Output_mp3 plugin

FMOD Engine
1

We try to use two samples from FMOD engine, SimpleEvent and Output_mp3, to output a mp3 file for a given event.

We first build the output_mp3L64.dll using output_mp3 project. and then use following code.

The problem is output_state->readfrommixer(output_state, destptr, l); always returns FMOD_ERR_INTERNAL. Please help us to indicate why, thank you!

/*==============================================================================
Simple Event Example
Copyright (c), Firelight Technologies Pty, Ltd 2012-2019.

This example demonstrates the various ways of playing an event.

Explosion Event

This event is played as a one-shot and released immediately after it has been
created.

Looping Ambience Event

A single instance is started or stopped based on user input.

Cancel Event

This instance is started and if already playing, restarted.

==============================================================================*/
#include “fmod_studio.hpp”
#include “fmod.hpp”
#include “common.h”

int FMOD_Main()
{
void* extraDriverData = NULL;
Common_Init(&extraDriverData);

FMOD::Studio::System* system = NULL;
ERRCHECK(FMOD::Studio::System::create(&system));

// The example Studio project is authored for 5.1 sound, so set up the system output mode to match
FMOD::System* coreSystem = NULL;
ERRCHECK(system->getCoreSystem(&coreSystem));

unsigned int pluginHandle = 0;
ERRCHECK(coreSystem->loadPlugin("output_mp3L64.dll", &pluginHandle));
ERRCHECK(coreSystem->setOutputByPlugin(pluginHandle));

ERRCHECK(coreSystem->setSoftwareFormat(0, FMOD_SPEAKERMODE_5POINT1, 0));


ERRCHECK(system->initialize(1024, FMOD_STUDIO_INIT_NORMAL, FMOD_INIT_NORMAL, extraDriverData));

FMOD::Studio::Bank* masterBank = NULL;
ERRCHECK(system->loadBankFile(Common_MediaPath("Master.bank"), FMOD_STUDIO_LOAD_BANK_NORMAL, &masterBank));

FMOD::Studio::Bank* stringsBank = NULL;
ERRCHECK(system->loadBankFile(Common_MediaPath("Master.strings.bank"), FMOD_STUDIO_LOAD_BANK_NORMAL, &stringsBank));

FMOD::Studio::Bank* sfxBank = NULL;
ERRCHECK(system->loadBankFile(Common_MediaPath("Sound2D.bank"), FMOD_STUDIO_LOAD_BANK_NORMAL, &sfxBank));

// Get the Single Explosion event
FMOD::Studio::EventDescription* eventDescription = NULL;
ERRCHECK(system->getEvent("event:/Sound2D/ui_boss_1", &eventDescription));

// Get instance
FMOD::Studio::EventInstance* eventInstance = NULL;
ERRCHECK(eventDescription->createInstance(&eventInstance));

ERRCHECK(eventInstance->start());

// Wait for the event to finish playing
FMOD_STUDIO_PLAYBACK_STATE state;
do {
    ERRCHECK(eventInstance->getPlaybackState(&state));
    ERRCHECK(system->update());

    Common_Sleep(50);
} while (state != FMOD_STUDIO_PLAYBACK_STOPPED);

// Release the event instance after playback
ERRCHECK(eventInstance->release());

ERRCHECK(sfxBank->unload());
ERRCHECK(stringsBank->unload());
ERRCHECK(masterBank->unload());

ERRCHECK(system->release());

Common_Close();


return 0;

}

2

Hi,

Thank you for sharing the information and code.

May I confirm which version of FMOD Engine you are using?

The issue is likely caused by the mixer being configured for 5.1 output.

The output_mp3 example only supports mono or stereo input, so requesting a 5.1 mix might vcause readfrommixer to return FMOD_ERR_INTERNAL.

Could you please try forcing the software format to stereo before calling initialize, for example:

ERRCHECK(coreSystem->setSoftwareFormat(48000, FMOD_SPEAKERMODE_STEREO, 0));

Let me know if the issue persists.

3

Thank you very much!

We changed from FMOD_SPEAKERMODE_5POINT1 to FMOD_SPEAKERMODE_STEREO, but the issue persists.

We are using FMOD Studio API Windows version 2.00.06.

We also tried FMOD Studio API Windows version 2.03.10, the problem is the same.

Thanks again!

4

Thanks for trying that!

I was able to reproduce the behavior you described on my side as well.
I’ve passed the details on to our dev team so they can take a closer look.

Thank you for bringing this to our attention