[FFmpeg-devel] [PATCH 3/8] libavformat/flacdec: Export samples md5 as metadata

[Michael Niedermayer]

Hi
On Wed, Feb 12, 2025 at 11:56:16AM +0100, Tomas Härdin wrote:
> tor 2025-02-06 klockan 16:07 +0100 skrev Michael Niedermayer:
> > Hi Tomas
> > 
> > On Wed, Feb 05, 2025 at 03:20:09PM +0100, Tomas Härdin wrote:
[...]
> > > diff --git a/libavformat/flacdec.c b/libavformat/flacdec.c
> > > index 3c317acaee..9f65c25864 100644
> > > --- a/libavformat/flacdec.c
> > > +++ b/libavformat/flacdec.c
> > > @@ -33,6 +33,7 @@
> > >  #include "replaygain.h"
> > >  
> > >  #define SEEKPOINT_SIZE 18
> > > +#define MD5_BYTE_SIZE 16
> > >  
> > >  typedef struct FLACDecContext {
> > >      FFRawDemuxerContext rawctx;
> > > @@ -109,6 +110,7 @@ static int flac_read_header(AVFormatContext *s)
> > >          if (metadata_type == FLAC_METADATA_TYPE_STREAMINFO) {
> > >              uint32_t samplerate;
> > >              uint64_t samples;
> > > +            char md5hex[MD5_BYTE_SIZE*2+1]; // hex representation
> > > plus null terminator
> > >  
> > >              /* STREAMINFO can only occur once */
> > >              if (found_streaminfo) {
> > > @@ -133,6 +135,10 @@ static int flac_read_header(AVFormatContext
> > > *s)
> > >                  if (samples > 0)
> > >                      st->duration = samples;
> > >              }
> > > +
> > > +            ff_data_to_hex(md5hex, st->codecpar->extradata+18,
> > > MD5_BYTE_SIZE, 1 /* lowercase */);
> > > +            md5hex[sizeof(md5hex)-1] = '\0';
> > > +            av_dict_set(&s->metadata, "samples_md5", md5hex, 0);
> > 
> > I think "samples_md5" should be documented, so that other decoders
> > can use
> > the same
> > i also see a verify_md5() in hevc
> > and crc seems frequently used in decoders
> 
> Documented where? doc/metadata.texi doesn't seem like the place for it.
> doc/demuxers.texi maybe?

honestly, i didnt think about "where", just that it should be documented
somewhere

thx

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Those who are best at talking, realize last or never when they are wrong.
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