Skip to main content

Notice

Please note that most of the software linked on this forum is likely to be safe to use. If you are unsure, feel free to ask in the relevant topics, or send a private message to an administrator or moderator. To help curb the problems of false positives, or in the event that you do find actual malware, you can contribute through the article linked here.
Topic: Is ffmpeg or fdk-aac support AAC metadata and apply DRC? (Read 2867 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.

Is ffmpeg or fdk-aac support AAC metadata and apply DRC?

I've revised FDK-AAC and embedded DRC value in metadata and encoded an AAC stream.
But I found it was invalid when I used ffmpeg for decoding this stream, there was nothing changed in Audio gain value.

I confirmed DRC data already embedded in AAC stream, so what do you guys think of this problem? Thanks a lot.

Main revision as below:
(1)fdk-aac\libAACenc\src\aacenc_lib.cpp, modified below flag.
            config->userMetaDataMode   = 1;
  (2)  fdk-aac\libAACenc\src\metadata_main.cpp,modified below default setting.
  static const AACENC_MetaData defaultMetaDataSetup = {
         AACENC_METADATA_DRC_MUSICSTANDARD, //AACENC_METADATA_DRC_NONE,
         AACENC_METADATA_DRC_MUSICSTANDARD, //AACENC_METADATA_DRC_NONE,
         -(31<<16),
         -(31<<16),
         1, //0,
          .....
        };

 

Re: Is ffmpeg or fdk-aac support AAC metadata and apply DRC?

Reply #1
I've revised FDK-AAC and embedded DRC value in metadata and encoded an AAC stream.
But I found it was invalid when I used ffmpeg for decoding this stream, there was nothing changed in Audio gain value.

I confirmed DRC data already embedded in AAC stream, so what do you guys think of this problem? Thanks a lot.

ffmpeg's native AAC decoder does not support DRC metadata for AAC (they are parsed, but just thrown away).
You can download samples from https://www2.iis.fraunhofer.de/AAC/metadata.html and test yourself.


 
SimplePortal 1.0.0 RC1 © 2008-2021