Mikemon/libs/SDL3_mixer/test/testmixer.c

/*
  SDL_mixer:  An audio mixer library based on the SDL library
  Copyright (C) 1997-2026 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/

/*
  PLEASE NOTE THAT THE CODE IN THIS FILE IS ATROCIOUS, DON'T USE IT AS A
  FOUNDATION FOR YOUR OWN PROGRAMS.

  This is mostly just meant to test various things in quick-and-dirty ways.

  I might delete it later.

  I strongly recommend you use the programs in the "examples" directory to
  get started. You can see them running in your web browser at:

  https://examples.libsdl.org/SDL3_mixer/
*/

#define SDL_MAIN_USE_CALLBACKS 1  /* use the callbacks instead of main() */
#include <SDL3/SDL.h>
#include <SDL3/SDL_main.h>
#include "SDL3_mixer/SDL_mixer.h"

#define USE_MIX_GENERATE 0
#define TEST_TAGS 0

//static SDL_Window *window = NULL;
//static SDL_Renderer *renderer = NULL;
static MIX_Mixer *mixer = NULL;
static MIX_Track *track1 = NULL;
static MIX_Track *track2 = NULL;

#if USE_MIX_GENERATE
static SDL_IOStream *io = NULL;
#endif

static SDL_IOStream *ioraw = NULL;
static SDL_IOStream *iocooked = NULL;
static SDL_IOStream *iopostmix = NULL;

static void SDLCALL WritePCMCallback(void *userdata, MIX_Track *track, const SDL_AudioSpec *spec, float *pcm, int samples)
{
    SDL_WriteIO((SDL_IOStream *) userdata, pcm, samples * sizeof (float));
}

static void SDLCALL WritePostmixPCMCallback(void *userdata, MIX_Mixer *mixer, const SDL_AudioSpec *spec, float *pcm, int samples)
{
    WritePCMCallback(userdata, NULL, spec, pcm, samples);
}

static void LogMetadata(SDL_PropertiesID props, const char *name)
{
    switch (SDL_GetPropertyType(props, name)) {
        case SDL_PROPERTY_TYPE_INVALID:
            SDL_Log(" - %s [invalid type]", name);
            break;

        case SDL_PROPERTY_TYPE_POINTER:
            SDL_Log(" - %s [pointer=%p]", name, SDL_GetPointerProperty(props, name, NULL));
            break;

        case SDL_PROPERTY_TYPE_STRING:
            SDL_Log(" - %s [string=\"%s\"]", name, SDL_GetStringProperty(props, name, ""));
            break;

        case SDL_PROPERTY_TYPE_NUMBER:
            SDL_Log(" - %s [number=%" SDL_PRIs64 "]", name, SDL_GetNumberProperty(props, name, 0));
            break;

        case SDL_PROPERTY_TYPE_FLOAT:
            SDL_Log(" - %s [float=%f]", name, SDL_GetFloatProperty(props, name, 0.0f));
            break;

        case SDL_PROPERTY_TYPE_BOOLEAN:
            SDL_Log(" - %s [boolean=%s]", name, SDL_GetBooleanProperty(props, name, false) ? "true" : "false");
            break;

        default:
            SDL_Log(" - %s [unknown type]", name);
            break;
    }
}

typedef struct MetadataKeys
{
    char **keys;
    size_t num_keys;
} MetadataKeys;

static void SDLCALL CollectMetadata(void *userdata, SDL_PropertiesID props, const char *name)
{
    MetadataKeys *mkeys = (MetadataKeys *) userdata;
    char *key = SDL_strdup(name);
    if (key) {
        void *ptr = SDL_realloc(mkeys->keys, (mkeys->num_keys + 1) * sizeof (*mkeys->keys));
        if (!ptr) {
            SDL_free(key);
        } else {
            mkeys->keys = (char **) ptr;
            mkeys->keys[mkeys->num_keys++] = key;
        }
    }
}

static int SDLCALL CompareMetadataKeys(const void *a, const void *b)
{
    return SDL_strcmp(*(const char **) a, *(const char **) b);
}

#if TEST_TAGS
static void showtags(MIX_Track *track, const char *when)
{
    int count;
    char **tags = MIX_GetTrackTags(track, &count);
    if (!tags) {
        SDL_Log("GETTRACKTAGS FAILED!  %s", SDL_GetError());
        return;
    }

    SDL_Log("Track tags %s (%d):", when, count);
    for (int i = 0; i < count; i++) {
        SDL_Log(" - %s", tags[i]);
    }

    SDL_assert(tags[count] == NULL);
    SDL_free(tags);
}
#endif

SDL_AppResult SDL_AppInit(void **appstate, int argc, char *argv[])
{
    SDL_SetAppMetadata("Test SDL_mixer", "1.0", "org.libsdl.testmixer");
#if USE_MIX_GENERATE
    const SDL_AudioSpec spec = { SDL_AUDIO_S16, 2, 48000 };
#endif

    if ((argc != 2) && (argc != 3)) {
        SDL_Log("USAGE: %s <file_to_play1> [file_to_play2]", argv[0]);
        return SDL_APP_FAILURE;
    } else if (!SDL_Init(SDL_INIT_VIDEO)) {   // it's safe to SDL_INIT_AUDIO, but MIX_Init will do it for us.
        SDL_Log("Couldn't initialize SDL: %s", SDL_GetError());
        return SDL_APP_FAILURE;
    } else if (!MIX_Init()) {
        SDL_Log("Couldn't initialize SDL_mixer: %s", SDL_GetError());
        return SDL_APP_FAILURE;
//    } else if (!SDL_CreateWindowAndRenderer("testmixer", 640, 480, 0, &window, &renderer)) {
//        SDL_Log("Couldn't create window/renderer: %s", SDL_GetError());
//        return SDL_APP_FAILURE;
#if USE_MIX_GENERATE
    } else if ((io = SDL_IOFromFile("dump.raw", "wb")) == NULL) {
        SDL_Log("Couldn't create dump.raw: %s", SDL_GetError());
        return SDL_APP_FAILURE;
    } else if ((mixer = MIX_CreateMixer(&spec)) == NULL) {
#else
    } else if ((mixer = MIX_CreateMixerDevice(SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK, NULL)) == NULL) {
#endif
        SDL_Log("Couldn't create mixer: %s", SDL_GetError());
        return SDL_APP_FAILURE;
    }

    SDL_AudioSpec mixerspec;
    MIX_GetMixerFormat(mixer, &mixerspec);
    SDL_Log("Mixer is format %s, %d channels, %d frequency", SDL_GetAudioFormatName(mixerspec.format), mixerspec.channels, mixerspec.freq);

    SDL_Log("Available decoders:");
    const int num_decoders = MIX_GetNumAudioDecoders();
    if (num_decoders < 0) {
        SDL_Log(" - [error (%s)]", SDL_GetError());
    } else if (num_decoders == 0) {
        SDL_Log(" - [none]");
    } else {
        for (int i = 0; i < num_decoders; i++) {
            SDL_Log(" - %s", MIX_GetAudioDecoder(i));
        }
    }
    SDL_Log("%s", "");

    const char *audiofname = argv[1];
#if 1
    MIX_Audio *audio = MIX_LoadAudio(mixer, audiofname, false);
#else
    size_t databuffersize = 0;
    void *databuffer = SDL_LoadFile(audiofname, &databuffersize);
    if (!databuffer) {
        SDL_Log("Failed to load file '%s' from disk: %s", audiofname, SDL_GetError());
        return SDL_APP_FAILURE;
    }
    MIX_Audio *audio = MIX_LoadAudioNoCopy(mixer, databuffer, databuffersize, true);
#endif

    //MIX_Audio *audio = MIX_CreateSineWaveAudio(mixer, 300, 0.25f, 5000);
    if (!audio) {
        SDL_Log("Failed to load '%s': %s", audiofname, SDL_GetError());
        return SDL_APP_FAILURE;
    }

    SDL_AudioSpec audiospec;
    MIX_GetAudioFormat(audio, &audiospec);
    SDL_Log("%s: %s, %d channel%s, %d freq", audiofname, SDL_GetAudioFormatName(audiospec.format), audiospec.channels, (audiospec.channels == 1) ? "" : "s", audiospec.freq);

    SDL_Log("%s metadata:", audiofname);
    SDL_PropertiesID props = MIX_GetAudioProperties(audio);
    bool had_metadata = false;
    if (props) {
        MetadataKeys mkeys;
        SDL_zero(mkeys);
        SDL_EnumerateProperties(props, CollectMetadata, &mkeys);
        if (mkeys.num_keys > 0) {
            SDL_qsort(mkeys.keys, mkeys.num_keys, sizeof (*mkeys.keys), CompareMetadataKeys);
            for (size_t i = 0; i < mkeys.num_keys; i++) {
                LogMetadata(props, mkeys.keys[i]);
                SDL_free(mkeys.keys[i]);
                had_metadata = true;
            }
        }
        SDL_free(mkeys.keys);
    }

    if (!had_metadata) {
        SDL_Log(" - [none]");
    }
    SDL_Log("%s", "");

    track1 = MIX_CreateTrack(mixer);

    //ioraw = SDL_IOFromFile("trackraw.raw", "wb"); if (ioraw) { MIX_SetTrackRawCallback(track1, WritePCMCallback, ioraw); }
    //iocooked = SDL_IOFromFile("trackcooked.raw", "wb"); if (iocooked) { MIX_SetTrackCookedCallback(track1, WritePCMCallback, iocooked); }
    //iopostmix = SDL_IOFromFile("postmix.raw", "wb"); if (iopostmix) { MIX_SetPostMixCallback(mixer, WritePostmixPCMCallback, iopostmix); }
    (void) WritePostmixPCMCallback;  // stop a compiler warning when not using the callbacks.

    //const int chmap[] = { 1, 0 }; MIX_SetTrackOutputChannelMap(track1, chmap, SDL_arraysize(chmap));
    MIX_SetTrackAudio(track1, audio);
    if (argv[2]) {
        track2 = MIX_CreateTrack(mixer);
        MIX_SetTrackIOStream(track2, SDL_IOFromFile(argv[2], "rb"), true);
    }

    SDL_PropertiesID options;

    #if TEST_TAGS
    MIX_TagTrack(track1, "Abc");
    MIX_TagTrack(track1, "xyZ");
    MIX_TagTrack(track1, "1234567890");
    MIX_TagTrack(track1, "TopSecret");
    MIX_TagTrack(track1, "MyFavoriteTrack");
    MIX_TagTrack(track1, "Can I put spaces and punctuation in here?");
    MIX_TagTrack(track1, "Music");
    MIX_TagTrack(track1, "NotImportant");
    MIX_TagTrack(track1, "Orange");
    int tagged_count = 77;
    MIX_Track **tagged = MIX_GetTaggedTracks(mixer, "TopSecret", &tagged_count);
    SDL_Log("MIX_GetTaggedTracks is %sworking", (tagged && (tagged_count == 1) && (tagged[0] == track1) && (tagged[1] == NULL)) ? "" : "NOT ");
    SDL_free(tagged);
    showtags(track1, "at startup");
    MIX_UntagTrack(track1, "TopSecret");
    showtags(track1, "after removing 'TopSecret'");
    MIX_UntagTrack(track1, NULL);
    showtags(track1, "after removing everything");
    #endif

    options = SDL_CreateProperties();
    SDL_SetNumberProperty(options, MIX_PROP_PLAY_MAX_MILLISECONDS_NUMBER, 9440);
    SDL_SetNumberProperty(options, MIX_PROP_PLAY_LOOPS_NUMBER, 3);
    SDL_SetNumberProperty(options, MIX_PROP_PLAY_LOOP_START_MILLISECOND_NUMBER, 6097);
    SDL_SetNumberProperty(options, MIX_PROP_PLAY_FADE_IN_MILLISECONDS_NUMBER, 30000);
    //SDL_SetFloatProperty(options, MIX_PROP_PLAY_FADE_IN_START_GAIN_FLOAT, 0.25f);
    SDL_SetNumberProperty(options, MIX_PROP_PLAY_APPEND_SILENCE_MILLISECONDS_NUMBER, 30000);
    MIX_PlayTrack(track1, options);
    SDL_DestroyProperties(options);

    if (track2) {
        options = SDL_CreateProperties();
        SDL_SetNumberProperty(options, MIX_PROP_PLAY_LOOPS_NUMBER, -1);
        MIX_PlayTrack(track2, options);
        SDL_DestroyProperties(options);
    }

    // we cheat here with PlayAudio, since the sinewave decoder produces infinite audio.
    //MIX_PlayAudio(mixer, MIX_CreateSineWaveAudio(mixer, 300, 0.25f, -1));

    return SDL_APP_CONTINUE;
}

SDL_AppResult SDL_AppEvent(void *appstate, SDL_Event *event)
{
    if (event->type == SDL_EVENT_QUIT) {
        return SDL_APP_SUCCESS;
    }
    return SDL_APP_CONTINUE;
}

SDL_AppResult SDL_AppIterate(void *appstate)
{
    #if USE_MIX_GENERATE
    float buf[1024];
    const int br = MIX_Generate(mixer, buf, sizeof (buf));
    if (br == -1) {
        SDL_Log("MIX_Generate failed: %s", SDL_GetError());
        return SDL_APP_FAILURE;
    }
    //SDL_Log("MIX_Generate() came through with %d bytes vs %d requested", br, (int) sizeof (buf));
    SDL_WriteIO(io, buf, br);
    #endif

//    SDL_RenderClear(renderer);
//    SDL_RenderPresent(renderer);

    #if 0
    float ratio = ((float) ((((Sint64) SDL_GetTicks()) - 1000) / 1000)) * 0.10f;
    ratio = SDL_clamp(ratio, 0.1f, 5.0f);
    static float prev_ratio = 1.0f;
    if (ratio != prev_ratio) {
        SDL_Log("new frequency ratio: %f", ratio);
        MIX_SetTrackFrequencyRatio(track1, ratio);
        prev_ratio = ratio;
    }
    #endif

    return MIX_TrackPlaying(track1) ? SDL_APP_CONTINUE : SDL_APP_SUCCESS;
}

void SDL_AppQuit(void *appstate, SDL_AppResult result)
{
    // SDL will clean up the window/renderer for us.
    // SDL_mixer will clean up the tracks and audio.
    MIX_Quit();

    if (ioraw) { SDL_CloseIO(ioraw); }
    if (iocooked) { SDL_CloseIO(iocooked); }
    if (iopostmix) { SDL_CloseIO(iopostmix); }

    #if USE_MIX_GENERATE
    SDL_CloseIO(io);
    #endif
}