al_load_sample's loading many data

no-reply@allegro.cc (JurekGP) — Mon, 23 Feb 2015 23:18:36 +0000

Few days ago, I tried to include music files for my program. I wrote right function which read my file with headers of files music and same files.
I have not used music file yet. And now when I want load this 19 files (33 MB), I'm loading this samples and I get over 700 MB data in memory too.

I'm reading these files from my file:

#SelectExpand
  1for(unsigned i = 0; i < songCount; i++)
  2{
buffer = new char[songs[i]->fileLength];
file.read(buffer, songs[i]->fileLength);
alFile = al_open_memfile((void*)buffer, songs[i]->fileLength, "rb");
ALLEGRO_SAMPLE *sample = al_load_sample_f(alFile, songs[i]->fileType.c_str());
songs[i]->addSongFile(sample);
std::cout << &buffer << " " << alFile << " " << sample << std::endl;
al_fclose(alFile);
alFile = NULL;
delete[] buffer;
buffer = NULL;
 13}

I thought that I do something wrong, and get memory leak. So I tried load these files "manually":

#SelectExpand
  2ALLEGRO_SAMPLE *sample = NULL;
  3sample = al_load_sample("music.ogg");
  4songs[0]->addSongFile(sample);
  5sample = al_load_sample("music.ogg");
  6songs[1]->addSongFile(sample);
  7sample = al_load_sample("music.ogg");
  8songs[2]->addSongFile(sample);
  9sample = al_load_sample("music.ogg");
 10songs[3]->addSongFile(sample);
 11sample = al_load_sample("music.ogg");
 12songs[4]->addSongFile(sample);
 13sample = al_load_sample("music.ogg");
 14songs[5]->addSongFile(sample);
 15sample = al_load_sample("music.ogg");
 16songs[6]->addSongFile(sample);
 17sample = al_load_sample("music.ogg");
 18songs[7]->addSongFile(sample);
 19sample = al_load_sample("music.ogg");
 20songs[8]->addSongFile(sample);
 21sample = al_load_sample("music.ogg");
 22songs[9]->addSongFile(sample);
 23sample = al_load_sample("music.ogg");
 24songs[10]->addSongFile(sample);
 25sample = al_load_sample("music.ogg");
 26songs[11]->addSongFile(sample);
 27sample = al_load_sample("music.ogg");
 28songs[12]->addSongFile(sample);
 29sample = al_load_sample("music.ogg");
 30songs[13]->addSongFile(sample);
 31sample = al_load_sample("music.ogg");
 32songs[14]->addSongFile(sample);
 33sample = al_load_sample("music.ogg");
 34songs[15]->addSongFile(sample);
 35sample = al_load_sample("music.ogg");
 36songs[16]->addSongFile(sample);
 37sample = al_load_sample("music.ogg");
 38songs[17]->addSongFile(sample);
 39sample = al_load_sample("music.ogg");
 40songs[18]->addSongFile(sample);

For simplification I loading one file 19 times.

Two this ways doesn't load sample file correctly. After loading I should get about 33 MB data, but I get over than 700 MB.

Did you heard about problem like this? I use Allegro 5.0.10. I tried load this way in two projects to be sure.

If you understand, I send link for my topic about this on a Polish forum PC Format: http://forum.pcformat.pl/C-Allegro-5-Dealokacja-pliku-ALLEGRO-FILE-t

no-reply@allegro.cc (Thomas Fjellstrom) — Mon, 23 Feb 2015 23:25:31 +0000

Ogg is compressed. al_load_sample loads the audio and decompresses it into raw PCM data.

If you want to use music, you're best off using streaming^[1]

References

see http://www.liballeg.org/a5docs/refman/audio.html#stream-functions

no-reply@allegro.cc (JurekGP) — Tue, 24 Feb 2015 21:57:52 +0000

Ok, thanks!
Now I know why I get so many megabytes of data.
But I'd ask if I understand everything correctly and I'm doing everything what I should.

There is cool example which I base: ex_stream_file, but I'm not sure that I'm understanding everything right.

So, now I would like to summary what I centrainly do. This is test project, but there I include every step, which I want implement in my game. Only difference that I read music files from one file by al_load_audio_stream_f.

1. When I'm initializing Allegro, I turn on audio streaming. I'm saving a frequency, mixerDepth, voiceDepth and channel conf. I'm creating mixer and voice.
2. In my player I will have pointer on ALLEGRO_AUDIO_STREAM - *musicStream. On begin set on NULL.
3. Now when I want to handle stream:
a) If I want play stream, I call my function playStream:

#SelectExpand
  1void TestGame::playStream(std::string filePath)
  2{
  3  if(musicStream)
  4    al_destroy_audio_stream(musicStream);
  5  musicStream = al_load_audio_stream(filePath.c_str(), 4, 2048);
  6  al_register_event_source(gameCore->alManager->getAllegroEventQueue(), al_get_audio_stream_event_source(musicStream));
  7  al_attach_audio_stream_to_mixer(musicStream, gameCore->alManager->getAllegroMixer());
  8}

b) If I want change volume, call this function: al_set_audio_stream_gain(musicStream, 'float value');
c) If I want stop stream, call this function: al_detach_audio_stream(musicStream);

Two asks:
1. How is difference between function above and al_drain_audio_stream? What should I use?
2. I'm not sure what means second and third argument of al_load_audio_stream.
- Second is probably size (on kilobytes?) of stream, which will be loading to play like one piece of stream.
- Third is for information how many streams can play at the same time, through my pointer musicStream? Can I change to 1? At the same time I will playing only one sample. Maybe is nonsense give 2048?

So, this is everything what I should do for correctly handling audio stream in Allegro? Of course, in the end, I'm destroing audio stream, mixer and voice.