[Asterisk-Users] fax still fails, ideas sought! Re: rxfax/spandsp fails to decode

[Steve Underwood]

Stephen J. Wilcox wrote:

>Okay having taken in some suggestions and googled this topic to death I'm still 
>stuck - anyone got any ideas?
>
>To recap, the faxes are coming in via a digium E1 card but failing to train 
>properly or if they manage it sending a garbled and very truncated fax.
>
>A number of folks have suggested clock sync issues.. my zaptel.conf is set to 
>use the PRI as primary clock, i have no evidence of issues altho dont know how 
>to check (other than the call quality is fine, no clicks, no pri down/ups).
>  
>
If you wanttttevidence of problems, look a the spandsp log. You have the 
evidence, but you are ignoring it.

>What can i try?
>  
>
I really should make spandsp smart enough to actually detect the timing 
jumps and put out a nice big

**** FIX YOUR TIMING, AND NO COMPLAINTS UNTIL YOU DO *****

message. :-)

>Steve
>
>On Mon, 12 Jul 2004, Stephen J. Wilcox wrote:
>
>  
>
>>Hi,
>> I just sent this to Steve Underwood, but then found a bunch of posts on the
>>mailing list about similar issues.. does anyone have the fix?
>>
>>I'm running asterisk CVS-HEAD-06/28/04-18:13:13, spandsp 0.0.1k, libtif 3.5.7
>>
>>one thing i just noticed is that calls come in with format '72' which is
>>G711A-law or LinearPCM.. it uses PCM for the call, i assume this is ok
>>
>>the results of RxFAX vary, it sometimes saves the file in which case i get 
>>errors: 
>>Fax3Decode2D: Warning, (FakeInput): Line length mismatch at scanline 0 (got 
>>2383, expected 1728).
>>Fax3Decode2D: (FakeInput): Bad code word at scanline 1 (x 137).
>>
>>and the resulting tif looks to be only a few rows long
>>
>>or more commonly it just fails entirely.. i paste the output below so you can 
>>see. is there anything obvious i'm doign wrong here?
>>
>>TIA! Steve.
>>
>>    -- Executing RxFAX("Zap/1-1", 
>>"/var/spool/asterisk/faxes/20040712-183339.tif") in new stack
>>Changed from phase 0 to 1
>>Start receiving document
>>Changed from phase 1 to 4
>>Sending ident
>>    
>>
>>>>>CSI: 40 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
>>>>>          
>>>>>
>>DIS:
>>Preferred octets: 256
>>Can receive fax
>>Supported data signalling rates: V.27ter and V.29
>>R8x7.7lines/mm and/or 200x200pels/25.4mm OK
>>2D coding OK
>>Scan line length: 215mm
>>Recording length: A4 (297mm)
>>Receiver's minimum scan line time: 0ms at 3.85 l/mm: T7.7 = T3.85
>>R8x15.4lines/mm OK
>>Minimum scan line time for higher resolutions: T15.4 = T7.7
>>    
>>
>>>>>DIS: 80 00 ce f0 80 80 01
>>>>>          
>>>>>
>>HDLC underflow in state 9
>>Changed from phase 4 to 3
>>Slow carrier up
>><<< TSI: 43 31 37 31 31 36 35 34 35 34 38 30 20 20 20 20 20 20 20 20 20
>>TSI without final frame tag
>>Remote fax gave TSI as: "xxxx"
>><<< DCS: 83 00 86 90 00
>>DCS with final frame tag
>>In state 9
>>DCS:
>>Can receive fax
>>Selected data signalling rate: V.29, 9600bps
>>2D coding OK
>>Scan line length: 215mm
>>Recording length: A4 (297mm)
>>Minimum scan line time: 5ms
>>Get at 9600
>>Changed from phase 3 to 5
>>Fast carrier up
>>Fast carrier down
>>Fast carrier up
>>Coarse carrier frequency 1699.90 (64)
>>Training error 56.874846
>>Training succeeded (constellation mismatch 44.212022)
>>Fast carrier trained
>>Fast carrier down
>>Trainability test failed - longest run of zeros was 14
>>    
>>
>>>>>FTT: 44
>>>>>          
>>>>>
>>Fast carrier up
>>Training failed (sequence failed)
>>Fast carrier training failed
>>Fast carrier down
>>Fast carrier up
>>Coarse carrier frequency 1700.33 (64)
>>Training error 51.989152
>>Training succeeded (constellation mismatch 37.988826)
>>Fast carrier trained
>>Fast carrier down
>>Trainability test failed - longest run of zeros was 15
>>    
>>
>>>>>FTT: 44
>>>>>          
>>>>>
>>Fast carrier up
>>Training failed (sequence failed)
>>Fast carrier training failed
>>Fast carrier down
>>Fast carrier up
>>Coarse carrier frequency 1700.32 (64)
>>Training error 60.898646
>>Training succeeded (constellation mismatch 46.138793)
>>Fast carrier trained
>>Fast carrier down
>>Trainability test failed - longest run of zeros was 17
>>    
>>
>>>>>FTT: 44
>>>>>          
>>>>>
>>Fast carrier up
>>Training failed (sequence failed)
>>Fast carrier training failed
>>Fast carrier down
>>Fast carrier up
>>Coarse carrier frequency 1795.61 (4)
>>Fast carrier down
>>Fast carrier up
>>Coarse carrier frequency 1789.60 (4)
>>Fast carrier down
>>    -- Channel 0/1, span 1 got hangup
>>    -- Hungup 'Zap/1-1'
>>    
>>
Regards,
Steve