Up until now, an AVFilter's lists of input and output AVFilterPads
were terminated by a sentinel and the only way to get the length
of these lists was by using avfilter_pad_count(). This has two
drawbacks: first, sizeof(AVFilterPad) is not negligible
(i.e. 64B on 64bit systems); second, getting the size involves
a function call instead of just reading the data.
This commit therefore changes this. The sentinels are removed and new
private fields nb_inputs and nb_outputs are added to AVFilter that
contain the number of elements of the respective AVFilterPad array.
Given that AVFilter.(in|out)puts are the only arrays of zero-terminated
AVFilterPads an API user has access to (AVFilterContext.(in|out)put_pads
are not zero-terminated and they already have a size field) the argument
to avfilter_pad_count() is always one of these lists, so it just has to
find the filter the list belongs to and read said number. This is slower
than before, but a replacement function that just reads the internal numbers
that users are expected to switch to will be added soon; and furthermore,
avfilter_pad_count() is probably never called in hot loops anyway.
This saves about 49KiB from the binary; notice that these sentinels are
not in .bss despite being zeroed: they are in .data.rel.ro due to the
non-sentinels.
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
The current way of doing it involves writing the ctx parameter twice.
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
It will allow to refernce it as a whole without clunky macros.
Most of the changes have been automatically made with sed:
sed -i '
s/-> *in_formats/->incfg.formats/g;
s/-> *out_formats/->outcfg.formats/g;
s/-> *in_channel_layouts/->incfg.channel_layouts/g;
s/-> *out_channel_layouts/->outcfg.channel_layouts/g;
s/-> *in_samplerates/->incfg.samplerates/g;
s/-> *out_samplerates/->outcfg.samplerates/g;
' src/libavfilter/*(.)
The query_formats function of the remap filter tries to allocate
two lists of formats which on success are attached to more permanent objects
(AVFilterLinks) for storage afterwards. If attaching a list to an
AVFilterLink succeeds, it is in turn owned by the AVFilterLink (or more
exactly, the AVFilterLink becomes one of the common owners of the list).
Yet if attaching a list to one of its links succeeds and an error happens
lateron, both lists were manually freed, which means that is wrong if the
list is already owned by one or more links; these links' pointers to
their lists will become dangling and there will be a double-free/use-after-
free when these links are cleaned up automatically.
This commit fixes this by removing the custom free code; this will
temporarily add a leaking codepath (if attaching a list not already
owned by a link to a link fails, the list will leak), but this will
be fixed soon by making sure that an AVFilterFormats without owner will
be automatically freed when attaching it to an AVFilterLink fails.
Notice at most one list leaks because a new list is only allocated
after the old list has been successfully attached to a link.
Reviewed-by: Nicolas George <george@nsup.org>
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
