Hi Everyone,
My first posting to the list. Longtime Ogg fan, have created many
.oggs, but this is the first time needing help.
I've been transferring CDs to Ogg files using crip. I've been in the
process of setting up a bunch of mules to transfer my music collection to
electronic format, but I've found an oddity:
>bash$ oggenc -q 5 oddity.wav
>Opening with wav module: WAV file reader
>Encoding "oddity.wav" to
> "oddity.ogg"
>at quality 5.00
> [ 7.9%] [ 3m52s remaining] \
...>Done encoding file "oddity.ogg"
>
> File length: 2m 03.0s
> Elapsed time: 4m 17.1s
> Rate: 0.4798
> Average bitrate: 149.6 kb/s
<p> You can see what I mean by grabbing oddity.ogg at
http://www.glowingplate.com/oddity.ogg
(about 2.2 megs)
The artifacts are utterly intolerable, and seem to be most obvious
during quiet passages. (That and the pun are the reasons for the choice in
song...)
It's definitely the compression process. The ripped wav is
indistinguishable from the CD, even with a pair of sexy old Acoustic
Research AR-4x speakers.
My configuration? Junker machines ranging from a 486DX-33 to a Pentium
166 (no MMX). Generic hardware, etc.
Common to all of them:
- Red Hat 6.2 - because it's quick and easy to install, and doesn't
balk about the 16 megs of 30 pin RAM on the 486...
- No X.
- Samba server allowing me to conveniently test the files in situ, then
drag and drop 'em to my fileserver.
- crip and associated requirements.
>bash$ cat /proc/version
>Linux version 2.2.14-5.0 (root@porky.devel.redhat.com) (gcc version
>egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)) #1 Tue Mar 7 20:53:41
>EST 2000
In each machine, I've compiled from source available at
http://www.vorbis.com/download_unix.psp .
In order of compilation:
libao 0.8.3
libogg 1.0
libvorbis 1.0
vorbis-tools 1.0.
Compiling according to the INSTALL file, using "./configure &&
make &&
make install" in each case. Made ldconfig changes where required. Waited
until one had compiled happily before proceeding to the next.
I've surfed the 'Net looking for info, but so far have had no luck.
What's going on here? Any ideas?
Thanks,
Lawrence
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>>bash$ cat /proc/version >>Linux version 2.2.14-5.0 (root@porky.devel.redhat.com) (gcc version >>egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)) #1 Tue Mar 7 20:53:41 >>EST 2000Four years old gcc 2.91.66 is known to create broken code for 386. You have to recompile libvorbis with a more recent release of gcc. Oh, and remember to reencode all your music :)) <p>Bye. --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
> > >bash$ cat /proc/version > >Linux version 2.2.14-5.0 (root@porky.devel.redhat.com) (gcc version > >egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)) #1 Tue Mar 7 20:53:41 > >EST 2000You quite likely have problems with either that compiler (old egcs versions were pretty buggy, and particularly bad when doing complex floating point code like libvorbis), or your libc - some versions (and redhat 6.2 is about the right age to have these problems) had broken inline asm for maths functions. I think we used to check for these in configure, but those checks may no longer be around (the problem is long-since fixed, and not commonly encountered on modern machines). Can you build at least libvorbis using a modern-ish system, and then run it on your system (or build the whole lot on another system, if you want), OR provide a small test case in wav form for us to test (a couple of meg is suitable - cutting out part of what you provided in ogg form would be good). <p>Mike --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
At 02:38 AM 6/10/2003 -0400, I wrote:>...a big long rambling question which boiled down to the fact that Red Hat >6.2 ships with a defective compiler. (No wonder those setiathome people >only provide binaries...)Thanks for the help, everyone. I was having problems not only with oggenc producing crappy files, but also with sox crashing when I tried to adjust the volume of a file. Indeed, both problems seem to be related to Red Hat 6.x's defective compiler because both went away when I compiled from source on another system. Initially, I tried to install binaries on the Red Hat machines, but it was getting to be too much of the usual cyclical nightmare of dependencies. ("Can"t install vorbis-tools. Need lssl. Can't install ssl.blah.rpm, need curl. Can't install curl, need ssl.blah.rpm. Can't install libvorbis, need mod.so.impossible_to_find.2." [grumble grumble] Screw curl, it's not like I'm gonna try to stream oggs with a machine that has no sound card...) I've installed Slackware 8.1 on the bunch of old relics, and they're chugging away happily now. No more bad-sounding oggs, no more sox crashing. Everything seem to be working pretty well. As a user rather than a developer, I have a couple of thoughts about my experience, and some of the answers I got to my initial question: - it would probably take no more than a couple of lines in the configure script to have it check for borken compilers and warn the potential user that the output binaries will be useless. Right? - average users (ie. those who really think that their "300W" speakers powered by the 9V 300mA AC adapter are capable of putting out 300W) are potentially not going to notice the flaws in the ogg files created with defective compilers. Playing hard rock into a pair of very nice Celestion Ditton 44 speakers, I didn't really notice the flaw for a couple of minutes; I thought my ears were playing tricks on me and that I was being hypercritical. (Space Oddity and Pink Floyd's Comfortably Numb confirmed my fears that the first few CDs I'd ripped were broken.) - Ogg files are still pretty rare on Kazaa and other file sharing systems. Flawed oggs being generated by bad compilers hurt the credibility of the ogg as a high-fidelity alternative to the MP3. Most end-users aren't gonna know how or why, they're just not gonna bother anymore. (Of course, none of those shared oggs are gonna be copyright material...) - don't assume the user will always be running a new machine. Ask no questions whatsoever, and try to keep the software requirements as low as possible. Low software requirements will keep the hardware requirements down, which increases the portability and enhances the ability of the software to be used anywhere. It's also in keeping with Unix' frugal nature. (Ken Thompson wrote Unix on a scavenged PDP-7.) Support for old compilers and libraries should continue as long as it doesn't cause an impediment to progress. - Red Hat is the most popular distribution of Linux, and 6.x versions remain quite popular still running on workhorses all over the place - I can think of a dozen still in use among workplaces and friends. While it's reprehensible that their compiler was defective, it's a fact of life. - Finding a modern but really compact no-frills text-only takes-no-time-to-install lemme-ping-another-host-and-compile-libvorbis Linux distribution is getting tough. - When one attempts to rip a scratched CD using cdparanoia, one can also oggenc another file on the same host. Even if the host is a mere 486DX-66, oggenc will finish encoding a CD before cdparanoia has finished ripping the next one. This allows two instances of crip to run concurrently on all 6 hosts, processing 12 compact discs at any given moment. The 486DX-33 lacks cache RAM and so is painfully slow at encoding, doing one CD every 14 hours or so. (Usual copyright personal use only disclaimer applies...) - As an extension of the really great crip utility, I toyed with the idea of creating a live CD which would boot, create a swap file and /tmp in empty space on a hard disk's existing filesystem, request an IP address by DHCP, set itself up as a Samba server using the machine's MAC address as a hostname, and allow passwordless incoming telnet sessions for control, then eject the boot CD. The system would then accept a CD, crip it under control from the telnet session, and make the files available to be removed. A quick and dirty distro like this would be convenient to have a collection of machines easily and painlessly encoding and provide Windows users an instantly useful Linux introduction. - Ogg kicks butt. I used to work in the professional audio field and have done sound for The Three Tenors, Harry Belafonte and Garth Brooks, to do a little namedropping. At -q 5, I cannot consistently tell the difference from the ogg and the original wav file. With MP3, I cannot do that until I've encoded with the Fraunhofer encoder above 192kbps, which results in a considerably larger mp3 than the ogg. - Rudimentary consistency and sanity checking as suggested by one of the replies would be a great idea if it can be implemented reasonably efficiently. Of course, given the fact that this is necessarily a lossy codec, this would be imperfect but might serve as the canary in the coal mine before a user floods a filesharing system with bad oggs of his high school choir. Can it be done effectively enough to catch fidelity problems more subtle than mine? It's hard to predict the next bad compiler or whether the Pentium V will have the same math error as the Pentium 60. Thoughts? Flames? "You've completely missed the point!" rants? Thank you all for Ogg Vorbis and the help, Lawrence Wade <p>--- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
Warning - OT reply but worth the read.... Lawrence Wade [mailto:vorbis@glowingplate.com] wrote on Sunday, 20030615,22:27EDT>At 11:29 AM 6/16/2003 +1000, you wrote: >>The problem is more complex than that - figuring out exactly which >>compilers/versions are broken, and on what platforms, and with whatoptions,>>is quite difficult. Actually, doing anything at all with autoconf is >>difficult, but this is more difficult than most :-) > > Oh. Okay, then I can understand. > > My programming style is so much brute force and ignorance that >Microsoft tried to hire me to write security patches for Outlook Express. I>haven't cut my own source since I finished a horrible C++ course in >university. Forgive me for not knowing what is and isn't realistically >possible. > >>If you want to contribute checks for "known-bad" sets of >>compiler/platform/options/etc., we'd happily add them - but it's a lot of >>work for pretty minimal (these days - _most_ people who compile their own >>software have more recent development tools) gain. > > I generally compile my own stuff because, even on a newer system where >all binaries are readily available, I find it to be faster and easier than >fighting through dependencies - for some reason, compiling from source just>*works* 90+% of the time. > > Into the READMEs: > >******************************** >SOUND QUALITY WARNING: > >This codec does some pretty big math involving Fourier transforms and other>scary things. Some combinations of compilers, assemblers, linkers, >libraries and processors don't play nicely together, causing subtle >calculation errors which might or might not always be apparent during >playback. Typical symptoms include reverb-ish artifacts most apparent >during playback of quiet musical passages.I know that this i COMPLETELY off topic but I just -gotta- know. houldn't you suggest reverb-ish artifacts that sounds like "wet chewing"?? http://slashdot.org/comments.pl?sid=42736&threshold=1&commentsort=0&tid=159& mode=thread&cid=4486745 <p>>Combinations which are known to cause problems include:> > > - gcc/egcs-2.91.66 on Intel/AMD (RedHat 6.x users take note!) > - [add more] >Leko stage lighting, fogmachines and too much free time...>Potential solutions in order of preference: upgrade the operating system, >upgrade the compiler and libraries, or install precompiled binaries >(including .rpm files). > >Since these compiler combinations have caused bizarre mathematical, >performance and reliability problems with many other software packages, it >is *highly* recommended that you find a means to use another compiler. >*********************************** > > That way, people have at least been warned... > > Lawrence Wade, BOFH > www.glowingplate.com<p>You really should have that url from my favourites linked somewhere on your homepage :) -Myles Buckley --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.