[Ffmpeg-devel] [PATCH] Use ff_eval for AVOption parsing
Sun Sep 24 14:41:51 CEST 2006
On Sun, Sep 24, 2006 at 01:50:54PM +0200, Panagiotis Issaris wrote:
> On za, 2006-09-23 at 12:33 +0200, Panagiotis Issaris wrote:
> > The attached patch changes the AVOption parsing code to use ff_eval
> > instead of av_strtod. As ff_eval uses av_strtod, the postfix ('k',
> > 'M', ...) functionality is not lost.
> > It does this, by moving av_strtod to eval.c as this is the only place
> > where it is used now. Furthermore, one parser log message has been
> > decreased in severness as it kept complaining about missing '(' in
> > "bitexact", "fastint", etc. which are all parsed by eval now, and aren't
> > errors. Parsing failures were/are indicated by NAN (the infrastructure
> > was partly there, but they returned 0 not NAN). For the moment I've
> > only added the QP2LAMBDA option to the eval's constants, so that
> > ffmpeg -i src.avi -lmax 10*QP2LAMBDA dst.avi
> > would work. After I sent a patch to migrate lmax from OptionDef to
> > AVOptions that is.
> > One more thing is that I had to add four "if isnan returns" in the code,
> > because parsing would fail (segfault in fact) if parsing continued when
> > using "max", "default" or "min" as options:
> > ffmpeg -i src.avi -b max dst.avi
> > To be able to add these escapes, I introduced a temporary variable in
> > two out of four cases.
> > [...]
> Okay, after tracing ff_eval for too many hours, the bug in eval.c is
> fixed now, so no "if ... returns" are necessary anymore.
> So, this is an updated version of the older patch, with these checks
> removed. Regression tests succeed.
> These all work now:
> ffmpeg -i src.avi -b 100k dst.avi
> ffmpeg -i src.avi -b 8*9k dst.avi
> ffmpeg -i src.avi -b default dst.avi
> ffmpeg -i src.avi -b QP2LAMDBA*10k dst.avi
> The last one is not useful for -b, but will be for the next patches in
> my queue (the ones for migrating lmax and others).
> And this fails cleanly (no segfaulting or anything):
> ffmpeg -i src.avi -b takis dst.avi
> eval.c | 62 +++++++++++++++++++++++++++++++++++++++++++--
> opt.c | 89 +++++++++++++----------------------------------------------------
> 2 files changed, 78 insertions(+), 73 deletions(-)
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