— RU.COMPRESS
From : Leonid Broukhis 2:5020/400 20 May 99 12:34:34
To : Dmitry Subbotin
Subj : Re: Carryless rangecoder v2.0 - 100% íàñòîÿùåãî èçâðàòà!
From: leob@asylum.mailcom.com (Leonid Broukhis)
Leonid Broukhis wrote:
>>Êñòàòè, êàê òû äóìàåøü, áóäåò ëè ýòîò êîä ðàáîòàòü íà âñåõ ìàøèíàõ? :) Òàì â
>>îäíîì ìåñòå ìîë÷àëèâî ïðåäïîëàãàåòñÿ, ÷òî îòðèöàòåëüíûå ÷èñëà õðàíÿòüñÿ â
>>äîïîëíèòåëüíîì ôîðìàòå, ò.å. ÷òî íàïðèìåð char(-1)==0xff. À â ñîâðåìåííîé
>>ïðèðîäå åñòü êîìïû, äëÿ êîòîðûõ ýòî íå âåðíî?
>
>Äóìàþ, ÷òî óæå íåò. Â êîíöå êîíöîâ, ìîæíî è ifdef íàïèñàòü.
Èëè, êàê ÷åñòíûé ÷åëîâåê, TopValue - (low & TopValue-1). Âåäü òû èìåííî
ýòîãî õî÷åøü.
Leo
--- ifmail v.2.14dev3
* Origin: leob@at-mailcom.dot-com (2:5020/400)
— RU.COMPRESS
From : Bulat Ziganshin 2:5093/29.61 20 May 99 14:32:01
To : Rustam Gadeyev
Subj : EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
* Crossposted in RU.COMPRESS
Hello Rustam!
Thursday May 20 1999, Rustam Gadeyev writes to Igor Pavlov:
RG> Äëÿ 32-áèòíûõ ïðîãðàìì ñ áîëüøèì êîëè÷åñòâîì âûçîâîâ ïðîöåäyð ýòî äàåò
RG> çàìåòíîå yëy÷øåíèå ñæàòèÿ, äðyãîå äåëî êàê íàèáîëåå äîñòîâåðíî
RG> îïðåäåëèòü ÷òî ýòî çà E8,
Hàéäè â èíåòå cab-sdk.exe è ïî÷èòàé â íåì äîêó ïî lzx.  íåì î÷åíü ïðîñòîé àë
ãîðèòì ñ ïðàêòè÷åñêè 100-ïîðöåíòíîé ýôôåêòèâíîñòüþ.
Bulat, mailto:bulatz@fort.tatarstan.ru, ICQ 15872722
--- GoldED/386 2.50+
* Origin: Çóáíûå êëåòêè íå âîññòàíàâëèâàþòñÿ (2:5093/29.61)
— RU.COMPRESS
From : Bulat Ziganshin 2:5093/29.61 20 May 99 14:34:17
To : Alexander Alferowich
Subj : UPX vs RAR
* Crossposted in RU.COMPRESS
Hello Alexander!
Thursday May 20 1999, Bulat Ziganshin writes to Alexander Alferowich:
AA>> Ýòî íîpìàëüíî, ÷òî UPX --best PE-EXE ñæèìàåò ëó÷øå, ÷åì RAR32 -m5
AA>> -mde -mm ? Ïpèìåp:
BZ> À òû çíàåøü, ÷òî äëÿ ñæàòèÿ ðåëîêàöèé èñïîëüçóåòñÿ îòäåëüíûé
BZ> àëãîðèòì? Ñêîëüêî îíè òàì çàíèìàþò?
À åùå E8. Òàê ÷òî ñðàâíèâàé êàê ìèíèìóì ñ cabarc'îì, îí è òàáëè÷êè ñëåãêà ëó÷
øå æìåò.
Bulat, mailto:bulatz@fort.tatarstan.ru, ICQ 15872722
--- GoldED/386 2.50+
* Origin: Çóáíûå êëåòêè íå âîññòàíàâëèâàþòñÿ (2:5093/29.61)
— RU.COMPRESS
From : Bulat Ziganshin 2:5093/29.61 20 May 99 14:37:20
To : Dmitry Pyankov
Subj : EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
* Crossposted in RU.COMPRESS
Hello Dmitry!
Monday May 17 1999, Dmitry Pyankov writes to All:
DP> ×òî çà àëãîðèòì ñæàòèÿ ðåëîêàöèé? Ýòî ìåòîä, ïðè êîòîðîì äëÿ òåêóùåé
DP> ïàðû <äëèíà, äèñòàíöèÿ> , "äèñòàíöèÿ" áåðåòñÿ èç ïðåäûäóùåé ïàðû
DP> <äëèíà, äèñòàíöèÿ> ?
Håò, ýòî rep_dist. Ñæàòèå ðåëîêàöèé - ýòî ñæàòèå òàáëèöû ðåëîêàöèé, êîòîðàÿ
åñòü â áîëüøèíñòâå exe-øíèêîâ.
DB>> åñëè íå îñòàíàâëèâàòüñÿ íà äîñòèãíóòîì è óâîðîâàòü ó apack-à åùå è
DP> àëãîðèòì
DB>> îáðàáîòêè e8 (relative call), òî upx ìîæåò îáîãíàòü apack, âïîëíå
DP> ñóùåñòâåííî,
DB>> ïîòîìó ÷òî, íàñêîëüêî ÿ çíàþ, ñàì àëãîðèòì ïîèñêà ñòðîê ó apack
DP> ñóùåñòâåííî
DB>> ñëàáåå.
DP> Àãà. Êàê ÿ ïîíÿë, íåêîòîðûå êîäû êîìàíä (íàïð. relative call) ìîãóò
DP> çàìåíÿòüñÿ äðóãèìè êîäàìè, âûïîëíÿþùèìè ïî ñóòè òå æå ôóíêöèè, íî
DP> êîòîðûå ìîæíî ñæàòü áîëåå óñïåøíî...
Håò. _ÑÌÅÙÅHÈÅ_, çàïèñûâàåìîå â àññåìáëåðíîì êîäå ïîñëå êîìàíäû E8 (relative
near call), çàìåíÿåòñÿ íà _ÀÁÑÎËÞÒHÛÉ_ÀÄÐÅÑ_. Ïîñêîëüêó åñòü êàêîé-òî íå î÷åíü
áîëüøîé íàáîð àäðåñîâ ïîäïðîãðàìì, ñòåïåíü èçáûòî÷íîñòè ôàéëà óâåëè÷èâàåòñÿ. Â
ufa/777 âåðñèé 0.04 ýòîò ìåòîä îòêëþ÷àåòñÿ, âîò è ïîïðîáóé åãî íà 32-áèòíûõ
exe-øíèêàõ.
DP> Hî ÿ íå ñîâñåì êîððåêòíî çàäàë
DP> âîïðîñ, à òî÷íåå - ìåíÿ áîëüøå èíòåðåñóþò íå EXE ïàêåðû êàê òàêîâûå,
DP> ÿ
DP> õîòåë áîëåå ïîäðîáíî óçíàòü î ìåòîäàõ, ïðè ðåàëèçàöèè êîòîðûõ è
DP> ïàêîâêà ñèëüíàÿ, è ðàñïàêîâùèê êîðîòêèé...
optimal lzh, ïîäðîáíîñòè ïóáëèêîâàë Èãîðü Ïàâëîâ â ÿíâàðå ãäå-òî.
DP> Äîïóñòèì, êîäîâ Õàôôìàíà áóäåò âñåãî 16 :). Òîãäà â òàêîì ñëó÷àå íà
DP> õðàíåíèå äåðåâà(êîäîâ) Õàôôìàíà óéäåò ïðèìåðíî 5*16*2=160áèò=20 áàéò.
DP> Äà è ñàìà ïðîöåäóðà ïðîñòà è ëåãêà äëÿ ïîíèìàíèÿ :). 16 Êîäîâ
DP> Õàôôìàíà, ýòî êîíå÷íî ìàëîâàòî, íî âñå æå.
Äèìà ñåãîäíÿ ãîâîðèë, ÷òî òàì ïðîñòî íå÷åãî õàôôìåíîì ñæèìàòü - ïðîùå ãàììîé
è ôèêñèðîâàííûìè êîäàìè.
DP>> Ñ óâàæåíèåì, Äèìà.
DB>> ditto :)
DP> ×òî ýòî? ;)
Ïîâòîðåíèå ïðåäûäóùåé ñòðîêè :)
Bulat, mailto:bulatz@fort.tatarstan.ru, ICQ 15872722
--- GoldED/386 2.50+
* Origin: Çóáíûå êëåòêè íå âîññòàíàâëèâàþòñÿ (2:5093/29.61)
— RU.COMPRESS
From : Evgeny Sharandin 2:5020/755.12 20 May 99 20:56:00
To : Dmitry Subbotin
Subj : Carryless rangecoder v2.0 - 100% íàñòîÿùåãî èçâðàòà!
Reply-To: shar@nep.cplire.ru
Hello, Dmitry!
Ñpä Ìàé 19 1999 03:35, Dmitry Subbotin íàïèñàë Leonid Broukhis:
DS> îòðèöàòåëüíûå ÷èñëà õðàíÿòüñÿ â äîïîëíèòåëüíîì ôîðìàòå, ò.å. ÷òî
DS> íàïðèìåð char(-1)==0xff. À â ñîâðåìåííîé ïðèðîäå åñòü êîìïû, äëÿ
DS> êîòîðûõ ýòî íå âåðíî?
Øèpîêîpàñïpîñòpàíåííûõ êîìïîâ - ñåé÷àñ âpÿä ëè. Õîòÿ èìååò ìåñòî êó÷à
äîèñòîpè÷åñêèõ ñïåöâû÷èñëèòåëåé, êîòîpûå áóäóò ýêñïëóàòèpîâàòüñÿ åùå ëåò 20-30,
èìåþùèõ èíûå ñîãëàøåíèÿ (íàïpèìåp, öâì ïåpåäpàííàÿ äëÿ âåñüìà çíàìåíèòîãî
êîìïëåêñà ó Áîèíãà, âîîáùå âñå ÷èñëà äåpæèò â äâîè÷íî-äåñÿòè÷íîì ôîpìàòå). Hî
òàêèì è òâîé êîäåp íå íóæåí ;).
Ñ óâàæåíèåì, Åâãåíèé
--- GoldED 2.42.G0214+
* Origin: LID, Evgeny Sharandin (2:5020/755.12)
— RU.COMPRESS
From : Max Smirnov 2:5030/706.11 20 May 99 21:55:12
To : Leonid Broukhis
Subj : Re: DAKX method
Ïðèâåò, Leonid!
Âòp Àïp 27 1999, Leonid Broukhis writes to Maxime Zakharov:
>> Hello All,
>>
>> http://dakx.com
>>
LB> Îíî, ê ñîæàëåíèþ, çàïàòåíòîâàíî. Åñëè è ýòî ïàòåíòóþò, òî ÿ ïðîñòî
LB> íå çíàþ, ÷òî íåëüçÿ çàïàòåíòîâàòü.
ïpî÷èòàë è íå ïîíÿë, ÷òî òàì ìîæíî çàïàòåíòîâàòü. Hà ÷òî èìåííî áûë ïîëó÷åí ïàò
åíò? Hà äîïîëíèòåëüíûé êîä? ;)
Max
--- --- ---
* Origin: -= Ñëîíû íîí÷å âçäîðîæàëè =- (2:5030/706.11)
— RU.COMPRESS
From : Rustam Gadeyev 2:5008/7.10 20 May 99 23:42:32
To : Igor Pavlov
Subj : Re: EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
Hello, Igor!
 ñðåäó Ìàÿ 19 1999 22:01, Igor Pavlov wrote All:
>> DP>> ×åì UPX âûèãðûâàåò ó APACK ?
>> DB> êîëè÷åñòâîì ïîääåðæèâàåìûõ òèïîâ ïðîãðàìì. â ïîñëåäíåå âðåìÿ,
>> DB> ïîñëå èçìåíåíèé â àëãîðèòìå ñæàòèÿ ðåëîêàöèé (ñîäðàííîì ó
>> DB> apack-à) - äîãîíÿåò, à èíîãäà è îáãîíÿåò íà ñæàòèè dos exe ñàì
>> DB> apack (â îñíîâíîì íà ïàñêàëåâñêèõ exe). âîîáùå åñëè íå
>> DB> îñòàíàâëèâàòüñÿ íà äîñòèãíóòîì è óâîðîâàòü ó apack-à åùå è
>> DB> àëãîðèòì îáðàáîòêè e8 (relative call)
>>
>>  ïîñëåäíèõ upx óæå åñòü e8-e9. Ïðè÷åì ñ èíòåðåñíîé äîáàâêîé -
>> çàïèñüþ àáñîëþòíûõ àäðåñîâ ñòàðøèìè áàéòàìè âïåðåä.
IP> Â ñâîå âðåìÿ ÿ ïðîâåðÿë ýòó ôè÷ó äëÿ e8.
IP> È îòêàçàëñÿ îò íåå. Imho îíà ÷àùå ìåøàåò.
IP> Ìîæåò áûòü, ÿ îøèáñÿ.
Äëÿ 32-áèòíûõ ïðîãðàìì ñ áîëüøèì êîëè÷åñòâîì âûçîâîâ ïðîöåäyð ýòî äàåò çàìåòíîå
yëy÷øåíèå ñæàòèÿ, äðyãîå äåëî êàê íàèáîëåå äîñòîâåðíî îïðåäåëèòü ÷òî ýòî çà E8,
CALL ýòî èëè ïðîñòî áàéò. Hàïðèìåð òàê: àáñîëþòíûé àäðåñ â CALL íå äîëæåí áûòü
áîëüøå, ÷åì äëèíà ôàéëà, ñàìà êîìàíäà CALL íå äîëæíà ïåðåñå÷üñÿ ñ relocation.
Êàæäûé E8, êîòîðûé CALL ñ ïåðåâåðíyòûì àáñîëþòíûì àäðåñîì, ïîìå÷àåòñÿ ôëàãîì -
ñëåäyþùèé áàéò çà E8 èìååò îïðåäåëåííîå çíà÷åíèå, êîòîðûé âû÷èñëÿåòñÿ ïðè
ïðåäâàðèòåëüíîì àíàëèçå êîäà. Ýòî êîíå÷íî îãðàíè÷èâàåò ðàçìåð ôàéëà 16
ìåãàáàéòàìè, íî ýòî íå ñëèøêîì áîëüøàÿ ïëàòà çà yëy÷øåíèå ñæàòèÿ. Ìîæåò áûòü
çäåñü ìîæíî åùå ÷òî-òî yëy÷øèòü, íî ýòî ñîìíèòåëüíî. Êñòàòè E8 è E9 â UPX
îáðàáàòûâàþòñÿ íåðàçäåëüíî, îáùàÿ ïðîöåäyðà ðàñêîäèðîâêè è ôëàã.
Ñæàòèå y UPX ëy÷øå ÷åì y APACK íà÷èíàÿ ñî 100 êá, âèäèìî UPX èìååò îêíî â LZ
àëãîðèòìå ñyùåñòâåííî áîëüøå ÷åì 57300 áàéò y APACK. Hà ìåíüøèõ ôàéëàõ APACK
âñåãäà âûèãðûâàåò, âèäèìî çà ñ÷åò áîëåå îïòèìàëüíîé êîäèðîâêè.
Good Bye.
--- ( ) ---
* Origin: Ulan-Ude. Buriatia. (2:5008/7.10)
— RU.COMPRESS
From : Dima Petukhov 2:5020/1517.12 21 May 99 01:14:13
To : Dmitry Shkarin
Subj : FAQ need (or answer for me)
Hello Dmitry.
Wednesday May 19 1999 18:12, Dmitry Shkarin íàïèñàë(à) ê All:
>> áèò) (çàäàåòñÿ îäèí pàç äëÿ âñåãî ôàéëà), íî _îáÿçàòåëüíî_ ñî
>> ñòàòè÷åñêèì ñëîâàpåì ïpè _î÷åíü_ áûñòpîé pàñïàêîâêå (äî ñîòíè òàêòîâ
DS> Áîþñü, ÷òî èñïîëüçóÿ ñòàòè÷åñêèé(îïòèìàëüíûé) ñëîâàðü òû ëèáî
ß íå ãîâîpèë ÷òî ñëîâàpü _äîëæåí_ áûòü îïòèìàëüíûì - õîpîøî áû, íî åñëè íåò, òî
íåò. À âîò ñòàòè÷åñêèì îí áûòü îáÿçàí! :)) - ïî óñëîâèþ çàäà÷è.
DS> ñèëüíî ïðîèãðàåøü â ñæàòèè(åñëè ïåðåäàâàòü ñëîâàðü ïåðåä ôàéëîì),
Ïpîèãpàþ ïî îòíîøåíèþ ê êîìó? Pàçóìååòñÿ ÿ ó÷èòûâàþ îáúåì ñëîâàpÿ ïpè pàñ÷åòå
êîýôôèöèåíòà óïàêîâêè (ïîòîìó è õîòåë ÷òîá îí óêëàäûâàëñÿ â ïàpó Êá).
DS> ëèáî â ñêîðîñòè, ò.ê ïðèäåòñÿ ñòðîèòü ñëîâàðü âî âðåìÿ ðàñïàêîâêè.
Hå ïîäõîäèò ïî óñëîâèÿì çàäà÷è.
DS> Âûèãðûø îò îïòèìàëüíîãî ñëîâàðÿ î÷åíü ìàë(1-2%).
Ïî îòíîøåíèþ ê êàêîìó ñëîâàpþ ìàë?
Ìåíÿ èíòåpåñóåò íå âûèãpûø îò îïòèìàëüíîãî ñëîâàpÿ è íå ïpîèãpûø îò
ñòàòè÷åñêîãî, à àëãîpèòì påøåíèÿ çàäà÷è ñ òàêèìè îãpàíè÷åíèÿìè.
DS> Hàèáîëåå áûñòðóþ ðàñïàêîâêó äàåò LZ77, ò.ê. îí ñâîäèòñÿ ïðîñòî ê
DS> êîïèðîâàíèþ áàéòîâ, ïîòðåáíîñòè â ïàìÿòè òîæå íåâåëèêè(ðàçìåð îêíà).
Ïàìÿòè âî âpåìÿ pàñïàêîâêè ìîæíî ñ÷èòàòü ÷òî âîîáùå íåò - î ìîäèôèêàöèè ñëîâàpÿ
íå ìîæåò áûòü è på÷è (íó pàçâå ÷òî åñëè îí âñåãî èç äåñÿòêà áàéò :)).
LZ è LZW (ýòî pàçâå íå îäíî è òîæå ïî ñìûñëó?) ìíå ípàâèòñÿ òåì, ÷òî îí ïpè
pàñïàêîâêå îäíîãî âõîäíîãî êîäà ìîæåò âûäàòü êó÷ó âûõîäíûõ êîäîâ (åñëè
çàêîäèpîâàíû äîñòàòî÷íî äëèííûå ñòpîêè) - óâåëè÷èâàåòñÿ ñpåäíÿÿ ñêîpîñòü.
 îáùåì, ñïàñèáî çà îòâåò, íî îí íåìíîãî íå ïî ìîåé òåìå ... :)
Ìîæåò åùå êòî ÷åãî ïîñîâåòóåò?
Äèìà
ß íå ïðîùàþñü - åùå óâèäèìñÿ...
... ß íèêîãî íå óáèâàë ...
--- GoldED 3.00+ Alpha 5
* Origin: /dev/null (FidoNet 2:5020/1517.12)
— RU.COMPRESS
From : Igor Pavlov 2:5020/400 21 May 99 01:31:46
To : All
Subj : Re: EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
From: "Igor Pavlov" <igor@vtizi.ugatu.ac.ru>
Reply-To: "Igor Pavlov" <igor@vtizi.ugatu.ac.ru>
Hello Rustam!
Rustam Gadeyev <Rustam.Gadeyev@p10.f7.n5008.z2.fidonet.org> wrote in message
news:927244726@p10.f7.n5008.z2.ftn...
> >>  ïîñëåäíèõ upx óæå åñòü e8-e9. Ïðè÷åì ñ èíòåðåñíîé äîáàâêîé -
> >> çàïèñüþ àáñîëþòíûõ àäðåñîâ ñòàðøèìè áàéòàìè âïåðåä.
>
> IP> Â ñâîå âðåìÿ ÿ ïðîâåðÿë ýòó ôè÷ó äëÿ e8.
> IP> È îòêàçàëñÿ îò íåå. Imho îíà ÷àùå ìåøàåò.
> IP> Ìîæåò áûòü, ÿ îøèáñÿ.
> Äëÿ 32-áèòíûõ ïðîãðàìì ñ áîëüøèì êîëè÷åñòâîì âûçîâîâ ïðîöåäyð ýòî äàåò
> çàìåòíîå yëy÷øåíèå ñæàòèÿ,
À ó ìåíÿ áûëè äðóãèå ðåçóëüòàòû. Ïîïðîáóþ ïðîâåðèòü åùå ðàç.
> äðyãîå äåëî êàê íàèáîëåå äîñòîâåðíî îïðåäåëèòü ÷òî ýòî çà E8,
> CALL ýòî èëè ïðîñòî áàéò. Hàïðèìåð òàê: àáñîëþòíûé àäðåñ â CALL íå äîëæåí
> áûòü áîëüøå, ÷åì äëèíà ôàéëà
Ýòî ïîíÿòíî.
> ñàìà êîìàíäà CALL íå äîëæíà ïåðåñå÷üñÿ ñ relocation.
×òî ýòî çíà÷èò?
È ÷òî òàêîå relocation?
> Êàæäûé E8, êîòîðûé CALL ñ ïåðåâåðíyòûì àáñîëþòíûì àäðåñîì, ïîìå÷àåòñÿ ôëàãîì
> - ñëåäyþùèé áàéò çà E8 èìååò îïðåäåëåííîå çíà÷åíèå, êîòîðûé âû÷èñëÿåòñÿ
> ïðè ïðåäâàðèòåëüíîì àíàëèçå êîäà. Ýòî êîíå÷íî îãðàíè÷èâàåò ðàçìåð ôàéëà
> 16 ìåãàáàéòàìè, íî ýòî íå ñëèøêîì áîëüøàÿ ïëàòà çà yëy÷øåíèå ñæàòèÿ.
Hè÷åãî íå ïîíÿë. Îáúÿñíè ïîäðîáíåå.
> Ìîæåò áûòü
> çäåñü ìîæíî åùå ÷òî-òî yëy÷øèòü, íî ýòî ñîìíèòåëüíî. Êñòàòè E8 è E9 â UPX
> îáðàáàòûâàþòñÿ íåðàçäåëüíî, îáùàÿ ïðîöåäyðà ðàñêîäèðîâêè è ôëàã.
> Ñæàòèå y UPX ëy÷øå ÷åì y APACK íà÷èíàÿ ñî 100 êá, âèäèìî UPX èìååò îêíî â LZ
> àëãîðèòìå ñyùåñòâåííî áîëüøå ÷åì 57300 áàéò y APACK. Hà ìåíüøèõ ôàéëàõ APACK
> âñåãäà âûèãðûâàåò, âèäèìî çà ñ÷åò áîëåå îïòèìàëüíîé êîäèðîâêè.
>
> Good Bye.
>
- ---
Igor Pavlov
igorp@geocities.com
http://compress.da.ru
Compression tools
--- ifmail v.2.14dev3
* Origin: Ufa State Aviation Technical University (2:5020/400)
— RU.COMPRESS
From : Dmitry Subbotin 2:5020/530.18 21 May 99 04:03:54
To : Bulat Ziganshin
Subj : Carryless rangecoder v2.0 - 100% íàñòîÿùåãî èçâðàòà!
Hi, Bulat!
"Bulat Ziganshin" sendTo: "Leonid Broukhis" when: [20 May 99] msg:
>>> Äà, à ñðàâíèòü ñàáæ ñ îðèãèíàëüíûì ðàí÷êîäåðîì?
Ïî ñðàâíåíþ ñ øèíäëåðîâñêèì îðèãèíàëüíûì ñóáæ
1. ïðîùå è êîðî÷å, ðàçà òàê â òðè
2. äîëæåí ðàáîòàòü íà íåñêîëüêî òàêòîâ áûñòðåå, ÷òî â îáùåì-òî ôèãíÿ
3. òåðÿåò äîïîëíèòåëüíî ~0.05%, ÷òî òîæå ôèãíÿ
LB>> Ýòî ê Äìèòðèþ Ñóááîòèíó. Hî ÿ íå äóìàþ, ÷òî áóäåò ñóùåñòâåííàÿ
LB>> ðàçíèöà.
BZ> Òîãäà îáúÿñíèòå, â ÷åñòü ÷åãî ïðàçäíèê?
 ÷åñòü î÷åðåäíîé ïîáåäû ðàçóìà íàä àëãîðèòìîì àðèôìåòè÷åñêîãî êîäèðîâàíèÿ. ;)
taste you later,
morf
--- GoldED 2.50+
* Origin: morf@softhome.net (2:5020/530.18)
— RU.COMPRESS
From : Dmitry Subbotin 2:5020/530.18 21 May 99 04:34:53
To : Igor Pavlov
Subj : EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
Hi, Igor!
"Igor Pavlov" sendTo: "All" when: [19 May 99] msg:
>>  ïîñëåäíèõ upx óæå åñòü e8-e9. Ïðè÷åì ñ èíòåðåñíîé äîáàâêîé -
>> çàïèñüþ àáñîëþòíûõ àäðåñîâ ñòàðøèìè áàéòàìè âïåðåä.
IP> Â ñâîå âðåìÿ ÿ ïðîâåðÿë ýòó ôè÷ó äëÿ e8.
IP> È îòêàçàëñÿ îò íåå. Imho îíà ÷àùå ìåøàåò.
Ïî ìîèì íàáëþäåíèÿì, îíà ìåøàåò íà exe, ãäå ïî calling convention àãðóìåíòû èç
ñòåêà äîñòàåò âûçûâàþùàÿ ïðîöåäóðà, i.e. ãäå çà êàæäûì call èäåò ÷òî-òî âðîäå
add esp,nn. Hà äðóãèõ exe ïîëó÷àåòñÿ íåáîëüøîå óëó÷øåíèå.
Hà e9 ýôôåêò áûë âñåãäà ïîëîæèòåëüíûì.
Âïðî÷åì, âñå ýòî åðóäíà. Hà íàñòîÿùåì ðàçáîðå êîìàíä ìîæíî âûèãðàòü íàìíîãî
áîëüøå.
taste you later,
morf
--- GoldED 2.50+
* Origin: morf@softhome.net (2:5020/530.18)
— RU.COMPRESS
From : Leonid Broukhis 2:5020/400 21 May 99 04:59:23
To : Bulat Ziganshin
Subj : Re: Carryless rangecoder v2.0 - 100% íàñòîÿùåãî èçâðàòà!
From: leob@asylum.mailcom.com (Leonid Broukhis)
Bulat Ziganshin wrote:
> >> Äà, à ñðàâíèòü ñàáæ ñ îðèãèíàëüíûì ðàí÷êîäåðîì?
>
> LB> Ýòî ê Äìèòðèþ Ñóááîòèíó. Hî ÿ íå äóìàþ, ÷òî áóäåò ñóùåñòâåííàÿ
> LB> ðàçíèöà.
>
> Òîãäà îáúÿñíèòå, â ÷åñòü ÷åãî ïðàçäíèê?
Ïðàçäíèê â ÷åñòü ïðîñòîòû è êîìïàêòíîñòè. È ñêîðîñòè, íàäî ïîëàãàòü.
Leo
--- ifmail v.2.14dev3
* Origin: leob@at-mailcom.dot-com (2:5020/400)
— RU.COMPRESS
From : Dmitry Pyankov 2:5020/400 21 May 99 08:04:05
To : All
Subj : EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
From: "Dmitry Pyankov" <dp@fmf.gasu.gorny.ru>
Hello, Bulat!
DP> Hî ÿ íå ñîâñåì êîððåêòíî çàäàë
DP> âîïðîñ, à òî÷íåå - ìåíÿ áîëüøå èíòåðåñóþò íå EXE ïàêåðû êàê òàêîâûå,
DP> ÿ
DP> õîòåë áîëåå ïîäðîáíî óçíàòü î ìåòîäàõ, ïðè ðåàëèçàöèè êîòîðûõ è
DP> ïàêîâêà ñèëüíàÿ, è ðàñïàêîâùèê êîðîòêèé...
BZ> optimal lzh, ïîäðîáíîñòè ïóáëèêîâàë Èãîðü Ïàâëîâ â ÿíâàðå ãäå-òî.
DP> Äîïóñòèì, êîäîâ Õàôôìàíà áóäåò âñåãî 16 :). Òîãäà â òàêîì ñëó÷àå íà
DP> õðàíåíèå äåðåâà(êîäîâ) Õàôôìàíà óéäåò ïðèìåðíî 5*16*2=160áèò=20 áàéò.
DP> Äà è ñàìà ïðîöåäóðà ïðîñòà è ëåãêà äëÿ ïîíèìàíèÿ :). 16 Êîäîâ
DP> Õàôôìàíà, ýòî êîíå÷íî ìàëîâàòî, íî âñå æå.
BZ> Äèìà ñåãîäíÿ ãîâîðèë, ÷òî òàì ïðîñòî íå÷åãî õàôôìåíîì ñæèìàòü - ïðîùå
ãàììîé
BZ>è ôèêñèðîâàííûìè êîäàìè.
Ñðàçó âîïðîñ: ×òî òàêîå ãàììà?
Hó à ÷òî êàñàåòñÿ ôèêñèðîâàííûõ êîäîâ, òî ó ìåíÿ ïîëó÷àåòñÿ, ÷òî åñëè ÿ
ïîäáåðó êîäû äëÿ îäíîãî òèïà ôàéëîâ, òî ÿ ïðîèãðûâàþ íà äðóãîì òèïå ôàéëîâ.
- Ôàéëû ó ìåíÿ íå EXE, à ëþáûå. Äèìà íàâåðíî òîëüêî ïðî EXE ãîâîðèë.
Ñ óâàæåíèåì, Äèìà.
--- ifmail v.2.14dev3
* Origin: Unknown (2:5020/400)
— RU.COMPRESS
From : Bulat Ziganshin 2:5093/29.61 21 May 99 13:16:04
To : Rustam Gadeyev
Subj : EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
*** Answering a msg posted in area BAD_MAIL (BAD_MAIL).
* Crossposted in RU.COMPRESS
Hello Rustam!
Friday May 21 1999, Rustam Gadeyev writes to Bulat Ziganshin:
RG>>> Äëÿ 32-áèòíûõ ïðîãðàìì ñ áîëüøèì êîëè÷åñòâîì âûçîâîâ ïðîöåäyð
RG>>> ýòî äàåò çàìåòíîå yëy÷øåíèå ñæàòèÿ, äðyãîå äåëî êàê
RG>>> íàèáîëåå äîñòîâåðíî îïðåäåëèòü ÷òî ýòî çà E8,
RG> ß èìåë â âèäy, ÷òî ïðîáëåìà îïðåäåëèòü ýòî ïðè êîäèðîâàíèè, à íå ïðè
RG> äåêîäèðîâàíèè.
BZ>> Hàéäè â èíåòå cab-sdk.exe è ïî÷èòàé â íåì äîêó ïî lzx.  íåì
BZ>> î÷åíü ïðîñòîé àëãîðèòì ñ ïðàêòè÷åñêè 100-ïîðöåíòíîé
BZ>> ýôôåêòèâíîñòüþ.
RG> Çäåñü äàåòñÿ ëèøü ñïîñîá êîäèðîâàíèÿ offset y êîìàíäû CALL, ïðè÷åì
RG> èç-çà òîãî, ÷òî äëÿ îïðåäåëåíèÿ êîäèðîâàííûé ýòî offset èëè íåò,
RG> èñïîëüçyþòñÿ ãðàíèöû -curpos è filesize, îíè áûëè âûíyæäåíû òàêæå
RG> äîïîëíèòåëüíî êîäèðîâàòü offset y ÿêîáû CALL-îâ, ññûëàþùèåñÿ íà
RG> îáëàñòü îò filesize äî filesize+curpos, ÷òî åñòåñòâåííî ñíèæàåò
RG> ñæàòèå, òàê êàê êîäèðyþòñÿ dwords, êîòîðûå íå äîëæíû áûëè áûòü
RG> çàêîäèðîâàíû.
Òàêèõ î÷åíü ìàëî, èìõî.
RG> Ïëþñ íåâîçìîæíîñòü ïðèìåíèòü ïåðåâîðà÷èâàíèå áàéòîâ
RG> offset.
Hó äà. ß ïðîáîâàë, ïðîñòî ñæàòèå ñòàëî õóæå. Hèêàêèõ ïðîáëåì ñ îäíîçíà÷íûì
äåêîäèðîâàíèåì íåò - ïîñëå ëþáîãî E8 ÷èòàåì 4 áàéòà, ïåðåâîðà÷èâàåì è òîãäà óæ
ñìîòðèì ðåçóëüòàò.
RG> Ñïîñîá êîäèðîâàíèÿ offset y CALL â UPX ìîæåò êîäèðîâàòü
RG> èñêëþ÷èòåëüíî òî, ÷òî íyæíî, äðyãîå äåëî, ÷òî íà ýòàïå ïðåïðîöåññèíãà
RG> äîñòîâåðíî îïðåäåëèòü êîìàíäà ýòî èëè ïðîñòî áàéò íåâîçìîæíî, èëè
RG> ïðîãðàììà äîëæíà èìåòü íå÷òî âðîäå èíòåëëåêòyàëüíîãî äèçàññåìáëåðà.
RG> Îäíàêî òå ñêèïíyòûå òîáîé yñëîâèÿ ïîçâîëÿþò äîâîëüíî íåïëîõî îòñåÿòü
RG> òå E8/E9, êîòîðûå íå ÿâëÿþòñÿ êîìàíäàìè.
Ãì, ìîæåò äåéñòâèòåëüíî òâîé (èëè òû îïèñûâàë èìåííî upx'îâñêèé?) ìåòîä
ëó÷øå. ×òî èíòåðåñíî - â apack ýòî è äëÿ 16-ðàçðÿäíûõ exe-øíèêîâ äåëàåòñÿ.
Bulat, mailto:bulatz@fort.tatarstan.ru, ICQ 15872722
--- GoldED/386 2.50+
* Origin: Çóáíûå êëåòêè íå âîññòàíàâëèâàþòñÿ (2:5093/29.61)
— RU.COMPRESS
From : Rustam Gadeyev 2:5008/7.10 21 May 99 13:34:28
To : Igor Pavlov
Subj : Re: EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
Hello, Igor!
 ïÿòíèöó Ìàÿ 21 1999 01:31, Igor Pavlov wrote All:
>> äðyãîå äåëî êàê íàèáîëåå äîñòîâåðíî îïðåäåëèòü ÷òî ýòî çà E8,
>> CALL ýòî èëè ïðîñòî áàéò. Hàïðèìåð òàê: àáñîëþòíûé àäðåñ â CALL íå
>> äîëæåí áûòü áîëüøå, ÷åì äëèíà ôàéëà
IP> Ýòî ïîíÿòíî.
>> ñàìà êîìàíäà CALL íå äîëæíà ïåðåñå÷üñÿ ñ relocation.
IP> ×òî ýòî çíà÷èò?
IP> È ÷òî òàêîå relocation?
Ïîä relocation ÿ îáîçíà÷èë àäðåñ èç òàáëèöû íàñòðîåê àäðåñîâ, êîòîðàÿ îáû÷íî
âñåãäà èìååòñÿ y EXE-ôàéëîâ. Êîìàíäà CALL íå èìååò íàñòðàèâàåìîãî àäðåñà,
ïîýòîìy åå àäðåñ íå äîëæåí ñîâïàäàòü ñ îäíèì èç àäðåñîâ èç òàáëèöû íàñòðîåê ñ
y÷åòîì ðàçìåðà 5-áàéòíîé êîìàíäû CALL è ðàçìåðîì â 4 áàéòà íàñòðàèâàåìîãî
ýëåìåíòà. Òàê èëè èíà÷å âûáèðàþòñÿ òå E8/E9, êîòîðûå äîëæíû ïåðåêîäèðîâàòüñÿ,
îòíîñèòåëüíûé àäðåñ ìåíÿåì íà àáñîëþòíûé, òðè ìëàäøèõ áàéòà äàþò 16-ìåãàáàéòíîå
ïðîñòðàíñòâî äëÿ ðàñïîëîæåíèÿ ïðîöåäyð, ýòî âïîëíå äîñòàòî÷íî äëÿ àáñîëþòíîãî
áîëüøèíñòâà ôàéëîâ, èíà÷å ýòîò CALL ïðîñòî áðàêyåòñÿ. Äàëåå âìåñòî ñòàðøåãî
áàéòà ïèøåòñÿ ôëàã - íåêèé áàéò, çíà÷åíèå êîòîðîãî îïðåäåëÿåòñÿ ïðè
ïðåäâàðèòåëüíîì ñêàíèðîâàíèè. Ïîñëå ôëàãà ïèøåòñÿ â îáðàòíîì ïîðÿäêå ìëàäøèå 3
áàéòà àáñîëþòíîãî àäðåñà èç êîìàíäû CALL. Âûèãðûø ïîëy÷àåòñÿ çà ñ÷åò áîëåå
äëèííûõ ïîâòîðîâ: E8, Fl, A2, A1, A0 - ïðîöåäyðû îáû÷íî ãðyïïèðyþòñÿ âìåñòå è
A2 ÷àñòåíüêî îêàçûâàåòñÿ îäèíàêîâûì.
Çíà÷åíèå ôëàãà îïðåäåëÿåòñÿ â îòäåëüíîì ïðîõîäå ïåðåä êîäèðîâàíèåì àäðåñîâ -
çàâîäèì òàáëèöy 0-255 è äëÿ êàæäîãî E8/E9, êîòîðûå íå êîäèðyþòñÿ áåðåì
ñëåäyþùèé áàéò è èñêëþ÷àåì åãî èç òàáëèöû, è òàê äàëåå ïîêà åñòü åùå áàéòû â
òàáëèöå è ïàêyåìûé êîä, ïðè ýòîì âû÷èñëÿåì êîëè÷åñòâî ãîäíûõ E8/E9 ÷òîáû
èñïîëüçîâàòü ïðè êîäèðîâàíèè è ïîòîì ïðè ðàñïàêîâêå. Äëÿ ôëàãà áåðåì òî, ÷òî
îñòàëîñü â òîé òàáëèöå, îáû÷íî ýòî áûâàåò 3 èëè 4.
Êñòàòè, íàñòðàèâàåìûå àäðåñà â ïàêyåìîé ïðîãðàììå òàêæå ïîäâåðãàþòñÿ
ïåðåâîðà÷èâàíèþ è ýòî äàåò íåìåäëåííûé ýôôåêò.
Good Bye.
--- ( ) ---
* Origin: Ulan-Ude. Buriatia. (2:5008/7.10)
— RU.COMPRESS
From : Rustam Gadeyev 2:5008/7.10 21 May 99 13:44:38
To : Bulat Ziganshin
Subj : Re: EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
Hello, Bulat!
 ÷åòâåðã Ìàÿ 20 1999 14:32, Bulat Ziganshin wrote Rustam Gadeyev:
RG>> Äëÿ 32-áèòíûõ ïðîãðàìì ñ áîëüøèì êîëè÷åñòâîì âûçîâîâ ïðîöåäyð ýòî
RG>> äàåò çàìåòíîå yëy÷øåíèå ñæàòèÿ, äðyãîå äåëî êàê íàèáîëåå
RG>> äîñòîâåðíî îïðåäåëèòü ÷òî ýòî çà E8,
ß èìåë â âèäy, ÷òî ïðîáëåìà îïðåäåëèòü ýòî ïðè êîäèðîâàíèè, à íå ïðè
äåêîäèðîâàíèè.
BZ> Hàéäè â èíåòå cab-sdk.exe è ïî÷èòàé â íåì äîêó ïî lzx.  íåì î÷åíü
BZ> ïðîñòîé àëãîðèòì ñ ïðàêòè÷åñêè 100-ïîðöåíòíîé ýôôåêòèâíîñòüþ.
Çäåñü äàåòñÿ ëèøü ñïîñîá êîäèðîâàíèÿ offset y êîìàíäû CALL, ïðè÷åì èç-çà òîãî,
÷òî äëÿ îïðåäåëåíèÿ êîäèðîâàííûé ýòî offset èëè íåò, èñïîëüçyþòñÿ ãðàíèöû
-curpos è filesize, îíè áûëè âûíyæäåíû òàêæå äîïîëíèòåëüíî êîäèðîâàòü offset y
ÿêîáû CALL-îâ, ññûëàþùèåñÿ íà îáëàñòü îò filesize äî filesize+curpos, ÷òî
åñòåñòâåííî ñíèæàåò ñæàòèå, òàê êàê êîäèðyþòñÿ dwords, êîòîðûå íå äîëæíû áûëè
áûòü çàêîäèðîâàíû. Ïëþñ íåâîçìîæíîñòü ïðèìåíèòü ïåðåâîðà÷èâàíèå áàéòîâ offset.
Ñïîñîá êîäèðîâàíèÿ offset y CALL â UPX ìîæåò êîäèðîâàòü èñêëþ÷èòåëüíî òî, ÷òî
íyæíî, äðyãîå äåëî, ÷òî íà ýòàïå ïðåïðîöåññèíãà äîñòîâåðíî îïðåäåëèòü êîìàíäà
ýòî èëè ïðîñòî áàéò íåâîçìîæíî, èëè ïðîãðàììà äîëæíà èìåòü íå÷òî âðîäå
èíòåëëåêòyàëüíîãî äèçàññåìáëåðà. Îäíàêî òå ñêèïíyòûå òîáîé yñëîâèÿ ïîçâîëÿþò
äîâîëüíî íåïëîõî îòñåÿòü òå E8/E9, êîòîðûå íå ÿâëÿþòñÿ êîìàíäàìè.
Good Bye.
--- ( ) ---
* Origin: Ulan-Ude. Buriatia. (2:5008/7.10)
— RU.COMPRESS
From : Misha Fedorov 2:5020/238 21 May 99 22:49:55
To : Rustam Gadeyev
Subj : Re: EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
Hi !
RG> Äëÿ 32-áèòíûõ ïðîãðàìì ñ áîëüøèì êîëè÷åñòâîì âûçîâîâ ïðîöåäyð ýòî äàåò
RG> çàìåòíîå yëy÷øåíèå ñæàòèÿ, äðyãîå äåëî êàê íàèáîëåå äîñòîâåðíî
RG> îïðåäåëèòü ÷òî ýòî çà E8, CALL ýòî èëè ïðîñòî áàéò. Hàïðèìåð òàê:
RG> àáñîëþòíûé àäðåñ â CALL íå äîëæåí áûòü áîëüøå, ÷åì äëèíà ôàéëà, ñàìà
RG> êîìàíäà CALL íå äîëæíà ïåðåñå÷üñÿ ñ relocation. Êàæäûé E8, êîòîðûé
Ïðîâåðèòü, ïîïàäàåò ëè àäðåñ â ñîîòâåòñòâåííûå ãðàíèöû ñåêöèè, åñëè ðå÷ü
èäåò î PE
RG> CALL ñ ïåðåâåðíyòûì àáñîëþòíûì àäðåñîì, ïîìå÷àåòñÿ ôëàãîì - ñëåäyþùèé
RG> áàéò çà E8 èìååò îïðåäåëåííîå çíà÷åíèå, êîòîðûé âû÷èñëÿåòñÿ ïðè
RG> ïðåäâàðèòåëüíîì àíàëèçå êîäà. Ýòî êîíå÷íî îãðàíè÷èâàåò ðàçìåð ôàéëà 16
RG> ìåãàáàéòàìè, íî ýòî íå ñëèøêîì áîëüøàÿ ïëàòà çà yëy÷øåíèå ñæàòèÿ.
Îé, à òû âèäåë ôàéëû, ãäå áîëüøå 16Mb êîäà ?
RG> Ìîæåò áûòü çäåñü ìîæíî åùå ÷òî-òî yëy÷øèòü, íî ýòî ñîìíèòåëüíî. Êñòàòè
RG> E8 è E9 â UPX îáðàáàòûâàþòñÿ íåðàçäåëüíî, îáùàÿ ïðîöåäyðà ðàñêîäèðîâêè
Ëó÷øå áû îíè åùå êîíñòðóêöèè, ãäå ìíîãî ðàçíûõ push'åé ïîääåðæàëè
Hà ýòîì ìîæíî î÷åíü íåõèëî âûèãðàòü
À åùå êðó÷å - ñäåëàòü êîäèðîâàíèå èíñòðóêöèé áîëåå îïòèìèçèðîâàííûì, ÷åì ó
Intel. Hà óðîâíå îäíèõ òîëüêî áèòîâ ìîæíî 10% âûèãðàòü - ýòî êàê ìèíèìóì
Hî ýòî äîñòàòî÷íî ñëîæíàÿ çàäà÷à. À â ñâÿçè ñ âûõîäîì Merced'à îíà íåñêîëüêî
òåðÿåò ñìûñë
RG> è ôëàã. Ñæàòèå y UPX ëy÷øå ÷åì y APACK íà÷èíàÿ ñî 100 êá, âèäèìî UPX
RG> èìååò îêíî â LZ àëãîðèòìå ñyùåñòâåííî áîëüøå ÷åì 57300 áàéò y APACK.
RG> Hà ìåíüøèõ ôàéëàõ APACK âñåãäà âûèãðûâàåò, âèäèìî çà ñ÷åò áîëåå
RG> îïòèìàëüíîé êîäèðîâêè.
À åùå Petite 2.0 î÷åíü äàæå íè÷åãî. Ïî÷òè ê UPX'ó ïðèäëèæàåòñÿ íà
ìàêñèìàëüíîì ñæàòèè
--- Blue Wave v2.12 [NR]
* Origin: InfoScience BBS - USER's MESSAGE * (2:5020/238)
— RU.COMPRESS
From : Igor Pavlov 2:5020/400 22 May 99 01:01:30
To : All
Subj : Re: EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
From: "Igor Pavlov" <igor@vtizi.ugatu.ac.ru>
Reply-To: "Igor Pavlov" <igor@vtizi.ugatu.ac.ru>
Hello Dmitry!
Dmitry Subbotin <Dmitry.Subbotin@p18.f530.n5020.z2.fidonet.org> wrote in
message news:927261315@p18.f530.n5020.z2.ftn...
> >>  ïîñëåäíèõ upx óæå åñòü e8-e9. Ïðè÷åì ñ èíòåðåñíîé äîáàâêîé -
> >> çàïèñüþ àáñîëþòíûõ àäðåñîâ ñòàðøèìè áàéòàìè âïåðåä.
>
> IP> Â ñâîå âðåìÿ ÿ ïðîâåðÿë ýòó ôè÷ó äëÿ e8.
> IP> È îòêàçàëñÿ îò íåå. Imho îíà ÷àùå ìåøàåò.
>
> Ïî ìîèì íàáëþäåíèÿì, îíà ìåøàåò íà exe, ãäå ïî calling convention àãðóìåíòû
> èç ñòåêà äîñòàåò âûçûâàþùàÿ ïðîöåäóðà, i.e. ãäå çà êàæäûì call èäåò ÷òî-òî
> âðîäå add esp,nn.
Î÷åíü èíòåðåñíîå íàáëþäåíèå.
Imho áîëüøèíñòâî ôàéëîâ çàïèñàíû èìåííî òàê.
> Hà äðóãèõ exe ïîëó÷àåòñÿ íåáîëüøîå óëó÷øåíèå.
>
> Hà e9 ýôôåêò áûë âñåãäà ïîëîæèòåëüíûì.
À êîãäà e9-êîíâåðòèðîâàíèå âîîáùå ñðàáàòûâàåò?
Åñòü ëè êàêîé-íèáóäü ïðèçíàê?
- ---
Igor Pavlov
igorp@geocities.com
http://compress.da.ru
Compression tools
--- ifmail v.2.14dev3
* Origin: Ufa State Aviation Technical University (2:5020/400)
— RU.COMPRESS
From : Igor Pavlov 2:5020/400 22 May 99 01:01:33
To : All
Subj : Re: EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
From: "Igor Pavlov" <igor@vtizi.ugatu.ac.ru>
Reply-To: "Igor Pavlov" <igor@vtizi.ugatu.ac.ru>
Hello Rustam!
Rustam Gadeyev <Rustam.Gadeyev@p10.f7.n5008.z2.fidonet.org> wrote in message
news:927294287@p10.f7.n5008.z2.ftn...
> BZ> Hàéäè â èíåòå cab-sdk.exe è ïî÷èòàé â íåì äîêó ïî lzx.  íåì î÷åíü
> BZ> ïðîñòîé àëãîðèòì ñ ïðàêòè÷åñêè 100-ïîðöåíòíîé ýôôåêòèâíîñòüþ.
> Çäåñü äàåòñÿ ëèøü ñïîñîá êîäèðîâàíèÿ offset y êîìàíäû CALL, ïðè÷åì èç-çà
> òîãî, ÷òî äëÿ îïðåäåëåíèÿ êîäèðîâàííûé ýòî offset èëè íåò, èñïîëüçyþòñÿ
> ãðàíèöû -curpos è filesize, îíè áûëè âûíyæäåíû òàêæå äîïîëíèòåëüíî êîäèðîâàòü
> offset y ÿêîáû CALL-îâ, ññûëàþùèåñÿ íà îáëàñòü îò filesize äî
> filesize+curpos, ÷òî åñòåñòâåííî ñíèæàåò ñæàòèå, òàê êàê êîäèðyþòñÿ dwords,
> êîòîðûå íå äîëæíû áûëè áûòü çàêîäèðîâàíû. Ïëþñ íåâîçìîæíîñòü ïðèìåíèòü
> ïåðåâîðà÷èâàíèå áàéòîâ offset. Ñïîñîá êîäèðîâàíèÿ offset y CALL â UPX ìîæåò
> êîäèðîâàòü èñêëþ÷èòåëüíî òî, ÷òî íyæíî, äðyãîå äåëî, ÷òî íà ýòàïå
> ïðåïðîöåññèíãà äîñòîâåðíî îïðåäåëèòü êîìàíäà ýòî èëè ïðîñòî áàéò íåâîçìîæíî,
> èëè ïðîãðàììà äîëæíà èìåòü íå÷òî âðîäå èíòåëëåêòyàëüíîãî äèçàññåìáëåðà.
Ìîæíî ïîïðîáîâàòü äåðæàòü ñ÷åò÷èê êîëè÷åñòâà ïîïàäàíèé äëÿ
êàæäîãî àáñîëþòíîãî àäðåñà, ïîëó÷åííîãî èç e8.
if (aCounters[Hash(AbsAddress(x))] >= aThreshold)
ConvertAddress();
> Îäíàêî òå ñêèïíyòûå òîáîé yñëîâèÿ ïîçâîëÿþò
> äîâîëüíî íåïëîõî îòñåÿòü òå E8/E9, êîòîðûå íå ÿâëÿþòñÿ êîìàíäàìè.
>
> Good Bye.
>
--
Igor Pavlov
igorp@geocities.com
--- ifmail v.2.14dev3
* Origin: Ufa State Aviation Technical University (2:5020/400)
— RU.COMPRESS
From : Igor Pavlov 2:5020/400 22 May 99 01:01:33
To : All
Subj : Re: EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
From: "Igor Pavlov" <igor@vtizi.ugatu.ac.ru>
Reply-To: "Igor Pavlov" <igor@vtizi.ugatu.ac.ru>
Hello Rustam!
Rustam Gadeyev <Rustam.Gadeyev@p10.f7.n5008.z2.fidonet.org> wrote in message ne
ws:927294287@p10.f7.n5008.z2.ftn...
> BZ> Hàéäè â èíåòå cab-sdk.exe è ïî÷èòàé â íåì äîêó ïî lzx.  íåì î÷åíü
> BZ> ïðîñòîé àëãîðèòì ñ ïðàêòè÷åñêè 100-ïîðöåíòíîé ýôôåêòèâíîñòüþ.
> Çäåñü äàåòñÿ ëèøü ñïîñîá êîäèðîâàíèÿ offset y êîìàíäû CALL, ïðè÷åì èç-çà òîãî
,
> ÷òî äëÿ îïðåäåëåíèÿ êîäèðîâàííûé ýòî offset èëè íåò, èñïîëüçyþòñÿ ãðàíèöû
> -curpos è filesize, îíè áûëè âûíyæäåíû òàêæå äîïîëíèòåëüíî êîäèðîâàòü offset
y
> ÿêîáû CALL-îâ, ññûëàþùèåñÿ íà îáëàñòü îò filesize äî filesize+curpos, ÷òî
> åñòåñòâåííî ñíèæàåò ñæàòèå, òàê êàê êîäèðyþòñÿ dwords, êîòîðûå íå äîëæíû áûëè
> áûòü çàêîäèðîâàíû. Ïëþñ íåâîçìîæíîñòü ïðèìåíèòü ïåðåâîðà÷èâàíèå áàéòîâ offset
.
> Ñïîñîá êîäèðîâàíèÿ offset y CALL â UPX ìîæåò êîäèðîâàòü èñêëþ÷èòåëüíî òî, ÷ò
î
> íyæíî, äðyãîå äåëî, ÷òî íà ýòàïå ïðåïðîöåññèíãà äîñòîâåðíî îïðåäåëèòü êîìàíäà
> ýòî èëè ïðîñòî áàéò íåâîçìîæíî, èëè ïðîãðàììà äîëæíà èìåòü íå÷òî âðîäå
> èíòåëëåêòyàëüíîãî äèçàññåìáëåðà.
Ìîæíî ïîïðîáîâàòü äåðæàòü ñ÷åò÷èê êîëè÷åñòâà ïîïàäàíèé äëÿ
êàæäîãî àáñîëþòíîãî àäðåñà, ïîëó÷åííîãî èç e8.
if (aCounters[Hash(AbsAddress(x))] >= aThreshold)
ConvertAddress();
> Îäíàêî òå ñêèïíyòûå òîáîé yñëîâèÿ ïîçâîëÿþò
> äîâîëüíî íåïëîõî îòñåÿòü òå E8/E9, êîòîðûå íå ÿâëÿþòñÿ êîìàíäàìè.
>
> Good Bye.
>
--
Igor Pavlov
igorp@geocities.com
--- ifmail v.2.14dev3
* Origin: Ufa State Aviation Technical University (2:5020/400)
— RU.COMPRESS
From : Igor Pavlov 2:5020/400 22 May 99 01:01:35
To : All
Subj : Re: EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
From: "Igor Pavlov" <igor@vtizi.ugatu.ac.ru>
Reply-To: "Igor Pavlov" <igor@vtizi.ugatu.ac.ru>
Hello Rustam!
Rustam Gadeyev <Rustam.Gadeyev@p10.f7.n5008.z2.fidonet.org> wrote in message ne
ws:927294076@p10.f7.n5008.z2.ftn...
> Ïîä relocation ÿ îáîçíà÷èë àäðåñ èç òàáëèöû íàñòðîåê àäðåñîâ, êîòîðàÿ îáû÷íî
> âñåãäà èìååòñÿ y EXE-ôàéëîâ. Êîìàíäà CALL íå èìååò íàñòðàèâàåìîãî àäðåñà,
> ïîýòîìy åå àäðåñ íå äîëæåí ñîâïàäàòü ñ îäíèì èç àäðåñîâ èç òàáëèöû íàñòðîåê ñ
> y÷åòîì ðàçìåðà 5-áàéòíîé êîìàíäû CALL è ðàçìåðîì â 4 áàéòà íàñòðàèâàåìîãî
> ýëåìåíòà.
À êàêîâà âåðîÿòíîñòü òàêîãî ïîïàäàíèÿ?
> Òàê èëè èíà÷å âûáèðàþòñÿ òå E8/E9, êîòîðûå äîëæíû ïåðåêîäèðîâàòüñÿ,
> îòíîñèòåëüíûé àäðåñ ìåíÿåì íà àáñîëþòíûé, òðè ìëàäøèõ áàéòà äàþò 16-ìåãàáàéòí
îå
> ïðîñòðàíñòâî äëÿ ðàñïîëîæåíèÿ ïðîöåäyð, ýòî âïîëíå äîñòàòî÷íî äëÿ àáñîëþòíîãî
> áîëüøèíñòâà ôàéëîâ, èíà÷å ýòîò CALL ïðîñòî áðàêyåòñÿ. Äàëåå âìåñòî ñòàðøåãî
> áàéòà ïèøåòñÿ ôëàã - íåêèé áàéò, çíà÷åíèå êîòîðîãî îïðåäåëÿåòñÿ ïðè
> ïðåäâàðèòåëüíîì ñêàíèðîâàíèè. Ïîñëå ôëàãà ïèøåòñÿ â îáðàòíîì ïîðÿäêå ìëàäøèå
3
> áàéòà àáñîëþòíîãî àäðåñà èç êîìàíäû CALL. Âûèãðûø ïîëy÷àåòñÿ çà ñ÷åò áîëåå
> äëèííûõ ïîâòîðîâ: E8, Fl, A2, A1, A0 - ïðîöåäyðû îáû÷íî ãðyïïèðyþòñÿ âìåñòå
è
> A2 ÷àñòåíüêî îêàçûâàåòñÿ îäèíàêîâûì.
> Çíà÷åíèå ôëàãà îïðåäåëÿåòñÿ â îòäåëüíîì ïðîõîäå ïåðåä êîäèðîâàíèåì àäðåñîâ -
> çàâîäèì òàáëèöy 0-255 è äëÿ êàæäîãî E8/E9, êîòîðûå íå êîäèðyþòñÿ áåðåì
> ñëåäyþùèé áàéò è èñêëþ÷àåì åãî èç òàáëèöû, è òàê äàëåå ïîêà åñòü åùå áàéòû â
> òàáëèöå è ïàêyåìûé êîä, ïðè ýòîì âû÷èñëÿåì êîëè÷åñòâî ãîäíûõ E8/E9 ÷òîáû
> èñïîëüçîâàòü ïðè êîäèðîâàíèè è ïîòîì ïðè ðàñïàêîâêå. Äëÿ ôëàãà áåðåì òî, ÷òî
> îñòàëîñü â òîé òàáëèöå, îáû÷íî ýòî áûâàåò 3 èëè 4.
> Êñòàòè, íàñòðàèâàåìûå àäðåñà â ïàêyåìîé ïðîãðàììå òàêæå ïîäâåðãàþòñÿ
> ïåðåâîðà÷èâàíèþ è ýòî äàåò íåìåäëåííûé ýôôåêò.
Àëãîðèòì ñëîæíîâàò íåìíîãî: 2 ïðîõîäà è ò.ä.
Êñòàòè, ýòî ðåàëüíûé àëãîðèòì èç UPX?
- ---
Igor Pavlov
igorp@geocities.com
--- ifmail v.2.14dev3
* Origin: Ufa State Aviation Technical University (2:5020/400)
— RU.COMPRESS
From : Leonid Broukhis 2:5020/400 22 May 99 08:45:58
To : Max Smirnov
Subj : Re: DAKX method
From: leob@asylum.mailcom.com (Leonid Broukhis)
Max Smirnov wrote:
> >> http://dakx.com
> >>
> LB> Îíî, ê ñîæàëåíèþ, çàïàòåíòîâàíî. Åñëè è ýòî ïàòåíòóþò, òî ÿ ïðîñòî
> LB> íå çíàþ, ÷òî íåëüçÿ çàïàòåíòîâàòü.
>ïpî÷èòàë è íå ïîíÿë, ÷òî òàì ìîæíî çàïàòåíòîâàòü. Hà ÷òî èìåííî áûë ïîëó÷åí
>ïàòåíò? Hà äîïîëíèòåëüíûé êîä? ;)
Hà àäàïòèâíóþ ìîäåëü.
Leo
--- ifmail v.2.14dev3
* Origin: leob@at-mailcom.dot-com (2:5020/400)
— RU.COMPRESS
From : Bulat Ziganshin 2:5093/29.61 22 May 99 11:22:43
To : Igor Pavlov
Subj : EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
* Crossposted in RU.COMPRESS
Hello Igor!
Saturday May 22 1999, Igor Pavlov writes to All:
IP> À êîãäà e9-êîíâåðòèðîâàíèå âîîáùå ñðàáàòûâàåò?
Hà far.exe
IP> Åñòü ëè êàêîé-íèáóäü ïðèçíàê?
Ê Þêèíó, îí ÷òî-òî ìíå ïûòàëñÿ îáúÿñíèòü :)
Bulat, mailto:bulatz@fort.tatarstan.ru, ICQ 15872722
--- GoldED/386 2.50+
* Origin: Çóáíûå êëåòêè íå âîññòàíàâëèâàþòñÿ (2:5093/29.61)
— RU.COMPRESS
From : Max Smirnov 2:5030/706.11 23 May 99 16:43:36
To : Leonid Broukhis
Subj : Re: DAKX method
Ïðèâåò, Leonid!
Ñóá Ìàé 22 1999, Leonid Broukhis writes to Max Smirnov:
>> LB> ïðîñòî íå çíàþ, ÷òî íåëüçÿ çàïàòåíòîâàòü.
>> ïpî÷èòàë è íå ïîíÿë, ÷òî òàì ìîæíî çàïàòåíòîâàòü. Hà ÷òî èìåííî áûë
>> ïîëó÷åí ïàòåíò? Hà äîïîëíèòåëüíûé êîä? ;)
LB> Hà àäàïòèâíóþ ìîäåëü.
Ýòó "ìîäåëü" ãäå-òî ãîä ñ ëèøíèì íàçàä ÿ ïûòàëñÿ ïpèêpóòèòü ê lzw, ÷òîáû îòíîñè
òåëüíî äåøåâî óëó÷øèòü ñæàòèå áåç îñîáûõ âpåìåííûõ ïîòåpü (åñòåñòâåííî, ÷òî â î
áùåì ñëó÷àå íè÷åãî íå ïîëó÷èëîñü, à óæ ñ èíâåpñíûì êîäèpîâàíèåì è pÿäîì íå ëåæà
ëî). Äóìàþ, ÷òî íå âõîæó è â ïåpâóþ òûñÿ÷ó òåõ, êòî ïåpåîòêpûë òàêóþ øòóêó. Æóë
üíè÷åñòâî, à íå ïàòåíò.
Max
--- --- ---
* Origin: -= Ñëîíû íîí÷å âçäîðîæàëè =- (2:5030/706.11)
— RU.COMPRESS
From : Rustam Gadeyev 2:5008/7.10 23 May 99 22:44:26
To : Igor Pavlov
Subj : Re: EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
Hello, Igor!
 ñóááîòó Ìàÿ 22 1999 01:01, Igor Pavlov wrote All:
>> Ïîä relocation ÿ îáîçíà÷èë àäðåñ èç òàáëèöû íàñòðîåê àäðåñîâ,
>> êîòîðàÿ îáû÷íî âñåãäà èìååòñÿ y EXE-ôàéëîâ. Êîìàíäà CALL íå èìååò
>> íàñòðàèâàåìîãî àäðåñà, ïîýòîìy åå àäðåñ íå äîëæåí ñîâïàäàòü ñ îäíèì
>> èç àäðåñîâ èç òàáëèöû íàñòðîåê ñ y÷åòîì ðàçìåðà 5-áàéòíîé êîìàíäû
>> CALL è ðàçìåðîì â 4 áàéòà íàñòðàèâàåìîãî ýëåìåíòà.
IP> À êàêîâà âåðîÿòíîñòü òàêîãî ïîïàäàíèÿ?
Òî÷íî ñêàçàòü íå ìîãy, íå ïîìíþ, íî y ìåíÿ îíà áûëà íå íyëåâàÿ, ïðè÷åì ÿ íå
ñìîã ïðèäyìàòü äîïîëíèòåëüíî åùå íîðìàëüíûõ êðèòåðèåâ îòáîðà êîäîâ E8/E9.
IP> Àëãîðèòì ñëîæíîâàò íåìíîãî: 2 ïðîõîäà è ò.ä.
IP> Êñòàòè, ýòî ðåàëüíûé àëãîðèòì èç UPX?
Äâà ïðîõîäà ïðåäâàðèòåëüíîé îáðàáîòêè êîäà - ýòî íå òàê îáðåìåíèòåëüíî, êàê åãî
ïàêîâêà, ýòî äàæå ñîâñåì íå çàìåòíî. Hå ìîãy ñêàçàòü íàñêîëüêî ýòî ïîõîæå íà
ðåàëüíûé àëãîðèòì èç UPX, íî â ðåçyëüòàòå ïîëy÷àåòñÿ òîæå ñàìîå.  ðåàëüíîì
àëãîðèòìå èç UPX äîïîëíèòåëüíî ïðîèçâîäèòñÿ ïåðåâîðà÷èâàíèå àäðåñîâ y
íàñòðàèâàåìûõ ýëåìåíòîâ â ïðîãðàììå ïî òàáëèöå íàñòðîåê àäðåñîâ, à ñàìà òàáëèöà
àäðåñîâ êîäèðyåòñÿ ïî ïðîñòîìy àëãîðèòìy è ïàêyåòñÿ âìåñòå ñ êîäîì. Òî åñòü
àäðåñà ñîðòèðyþòñÿ ïî âîçðàñòàíèþ, çàòåì îíè êîäèðyåòñÿ ÷åðåç ðàçíîñòü äâyõ
ñîñåäíèõ ýëåìåíòîâ òàáëèöû:
00-7F ïðîñòî äîáàâëÿåòñÿ ê òåêyùåìy àäðåñy
F0-FF ñòàðøèé ïîëyáàéò îòáðàñûâàåì è ñ÷èòûâàåì åùå 2 áàéòà, ýòî ïîçâîëÿåò
êîäèðîâàòü ðàçíîñòü äî 1 ìåãàáàéòà âåëè÷èíîé.
ß ïðèìåíÿþ äðyãîé ñïîñîá:
00-7F òàêæå ïðîñòî äîáàâëÿåì ê òåêyùåìy àäðåñy
F0-FE ñ÷èòûâàåì åùå 1 áàéò, òî åñòü êîäèðyåòñÿ ðàçíîñòü äî 4êá
FF ñ÷èòûâàåì åùå 3 áàéòà, òî åñòü ìîæíî çàêîäèðîâàòü ðàçíîñòü äî 16ìá.
Ýòî äàåò íåìíîãî ëy÷øèé ðåçyëüòàò çà ñ÷åò òîãî, ÷òî ðàçíîñòè äî 4 êá
âñòðå÷àþòñÿ ãîðàçäî ÷àùå, ÷åì áîëüøèå.
Ïîõîæå ýòî îïòèìàëüíàÿ ïðåäâàðèòåëüíàÿ îáðàáîòêà êîäà ïî çàòðàòàì è ýôôåêòy
ïðèìåíåíèÿ, âñå îñòàëüíîå y ìåíÿ íå äàëî ñêîëüêî-íèáyäü ñyùåñòâåííîãî âûèãðûøà,
íî çàìåòíî yâåëè÷èâàëî ðàñïàêîâùèê.
Good Bye.
--- ( ) ---
* Origin: Ulan-Ude. Buriatia. (2:5008/7.10)
— RU.COMPRESS
From : Denis Moujjoukhin 2:5018/5 23 May 99 23:23:14
To : All
Subj : Àpèôìåòè÷åñêîå ñæàòèå
Hó çäpàâñòâóé, All!
Ñëûøàë, ÷òî ñàáæ - ñàìîå ýôôåêòèâíîå ñæàòèå áåç ïîòåpü... Òàê ëè ýòî? Ãäå è êàê
ìîæíî óçíàòü î ñàáæå ïî-ïîäpîáíåå? Çàpàíåå áëàãîäàpåí.
... Hubba Bubba Rox. :-)
* Origin: -=¦ Holy Gabber ¦=- (2:5018/5)
— RU.COMPRESS
From : Kirill Frolov 2:5030/643.9 24 May 99 04:52:28
To : All
Subj : Ñæàòü 261 áàéò (èëè ìåíüøå) â påàëòàéìå
Håìåäëåííî íàæìè íà RESET, All !
Âîò ñàáæ. Ñàìîå ãëàâíîå -- áûñòpî ñæàòü è áûñòpî pàñæàòü.
Äàííûå ìîãóò áûòü 3-õ òèïîâ: íåïàêóåìûå, òåêñò è ïîâòîpÿþùèåñÿ áàéòû.
Äî RLL ÿ óæå äîäóìàëñÿ, íî äëÿ òåêñòà ýòî íå ïîìîãàåò. Hà âñÿêèõ õàôôìàíîâ
âpåìåíè íåò è ñìûñëà -- ìàêñèìàëüíàÿ äëèíà 261 áàéò. LZW òîæå íå póëåç,
ÿ åù¸ íå ïûòàëñÿ ïîäñ÷èòàòü ñêîëüêî âpåìåíè çàéìåò, íî ïîèñê â 256 áàéòàõ
íå ìãíîâåííàÿ îïåpàöèÿ. Ìîæåò ìîæíî óñêîpèòü ? Åñòü êàêèå-ëèáî äpóãèå ïpèìèòè
âíûå è ñêîpîñòíûå ìåòîäû ?
Kirill Frolov. [ZX]
--- Ñîâåòñêèå ìèêpîêàëüêóëÿòîpû -- ñàìûå áîëüøèå ìèêpîêàëüêóëÿòîpû â ìèpå !
* Origin: runtime error at (2:5030/643.9)
— RU.COMPRESS
From : Dmitry Pyankov 2:5020/400 24 May 99 08:41:20
To : All
Subj : Re: Ñæàòü 261 áàéò (èëè ìåíüøå) â påàëòàéìå
From: "Dmitry Pyankov" <dp@fmf.gasu.gorny.ru>
Kirill Frolov <Kirill.Frolov@p9.f643.n5030.z2.fidonet.org> çàïèñàíî â
ñòàòüþ <>...
> Håìåäëåííî íàæìè íà RESET, All !
Hello, Kirill! Êîãî ÿ âèæó! [ZX]!
> Âîò ñàáæ. Ñàìîå ãëàâíîå -- áûñòpî ñæàòü è áûñòpî pàñæàòü.
> Äàííûå ìîãóò áûòü 3-õ òèïîâ: íåïàêóåìûå, òåêñò è ïîâòîpÿþùèåñÿ áàéòû.
> Äî RLL ÿ óæå äîäóìàëñÿ, íî äëÿ òåêñòà ýòî íå ïîìîãàåò. Hà âñÿêèõ
õàôôìàíîâ
> âpåìåíè íåò è ñìûñëà -- ìàêñèìàëüíàÿ äëèíà 261 áàéò. LZW òîæå íå póëåç,
> ÿ åù¸ íå ïûòàëñÿ ïîäñ÷èòàòü ñêîëüêî âpåìåíè çàéìåò, íî ïîèñê â 256
áàéòàõ
> íå ìãíîâåííàÿ îïåpàöèÿ. Ìîæåò ìîæíî óñêîpèòü ? Åñòü êàêèå-ëèáî äpóãèå
> ïpèìèòèâíûå è ñêîpîñòíûå ìåòîäû ?
À - ëÿ LZ77 - Ïîäîéäåò. Ñæàòèå 261áàéòà - äëÿ ZX èëè PC? Åñëè äëÿ ZX, òî
ìîãó ïðîöåäóðó áûñòðîãî ïîèñêà âûñëàòü.
> Kirill Frolov.
[ZX]
>
Dmitry Pyankov. [ZX]
--- ifmail v.2.14dev3
* Origin: Unknown (2:5020/400)
— RU.COMPRESS
From : Kirill Frolov 2:5030/643.9 24 May 99 08:50:02
To : All
Subj : Ñæàòü 261 áàéò (èëè ìåíüøå) â påàëòàéìå
Håìåäëåííî íàæìè íà RESET, All !
24 May 99 04:52, Kirill Frolov wrote to All:
KF> Âîò ñàáæ. Ñàìîå ãëàâíîå -- áûñòpî ñæàòü è áûñòpî pàñæàòü.
KF> Äàííûå ìîãóò áûòü 3-õ òèïîâ: íåïàêóåìûå, òåêñò è ïîâòîpÿþùèåñÿ áàéòû.
KF> Äî RLL ÿ óæå äîäóìàëñÿ, íî äëÿ òåêñòà ýòî íå ïîìîãàåò. Hà âñÿêèõ
KF> õàôôìàíîâ âpåìåíè íåò è ñìûñëà -- ìàêñèìàëüíàÿ äëèíà 261 áàéò. LZW
Ýòî ÿ âñ¸ ïåpåïóòàë òóò, èäåÿ òîëüêî îäíà âåpíàÿ åñòü -- õàôôìàí ñ
îäíîé åäèíñòâåííîé, çàpàíåå îïpåäåëåííîé è îïòèìàëüíûì îápàçîì ïîäîäÿùåé
êî âñåì òèïàì äàííûõ ÷àñòîòíîé òàáëèöåé. Hî åñëè åñòü òåêñò íà póññêîì ÿçûêå
â 866 êîäèpîâêå ýòî îäíî, à åñëè â êîè-7 òî äpóãîå... :-( Òàê âìåñòî
êîìïpåññèè ìîæíî çàïpîñòî ïîëó÷èòü îápàòíûé ýôôåêò. Âîò è äóìàþ, êàêóþ
òàáëèöó âûápàòü è êàê å¸ ñäåëàòü. Êîíå÷íî åñëè ïîñëå õàôìàíà ïîëó÷àåòñÿ
pàçìåp òîëüêî áîëüøå, òî ìîæíî îñòàâëÿòü áåç óïàêîâêè (only RLL / nothing).
Hî íå ípàâèòñÿ ìíå âñ¸ ýòî. Äà ÿ è íå óâåpåí â ñêîpîñòè -- åñòü ~100..200
òàêòîâ íà áàéò íà Z80.
Kirill Frolov. [ZX]
--- Ñîâåòñêèå ìèêpîêàëüêóëÿòîpû -- ñàìûå áîëüøèå ìèêpîêàëüêóëÿòîpû â ìèpå !
* Origin: runtime error at (2:5030/643.9)
— RU.COMPRESS
From : Kirill Frolov 2:5030/643.9 25 May 99 07:31:42
To : Dmitry Pyankov
Subj : Ñæàòü 261 áàéò (èëè ìåíüøå) â påàëòàéìå
Håìåäëåííî íàæìè íà RESET, Dmitry !
24 May 99 08:41, Dmitry Pyankov wrote to All:
>> Âîò ñàáæ. Ñàìîå ãëàâíîå -- áûñòpî ñæàòü è áûñòpî pàñæàòü.
>> Äàííûå ìîãóò áûòü 3-õ òèïîâ: íåïàêóåìûå, òåêñò è ïîâòîpÿþùèåñÿ
[...]
DP> À - ëÿ LZ77 - Ïîäîéäåò. Ñæàòèå 261áàéòà - äëÿ ZX èëè PC? Åñëè äëÿ ZX,
DP> òî ìîãó ïðîöåäóðó áûñòðîãî ïîèñêà âûñëàòü.
Äëÿ ZX -- â äpàéâåp ÌÌÄû. Âíà÷àëå ñæèìàåòñÿ, ïîòîì ïåpåäàåòñÿ. ×åì áûñòpåå
ñîæìåòñÿ, òåì áûñòpåå íà÷íåòñÿ ïåpåäà÷à. Åñëè î÷åíü äîëãî ñæèìàòü, òî áóäåò
áûñòpåå ïåpåäàòü íå ñæàòûå äàííûå.
Ñàìîå ãëàâíîå -- âpåìÿ ïåpåäà÷è áèòà 0 â 1.3 pàçà ìåíüøå âpåìåíè ïåpåäà÷è
áèòà 1 ! Ò.å. åñëè ÿ ïîëó÷ó áîëüøå íóëåâûõ áèòîâ, òî áóäåò áûñòpåå !
À ïpîöåäópó ïîèñêà äëÿ ZX äàé ïîñìîòpåòü -- íàâåpíîå îíà êàê â hrust
èëè hrum ?
Kirill Frolov. [ZX]
--- Ñîâåòñêèå ìèêpîêàëüêóëÿòîpû -- ñàìûå áîëüøèå ìèêpîêàëüêóëÿòîpû â ìèpå !
* Origin: runtime error at (2:5030/643.9)
— RU.COMPRESS
From : Maxime Zakharov 2:5020/400 25 May 99 12:22:45
To : All
Subj : Re: Ñæàòü 261 áàéò (èëè ìåíüøå) â påàëòàéìå
From: Maxime Zakharov <mbb@sochi.ru>
Kirill Frolov wrote:
> Ýòî ÿ âñ¸ ïåpåïóòàë òóò, èäåÿ òîëüêî îäíà âåpíàÿ åñòü -- õàôôìàí ñ
> îäíîé åäèíñòâåííîé, çàpàíåå îïpåäåëåííîé è îïòèìàëüíûì îápàçîì ïîäîäÿùåé
> êî âñåì òèïàì äàííûõ ÷àñòîòíîé òàáëèöåé. Hî åñëè åñòü òåêñò íà póññêîì ÿçûêå
> â 866 êîäèpîâêå ýòî îäíî, à åñëè â êîè-7 òî äpóãîå... :-( Òàê âìåñòî
> êîìïpåññèè ìîæíî çàïpîñòî ïîëó÷èòü îápàòíûé ýôôåêò. Âîò è äóìàþ, êàêóþ
> òàáëèöó âûápàòü è êàê å¸ ñäåëàòü.
À òû ïîïðîáóé ïåðåä Õàôìàíîì ïðîäåëàòü MTF, - ñòàòèñòèêà (è
ñæèìàåìîìñòü) èçìåíèòñÿ, íî íå áóäåøü çàâèñåòü îò êîäèðîâêè.
> Hî íå ípàâèòñÿ ìíå âñ¸ ýòî. Äà ÿ è íå óâåpåí â ñêîpîñòè -- åñòü ~100..200
> òàêòîâ íà áàéò íà Z80.
Ïîñìîòðè http://tnet.sochi.net/~maxime/src/mfarc.c - íåêîå ïîäîáèå
àðèôìåòè÷åñêîãî êîäåðà (áåç èñïîëüçîâàíèÿ îïåðàöèé óìíîæåíèÿ è äåëåíèÿ).
Ñæàòèå ïîëó÷àåòñÿ íå î÷åíü, çàòî áûñòðî, äà è â àññåìáëåðå äîëæíî ïðîñòî
ðåàëèçîâûâàòüñÿ...
--
Maxim Zakharov http://tnet.sochi.net/~maxime/
Sochi, Russia
--- ifmail v.2.14dev3
* Origin: Mosbusinessbank, Sochi branch (2:5020/400)
— RU.COMPRESS
From : Vadim Yoockin 2:5020/1042.50 25 May 99 23:04:04
To : Bulat Ziganshin
Subj : EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
Ïpèâåòñòâóþ, Bulat!
22 May 99, Bulat Ziganshin ïèñàë ê Igor Pavlov:
IP>> À êîãäà e9-êîíâåðòèðîâàíèå âîîáùå ñðàáàòûâàåò?
BZ> Hà far.exe
IP>> Åñòü ëè êàêîé-íèáóäü ïðèçíàê?
BZ> Ê Þêèíó, îí ÷òî-òî ìíå ïûòàëñÿ îáúÿñíèòü :)
À ÷åãî òóò îáúÿñíÿòü :) - â 1.60, íàïðèìåð, ïî ñìåùåíèþ 0x7800 èäóò,
âèäèìî, êóñî÷êè êàêîãî-òî switch/case. Êîòîðûå ïîõîæå è ñîçäàþò
òàêèå óäîáíûå äëÿ ïðåïðîöåññèíãà e9.
Âñåãî äîáðîãî. Vadim Yoockin
... A Smith and Wesson beats four aces.
--- Ñòàpûé Äåä ñòîèìîñòüþ 3.00.Alpha4 äîïëàòà â ÑÊÂ UNREG
* Origin: yoockinv@mtu-net.ru (2:5020/1042.50)
— RU.COMPRESS
From : Dmitry Subbotin 2:5020/530.18 26 May 99 05:42:07
To : Igor Pavlov
Subj : EXE ïàêåðû : APACKv0.98,APLIBv0.20 è UPXv0.70,v0.72
Hi, Igor!
"Igor Pavlov" sendTo: "All" when: [22 May 99] msg:
>> Ïî ìîèì íàáëþäåíèÿì, îíà ìåøàåò íà exe, ãäå ïî calling convention
>> àãðóìåíòû èç ñòåêà äîñòàåò âûçûâàþùàÿ ïðîöåäóðà, i.e. ãäå çà êàæäûì
>> call èäåò ÷òî-òî âðîäå add esp,nn.
IP> Î÷åíü èíòåðåñíîå íàáëþäåíèå.
IP> Imho áîëüøèíñòâî ôàéëîâ çàïèñàíû èìåííî òàê.
>> Hà äðóãèõ exe ïîëó÷àåòñÿ íåáîëüøîå óëó÷øåíèå.
>> Hà e9 ýôôåêò áûë âñåãäà ïîëîæèòåëüíûì.
IP> À êîãäà e9-êîíâåðòèðîâàíèå âîîáùå ñðàáàòûâàåò?
Hàïðèìåð, íà áîëüøèõ êîíñòðóêöèÿõ switch-case-break.
Êñòàòè, îïðåäåëÿòü ïðåõîäû â ïðîãðàììå ìîæíî ïî íàëè÷èþ 0000 èëè ffff â ñòàðøèõ
áàéòàõ ñìåùåíèÿ.
taste you later,
morf
--- GoldED 2.50+
* Origin: morf@softhome.net (2:5020/530.18)
— RU.COMPRESS
From : Andy Nikishin 2:5020/156 26 May 99 13:59:00
To : All
Subj : Microsoft CAB & LZX decompression
Ïpèâåò òåáå All! Çäîðîâåíüêè áóëû.
Óâàæàåìûå êîëëåãè, åñòü ëè ó êîãî-íèáóäü èñõîäíèêè äåêîìïðåññîðà äëÿ LZX?
Âñåãî òåáå, All...,
Andy Nikishin
MCPS Win 3.x, Win'95 [AVP Team] http://www.avp.ru
--- GoldED 2.42.G1219+
* Origin: Avp BBS 095-948-6333, 095-948-3601 V34 24h (2:5020/156)
— RU.COMPRESS
From : Leonid Broukhis 2:5020/400 26 May 99 20:58:23
To : Max Smirnov
Subj : Re: DAKX method
From: leob@asylum.mailcom.com (Leonid Broukhis)
Max Smirnov wrote:
>Ñóá Ìàé 22 1999, Leonid Broukhis writes to Max Smirnov:
> >> LB> ïðîñòî íå çíàþ, ÷òî íåëüçÿ çàïàòåíòîâàòü.
> >> ïpî÷èòàë è íå ïîíÿë, ÷òî òàì ìîæíî çàïàòåíòîâàòü. Hà ÷òî èìåííî áûë
> >> ïîëó÷åí ïàòåíò? Hà äîïîëíèòåëüíûé êîä? ;)
> LB> Hà àäàïòèâíóþ ìîäåëü.
>Ýòó "ìîäåëü" ãäå-òî ãîä ñ ëèøíèì íàçàä ÿ ïûòàëñÿ ïpèêpóòèòü ê lzw, ÷òîáû
>îòíîñèòåëüíî äåøåâî óëó÷øèòü ñæàòèå áåç îñîáûõ âpåìåííûõ ïîòåpü (åñòåñòâåííî,
>÷òî â îáùåì ñëó÷àå íè÷åãî íå ïîëó÷èëîñü, à óæ ñ èíâåpñíûì êîäèpîâàíèåì è pÿäîì
>íå ëåæàëî). Äóìàþ, ÷òî íå âõîæó è â ïåpâóþ òûñÿ÷ó òåõ, êòî ïåpåîòêpûë òàêóþ
>øòóêó. Æóëüíè÷åñòâî, à íå ïàòåíò.
Håò ïðîáëåì. Åñëè òåáå óäàñòñÿ íàéòè â ëþáîì îòêðûòîì èñòî÷íèêå îïèñàíèå
òîãî, ÷òî çàïàòåíòîâàíî ó DAKX, ñ äàòîé ïóáëèêàöèè ðàíüøå, ÷åì äàòà
ïîäà÷è ïàòåíòà (17 àâãóñòà 1995 ãîäà), òû ìîæåøü, äà è âñå îñòàëüíûå
òîæå ìîãóò, ñ ïîëíûì îñíîâàíèåì êëàñòü íà ýòîò ïàòåíò ñ ïðèáîðîì.
Çàêðûòûé èñòî÷íèê (òèïà èñõîäíîãî
òåêñòà êîììåð÷åñêîé ïðîãðàììû), âïðî÷åì, òîæå ïîäîéäåò: ãëàâíîå, ÷òîáû
äàòèðîâêà áûëà äîñòîâåðíàÿ.
Èíòåðåñíàÿ èñòîðèÿ ñëó÷èëàñü íåñêîëüêî ëåò íàçàä ñ LZRW1, êîãäà
îêàçàëîñü, ÷òî îí çàïàòåíòîâàí íåêèìè Gibson & Graybill. Ross Williams
òîãäà ñòàë ñîáèðàòü âñå äàòèðîâàííûå óïîìèíàíèÿ î ñâîåì àëãîðèòìå,
íî, âðîäå, òàê è íå ñìîã íàéòè ïîäòâåðæäåííûõ óïîìèíàíèé (â ò.÷. e-mail),
êîòîðûå áûëè áû ðàíüøå äàòû _ïîäà÷è_ Gibson & Graybill. Òàê ÷òî åñëè
êòî ÷òî ïðèäóìàë è ñàì ïàòåíòîâàòü íå õî÷åò (èëè íå ìîæåò), òî ëó÷øåå
ðåøåíèå - îïóáëèêîâàòü êàê ìîæíî áûñòðåå, ÷òîáû ïîòîì ëîêòè íå êóñàòü,
åñëè êòî-òî ïðèäóìàåò òî æå ñàìîå ÷åðåç ìåñÿö è òóò æå ïîäàñò çàÿâêó
íà ïàòåíò.
Leo
--- ifmail v.2.14dev3
* Origin: leob@at-mailcom.dot-com (2:5020/400)
— RU.COMPRESS
From : Dima Kirnocenskij 2:5020/1129.11 28 May 99 00:31:01
To : All
Subj : Øèôðóåìñÿ
Hello All.
Ëþäè, ðàññêàæèòå êàê ëó÷øå ñäåëàòü - ïèøåòñÿ ìîäåëüíûé àðõèâàòîð ñ ïàðîëåì.
Àðõèâàòîð - ïðîñòî LZW ñàìûé ñòàíäàðòíûé. Òàê âîò, êóäà ëó÷øå âñòðîèòü
íàëîæåíèå ãàììû ïàðîëÿ, ïðè òîì ÷òî íàëîæåíèå åå ïðîñòî íà âûõîäíîé ïîòîê íå
ïîäõîäèò. Hóæíî "ïîäìåøàòü" ãàììó êóäà-òî ãëóáæå. Âîïðîñ - êóäà.
Ñðàçó ðàññêàçûâàþ ïî÷åìó íå ïîäõîäèò øèôðîâàíèå ïðîñòî âûõîäà -
àðõèâàòîð äàåòñÿ ÷åëîâåêó, êîòîðîé óìååò ïîëüçîâàòüñÿ îòëàä÷èêîì,
äèçàññåìáëåðîì è ò.ä. È ïî óñëîâèþ âàæíî íå äàòü åìó âîçìîæíîñòü "îòêóñèòü"
ïðîöåäóðó êðèïòîâàíèÿ. Ò.å ñäåëàòü òàê, ÷òîáû èçãîòîâèòü èý ýòîãî "àðõèâàòîð
áåç ïàðîëÿ" áûëî áû íå ìíîãèì ïðîùå íàïèñàòü ñâîé çàíîâî.
ÇÛ : Òóò îäèí óìíèê ïðåäëîæèë êðèïòîâàòü ÄÎ àðõèâàöèè. Þìîðèñò :)
Dima
... There are no unlockable doors...
--- Îí, ðîäèìûé ...
* Origin: À ÿ è òàê óæå êóñî÷íî-ãëàäêèé ... (2:5020/1129.11)
— RU.COMPRESS
From : Igor Dolgov 2:5020/1562.30 28 May 99 01:01:46
To : All
Subj : Help!
Hello'y, All.
Ïîìîãèòå ÷àéíèêó äîñòàòü îïèñàíèÿ ñòàíäàðòíûõ
(íàèáîëåå èçâåñòíûõ è ðàñïðîñòðàíåííûõ) àëãîðèòìîâ
ñæàòèÿ íà ðóññêîì ÿçûêå â ýëåêòðîííîì âèäå.
ÇÛ. íà èíåò ññûëîê íå äàâàéòå, åãî ó ìåíÿ íåòó.
ÇÇÛ. à åñëè åùå è ñûðöû òî âàùå îáðàäóþñü.
Çàðàíåå ÑÏÀÑÈÁÎ!
GoodBye, All.
--- Ìàòðè÷íûé ïðèíòåð â ãîðåñòíûé ÷àñ êàæäîé èãîëî÷êîé ðàäóåò íàñ.
* Origin: Âñÿêîé òâàðå ïî NetWare. (2:5020/1562.30)
— RU.COMPRESS
From : Bulat Ziganshin 2:5093/28.26 28 May 99 06:22:11
To : All
Subj : Ñæàòü 261 áàéò (èëè ìåíüøå) â påàëòàéìå
* Crossposted in RU.COMPRESS
Hello All!
Tuesday May 25 1999, Kirill Frolov writes to Dmitry Pyankov:
KF> Ñàìîå ãëàâíîå -- âpåìÿ ïåpåäà÷è áèòà 0 â 1.3 pàçà ìåíüøå âpåìåíè
KF> ïåpåäà÷è áèòà 1 ! Ò.å. åñëè ÿ ïîëó÷ó áîëüøå íóëåâûõ áèòîâ, òî áóäåò
KF> áûñòpåå !
Håò, áèò òàê æå íåèñ÷åðïàåì, êàê è àòîì! :)
Bulat, mailto:bulatz@fort.tatarstan.ru, ICQ 15872722
--- GoldED/386 2.50+
* Origin: Äâîðåöêèé ðàçáóäèë Ãåðöåíà. Äåêàáðèñòû ïðîñïàëè... (2:5093/28.26)
— RU.COMPRESS
From : Bulat Ziganshin 2:5093/28.26 28 May 99 06:25:57
To : Victor Soroka
Subj : Ðîçûñê
* Crossposted in RU.COMPRESS
Hello Victor!
Monday May 24 1999, Victor Soroka writes to All:
VS> Ðàçûñêèâàåòñÿ ìàøèíà ñ íîìåðîì 0668 XA - ïåðâàÿ áóêâà íîìåðà
VS> íåèçâåñòíà. Ìàøèíà áåëîãî öâåòà, æèãóëè (4 äâåðè), ìîäåëü íå èçâåñòíà.
Çðÿ òû â ýòîé ýõå ñâîå îáúÿâëåíèå îïóáëèêîâàë. Òåïåðü òåáå åñëè ÷òî è âåðíóò,
òî òîëüêî ìîäåëü 1:43 :)
Bulat, mailto:bulatz@fort.tatarstan.ru, ICQ 15872722
--- GoldED/386 2.50+
* Origin: Äâîðåöêèé ðàçáóäèë Ãåðöåíà. Äåêàáðèñòû ïðîñïàëè... (2:5093/28.26)
— RU.COMPRESS
From : Bulat Ziganshin 2:5093/28.26 29 May 99 11:36:17
To : Dima Kirnocenskij
Subj : Øèôðóåìñÿ
* Crossposted in RU.COMPRESS
Hello Dima!
Friday May 28 1999, Dima Kirnocenskij writes to All:
DK> Ëþäè, ðàññêàæèòå êàê ëó÷øå ñäåëàòü - ïèøåòñÿ ìîäåëüíûé àðõèâàòîð ñ
DK> ïàðîëåì. Àðõèâàòîð - ïðîñòî LZW ñàìûé ñòàíäàðòíûé. Òàê âîò, êóäà ëó÷øå
DK> âñòðîèòü íàëîæåíèå ãàììû ïàðîëÿ, ïðè òîì ÷òî íàëîæåíèå åå ïðîñòî íà
DK> âûõîäíîé ïîòîê íå ïîäõîäèò. Hóæíî "ïîäìåøàòü" ãàììó êóäà-òî ãëóáæå.
DK> Âîïðîñ - êóäà.
Òàê, êàê ýòî äåëàåòñÿ ïðè îáû÷íîé çàùèòå - ñäåëàòü lzw-âûâîä íà ìàêðîñàõ è
òóäà æå âñòàâèòü êðèïòîâêó. Ïðîïóñòèòü ýòî ÷åðåç æóòêî-îïòèìèçèðóþùèé
êîìïèëÿòîð. Âïðî÷åì, êîíêðåòíî äëÿ lzw ìîæíî åùå âñòàâèòü ïåðåìåøèâàíèå êîäîâ,
âñå ðàâíî îíè âñå êîäèðóþòñÿ îäèíàêîâûì ÷èñëîì áèò.
Bulat, mailto:bulatz@fort.tatarstan.ru, ICQ 15872722
--- GoldED/386 2.50+
* Origin: Äâîðåöêèé ðàçáóäèë Ãåðöåíà. Äåêàáðèñòû ïðîñïàëè... (2:5093/28.26)
— RU.COMPRESS
From : Bulat Ziganshin 2:5093/28.26 29 May 99 11:41:01
To : Leonid Broukhis
Subj : DAKX method
* Crossposted in RU.COMPRESS
Hello Leonid!
Wednesday May 26 1999, Leonid Broukhis writes to Max Smirnov:
LB> Èíòåðåñíàÿ èñòîðèÿ ñëó÷èëàñü íåñêîëüêî ëåò íàçàä ñ LZRW1, êîãäà
LB> îêàçàëîñü, ÷òî îí çàïàòåíòîâàí íåêèìè Gibson & Graybill. Ross Williams
LB> òîãäà ñòàë ñîáèðàòü âñå äàòèðîâàííûå óïîìèíàíèÿ î ñâîåì àëãîðèòìå,
LB> íî, âðîäå, òàê è íå ñìîã íàéòè ïîäòâåðæäåííûõ óïîìèíàíèé (â ò.÷.
LB> e-mail), êîòîðûå áûëè áû ðàíüøå äàòû _ïîäà÷è_ Gibson & Graybill. Òàê
LB> ÷òî åñëè êòî ÷òî ïðèäóìàë è ñàì ïàòåíòîâàòü íå õî÷åò (èëè íå ìîæåò),
LB> òî ëó÷øåå ðåøåíèå - îïóáëèêîâàòü êàê ìîæíî áûñòðåå,
Ýòà ýõà ïîäõîäèò? :) Êñòàòè, îíà âåäü åñòü íà dejanews?
Bulat, mailto:bulatz@fort.tatarstan.ru, ICQ 15872722
--- GoldED/386 2.50+
* Origin: Äâîðåöêèé ðàçáóäèë Ãåðöåíà. Äåêàáðèñòû ïðîñïàëè... (2:5093/28.26)
— RU.COMPRESS
From : Bulat Ziganshin 2:5093/28.26 30 May 99 02:34:47
To : Leonid Broukhis
Subj : DAKX method
*** Answering a msg posted in area CARBON_COPIES (CARBON_COPIES).
* Crossposted in RU.COMPRESS
Hello Leonid!
Sunday May 30 1999, Leonid Broukhis writes to Bulat Ziganshin:
>> Ýòà ýõà ïîäõîäèò? :) Êñòàòè, îíà âåäü åñòü íà dejanews?
LB> Ïîäõîäèò. Hî ÿ íå óâåðåí, ÷òî ýòà ýõà áûëà íà dejanews â 1995 ãîäó.
LB> Èëè òû óæå íå î DAKX, à î ÷åì-òî ñâîåì?
Äà, ÿ îáî âñåì, ÷òî çäåñü ïèøåòñÿ. Òàê ÷òî ìíå ëè÷íî èþëÿ 97-ãî õâàòèò.
Bulat, mailto:bulatz@fort.tatarstan.ru, ICQ 15872722
--- GoldED/386 2.50+
* Origin: Äâîðåöêèé ðàçáóäèë Ãåðöåíà. Äåêàáðèñòû ïðîñïàëè... (2:5093/28.26)
— RU.COMPRESS
From : Leonid Broukhis 2:5020/400 30 May 99 05:59:33
To : Bulat Ziganshin
Subj : Re: DAKX method
From: leob@asylum.mailcom.com (Leonid Broukhis)
Bulat Ziganshin wrote:
> LB> Èíòåðåñíàÿ èñòîðèÿ ñëó÷èëàñü íåñêîëüêî ëåò íàçàä ñ LZRW1, êîãäà
> LB> îêàçàëîñü, ÷òî îí çàïàòåíòîâàí íåêèìè Gibson & Graybill. Ross Williams
> LB> òîãäà ñòàë ñîáèðàòü âñå äàòèðîâàííûå óïîìèíàíèÿ î ñâîåì àëãîðèòìå,
> LB> íî, âðîäå, òàê è íå ñìîã íàéòè ïîäòâåðæäåííûõ óïîìèíàíèé (â ò.÷.
> LB> e-mail), êîòîðûå áûëè áû ðàíüøå äàòû _ïîäà÷è_ Gibson & Graybill. Òàê
> LB> ÷òî åñëè êòî ÷òî ïðèäóìàë è ñàì ïàòåíòîâàòü íå õî÷åò (èëè íå ìîæåò),
> LB> òî ëó÷øåå ðåøåíèå - îïóáëèêîâàòü êàê ìîæíî áûñòðåå,
>
> Ýòà ýõà ïîäõîäèò? :) Êñòàòè, îíà âåäü åñòü íà dejanews?
Ïîäõîäèò. Hî ÿ íå óâåðåí, ÷òî ýòà ýõà áûëà íà dejanews â 1995 ãîäó. Èëè
òû óæå íå î DAKX, à î ÷åì-òî ñâîåì?
Leo
--- ifmail v.2.14dev3
* Origin: leob@at-mailcom.dot-com (2:5020/400)
— RU.COMPRESS
From : Boris Batkin 2:5025/1024.8 31 May 99 02:00:03
To : Dima Kirnocenskij
Subj : Øèôðóåìñÿ
Hello, Dima!
Ïÿò Ìàé 28 1999 00:31, Dima Kirnocenskij wrote to All:
DK> Ëþäè, ðàññêàæèòå êàê ëó÷øå ñäåëàòü - ïèøåòñÿ ìîäåëüíûé àðõèâàòîð ñ
DK> ïàðîëåì. Àðõèâàòîð - ïðîñòî LZW ñàìûé ñòàíäàðòíûé. Òàê âîò, êóäà ëó÷øå
DK> âñòðîèòü íàëîæåíèå ãàììû ïàðîëÿ, ïðè òîì ÷òî íàëîæåíèå åå ïðîñòî íà
DK> âûõîäíîé ïîòîê íå ïîäõîäèò. Hóæíî "ïîäìåøàòü" ãàììó êóäà-òî ãëóáæå.
DK> Âîïðîñ - êóäà.
èìõî â hash. âîçüìåì êàêóþ ëèáî äóáîâóþ õåø ôóíêöèþ äëÿ ìàññèâà pàçìåpîì
n è èíêpåìåòà m. ïpè÷åì m è n - äîñòàòî÷íî áîëüøèå ïpîñòûå, ïîpÿäêà
1000000 > n > 20000. òîãäà ñîáñòâåííî n è m - ïàpîëü. à âîò êàê
ïîëó÷èòü èç áóêâåííîãî ïàpîëÿ äâà ïpîñòûõ - óæå òâîå äåëî.
Good bye. Boris
--- GoldED/386 3.00.LzyPnt+
* Origin: Boris_PC (2:5025/1024.8)
— RU.COMPRESS
From : Marat Sadykov 2:5049/49.13 31 May 99 08:29:40
To : Igor Dolgov
Subj : Help!
Hello Igor.
Ïÿòíèöà Ìàé 28 1999 01:01, Igor Dolgov wrote to All:
ID> Ïîìîãèòå ÷àéíèêó äîñòàòü îïèñàíèÿ ñòàíäàðòíûõ
ID> (íàèáîëåå èçâåñòíûõ è ðàñïðîñòðàíåííûõ) àëãîðèòìîâ
ID> ñæàòèÿ íà ðóññêîì ÿçûêå â ýëåêòðîííîì âèäå.
Æópíàë "Ìîíèòîp", òàê æàëü, ÷òî îí óìåp :(
çà 1994-1995 ãîäû.
Marat
--- msadykov@mail.zarech.ru
* Origin: Ìåðòâîé ðûáîé ïî ñòîëó íå ñòó÷àòü! (2:5049/49.13)
— RU.COMPRESS
From : Vlad Kondratyev 2:5023/23 31 May 99 18:59:18
To : All
Subj : mp3 êîïðåññèÿ
Ãäå ìîæíî óçíàòü àëãîðèòì ñæàòèÿ mp3(URL)?
Vlad http://i.am/fidoholic
--- Sleep with one eye open
* Origin: Unforgiven (2:5023/23)
— RU.COMPRESS
From : AmiS 2:5020/659.51 09 Jun 99 23:13:27
To : Bulat Ziganshin
Subj : MS-ZIP & LZX - rar òî óñòàâëÿåò à îñòàëüíûå ?
@TEAM: PC SUX! 2
Ïðèâåò, Bulat!
Kàê-òî ðàç 09 Jun 99 Bulat Ziganshin íàïèñàë äëÿ ìåíÿ ñëåäóþùåå:
AB>>> P.S. èñõîäíèêè äëÿ LZX åñëè ó êîãî åñòü, ïðèøëèòå ïîæàëóéòà!
AB>>> Áóäó î÷åíü áëàãîäàðåí.
A>> Èìåþòñÿ èñõîäíèêè òîëüêî äëÿ UnLzx. Èíòåðåñóåò?
BZ> Äà. Õîòÿ, êàê ÿ ïîíèìàþ, ýòî àìèãîâñêèé? Êàê èõ ó òåáÿ âçÿòü ìîæíî?
Äà Àìèãîâñêèå, íî äëÿ PPC. Åñëè åù¸ êîãî èíòåðåñóåò ïèøèòå ìûëîì.
C óâàæåíèåì, Aëåêñåé (/AmiS/)
__
__/ / /Powered/ /Team:/ *FireBall Interacticve*
\_\/ /by/ *MOTOROLA*
--- amis@linux.cch.pmc.ru *095*+*146*-*0351*
* Origin: Õèðîñèìà'45, ×åðíîáûëü'86, Bèíäîóç'95 (2:5020/659.51)
— RU.COMPRESS
From : Dima Kirnocenskij 2:5020/1129.11 10 Jun 99 09:24:22
To : Sergey Mishin
Subj : ADPCM
Hello Sergey.
07 Jun 99 19:13, Sergey Mishin wrote to All:
SM> Kòî-íèáóäü ìîæåò ïîïóëÿpíî îáúÿñíèòü ìåòîä ñæàòèÿ çâóêà ADPCM?
Hó åñëè ñîâñåì "íà ïàëüöàõ" òî òàê:
A - Àäàïòèâíîå
D - Ðàçíîñòíîå
PCM - PCM îí è åñòü PCM - ïðîñòî âûõîä ÀÖÏ
Âîò è êîäèðóåì (êîíå÷íî ñ ïîòåðÿìè), èñïîëüçóÿ 2 ïðåäïîëîæåíèÿ
1. Ñ÷èòàåòñÿ ÷òî "õîðîøèé" çâóê íå ñèëüíî ìåíÿåòñÿ îò îò÷åòà ê îò÷åòó.
Ïîýòîìó âìåñòî sample[1], sample[2], ... sample[n] ìîæíî õðàíèòü
sample[1], delta[1], delta[2] ... delta[n-1] è ïîä delta[i] îòâîäèòü ìåíüøå
ðàçðÿäîâ - íó îíè æå ìàëåíüêèå :) Ýòî áóäåò ïðîñòî DPCM - ðàçíîñòíîå
êîäèðîâàíèå.
2. Ñ÷èòàåòñÿ (ïî ôèçèîëîãè÷åñêèì ïðè÷èíàì) ÷òî ÷åëîâåê âîñïðèíèìàåò ðàçíèöó â
âåëè÷èíå îòñ÷åòà íå "ëèíèíåéíî", à "ëîãàðèôìè÷åñêè", ò.å. ðàçíèöó ìåæäó
ìàëåíüêèìè îòñ÷åòàìè íóæíî êîäèðîâàòü òî÷íî, à ìåæäó áîëüøèìè - ìîæíî ãðóáî.
Òîãäà è çàïèñûâàåì â âûõîä ÷òî-òî òèïà log(delta[i]) à ïîòîì áåðåì
exp(delta[i]). Êîíêðåòíûé âèä ýòèõ ôóíêöèè è ñîñòîâëÿåò "ôèðìåííûé ñåêðåò"
ìåòîäà.
Îáû÷íî ïîòåíöèèðîâàíèå è ëîãàðèôìèðîâàíèå íå îñóùåñòâëÿåòñÿ íåïîñðåäñòâåííî, à
èìåþòñÿ ãîòîâûå òàáëèöû.
Âîò òåáå ñõåìà àëãîðèòìà êîäåðà è äåêîäåðà
Êîäåð:
òàáëèöà exp; // òàáëèöà exp(i)
òàáëèöà log; // òàáëèöà ñîîòâåòñòâóþùèõ log(j)
c_value=sample[0];
îòäåëüíî ïîìåñòèòü â âûõ. ïîòîê c_value;
i=1;
ïîêà åñòü ÷åãî êîäèòü {
delta=sample[i]-c_value;
index=log(delta);
outbuf[i]=index;
c_value=c_value+exp(index);
i++;
}
Äåêîäåð:
âçÿòü òî ñàìîå îòäåëüíî ëåæàùåå c_value;
i=1;
ïîêà åñòü ÷åãî äåêîäèòü {
c_value=c_value+exp(outbuf[i]);
sample[i]=c_value;
}
Âîò.
Ïðè õîðîøèõ òàáëèöàõ ìîæíî ñæàòü 16 bit per sample PCM â 4 bit per code ADPCM.
Dima
... There are no unlockable doors...
--- Îí, ðîäèìûé ...
* Origin: Óæå â ïÿòü ëåò îí óñòîé÷èâî ëåâèòèðîâàë ... (2:5020/1129.11)
— RU.COMPRESS
From : Dmitry Belash 2:5030/856.12 13 Jun 99 03:08:05
To : All
Subj : Ïàðî÷êà ãëóïûõ âîïðîñîâ :)
¦_¦*
¦ ¦¦ All!
ß ñîâñåì íåäàâíî ñâÿçàëñÿ ñ ýõîòàãîì, è ïîòîìó ñàáæ (äà ïðîñòÿò ìåíÿ ìîäåðàòîð
è äðóãèå ïî÷åòíûå ïðåäñòàâèòåëè ýõîòàæíîãî ñîîáùåñòâà):
1. Ïðàâäà, ÷òî êîäåð, êîòîðûé ñæèìàë áû _ëþáûå_ äàííûå äî ðàçìåðà, ïðàêòè÷åñêè
íå îòëè÷àþùåãîñÿ îò èõ ýíòðîïèè (êîðî÷å, óäàëÿë áû âñþ èçáûòî÷íîñòü), íå ìîæåò
ñóùåñòâîâàòü, à åñëè áû è ñóùåñòâîâàë, òî áûë áû áåñêîíå÷íî ñëîæåí è òðåáîâàë
áû áåñêîíå÷íîãî âðåìåíè, è, âîçìîæíî, ðåñóðñîâ äëÿ ðàáîòû?
2. Êàêîâà ýíòðîïèÿ ïîñëåäîâàòåëíîñòè, ïîëó÷åííîé ñ ïîìîùüþ RND?
Bye!
Dmitry.
--- @c:\windows\win386.swp
* Origin: xxxxxxns smopu!M (2:5030/856.12)
— RU.COMPRESS
From : Bulat Ziganshin 2:5093/28.26 13 Jun 99 11:18:16
To : Vasya Danilov
Subj : àpèôìåòè÷åñêèé àëãîpèòì
* Crossposted in RU.COMPRESS
Hello Vasya!
Saturday June 12 1999, Vasya Danilov writes to All:
VD> îáúÿñíèòå ñàáæ ! à òî äî íà àíãëèéñêîì ÷èòàë - íè÷åãî íå ïîíÿë.
=== Cut ===
Âîò ñåé÷àñ ñîâåðøåííî ñëó÷àéíî íàøåë ó ñåáÿ áëåñòÿùåå îïèñàíèå àðèôìåòèêè -
îò òåîðåòè÷åñêîé ìîäåëè äî òîíêîñòåé ïðàêòè÷åñêîé ðåàëèçàöèè. Ïîëíîñòüþ ñòàòüÿ
ïîéäåò â ôýõó adevcomp (arithm.rar), à åå íà÷àëî êèäàþ ñþäà. ×òî êàñàåòñÿ
ãîòîâûõ ðåàëèçàöèé, òî ëó÷øå âñåãî âîñïîëüçîâàòüñÿ áàéò-îðèåíòèðîâàííûì
óïàêîâùèêîì Øèíäëåðà (ari_b.zip â òîé æå ôýõå)
=== Cut ===
ÈÄÅß ÀÐÈÔÌÅÒÈ×ÅÑÊÎÃÎ ÊÎÄÈÐÎÂÀHÈß.
Ïpè àpèôìåòè÷åñêîì êîäèpîâàíèè òåêñò ïpåäñòàâëÿåòñÿ âåùåñòâåííûìè
÷èñëàìè â èíòåpâàëå îò 0 äî 1. Ïî ìåpå êîäèpîâàíèÿ òåêñòà, îòîápàæàþ-
ùèé åãî èíòåpâàë óìåíüøàåòñÿ, à êîëè÷åñòâî áèòîâ äëÿ åãî ïpåäñòàâëåíèÿ
âîçpàñòàåò. Î÷åpåäíûå ñèìâîëû òåêñòà ñîêpàùàþò âåëè÷èíó èíòåpâàëà èñ-
õîäÿ èç çíà÷åíèé èõ âåpîÿòíîñòåé, îïpåäåëÿåìûõ ìîäåëüþ. Áîëåå âåpîÿò-
íûå ñèìâîëû äåëàþò ýòî â ìåíüøåé ñòåïåíè, ÷åì ìåíåå âåpîÿòíûå, è, ñëå-
äîâàòåëüíî, äîâàáëÿþò ìåíüøå áèòîâ ê påçóëüòàòó.
Ïåpåä íà÷àëîì pàáîòû ñîîòâåòñòâóþùèé òåêñòó èíòåpâàë åñòü [0; 1).
Ïpè îápàáîòêå î÷åpåäíîãî ñèìâîëà åãî øèpèíà ñóæàåòñÿ çà ñ÷åò âûäåëåíèÿ
ýòîìó ñèìâîëó ÷àñòè èíòåpâàëà. Hàïpèìåp, ïpèìåíèì ê òåêñòó "eaii!" àë-
ôàâèòà { a,e,i,o,u,! } ìîäåëü ñ ïîñòîÿííûìè âåpîÿòíîñòÿìè, çàäàííûìè â
Òàáëèöå I.
Òàáëèöà I. Ïpèìåp ïîñòîÿííîé ìîäåëè äëÿ àëôàâèòà { a,e,i,o,u,! }.
Ñèìâîë Âåpîÿòíîñòü Èíòåpâàë
a .2 [0.0; 0.2)
e .3 [0.2; 0.5)
i .1 [0.5; 0.6)
o .2 [0.6; 0.8)
u .1 [0.8; 0.9)
! .1 [0.9; 1.0)
È êîäèpîâùèêó, è äåêîäèpîâùèêó èçâåñòíî, ÷òî â ñàìîì íà÷àëå èíòåp-
âàë åñòü [0; 1). Ïîñëå ïpîñìîòpà ïåpâîãî ñèìâîëà "e", êîäèpîâùèê ñóæà-
åò èíòåpâàë äî [0.2; 0.5), êîòîpûé ìîäåëü âûäåëÿåò ýòîìó ñèìâîëó. Âòî-
pîé ñèìâîë "a" ñóçèò ýòîò íîâûé èíòåpâàë äî ïåpâîé åãî ïÿòîé ÷àñòè,
ïîñêîëüêó äëÿ "a" âûäåëåí ôèêñèpîâàííûé èíòåpâàë [0.0; 0.2). Â påçóëü-
òàòå ïîëó÷èì pàáî÷èé èíòåpâàë [0.2; 0.26), ò.ê. ïpåäûäóùèé èíòåpâàë
èìåë øèpèíó â 0.3 åäèíèöû è îäíà ïÿòàÿ îò íåãî åñòü 0.06. Ñëåäóþùåìó
ñèìâîëó "i" ñîîòâåòñòâóåò ôèêñèpîâàííûé èíòåpâàë [0.5; 0.6), ÷òî ïpè-
ìåíèòåëüíî ê pàáî÷åìó èíòåpâàëó [0.2; 0.26) ñóæèâàåò åãî äî èíòåpâàëà
[0.23, 0.236). Ïpîäîëæàÿ â òîì æå äóõå, èìååì:
 íà÷àëå [0.0; 1.0 )
Ïîñëå ïpîñìîòpà "e" [0.2; 0.5 )
-"-"-"- "a" [0.2; 0.26 )
-"-"-"- "i" [0.23; 0.236 )
-"-"-"- "i" [0.233; 0.2336)
-"-"-"- "!" [0.23354; 0.2336)
Ïpåäïîëîæèì, ÷òî âñå ÷òî äåêîäèpîâùèê çíàåò î òåêñòå, ýòî êîíå÷íûé
èíòåpâàë [0.23354; 0.2336). Îí ñpàçó æå ïîíèìàåò, ÷òî ïåpâûé çàêîäèpî-
âàííûé ñèìâîë åñòü "e", ò.ê. èòîãîâûé èíòåpâàë öåëèêîì ëåæèò â èíòåp-
âàëå, âûäåëåííîì ìîäåëüþ ýòîìó ñèìâîëó ñîãëàñíî Òàáëèöå I. Òåïåpü ïîâ-
òîpèì äåéñòâèÿ êîäèpîâùèêà:
Ñíà÷àëà [0.0; 1.0)
Ïîñëå ïpîñìîòpà "e" [0.2; 0.5)
Îòñþäà ÿñíî, ÷òî âòîpîé ñèìâîë - ýòî "a", ïîñêîëüêó ýòî ïpèâåäåò ê
èíòåpâàëó [0.2; 0.26), êîòîpûé ïîëíîñòüþ âìåùàåò èòîãîâûé èíòåpâàë
[0.23354; 0.2336). Ïpîäîëæàÿ pàáîòàòü òàêèì æå îápàçîì, äåêîäèpîâùèê
èçâëå÷åò âåñü òåêñò.
Äåêîäèpîâùèêó íåò íåîáõîäèìîñòè çíàòü çíà÷åíèÿ îáåèõ ãpàíèö èòîãî-
âîãî èíòåpâàëà, ïîëó÷åííîãî îò êîäèpîâùèêà. Äàæå åäèíñòâåííîãî çíà÷å-
íèÿ, ëåæàùåãî âíóòpè íåãî, íàïpèìåp 0.23355, óæå äîñòàòî÷íî. (Äpóãèå
÷èñëà - 0.23354,0.23357 èëè äàæå 0.23354321 - âïîëíå ãîäÿòñÿ). Îäíàêî,
÷òîáû çàâåpøèòü ïpîöåññ, äåêîäèpîâùèêó íóæíî âîâpåìÿ pàñïîçíàòü êîíåö
òåêñòà. Êpîìå òîãî, îäíî è òî æå ÷èñëî 0.0 ìîæíî ïpåäñòàâèòü è êàê
"a", è êàê "aa", "aaa" è ò.ä. Äëÿ óñòpàíåíèÿ íåÿñíîñòè ìû äîëæíû îáîç-
íà÷èòü çàâåpøåíèå êàæäîãî òåêñòà ñïåöèàëüíûì ñèìâîëîì EOF, èçâåñòíûì è
êîäèpîâùèêó, è äåêîäèpîâùèêó. Äëÿ àëôàâèòà èç Òàáëèöû I äëÿ ýòîé öåëè,
è òîëüêî äëÿ íåå, áóäåò èñïîëüçîâàòüñÿ ñèìâîë "!". Êîãäà äåêîäèpîâùèê
âñòpå÷àåò ýòîò ñèìâîë, îí ïpåêpàùàåò ñâîé ïpîöåññ.
Äëÿ ôèêñèpîâàííîé ìîäåëè, çàäàâàåìîé ìîäåëüþ Òàáëèöû I, ýíòpîïèÿ 5-
ñèìâîëüíîãî òåêñòà "eaii!" áóäåò:
- log 0.3 - log 0.2 - log 0.1 - log 0.1 - log 0.1 =
= - log 0.00006 ~ 4.22.
(Çäåñü ïpèìåíÿåì ëîãàpèôì ïî îñíîâàíèþ 10, ò.ê. âûøåpàññìîòpåííîå êî-
äèpîâàíèå âûïîëíÿëîñü äëÿ äåñÿòè÷íûõ ÷èñåë). Ýòî îáúÿñíÿåò, ïî÷åìó
òpåáóåòñÿ 5 äåñÿòè÷íûõ öèôp äëÿ êîäèpîâàíèÿ ýòîãî òåêñòà. Ïî ñóòè, øè-
pèíà èòîãîâîãî èíòåpâàëà åñòü 0.2336 - 0.23354 = 0.00006, à ýíòpîïèÿ -
îòpèöàòåëüíûé äåñÿòè÷íûé ëîãàpèôì ýòîãî ÷èñëà. Êîíå÷íî, îáû÷íî ìû pà-
áîòàåì ñ äâîè÷íîé àpèôìåòèêîé, ïåpåäàåì äâîè÷íûå ÷èñëà è èçìåpÿåì ýíò-
pîïèþ â áèòàõ.
Ïÿòè äåñÿòè÷íûõ öèôp êàæåòñÿ ñëèøêîì ìíîãî äëÿ êîäèpîâàíèÿ òåêñòà
èç 4-õ ãëàñíûõ! Ìîæåò áûòü íå ñîâñåì óäà÷íî áûëî çàêàí÷èâàòü ïpèìåp
pàçâåpòûâàíèåì, à íå ñæàòèåì. Îäíàêî, ÿñíî, ÷òî pàçíûå ìîäåëè äàþò
pàçíóþ ýíòpîïèþ. Ëó÷øàÿ ìîäåëü, ïîñòîåííàÿ íà àíàëèçå îòäåëüíûõ ñèìâî-
ëîâ òåêñòà "eaii!", åñòü ñëåäóþùåå ìíîæåñòâî ÷àñòîò ñèìâîëîâ:
{ "e"(0.2), "a"(0.2), "i"(0.4), "!"(0.2) }.
Îíà äàåò ýíòpîïèþ, pàâíóþ 2.89 â äåñÿòè÷íîé ñèñòåìå ñ÷èñëåíèÿ, ò.å.
êîäèpóåò èñõîäíûé òåêñò ÷èñëîì èç 3-õ öèôp. Îäíàêî, áîëåå ñëîæíûå ìî-
äåëè, êàê îòìå÷àëîñü pàíåå, äàþò â îáùåì ñëó÷àå ãîpàçäî ëó÷øèé påçóëü-
òàò.
ÏÐÎÃÐÀÌÌÀ ÄËß ÀÐÈÔÌÅÒÈ×ÅÑÊÎÃÎ ÊÎÄÈÐÎÂÀHÈß.
Hà Ðèñóíêå 1 ïîêàçàí ôpàãìåíò ïñåâäîêîäà, îáúåäèíÿþùåãî ïpîöåäópû
êîäèpîâàíèÿ è äåêîäèpîâàíèÿ, èçëàãàåìûå â ïpåäûäóùåì pàçäåëå. Ñèìâîëû
â íåì íóìåpóþòñÿ êàê 1,2,3... ×àñòîòíûé èíòåpâàë äëÿ i-ãî ñèìâîëà çà-
äàåòñÿ îò cum_freq[i] äî cum_freq[i-1]. Ïpè óáûâàíèè i cum_freq[i] âî-
çpàñòàåò òàê, ÷òî cum_freq[0] = 1. (Ïpè÷èíà òàêîãî "îápàòíîãî" ñîãëà-
øåíèÿ ñîñòîèò â òîì, ÷òî cum_freq[0] áóäåò ïîòîì ñîäåpæàòü íîpìàëèçóþ-
ùèé ìíîæèòåëü, êîòîpûé óäîáíî õpàíèòü â íà÷àëå ìàññèâà). Òåêóùèé pàáî-
÷èé èíòåpâàë çàäàåòñÿ â [low; high] è áóäåò â ñàìîì íà÷àëå pàâåí
[0; 1) è äëÿ êîäèpîâùèêà, è äëÿ pàñêîäèpîâùèêà.
Ê ñîæàëåíèþ ýòîò ïñåâäîêîä î÷åíü óïpîùåí, êîãäà êàê íà ïpàêòèêå ñó-
ùåñòâóåò íåñêîëüêî ôàêòîpîâ, îñëîæíÿþùèõ è êîäèpîâàíèå, è äåêîäèpîâà-
íèå.
/* ÀËÃÎÐÈÒÌ ÀÐÈÔÌÅÒÈ×ÅÑÊÎÃÎ ÊÎÄÈÐÎÂÀHÈß */
/* Ñ êàæäûì ñèìâîëîì òåêñòà îápàùàòüñÿ ê ïpîöåäópå encode_symbol() */
/* Ïpîâåpèòü, ÷òî "çàâåpøàþùèé" ñèìâîë çàêîäèpîâàí ïîñëåäíèì */
/* Âûâåñòè ïîëó÷åííîå çíà÷åíèå èíòåpâàëà [low; high) */
encode_symbol(symbol,cum_freq)
range = high - low
high = low + range*cum_freq[symbol-1]
low = low + range*cum_freq[symbol]
/* ÀËÃÎÐÈÒÌ ÀÐÈÔÌÅÒÈ×ÅÑÊÎÃÎ ÄÅÊÎÄÈÐÎÂÀHÈß */
/* Value - ýòî ïîñòóïèâøåå íà âõîä ÷èñëî */
/* Îápàùåíèå ê ïpîöåäópå decode_symbol() ïîêà îíà íå âîçâpàòèò */
/* "çàâåpøàþùèé" ñèìâîë */
decode_symbol(cum_freq)
ïîèñê òàêîãî ñèìâîëà, ÷òî
cum_freq[symbol] <= (value - low)/(high - low) < cum_freq[symbol-1]
/* Ýòî îáåñïå÷èâàåò pàçìåùåíèå value âíóòpè íîâîãî èíòåpâàëà */
/* [low; high), ÷òî îòpàæåíî â îñòàâøåéñÿ ÷àñòè ïpîãpàììû */
range = high - low
high = low + range*cum_freq[symbol-1]
low = low + range*cum_freq[symbol]
return symbol
Ðèñóíîê 1. Ïñåâäîêîä àpèôìåòè÷åñêîãî êîäèpîâàíèÿ è äåêîäèpîâàíèÿ.
Ïpèpàùàåìûå ïåpåäà÷à è ïîëó÷åíèå èíôîpìàöèè. Îïèñàííûé àëãîpèòì êî-
äèpîâàíèÿ íè÷åãî íå ïåpåäàåò äî ïîëíîãî çàâåpøåíèÿ êîäèpîâà-
íèÿ âñåãî òåêñòà, òàêæå è äåêîäèpîâùèê íå íà÷èíàåò ïpîöåññ,
ïîêà íå ïîëó÷èò ñæàòûé òåêñò ïîëíîñòüþ. Äëÿ áîëüøèíñòâà ñëó-
÷àåâ íåîáõîäèì ïîñòåïåííûé påæèì âûïîëíåíèÿ.
Æåëàòåëüíîå èñïîëüçîâàíèå öåëî÷èñëåííîé àpèôìåòèêè. Òpåáóåìàÿ äëÿ
ïpåäñòàâëåíèÿ èíòåpâàëà [low; high ) òî÷íîñòü âîçpàñòàåò âìå-
ñòå ñ äëèíîé òåêñòà. Ïîñòåïåííîå âûïîëíåíèå ïîìîãàåò ïpåîäî-
ëåòü ýòó ïpîáëåìó, òpåáóÿ ïpè ýòîì âíèìàòåëüíîãî ó÷åòà âîç-
ìîæíîñòåé ïåpåïîëíåíèÿ è îòpèöàòåëüíîãî ïåpåïîëíåíèÿ.
Ýôôåêòèâíàÿ påàëèçàöèÿ ìîäåëè. Ðåàëèçàöèÿ ìîäåëè äîëæíà ìèíèìèçèpî-
âàòü âpåìÿ îïpåäåëåíèÿ ñëåäóþùåãî ñèìâîëà àëãîpèòìîì äåêîäè-
pîâàíèÿ. Êpîìå òîãî, àäàïòèâíûå ìîäåëè äîëæíû òàêæå ìèíèìèçè-
pîâàòü âpåìÿ, òpåáóåìîå äëÿ ïîääåpæàíèÿ íàêàïëèâàåìûõ ÷àñòîò.
=== Cut ===
Bulat, mailto:bulatz@fort.tatarstan.ru, ICQ 15872722
--- GoldED/386 2.50+
* Origin: Äâîðåöêèé ðàçáóäèë Ãåðöåíà. Äåêàáðèñòû ïðîñïàëè... (2:5093/28.26)
— RU.COMPRESS
From : Leonid Broukhis 2:5020/400 13 Jun 99 12:18:58
To : Dmitry Belash
Subj : Re: Ïàðî÷êà ãëóïûõ âîïðîñîâ :)
From: leob@asylum.mailcom.com (Leonid Broukhis)
Dmitry Belash wrote:
>ß ñîâñåì íåäàâíî ñâÿçàëñÿ ñ ýõîòàãîì, è ïîòîìó ñàáæ (äà ïðîñòÿò ìåíÿ ìîäåðàòîð
>è äðóãèå ïî÷åòíûå ïðåäñòàâèòåëè ýõîòàæíîãî ñîîáùåñòâà):
>1. Ïðàâäà, ÷òî êîäåð, êîòîðûé ñæèìàë áû _ëþáûå_ äàííûå äî ðàçìåðà, ïðàêòè÷åñêè
>íå îòëè÷àþùåãîñÿ îò èõ ýíòðîïèè (êîðî÷å, óäàëÿë áû âñþ èçáûòî÷íîñòü), íå ìîæåò
>ñóùåñòâîâàòü, à åñëè áû è ñóùåñòâîâàë, òî áûë áû áåñêîíå÷íî ñëîæåí è òðåáîâàë
>áû áåñêîíå÷íîãî âðåìåíè, è, âîçìîæíî, ðåñóðñîâ äëÿ ðàáîòû?
Êîíå÷íî. Âåäü â _ëþáûå_ äàííûå âõîäÿò äàííûå ëþáîé äëèíû.
>2. Êàêîâà ýíòðîïèÿ ïîñëåäîâàòåëíîñòè, ïîëó÷åííîé ñ ïîìîùüþ RND?
Åñëè ýòî äàò÷èê ïñåâäîñëó÷àéíûõ ÷èñåë, òî îíà ðàâíà ýíòðîïèè ïðîãðàììû,
ðåàëèçóþùåé ýòîò äàò÷èê + ýíòðîïèè íà÷àëüíîãî ñîñòîÿíèÿ äàò÷èêà
(òàê íàç. Êîëìîãîðîâñêàÿ ñëîæíîñòü). Åñëè äàò÷èê îñíîâûâàåòñÿ íà
ôèçè÷åñêè ñëó÷àéíûõ ïðîöåññàõ, òî îíà ïðîïîðöèîíàëüíà äëèíå ïîñëåäîâàòåëüíîñòè.
Leo
--- ifmail v.2.14dev3
* Origin: leob@at-mailcom.dot-com (2:5020/400)
— RU.COMPRESS
From : Leonid Broukhis 2:5020/400 13 Jun 99 12:19:00
To : Bulat Ziganshin
Subj : Re: ñæàòü
From: leob@asylum.mailcom.com (Leonid Broukhis)
Bulat Ziganshin wrote:
> DB>>> Èìååòñÿ ïîñëåäîâàòåëüíîñòü áèò, â êîòîðîé íóëåé ðàç â 5-6
> DB>>> áîëüøå, ÷åì åäèíèö. Êàê ñæàòü, äà ïîïëîòíåå? Åñòü áðåäîâàÿ èäåÿ
> BZ>> Äëÿ òîãî, ÷òîáû ïðèäóìàòü ÷òî-íèáóäü ïîëó÷øå, íàäî áîëüøå çíàòü î
> BZ>> òâîåé ïîñëåäîâàòåëüíîñòè, ïîêà ÷òî òû çíàåøü òîëüêî ÷òî òàì íóëåé
> BZ>> áîëüøå, ÷åì åäèíèö.
> DB> Ëàäíî, à åñëè òàì åñòü ïîâòîðåíèÿ? LZ÷òî ïðèìåíèòü è â êàêîì ìåñòå?
>
> Òåîðåòè÷åñêè - lzari íà óðîâíå áèòîâ. Ïðàêòè÷åñêè, ìîæåò òåáå óäàñòñÿ
>îáîéòèñü lzh-åì è/èëè ðàáîòîé íà óðîâíå áàéòîâ.
ß ïðåäïî÷èòàþ urban èç ñáîðíèêà ïðîãðàìì íà êîíêóðñ Dr.Dobbs. Òóò òåáå
è ìàðêîâñêèé êîäåð, è íà óðîâíå áèòîâ.
Leo
--- ifmail v.2.14dev3
* Origin: leob@at-mailcom.dot-com (2:5020/400)
— RU.COMPRESS
From : Vadim G Zabelin 2:5020/400 13 Jun 99 14:32:06
To : All
Subj : Re: Ïàðî÷êà ãëóïûõ âîïðîñîâ :)
From: Vadim G Zabelin <landcruiser@mailcity.com>
Dmitry Belash wrote:
> ß ñîâñåì íåäàâíî ñâÿçàëñÿ ñ ýõîòàãîì, è ïîòîìó ñàáæ (äà ïðîñòÿò ìåíÿ
> ìîäåðàòîð è äðóãèå ïî÷åòíûå ïðåäñòàâèòåëè ýõîòàæíîãî ñîîáùåñòâà): 1. Ïðàâäà,
> ÷òî êîäåð, êîòîðûé ñæèìàë áû _ëþáûå_ äàííûå äî ðàçìåðà, ïðàêòè÷åñêè íå
> îòëè÷àþùåãîñÿ îò èõ ýíòðîïèè (êîðî÷å, óäàëÿë áû âñþ èçáûòî÷íîñòü), íå
> ìîæåò ñóùåñòâîâàòü, à åñëè áû è ñóùåñòâîâàë, òî áûë áû áåñêîíå÷íî ñëîæåí è
> òðåáîâàë áû áåñêîíå÷íîãî âðåìåíè, è, âîçìîæíî, ðåñóðñîâ äëÿ ðàáîòû?
Åñëè ðå÷ü èäåò î êîíå÷íîé ïîñëåäîâàòåëüíîñòè ëþáûõ ñèìâîëîâ,
( òî åñòü, ñóùåñòâóåò íåêàÿ êîíå÷íàÿ ïîñëåäîâàòåëüíîñòü ñèìâîëîâ , èç
íåêîãî êîíå÷íîãî àëôàâèòà )
òî ìíå èçâåñòåí ìåòîä íàõîæäåíèÿ âñåõ ïîâòîðÿþùèõñÿ ïîñëåäîâàòåëüíîñòåé,
è îí ïðîñò, êàê âñå ãåíèàëüíîå ;)))
( ñîáðàòü äåéñòâóþùèé îáðàçåö ìîæíî èç ïîäðó÷íûõ ìàòåðèàëîâ ).
Hî ýòî íå êîäåð, à èìåííî ìåòîä íàõîæäåíèÿ èçáûòî÷íîñòè.
IMHO åñëè åñòü ìåòîä íàõîæäåíèÿ èçáûòî÷íîñòè -
( öèòàòà èç "Ìàòåìàòè÷åñêèé ýíöèêëîïåäè÷åñêèé ñëîâàðü",
Ìîñêâà, "Ñîâåòñêàÿ ýíöèêëîïåäèÿ", 1988 ãîä :
Èçáûòî÷íîñòü v ïîíÿòèå òåîðèè èíôîðìàöèè. Hàëè÷èå èçáûòî÷íîñòè
â çàïèñè ñîîáùåíèé êàêîãî-ëèáî èñòî÷íèêà èíôîðìàöèè ïðîÿâëÿåòñÿ
â âîçìîæíîñòè çàïèñàòü ýòè ñîîáùåíèÿ â ñðåäíåì áîëåå êðàòêî, èñïîëüçóÿ
òå æå ñàìûå çíàêè ( ò.å. çàìåíÿÿ îäèí êîä íà äðóãîé ñ òåì æå
àëôàâèòîì, ñì. Êîäèðîâàíèå ). )
òî ìîæíî ïîñòðîèòü è êîäåð.
Âðåìåíè íà ïîèñê âñåõ ïîâòîðÿþùèõñÿ ïîñëåäîâàòåëüíîñòåé óõîäèò
ó íåãî ïðèìåðíî ñòîëüêî æå, ñêîëüêî ó LZ-77 .
Áîëüøå íè÷åãî ñêàçàòü íå ìîãó, ñåé÷àñ ïèøó ñòàòüþ ïî ýòîìó ïîâîäó.
--- ifmail v.2.14dev3
* Origin: V. Zabelin Enterprises (2:5020/400)
— RU.COMPRESS
From : Anton Malykh 2:5070/108 13 Jun 99 21:00:23
To : Dima Kirnocenskij
Subj : ADPCM
Çäîðîâüÿ /Âàì/, Dima!
DK> Äåêîäåð:
DK> âçÿòü òî ñàìîå îòäåëüíî ëåæàùåå c_value;
DK> i=1;
DK> ïîêà åñòü ÷åãî äåêîäèòü {
DK> c_value=c_value+exp(outbuf[i]);
DK> sample[i]=c_value;
DK> }
Ñòpàííûé ADPCM, ïîñêîëüêó èìåííî àäàïòèâíîñòü íå ïpîñëåæèâàåòñÿ. Hå÷òî ïîäîáíîå
ÿ íàáëþë ïîä íàçâàíèåì Fibonacci Delta Encoding, òîëüêî òàì â êà÷åñòâå äàííûõ
òàáëèöû äåëüò èñïîëüçîâàëèñü ÷èñëà Ôèáîíà÷è.
Ñóòü æå íàñòîÿùåãî ADPCM ñîñòîèò â òîì, ÷òî pàçpåøåíèå äèñêpåòèçàöèè pàçíîñòè
ìåæäó îò÷¸òàìè ìàñøòàáèpóåòñÿ â çàâèñèìîñòè îò pàçëè÷íûé óñëîâèé (íàïpèìåp, îò
ópîâíÿ ñèãíàëà). Ò.å. åäèíèöà â âûõîäíûõ (äëÿ êîäåpà) äàííûõ ìîæåò îçíà÷àòü
óâåëè÷åíèå êàê íà äîñòàòî÷íî ìàëåíüêóþ âåëè÷èíó, òàê è íà î÷åíü áîëüøóþ.
Ðàçëè÷íûå ìåòîäû ADPCM êîäèpîâàíèÿ îòëè÷àþòñÿ ñïîñîáàìè âû÷èñëåíèÿ ýòîãî
ìàñøòàáà. Òàê æå áûâàåò (íàïpèìåp, â òîì æå ñàìîì MS ADPCM), ÷òî èñïîëüçóåòñÿ
pàçíîñòü íå ìåæäó ïpåäûäóùèì è òåêóùèì îò÷¸òàìè, à ìåæäó ïpåäñêàçàííûì (â
ñëó÷àå
MS ADPCM ýòî ïpîñòî ëèíåéíàÿ êîìáèíàöèÿ äâóõ ïpåäûäóùèõ îò÷¸òîâ ñ çàäàííûìè
êîýôôèöèåíòàìè) çíà÷åíèåì è èñòèííûì.
--- DA 0-10:29
* Origin: SYS1059 (2:5070/108)
— RU.COMPRESS
From : Bulat Ziganshin 2:5093/28.26 14 Jun 99 05:04:42
To : Kirill Frolov
Subj : àpèôìåòè÷åñêèé àëãîpèòì
* Crossposted in RU.COMPRESS
Hello Kirill!
Monday June 14 1999, Kirill Frolov writes to All:
VD>> îáúÿñíèòå ñàáæ ! à òî äî íà àíãëèéñêîì ÷èòàë - íè÷åãî íå ïîíÿë.
KF> È ìíå òîæå... Âîò ÿ äóìàþ, íàñêîëüêî ýôôåêòèâíî ïîáèòîâîå
KF> àpèôìåòè÷åñêîå êîäèpîâàíèå èëè ïîáàéòíîå ?
Ðàçìåð âûõîäíîãî ôàéëà - ñîâåðøåííî îäèíàêîâ. Êñòàòè, áîëåå ñîâðåìåííîå
íàçâàíèå ïîáàéòíîãî àðèôìåòè÷åñêîãî êîäèðîâàíèÿ - rangecoder
KF> È êàê ìîæíî áåç äåëåíèÿ âñ¸ çàêîäèpîâàòü ?
http://bbs.ogo.ru/ADEVCOMP/MFARC.RAR (Yet Another Realization of
Multiplication Free Arithmetic Code by Maxim Zakharov)
Ñòåïåíü ñæàòèÿ çàìåòíî õóæå, àôàèê.
Bulat, mailto:bulatz@fort.tatarstan.ru, ICQ 15872722
--- GoldED/386 2.50+
* Origin: Äâîðåöêèé ðàçáóäèë Ãåðöåíà. Äåêàáðèñòû ïðîñïàëè... (2:5093/28.26)