[Vorbis-dev] My Flash 10 attempt

[Tor-Einar Jarnbjo]

Hi everybody,

after hearing about the new Sound functionality in Flash 10, Arek's 
performance gain using the new Vector type instead of Array and not at 
least actually seeing the performance boost he achieved compared to my 
old Vorbis decoder, I found a few hours yesterday to migrate my old code.

First of all: the new PCM playback API for Flash is rather restricted 
and only allows 44.1 ksps, stereo. Implementing a generic Vorbis player 
for Flash would still require a software resampler between the decoder 
and the playback engine, but I guess most streams are encoded with those 
parameters anyway. Good news is at least that the new API seem to be 
much less critical to timing issues compared to the hack I used in the 
previous player, so it should be much easier now to operate the player 
together with a user interface.

Second: replacing Array with Vector simplified the code to some extent, 
but I am not able to measure any particular performance gain. I am not 
sure, but it looks almost to me as if the haXe compiler is producing 
much more efficient Flash bytecode compared to the Adobe AS compiler. I 
haven't bothered verifying this, but I've profiled my code and there is 
no "hotspot" where I'm doing something obviously wrong. Time divides 
between the components in almost the same manner as with my Java 
decoder, e.g. roughly 40% of the time is spent in the iMDCT code, 35-40% 
decoding floors and residues and most of the remainer is probably the 
Huffman code.

New attempt (requiring Flash 10 beta player):

http://flash.j-ogg.de/10/

Old player:

http://flash-j-ogg.de/

Can someone verify that the new player actually causes slightly more CPU 
load than the old player, or is it just my eyes fooling me?

Tor