[Info-vax] proper format for JPEG files

[Joseph Huber]

Phillip Helbig---undress to reply wrote:

> What is the "proper" format for JPEG files on VMS, in particular if they
> are served by a web server and displayed in a web browser?  I have some
> which are
> 
>    Record format:      Fixed length 512 byte records
>    Record attributes:  None
> 
> and some which are
> 
>    Record format:      Stream_LF, maximum 0 bytes, longest 32767 bytes
>    Record attributes:  Carriage return carriage control
> 
> and both work.  (The former were transferred via FTP from a Windows
> system (sorry, I don't have a VMS machine with a DVD reader) and the
> latter saved from the web via a web browser.)

Both record formats are o.k. since they are 'binary', and the programs 
reading them read it as binary, i.e. do not rely on any record structures 
(like lines terminated by LF or CR).
(VMS utilities of course like TYPE will fail for Stream_LF with 'record too 
large ...'if there are no bytes corresponding to LF).

If the record format would be VAR or indexed, then utilities like XV will 
choke.
A web browser does not know from which files the data are read, it is only 
the web server reading the file.

-- 
 
 Joseph Huber   - http://www.huber-joseph.de