[CELT-dev] stack + heap sizes

celt celt at platax.de
Wed Dec 1 02:44:33 PST 2010

hi ​Jean-Marc,
thanks for your answer.
But still I am struggling to find a reasonable upper limit for the RAM sizes.
You say we need 4.5/9.0 kB for enc/dec per channel.
But are those sizes really independent of any settings, like frame_size,
bitrate, complexity, etc. ?
at least in our configuration I find these requirements: 
 - native stack: < 2.1kB (enc or dec) measured by RealView Profiler
 - heap: (summing up the celt_alloc calls):
     mode_create: 2430
     enc_create: 10284
     dec_create: 17568
     not sure! (default = 100k ???)
     2k is not enough, 5k is ok.
our config:
 - version = 0.9.1
 - f<s> = 48kHz
 - frame_size = 240 (p.ch.) (--> 5ms) 
 - rate = 128 kbit/s (stereo)
 - vbr_rate = 0
 - prediction = 2
 - complexity = 10
Why do we need additionally a GLOBAL_STACK_SIZE ?
Could these allocations also be redirected to a common method, like celt_alloc()

It is not really clear to me what is the idea behind the switches VAR_ARRAYS,
USE_ALLOCA, GLOBAL_STACK_SIZE and how much RAM must be allocated (how/where?)
for any (or at least for our) configuration ?

thanks a lot for your answers,
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