[I'm not online regularly, so don't include me in any replies.]
[ taken from the web-ified list archive, so References: header
is missing the last Message-ID, sorry ]
Figuring the flac@ list is more appropriate, I move this from
the original location at vorbis@ to continue...
> > I used a recent ogg123 to play back a FLAC file I had created,
> > and saw it wasn't able to seek within the file. So, I thought
> > That ogg123 wasn't able to recognize the file as something it
> > if (len >= 32 && memcmp(buf, "OggS", 4) == 0
> > && memcmp(buf+28, "fLaC", 4) == 0)
> > return 1; /* Ogg FLAC */
> also in FLAC 1.1.1 is the first official (i.e. correct)
> FLAC->Ogg mapping. for more info about the history of it
Thanks for the pointer. Having grabbed all the latest source a
couple days ago and built everything new, I shall now pretend to
have a better idea of what needs to be patched.
The vorbis-tools/ogg123/flac_format.c seems to be unchanged, and
can recognize neither the OggFlac 1.1.1 files newly created, nor
those from my pre-1.1.1 source which pointed out the problem.
(Is there a more appropriate list for ogg-utilities, say, ogg-dev@,
to handle kitchen-sink applications like ogg123?)
I've now patched flac_format.c in my copy of the ogg123 distribution
based on the 1.1.1 description you pointed me to, and as an after-
thought, added my hacks to recognize the unofficial mapping that I
used to see, as well as the original code. (Was the original code
to find `fLaC' at position 28 ever correct?)
Here's my hack, in case someone who knows more about the history
of the FLAC->Ogg mapping wants to rewrite it to be correct and
apply it to vorbis-tools/ogg123/flac_format.c ...
--- flac_format.c-DIST Sun Aug 22 20:33:25 2004
+++ flac_format.c Fri Dec 17 10:41:57 2004
@@ -96,13 +96,35 @@
int oggflac_can_decode (data_source_t *source)
{
+#if 0 /* Wooo, this ain't right, at least not now... */
char buf[32];
+#else /* XXXX the below is based on observation of a real file 1.1.1 flac */
+ char buf[41];
+#endif
int len;
+#if 0 /* Wooo, this ain't right, at least not now... */
len = source->transport->peek(source, buf, sizeof(char), 32);
if (len >= 32 && memcmp(buf, "OggS", 4) == 0
&& memcmp(buf+28, "fLaC", 4) == 0)
+#else /* XXXX the below is based on observation of a real file 1.1.1 flac */
+ len = source->transport->peek(source, buf, sizeof(char), 41);
+
+/* single check if (len >= 32 && memcmp(buf, "OggS", 4) == 0
+ && memcmp(buf+29, "FLAC", 4) == 0
+ && memcmp(buf+37, "fLaC", 4) == 0) XXX */
+ if ( (len >= 32 && memcmp(buf, "OggS", 4) == 0
+ && memcmp(buf+29, "FLAC", 4) == 0
+ && memcmp(buf+37, "fLaC", 4) == 0)
+/* XXX HACK compatibility below with the original code, plus flac < 1.1.1 */
+/* my previous hack below */
+ || (len >= 32 && memcmp(buf, "OggS", 4) == 0
+ && memcmp(buf+28, "FLAC", 4) == 0)
+/* XXX HACK original below; did this ever work? */
+ || (len >= 32 && memcmp(buf, "OggS", 4) == 0
+ && memcmp(buf+28, "fLaC", 4) == 0) )
+#endif
return 1; /* Ogg FLAC */
else
return 0;
It still seems that seeking within the OggFLAC file within ogg123
does not work, and reading the source, probably doesn't work for
speex files either.
> > Out of curiosity, how easy should it be to implement
> > seeking within an OggFLAC file, as opposed to a plain
> > ordinary FLAC file?
> seeking was not supporting in libOggFLAC until FLAC 1.1.1
The deficiency is again in ogg123, flac_format.c , and probably
needs to be hacked based on, say, the ovf_seek function, somewhat
like I started, before I decided it needed more work than just
modifying ovf_seek as a template.
@@ -258,7 +280,27 @@
int flac_seek (decoder_t *decoder, double offset, int whence)
{
+#if 0 /* XXX Ugly HACK to see if we can get this working */
return 0; /* No seeking at this time */
+#else /* XXX */
+ flac_private_t *priv = decoder->private;
+ int ret;
+ double cur;
+#if 0 /* HACK stolen from ogg vorbis seek, but not ported to flac yet */
+ if (whence == DECODER_SEEK_CUR) {
+ cur = ov_time_tell(&priv->vf);
+ if (cur >= 0.0)
+ offset += cur;
+ else
+ return 0;
+ }
+ ret = ov_time_seek(&priv->vf, offset);
+ if (ret == 0)
+ return 1;
+ else
+#endif /* HACK stolen */
+ return 0;
+#endif
}
Hey, I just woke up. You expect me to come up with working code from
nothing? Anyway, I may poke at it later, if my brain ever gets started.
Or anyone else is welcome to come up with something.
thanks
barry bouwsma
_______________________________________________
Flac mailing list
[email protected]
http://lists.xiph.org/mailman/listinfo/flac
