Conflict between encoding charsets when generating irc stats from ZNC logs with PISG

Question

I'm using PISG to generate stats for an IRC channel.
Log files are from ZNC log module.
Logs are in this folder: ~/.znc/moddata/log/
The problem is that when i'm generating stats with PISG, my stats.html shows some stranges characters (�) in place of letters with accents (éèàç,..)

Additionnals infos :

• I use ZNC 1.4 and I cant update
• ZNC is using UTF-8 internaly
• I use PISG v0.73 which is the latest version
• Generated statistics are in french ( I need support of 'éèçàù' etc. )

PISG do have an option to specify LogCharset and Charset (Charset is used for generated page), but I'm unable to have it to display those letters in a correct way. I'm not sure about which charset to specify there.

Also, ZNC supports characters encoding in core since 1.6
but as i'm using 1.4 I need to use ZNC Charset/old module it is unclear to me of which charset i need to set-up.

If I do file -bi on any of my logfiles, it returns "application/stream charset:binary".

Here's a short version of my PISG config file:

<channel="#chanel">
    LogDir="/home/math/.znc/moddata/log"
    LogPrefix = "math_network_#chanel"
    Format = "energymech"
    Maintainer = "math"
    OutputFile = "/home/math/public_html/irc_stats/stats.html"
    Network = "Network"
    Lang = "FR"
</channel>

    <set channel="#chanel">
#   <set LogCharset="UTF-8">
#   <set Charset="UTF-8">

I'm about 90% certain that my problem could be solved with ZNC's charset/old module only.

Any idea would be welcome.