-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 No one has any idea on my question of recompressing ogg files? - -- Robert Cole -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.7 (GNU/Linux) iD8DBQE9P5QvOWbzte5wVEURAtnoAJ9d2c7ip94Qqte5AQWP2XaYZ/EQ+ACcDs9a sji3Mrw+X3ofLJ5lmyZN6oQ=3lh9 -----END PGP SIGNATURE----- <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.
Robert wrote:> No one has any idea on my question of recompressing ogg files?Monty claims to be on holiday, and AFAIK the bitrate stripping tools are a future project. As to whether decoding and re-encoding will introduce artifacts, I don't know. From Q9->Q7 is not an area I can perceive artifacts at, and I suspect most of the rest of the list feels similarly, if past discussions are any guide. My suggestion is to try it, and if it works for you do it. My feeling is that you will get extra artifacts compared to redoing the original material, it's just a question of how much extra work it is. In other words, I don't know ;-) Moz <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.
Transcoding ALWAYS results in a loss of quality, since the codec will try to encode any artifacts from the previous encode, being unable to distinguish it from "real" sound data. Peeling peels away data and should not result in a quality loss, but this is not yet finished. You can listen to it and see if it sounds satisfactory (q 9 is quite high), but it will be lower quality than from wav -> q7. If you have the audio source, it is probably not much harder to encode from that to ogg, in fact I think it might be easier.... Mark On Thu, 25 Jul 2002 16:01, Robert Cole wrote:> -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > No one has any idea on my question of recompressing ogg files? > - -- > Robert Cole > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.0.7 (GNU/Linux) > > iD8DBQE9P5QvOWbzte5wVEURAtnoAJ9d2c7ip94Qqte5AQWP2XaYZ/EQ+ACcDs9a > sji3Mrw+X3ofLJ5lmyZN6oQ> =3lh9 > -----END PGP SIGNATURE----- > > > --- >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.<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.
On Thu, 25 Jul 2002 18:01, Robert Cole wrote:> No one has any idea on my question of recompressing ogg files?If you can tell the difference between -q 7 and anything less, then you may introduce artifacts you can hear by re-encoding down to -q 7 from -q 9. If you can't, you might get away with it - try it, and trust your ears. Better to either re-encode form the original source, or wait out for the coming of the legendary bit peeling tool, though. Personally, I like to try ABX tests on a collection of samples, such as the various tricky ones used for codec testing, and music I'm very familar with. I try out various quality levels looking for a sweet spot, where I can no longer distinguish the encoded form from the original, then add about 0.5-1 to account for future improvements in sound gear, ear training, and those tricky to encode peices that I don't know about yet. Of course, if you're not fussy about storage size, pick something high, but bear in mind that the silly bitrates will almost certainly receive some extra tuning attention in the next 6 to 12 months. John <p><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.