[FFmpeg-devel] [RFC] Filters loglevel

Stefano Sabatini stefasab at gmail.com
Fri Jul 13 13:00:35 CEST 2012

On date Friday 2012-07-13 10:23:33 +0000, Carl Eugen Hoyos encoded:
> Stefano Sabatini <stefasab <at> gmail.com> writes:
> > Anton recently decreased the informational loglevel of many filters
> > from INFO to VERBOSE, with the purpose of decreasing the clutter we
> > currently have in the log
> I did not look at all at the patch, but in the past, some similar 
> changes have been very bad (removing the absolutely necessary 
> information for debugging).
> > (it has been observed that verbose output
> > has the tendency to make users hopeless about even trying to decode
> > all the noise, and thus ignoring the really important messages).
> I believe that is why errors nowadays show in red etc.
> I honestly don't think that argument is valid anymore.
> In the specific case, you have to decide if you need the information 
> to understand a user report or not. Generally, I believe that one 
> line that is only shown once for the whole transcoding on 
> initialization is ok (and actually wanted), repeated messages like 
> in some ticket I cannot find atm is not ok.

Trying to rationalize the meaning of INFO... it means something which
should be part of the "normal" output, and that is supposed to be read
by the user (as opposed to the developer). So yes all in all the
output of the kind:
[Parsed_boxblur_0 @ 0x30ef7b0] luma_radius:1 luma_power:1 chroma_radius:1 chroma_power:1 alpha_radius:1 alpha_power:1 w:320 chroma_w:160 h:240 chroma_h:120

really belongs to "verbose" or "debug".

Also note that we request the user to use -loglevel 99 when sending
reports, and I don't think that cluttering the output *in each case*
for helping reports from users which discard that directive is a good
idea (since it will do harm to *all* users indiscriminately).

Regarding the log colors, I assume that they are not always available
and I like to comply to the "unconditional usability/accessibility
principle", which states that the behavior of the program should be as
usable/accessible as possible without relying on facilities which may
not be available (also think about a daltonic user).
FFmpeg = Friendly and Fucking Mastodontic Porno Empowered Gangster

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