So this being so it would seem that 160kb/s MPEG2 is the best bit rate and format for layer 3 as MPEG2 is superior to MPEG1??
George On 11/22/06, Ruckert Martin <[EMAIL PROTECTED]> wrote: > > Thinks to keep apart: Version and Layer > > MPEG Version 1 specifies 3 Layers 1,2, and 3 > within Version 1 we have a restricted selection of three > sample rates: 32kHz, 44.1kHz or 48kHz > and bitrates: > 32kBit/s to 448kBit/s for layer 1 > 32kBit/s to 384kBit/s for layer 2 and > 32kBit/s to 320kBit/s for layer 3 > > MPEG Version 2 introduces new > sample rates: 16kHz, 22.05kHz or 24kHz > with different bitrates: > 32kBit/s to 256kBit/s for layer 1 > 8kBit/s to 160kBit/s for layer 2 and 3 > > There is an extension without a ISO Standard called MPEG version 2.5 > again with different > sample rates: 8kHz, 11.025kHz or 12kHz > with different bitrates: > 8kBit/s to 64kBit/s for layer 3 > > So you see: you have to switch the version, if the sample rate is > changing. > You have to switch the layer if the bitrate is changing. > Now to the question: > From the above, you see, that while encoding a version 2 stream with one > of the > version 2 sample rates in layer 2, you can use only bitrates between 8kBit > and 160kBit. > If the bitrate has to increase beyond 160kBit, you can not switch to MPEG > version 1, > (because the sample rate has not changed), but you must switch to layer 1, > because > in layer 1 you can use bitrates up to 256kBit/s. > On the other hand you must switch back, if the bitrate is below 32kBit. > > Now which is better: typically layer 3 gives you a more compact encoding > therefore smaller bitrates are sufficient. So go with layer 3. The > version depends on the sample rate. Higher sample rates are typicaly > better > but not as compact to encode then lower sample rates. lame will > automatically > downsample in needed. leave it to lame to decide. > > > Yours > Martin Ruckert > > PS: these and other such details, you find in "Understanding MP3", > Springer Verlag. > > george steeves wrote: > > mp3encoder@minnie.tuhs.org > > > > > > > > > > > > I have a question for which I can find no definitive answer. MPEG > layer3 > > files are in two flavors MPEG1 and MPEG2. I know this is true as the > > Lame_enc.dll switches from MPEG2 to MPEG1 when the bit rate is increased > > beyond 160kb/s. I have read the source code and I know this is so. Is > this > > only true of the Lame encoder or only true of the lame_enc.dll. What is > the > > difference? Which is better? Why? > > > > > > > -- > ------------------------------------- > Prof.Dr.Martin Ruckert > Munich University of Applied Sciences > FB07 Mathematics and Computer Science > Lothstrasse 34 > D-80335 Munich > GERMANY > _______________________________________________ > mp3encoder mailing list > mp3encoder@minnie.tuhs.org > https://minnie.tuhs.org/mailman/listinfo/mp3encoder > -- George Steeves Box 111 Gilboa, NY 12076 Web Site: georgesteeves.com 607-588-6324 _______________________________________________ mp3encoder mailing list mp3encoder@minnie.tuhs.org https://minnie.tuhs.org/mailman/listinfo/mp3encoder
