I've been loitering around ScummVM for a while, but only just got my hands on a nice spangly new LOOX N560. I'm very much looking forward to trying the new SVN build on it
I have one question (at the moment, that is): all my games (that allow it) are compressed with vorbis audio. Would I get better performance on a device like my loox if i re-compressed with mp3? I.e., do they have any sort of hardware decompression for mp3 that they lack for vorbis?
n00b pocketpc owner - ogg or mp3?
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- spookypeanut
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- robinwatts
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I haven't done measurements on the libraries as used by Scummvm, so other people may know more exactly than me, but I have some previous experiences with MP3 and Ogg decompression on ARMs.
Ogg decoding using Tremolo (an ARM optimised version of the Tremors lib) takes at least 50% more processing power than MP3 decoding (using an ARM optimised decoder).
Assuming that the C compiled versions of the libs exhibit similar relative performance, then yes, using MP3 files would probably get you better performance.
BUT... I wouldn't go recompressing stuff from Ogg -> MP3 willy nilly. Not only will you lose quality, your device has a 624MHz processor, which should be perfectly capable of coping with Ogg data - my 400MHz device copes just fine I think.
I am 99% sure that no form of hardware decompression is used for either MP3 or Vorbis as part of this port.
I am sure Knakos or someone that knows more will correct me if I'm wrong with any of this.
Hope this helps,
Robin
Ogg decoding using Tremolo (an ARM optimised version of the Tremors lib) takes at least 50% more processing power than MP3 decoding (using an ARM optimised decoder).
Assuming that the C compiled versions of the libs exhibit similar relative performance, then yes, using MP3 files would probably get you better performance.
BUT... I wouldn't go recompressing stuff from Ogg -> MP3 willy nilly. Not only will you lose quality, your device has a 624MHz processor, which should be perfectly capable of coping with Ogg data - my 400MHz device copes just fine I think.
I am 99% sure that no form of hardware decompression is used for either MP3 or Vorbis as part of this port.
I am sure Knakos or someone that knows more will correct me if I'm wrong with any of this.
Hope this helps,
Robin
as far a s I know you can't re-compress datafiles (i.e. everything apart from cd-audio) from one compressed format to another anyway since the compression tools can only cope with the original datafilesrobinwatts wrote:BUT... I wouldn't go recompressing stuff from Ogg -> MP3 willy nilly. Not only will you lose quality[..]
Yep, it is my impression too that MP3 decoding is less demanding than ogg.robinwatts wrote:Ogg decoding using Tremolo (an ARM optimised version of the Tremors lib) takes at least 50% more processing power than MP3 decoding (using an ARM optimised decoder).
AFAIK the libraries feature no device specific accelerations.robinwatts wrote:I am 99% sure that no form of hardware decompression is used for either MP3 or Vorbis as part of this port.
- spookypeanut
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Haven't even got an SD card yet, so haven't tried it I was guessing it would work fine for the 320x200 games, I was wondering more about ones like bs1&2 & comi: with a 640x480 screen they should display full res, but I guess it might be quite demanding. I'll let you know how I get on.robinwatts wrote: BUT... I wouldn't go recompressing stuff from Ogg -> MP3 willy nilly. Not only will you lose quality, your device has a 624MHz processor, which should be perfectly capable of coping with Ogg data - my 400MHz device copes just fine I think.
Thanks for all your answers.