[FFmpeg-devel] [PATCH 8/8] avcodec/codec_internal: Include codec_tags only when they are needed

[Michael Niedermayer]

On Fri, Mar 18, 2022 at 02:13:16PM +0100, Michael Niedermayer wrote:
> On Fri, Mar 18, 2022 at 11:52:54AM +0100, Andreas Rheinhardt wrote:
> > They are only needed for the fuzzer, so check for CONFIG_OSSFUZZ.
> > This decreases sizeof(FFCodec), which is important given that
> > FFCodecs reside in .data.rel.ro in case of ELF with
> > position-independent code which is always loaded and can't be shared
> > between processes.
> > 
> 
> They are currently only used by the fuzzer, if there is no other
> use, iam not sure. But i agree shareable memory would be better for them
> 
> 
> [...]
> > diff --git a/tools/target_dec_fuzzer.c b/tools/target_dec_fuzzer.c
> > index 288aa63313..77f4bb8dd8 100644
> > --- a/tools/target_dec_fuzzer.c
> > +++ b/tools/target_dec_fuzzer.c
> > @@ -279,12 +279,14 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
> >          ctx->sample_rate                        = bytestream2_get_le32(&gbc) & 0x7FFFFFFF;
> >          ctx->ch_layout.nb_channels              = (unsigned)bytestream2_get_le32(&gbc) % FF_SANE_NB_CHANNELS;
> >          ctx->block_align                        = bytestream2_get_le32(&gbc) & 0x7FFFFFFF;
> > +#if CONFIG_OSSFUZZ
> >          ctx->codec_tag                          = bytestream2_get_le32(&gbc);
> >          if (c->codec_tags) {
> >              int n;
> >              for (n = 0; c->codec_tags[n] != FF_CODEC_TAGS_END; n++);
> >              ctx->codec_tag = c->codec_tags[ctx->codec_tag % n];
> >          }
> > +#endif
> >          keyframes                               = bytestream2_get_le64(&gbc);
> >          request_channel_layout                  = bytestream2_get_le64(&gbc);
> >  
> 
> how does the fuzzer work without the fuzzer ?

or is the idea to build test this even without oss-fuzz somehow?

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The greatest way to live with honor in this world is to be what we pretend
to be. -- Socrates
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