Wireshark-dev: Re: [Wireshark-dev] [Wireshark-bugs] [Bug 2432] New: failed tshark PDML export t
From: Stig Bjørlykke <[email protected]>
Date: Sun, 13 Apr 2008 18:50:25 +0200
On 9. april. 2008, at 16.03, [email protected] wrote:

          Summary: failed tshark PDML export to file

[[email protected] ~]# tshark -i wlan0 -T pdml>video_pdml_version1.xml
Capturing on wlan0

** ERROR **: file print.c: line 707 (get_field_data): should not be reached

This was happening because we created a new tvb for unaligned decoded octet strings without adding it as a data source (broke in r22784). I have fixed this in r24992, but we still have some issues here:

I don't really like that we use a new tvb and a new data source for displaying unaligned octet strings, because the user cannot easily see where in the data package the values are from.
Maybe we should implement a "Packet Bits" pane for bit protocols?
Or just an option to turn the Bytes pane to a Bits pane?

Another problem is that the generated pdml (from the bug report) does not generate correct data for these fields, as the "pos" value is always zero (because we use a new tvb with offset 0). But I suppose it's difficult to fix this with byte values...
From the output of the given capturte.  Note the "pos" value:
<field name="mpeg-video.sequence" showname="MPEG sequence header" size="8" pos="493" show="" value=""> <field name="mpeg-pes.horizontal_size" showname="horizontal- size: 0140 [bit length 12]" size="2" pos="0" show="01:40" value="0140"/> <field name="mpeg-pes.vertical_size" showname="vertical-size: 00C8 [bit length 12]" size="2" pos="0" show="00:c8" value="00c8"/> <field name="mpeg-pes.aspect_ratio" showname="aspect-ratio: aspect-1to1 (1)" size="1" pos="496" show="1" value="11"/>

Stig Bjørlykke