sclsj commented 1 year ago

[-effect:] I can't find any documentation on what argument I can pass to this option. Is there a list of effects and what they do?

SakethSathuvalli commented 1 year ago

Hi @sclsj,

The effect types and their descriptions are part of the MPEG-D DRC specification

sclsj commented 1 year ago

Thank you! Is there a specific page number / range you can give me to the list of options?

sclsj commented 1 year ago

OK. I saw it in Table A.45. But do I use the bit position, drcseteffect, or shortname?

sclsj commented 1 year ago

And how can I set a lower gain? It seems like -target_loudness does nothing.

sclsj commented 1 year ago

It seems like it's still not working. For example, I tried effect:10, -effect:"Fade-in", and -effect:fade which all produced the same result if the flag is not specified. I though if it doesn't change the DRC parameters (maybe a limiter to avoid clipping is always applied), it should at least change something?

sclsj commented 1 year ago

I'm mainly trying to get #20 fixed because I felt like there is definitely a limiter applied overall because from experimenting rendering of different channel layout it seems like individual objects are not heavily compressed. I'm trying to see what options will allow me to override the encoder settings to compress heavily.

sclsj commented 1 year ago

So all in all, is there any option / set of options that will allow me to override the default specification and preserve the dynamic range of the source material?

SakethSathuvalli commented 1 year ago

Hi @sclsj,

It is possible to extract un-rendered signals from the decoder using the -ext_ren: command line option. However, there is no option to avoid the DRC processing happening on the stream if DRC paylod is present in the encoded bit-stream.

You can refer to our wiki page on external rendering interfaces for more information on using the option -ext_ren:

Thanks!

sclsj commented 1 year ago

Closing as duplicate of #20 and #19