Hi there,

I attempted to port this to Linux this morning, but it was non-trivial and after an hour I gave up. In theory all it should need is a few more #includes added, and removing functions that only exist in Microsoft's C library (_wremove). All of the dependencies are open source C libraries so on Linux you don't need to include those in the codebase, with the exception of the C++ json library being used here.

Thanks, I hope you decide to port this codebase in the future.

It seems that when you have a "pad_start" within the same track as "tempo", the resulting padding doesn't honor the value you set for it. This should be a fixed value that doesn't change when the tempo is affected. To reproduce:

"sub_channels": [
    {
        "file": "music.mp3",
        "pad_start": 22050,
        "tempo": 0.88,
        "fade_in": 11025,
        "trim_start": 211388,
        "trim_end": 423326
    }
]

The short-term workaround is to move the padding to an outside layer and sub_track the remaining track, although undesirable for simplicity sake:

"sub_channels": [
    {
        "pad_start": 22050,
        "file": "music.mp3",
        "sub_tracks": [
            {
                "tempo": 0.88,
                "fade_in": 11025,
                "trim_start": 211388,
                "trim_end": 423326
            }
        ]
    }
]

It should be made clear that qwertymodo/sox needs to be downloaded to the /3rdparty/sox directory in order to build the project. Maybe revise README.md with this info?

Also, building on my machine (Fedora Linux 36) doesn't work because of this:

make -C 3rdparty/sox -s
Making all in lpc10
Making all in libgsm
Making all in src
make -C msupcm++ -s
In file included from sox_main.h:8,
                 from SoxWrapper.h:2,
                 from AudioBase.cpp:3:
/usr/include/c++/12/codecvt: In constructor ‘std::codecvt_utf8<char16_t, _Maxcode, _Mode>::codecvt_utf8(std::size_t)’:
../3rdparty/sox/src/util.h:196:19: error: expected unqualified-id before ‘(’ token
  196 | #define min(a, b) ((a) <= (b) ? (a) : (b))
      |                   ^
[And more of this]

Obviously, it doesn't make sense that a macro is messing up constructors or templates or any of the stuff included from the STL/etc, so there must be an error further up in the header or in one of the other listed files that the compiler didn't like. I looked in the file and changed a few things in an attempt to get it to compile, but no dice after 2 hours of research..

It seems that when tempo is used, the outputted sample length is correct, but the inserted audio doesn't span the entire length of the track, so there is a null section at the end of the track. An example of this occurring is below:

"sub_channels": [
    {
        "pad_start": 22050,
        "file": "music.mp3",
        "sub_tracks": [
            {
                "tempo": 0.88,
                "fade_in": 11025,
                "trim_start": 211388,
                "trim_end": 423326
            }
        ]
    }
]

This one is a bit of an issue and doesn't seem to have any good workaround, other then artificially change the tempo value by trial and error until it stops at the right point, and sub_channel everything and manually throwing in paddings.

all the titles with apostrophes do not work and when changed to match the jsos file, they still do not work.

The "file" attribute doesn't properly default to the parent for each sub_channel. The workaround is to redefine the "file" on each sub_channel separately, but probably is an undesired solution.

Also, when the "file" attribute isn't defined, the program exits and doesn't offer any information/errors within the "verbosity" details.

pad_start applied to a top-level track seems to cause a song to start before the specified trim_start point instead of padding with silence. Also, when applied to the parent of a sub_track, it seems to just result in a silent track, the length of the pad, e.g.

    {
      "track_number": 60,
      "title": "Light World 2",
      "sub_tracks": [
        {
          "file": "Disc 3\\08. Song of the Ancients - Fate.mp3",
          "loop": 1012136,
          "trim_start": 1340951,
          "trim_end": 10944724,
          "fade_in": 5000
        }
      ],
      "pad_start": 20000
    },