app performance issue across phones

[col3-23]

I have an app that works great on the N95 and N82, but is extremely sluggish on others, such as N96, N81, E73, N85, N86. Once diff is the 95/82 have graphics hw accel, but graphics is not the issue. I have a number of short mp3 files that need to be played based on certain events. Each event triggers a specific sound, but if no events happen, the current sound must loop. Two players for each sound were instantiated and initialized at startup to eliminate startup time the first time a sound is played.

Using 2 players gets the looping ok on n95/n82 (a timer alternates starting one or the other near the end of the sound's cycle), with slight 'blip' on sound overlaps. Events can change very quickly from one to the next and the sounds start playing accordingly, pretty close to when the events happen. However, on the other phones, there is a distinct 1/4 to 1/2 sec or so pause in-between loops and sometimes only play a sound once without looping. Likewise, the same processing pause dramatically affects playing sounds for each succeeding event that comes in and the sound simply cannot keep up, making this function on these other phones absolutely useless.

The N95 and N81 have canvas double-buffering enabled, and I've also tried not doing any screen updates during this time, but there was no difference in sound performance (or lack of).

Can anyone provide an idea as to why the other phones have such a sluggish performance for this compared to the N95 and N82?

[r2j7]

Hello col3-23,

without knowing your code more in detail, have you implemented the players and related resource management accordingly the MMAPI design considerations which are defined in Forum Nokia Java Developer's Library?:

Java Developer's Library 3.5 > Developer's Guides > Multimedia > Creating multimedia applications > Using the Mobile Media API > Recommended practices > Application resource management

Java Developer's Library 3.5 > Developer's Guides > Multimedia > Creating multimedia applications > Using the Mobile Media API > Recommended practices > Minimizing media playback delay


Regards,
r2j7

[col3-23]

Thanks for the reference. Based on what those docs indicate for the rules they outline, unless I'm missing something, the setup and playing of sounds should be ok. In a nutshell, the flow of events:

main midp app:
startApp
- instantiates classes
- creates 2 players for each sound and puts them into the prefetch state. Each player is stored in a hashtable keyed by the sound name (one hashtable per player set of sounds).

all sounds are handled in a separate class running a thread. The thread looks for sounds that were added to a queue.
when sound is needed, its filename is added to the sound class queue. The sound thread starts the sound for that player's sound file by looking up the player in the hashtable.
a timer is started based on the length of the sound.
if no other sounds occur, the timer fires and the sound is restarted by starting it again using the sound's other player.
if another sound is needed, it is started and the sound being played is stopped.

This works great on the N95 and N82. All graphics and sound will keep up in real-time as they are dynamically changed. However, any other phone, such as N96, N81, N85, E73, N86, have a significant lag in sounds being played vs what should be played in realtime. Even graphics starts to lag as processing can't seem to keep up. Many times, the app will 'hang' to such a degree as requiring a power cycle of the phone. However, if you disable the sound functionality by not using the players, the graphics on these other phones will keep up in realtime as you should expect and the app runs with no problems.

This is not a gaming application but if it was, you wouldn't want it to be limited to just a few phones...you'd limit your audience and wouldn't sell many games. The only common thread in this is the N95/N82 have a 3d hw graphics accelerator and none of the others have it. Is this significant? Likewise, these 2 phones use a Dual Arm processor. However, the N96 has a dual, but it has the same problems with the sound.

Any further ideas?