Quoting Andreas Rheinhardt (2020-10-27 11:30:32)
> Andreas Rheinhardt:
> > If a static VLC table gets initialized a second time (or concurrently by
> > two threads) and if said VLC table uses symbols that have the sign bit
> > of VLC_TYPE (a typedef for int16_t) set, initializing the VLC fails. The
> > reason is that the type of the symbol in the temporary array is an
> > uint16_t and so comparing it to the symbol read from the VLC table will
> > fail, because only the lower 16bits coincide. Said failure triggers an
> > assert.
> >
> > Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@gmail.com>
> > ---
> > Found when playing around a bit with making the ClearVideo VLCs static.
> >
> > libavcodec/bitstream.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/libavcodec/bitstream.c b/libavcodec/bitstream.c
> > index 39749c6092..a908c10980 100644
> > --- a/libavcodec/bitstream.c
> > +++ b/libavcodec/bitstream.c
> > @@ -129,7 +129,7 @@ static int alloc_table(VLC *vlc, int size, int
> > use_static)
> >
> > typedef struct VLCcode {
> > uint8_t bits;
> > - uint16_t symbol;
> > + VLC_TYPE symbol;
> > /** codeword, with the first bit-to-be-read in the msb
> > * (even if intended for a little-endian bitstream reader) */
> > uint32_t code;
> >
> LGTM'ed by Lynne via email and pushed.
This is the second time I see this, why does that not go through the ML?
--
Anton Khirnov
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