Since the default in the libav fork is to only allow known layouts, making
unknown layouts allowed by default here can be a security risk for filters
directly merged from libav. However, usually it is simple to detect such cases,
use of av_get_channel_layout_nb_channels is a good indicator, so I suggest we
change this regardless.
See http://ffmpeg.org/pipermail/ffmpeg-devel/2016-November/203204.html.
This patch indirectly adds unknown channel layout support for filters where
query_formats is not specified:
abench
afifo
ainterleave
anullsink
apad
aperms
arealtime
aselect
asendcmd
asetnsamples
asetpts
asettb
ashowinfo
azmq
It introduces a query_formats callback for the asyncts filter, which only
supports known channel layouts since it is using libavresample.
And it removes .query_formats callback from filters where it was only there to
support unknown layouts, as this is now the default:
aloop
ametadata
anull
asidedata
asplit
atrim
Acked-by: Nicolas George <george@nsup.org>
Signed-off-by: Marton Balint <cus@passwd.hu>
This uses the av_warn_unused_result attribute liberally to catch some forms of improper
usage of functions defined in avfilter/formats.h.
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
The following commit:
b97d61f avfilter/ff_merge_formats: only merge if doing so does not loose chroma or alpha
introduced an exception to avoid lossy conversions.
Add a comment to explain the logic.
Fix the call to avoid applying it on audio formats.