[FFmpeg-devel] [RFC] Specifying KEYINT (-g) has no effect in libx264

Stefano Sabatini stefano.sabatini-lala at poste.it
Sun May 22 22:40:07 CEST 2011


see issue #157.

The problem was possibly introduced in:

commit 0140d3f0921e5cbb6ea8706acb0307f7ff57a133
Author: Baptiste Coudurier <baptiste.coudurier at gmail.com>
Date:   Sat Apr 16 16:50:50 2011 -0700

    In libx264 wrapper, add -preset and -tune options

and depends on the fact that x264_param_default_preset() which is
called in x264_init(), calls x264_param_default() which defaults the
already set options.

Indeed order of options matters, with the current mechanism options
are set in the relevant contexts, and globally processed in the object
initialization, so the order specified on the commandline is basically

In the case of libx264 we may process profile/preset *before* the
other options set in the context, so that specific settings will
override profile/preset information.

This has the problem that most of the times user-set options are
changed to medium profile or libx264 will complain&exit, see:

thus making fine-tuned user options pointless (since they are changed
to medium preset and/or will be rejected by libx264).
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