[FFmpeg-devel] Memory leak using bitstream filters with shared libs

[Reimar Döffinger]

On Sun, Mar 09, 2008 at 11:00:54PM +0100, Michael Niedermayer wrote:
> On Sun, Mar 09, 2008 at 07:50:16PM +0100, Reimar D?ffinger wrote:
> > On Sun, Mar 09, 2008 at 12:05:33AM +0000, M?ns Rullg?rd wrote:
> > > Baptiste discovered a rather nasty memory leak when using a bitstream
> > > filter with shared libraries.
> > > 
> > > In ffmpeg.c:write_frame() the output of bitstream filters is stored in
> > > an AVPacket, and its destruct function is set like this (line 417):
> > > 
> > >             new_pkt.destruct= av_destruct_packet;
> > > 
> > > Later on, in av_interleave_packet_per_dts(), AVPacket.destruct is
> > > compared against av_destruct_packet, like this (utils.c:2439):
> > > 
> > >         if(pkt->destruct == av_destruct_packet)
> > 
> > This seems like a misuse of pkt->destruct to me anyway, and for a simple
> > optimization in addition.
> > I am still not entirely certain I understood what this does, but I think
> > that a pkt->flag PKT_FREE_ON_DESTRUCT or some such would do.
> 
> ugh ....
> No it would not do. It completely defeats the sense behind destruct() that
> is to allow a destruct different from what av_free() does.

Huh? Of course the destruct pointer should stay, this flag would just
indicate if the destruct function does some kind of free in the data or
not, so that we know which way we need to use to copy etc. the AVPacket.

Greetings,
Reimar D?ffinger