From 8be701d9f7f77ff2282cc7fe6e0791ca5419de70 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Thu, 12 Aug 2021 13:05:31 +0200 Subject: avfilter/avfilter: Add numbers of (in|out)pads directly to AVFilter 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 Signed-off-by: Andreas Rheinhardt --- libavfilter/vf_field.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'libavfilter/vf_field.c') diff --git a/libavfilter/vf_field.c b/libavfilter/vf_field.c index 555e615d2e..8d06ffe663 100644 --- a/libavfilter/vf_field.c +++ b/libavfilter/vf_field.c @@ -89,7 +89,6 @@ static const AVFilterPad field_inputs[] = { .type = AVMEDIA_TYPE_VIDEO, .filter_frame = filter_frame, }, - { NULL } }; static const AVFilterPad field_outputs[] = { @@ -98,14 +97,13 @@ static const AVFilterPad field_outputs[] = { .type = AVMEDIA_TYPE_VIDEO, .config_props = config_props_output, }, - { NULL } }; const AVFilter ff_vf_field = { .name = "field", .description = NULL_IF_CONFIG_SMALL("Extract a field from the input video."), .priv_size = sizeof(FieldContext), - .inputs = field_inputs, - .outputs = field_outputs, + FILTER_INPUTS(field_inputs), + FILTER_OUTPUTS(field_outputs), .priv_class = &field_class, }; -- cgit v1.2.3