Slow seeking with large MP3 files

[NworbLegin]

Hi miniaudio users,

I'm currently coding playback of mp3 files for a cross-platform app (windows, iOS, Android) and I was hitting some really large delays seeking to a playback point. Our audiobook mp3 files are >45 mins, and the seek times in debug builds were really slowing down our development. (Seek times in a release build were also a little slow too - expecially on lower-end mobile devices).

It looks like this slowdown is caused by miniaudio attempting to seek through the mp3 file dynamically at run-time in a fairly inefficient fall-back process.

One thing that doesn't seem to be documented that seems to help with this is to specify a value for the ma_decoder_config that is passed into ma_decoder_init_file.

ma_decoder_config decoderConfig;
memset(&decoderConfig, 0, sizeof(ma_decoder_config));
decoderConfig.seekPointCount = 128;

result = ma_decoder_init_file(fullPath.c_str(), &decoderConfig, m_Decoder);

As far as I can tell this will create the specified number of seek points when the file is initialised. These seek points are then used as pre-generated indexes to speed up the seeking at run-time.

Maybe this should be documented somewhere. (Or maybe it is and I've missed it!)

I hope this helps someone.

Cheers

Nigella