[Tremor] Help required to compute mips for tremor (int ogg-vorbis decoder)

[madhav kulkarni]

Hi all,

I have some problem regarding the mips calculation of the tremor-fixed point 
version of ogg-vorbis audio decoder. Can any one look in to this?

I have done the profiling for the ogg-vorbis decoder for 1st 10 frames and 
observed that cycles taken by ov_read function is as follows:
1. 1 st frame takes 5,498,613 cycles on the arm9 platform.
2. 2nd frame onwards this code takes 555,647 cycles on the arm9 platform.

I have few questions related to this. I want to compute the mips for these 
cycles I get.

MIPS taken by ov_read function = ((cycles taken by ov_read function / 4096) 
* 44100) / 1,000,000

1. for 1st frame MIPS = ((5,498,613/4096) * 44100) / 1,000,000 = 59.2 MIPS
2. for 2nd frame onward MIPS = ((555,647/4096) * 44100) / 1,000,000 = 5.98 
MIPS

1st thing

Now i don't understand is this mips calculation correct? According my 
klnowledge i think i have applied the correct formulae for mips comutation. 
Is there any mistake in this formulae? Can anyone tell me?

2nd thing

1st frame takes much cycles due to
1. _make_decode_ready () which is memroy initialization and alocation &
2.  mdct_backward is called 4 times.

2nd frame onward mdct is called 2 times and length of mdct for these call is 
256 or sometime 2048.
Why it is so?

MIPS for any codec is estimated as the worst case. So here worst case is 1st 
frame. Can anyone tell, Is this assumption correct to consider the 1st frame 
cycles to estimate tremor ogg-vorbis decoder worst count?


With Best Regards,

Madhav Kulkarni

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