MP3 files

[miriamgs]

Is possible reproduce mp3 files using the class CMdaAudioPlayerUtility??? I´ve been trying it, I can´t heard the sound...
Thanks for reading this for your help
Miriam

[symbianyucca]

if I remmebr right, I think I was told that MP3's can only be played in the phones (that support it), but it can not be recorded.

yucca

[lukedau]

MP3 is supported in S60v21 and v22.
Emulator cannot play MIDI nor MP3.
Nokia 6630, 6670, 7610 and any new phone should able to play MP3

luke

[lukedau]

more technical speaking,

in S60V21 the MMF included MP3 decoder, but S60V20 doesn't, nor the MDA in V0.9-1.2. To playback MP3 in devices prior to S60v21, you need your own decoder, either:

a plug-ins for MMF of S60V20
or
your sound mixer and/or decoder

It's possible to playback if you have the decode plug-in/dll/whatever.

You must obtain MP3 decode license from MP3 licenseer, they will also send you a C/C++ source code. You can convert it to Symbian C++.

Just one thing I observed, the play back of general MP3 players for Symbian on the market weren't as good as the build-in one on S60v21 devices. May be the MMF MP3 plug-in/decoder was optimized.

Said too much. Good luck

luke

[jkekoni]

When converting you should remember that S60's do not have Floating point hardware.

So any codec that uses these extensively is likely to be too slow to play in real time.

If I remember correctly there is free OGG codec. So you could use that to compress audio.

[lukedau]

Yes, the weakness is the lack of floating point hardware.

Some alternative way is to try to multiply your value to some 1000 times or so. Then do your calculation in integer (TInt, 32 bits, right?) When you proved your new calculations are correct, you can try to speed it up by changing your code, for example, use shift when multiple by 2 (or 2 powers, both + and - )

My experience is, for some repeat millions calculation of some divide by 2, after this kind of optimization, usually 20% performance improvement.

To be more real, I shorten a lengthy calculation from 30 seconds down to 10 or 6 seconds (I forgot the exact value)

Good luck, Miriam

luke