Variable Video Compression in A720IS Finally Done! - page 4 - DryOS Development - CHDK Forum

Variable Video Compression in A720IS Finally Done!

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Offline vit40

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Re: Variable Video Compression in A720IS Finally Done!
« Reply #30 on: 11 / April / 2008, 15:37:18 »
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ewavr,

regarding video compression, is it possible to have smaller steps of this setting, say 1x, 0.9x, 0.8x, 0.7x, 0.6x .... (instead of 0.75x, 0.5x ...) or this is limited by firmware ?

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Offline ewavr

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Re: Variable Video Compression in A720IS Finally Done!
« Reply #31 on: 11 / April / 2008, 15:47:01 »
regarding video compression, is it possible to have smaller steps of this setting, say 1x, 0.9x, 0.8x, 0.7x, 0.6x .... (instead of 0.75x, 0.5x ...) or this is limited by firmware ?

Any step is possible. The only thing that it is necessary to make - to change the interface for input of bitrate (in gui.c).

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Offline wap4

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Re: Variable Video Compression in A720IS Finally Done!
« Reply #32 on: 12 / April / 2008, 12:07:36 »
 ewavr,

 This is just out of curiosity. I'm still in darkness about how you replaced the unk_XYZ values (unexplored bytes) by long compression tables. How did you get those values? Same question for def_tables.
 
 (After double clicking the unk_XYZ,IDA displays some hex values in that location,I've tried "mark as code/byte/
 word/dword" by right clicking it,but can't get those numbers of your long compression tables)
« Last Edit: 25 / April / 2008, 11:59:11 by wap4 »

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Offline ewavr

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Re: Variable Video Compression in A720IS Finally Done!
« Reply #33 on: 12 / April / 2008, 13:43:58 »
sub_FFD06188:
...skip...
ROM:FFD061BC                 LDR     R7, =dword_FFE5CFD8
...skip...
ROM:FFD06254                 LDR     R2, =dword_FFE5CF7C

ROM:FFE5CFD8 dword_FFE5CFD8  DCD 0x2000             
ROM:FFE5CFDC                 DCD 0x38D
ROM:FFE5CFE0                 DCD 0x788
ROM:FFE5CFE4                 DCD 0x5800
ROM:FFE5CFE8                 DCD 0x9C5
ROM:FFE5CFEC                 DCD 0x14B8
ROM:FFE5CFF0                 DCD 0x10000
... etc - this is def_table[]

ROM:FFE5CF7C dword_FFE5CF7C  DCD 0x54
ROM:FFE5CF80                 DCD 0x51
ROM:FFE5CF84                 DCD 0x4D
ROM:FFE5CF88                 DCD 0x48
ROM:FFE5CF8C                 DCD 0x42
ROM:FFE5CF90                 DCD 0x3B
ROM:FFE5CF94                 DCD 0x32
ROM:FFE5CF98                 DCD 0x29
... etc - this is camera compression rate table.
In original fimware, maximum quality is 84, minimum - 1 for A720 (and 11 for old VxWorks cameras).

Re: Variable Video Compression in A720IS Finally Done!
« Reply #34 on: 12 / April / 2008, 18:29:38 »
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« Last Edit: 22 / April / 2008, 17:31:31 by Barney Fife »
[acseven/admin commented out: please refrain from more direct offensive language to any user. FW complaints to me] I felt it imperative to withdraw my TOTAL participation. Nobody has my permission, nor the right, to reinstate MY posts. Make-do with my quoted text in others' replies only. Bye

 

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