[asterisk-users] Fax Problems with SpanDSP

[Steve Underwood]

Steve Davies wrote:
> On 8/29/07, Christian Peter <christian.peter at charlysworld.de> wrote:
>   
>> Am Mittwoch, den 29.08.2007, 20:13 +0800 schrieb Steve Underwood:
>>     
>>> Christian Peter wrote:
>>>       
>>>> Hi list,
>>>>
>>>> I'm running current SpanDSP
>>>> http://www.soft-switch.org/downloads/spandsp/spandsp-0.0.4pre6.tgz
>>>> with Asterisk 1.2.22 somewhat successfully.
>>>>
>>>> Most Fax machines do work but I have problems with people having
>>>> Tobit FaxWare and Shamrock CapiFax.
>>>>
>>>> http://www.tobit.com/login/mrd.asp?CategoryID=120
>>>> http://www.shamrock.de/
>>>>
>>>> I've got black bars over the pages. In Tobit some content is Ok, other
>>>> is covered by the black bars. Anyone else has simliar problems?
>>>>
>>>> I talked to Tobit and they said there should be an option somewhere in
>>>> SpanDSP to disable Fax header crossbars. But I found none.
>>>>
>>>> Can anybody help me with this issue. Please no "switch to Hylafax"
>>>> mails, because I'm very happy with SpanDSP, it integrates nicely and
>>>> works most time.
>>>>
>>>> Thank you,
>>>> Regards
>>>>
>>>> Christian Peter
>>>>
>>>>         
>>> I assume if you are using spandsp-0.0.4pre6 you have adapted
>>> app_rxfax.c. and app_txfax.c to work with it.
>>>       
>> Hi Steve,
>>
>> thank you for your help. I'm using
>>
>> http://www.soft-switch.org/downloads/snapshots/spandsp/test-apps-asterisk-1.2/
>>
>> without modifications.
>>
>>     
>>> I haven't heard from anyone using tobit or shamrock software (who on
>>> earth wants to call their company tobit? weird). I have no idea what fax
>>> header crossbars might be. Do they have some kind of bicycle integration
>>> in their product? :-\
>>>       
>> :) That was just a simple translation I looked up in a dictionary. Call
>> it blocks, or banners. I either don't know what they meant :)
>>
>>     
>>> Is your problem when sending from Asterisk or receiving? Can you enable
>>> debug and e-mail me a log and (assuming its a receive problem) the
>>> resulting TIFF file.
>>>       
>> The problems occur on receiving. I'll do that and send you the email
>> soon.
>>
>>     
>
> Hi,
>
> Did any progress occur on this? I too am using 0.0.4 spandsp snapshots
> to receive faxes with quite a significant degree of success on a
> 1.2.24 asterisk box. I also get the only 8-bytes in a TIFF file
> problem occasionally. Generally this occurs if there are also a number
> of line-errors shown in the page-received report (this is not
> scientifically correlated!)
>
> I always assumed that this was ECM causing a page to be abandoned if
> there were too many errors, but if I disable ECM in rxfax, I get the
> same results.
>
> Any feedback welcome.
>
> Regards,
> Steve
>   
This was fixed a few weeks ago. There was an error in the FAX decoder, 
but only a very few encoders create images that hit the issue. If you 
try 0.0.4pre11 you will find it fixes several other quirky compatibility 
issues. I have cleaned up several long standing issues, particularly 
with Canon machines, in the last few weeks.

Steve