So, can someone tell me what is a difference between: -b 320 -q 0 and -V 0 -b 320 --lowpass 20.5
dv1989, I understand all you talking about. But I whant find out the causes of this "phenomenon" (bits wasting)
halb27, see my previous posts. I was talking about restriction of minimal bitrate in VBR V0 mode. I'm using 3.98.3 of course...
as it turned out, in fact LAME didn't use 320 kbps for every frame and I've got 274 kbps (avg) bitrate after using mp3 repacker on VBR fileRepacked CBR file has 317 kbps average bitrate.I wonder why this happens - encoder don't use all bits for encoding
That's the space reserved to padding of ID3V2...
On the file posted by Steve, I would be interested to at how V0-encoded files compare to the 320 (with varying q levels). Steve, can you easily ABX this? Or /mnt?
foo_abx 1.3.4 reportfoobar2000 v1.0.12010/03/22 13:43:05File A: D:\Samples\Show_Me_Your_Spine__Sample_b320q0.mp3File B: D:\Samples\Show_Me_Your_Spine__Sample_V0.mp313:43:05 : Test started.13:43:27 : 01/01 50.0%13:43:31 : 02/02 25.0%13:43:35 : 03/03 12.5%13:43:39 : 04/04 6.3%13:43:44 : 05/05 3.1%13:43:55 : 06/06 1.6%13:44:02 : 07/07 0.8%13:44:07 : 08/08 0.4%13:44:12 : 09/09 0.2%13:44:18 : 10/10 0.1%13:44:23 : 11/11 0.0%13:44:28 : 12/12 0.0%13:44:32 : 13/13 0.0%13:44:35 : 14/14 0.0%13:44:40 : 15/15 0.0%13:44:45 : 16/16 0.0%13:44:46 : Test finished. ---------- Total: 16/16 (0.0%)
Quote from: Steve Forte Rio on 21 March, 2010, 07:07:31 AMhalb27, see my previous posts. I was talking about restriction of minimal bitrate in VBR V0 mode. I'm using 3.98.3 of course...Sorry, I didn't read carefully enough.As for your real question -b 320 together with -Vx isn't meaningful (except for the case you do need a constant bitrate but want to use VBR).What seems to be a problem in understanding is that frame bitrate is mixed up conceptually with audio data bit rate - quite a common misunderstanding unfortunately.-Vx -b 320 just means having Lame use frame bitrates of 320 kbps. It doesn't tell about the audio data contents within the 320 kbps frames.I remember having tried this a couple of years ago, and after mp3repacking -V0 and -V0 -b xxx yielded more or less the same bitrate (maybe it was even exactly the same).So both -Vx and -Vx -b320 provide (more or less or even exactly) the same audio data stream provided by the VBR mechanism, but with -b 320 added it's put into 320 kbps frames, leaving a lot of space unused.
And the stereo switch will definitely cause worse results than when it's off?
In light of this thread (Changing minimum bitrate for VBR), could you test "-V 0 -b 320" anyway? I'm curious if the increased bit-reservoir improves the artifacts in comparison to cbr and default vbr.
foo_abx 1.3.4 reportfoobar2000 v1.0.12010/03/22 17:04:31File A: D:\Samples\tyDi-Meet Me in Kyoto_sample_v0-b320.mp3File B: D:\Samples\tyDi-Meet Me in Kyoto_sample_v0.mp317:04:31 : Test started.17:05:06 : 01/01 50.0%17:05:13 : 02/02 25.0%17:05:21 : 03/03 12.5%17:05:29 : 04/04 6.3%17:05:37 : 05/05 3.1%17:05:45 : 06/06 1.6%17:05:53 : 06/07 6.3%17:06:05 : 07/08 3.5%17:06:12 : 08/09 2.0%17:06:20 : 09/10 1.1%17:06:30 : 10/11 0.6%17:06:37 : 10/12 1.9%17:07:12 : 11/13 1.1%17:07:25 : 12/14 0.6%17:07:33 : 13/15 0.4%17:07:40 : 14/16 0.2%17:07:42 : Test finished. ---------- Total: 14/16 (0.2%)
but you still like cbr320 better for this sample?
Command-line flag -F enforces the minimum allowed bitrate set by the -b flag.So try:-V 0 -b 320 -F --lowpass 20.5
It's not new, but worth considering:When using -V0 -b 320, the fast and lossless mp3packer procedure applied afterwards can save a significant amount of disk space.The '-b 320' added to -V0 makes better use of bit reservoir (we had that in another thread), but has the machinery unchanged in all other respects.As a result there's a lot of plain air in the output file which is removed by mp3packer.When struggling for high bitrate of real audio data (not just frame data) of -V0 it is necessary to make -V0 more defensive. -b 320 isn't doing this; it doesn't make -V0 want higher audio data bitrates, -b 320 just has less restrictions to achieve those bitrates -V0 wants).My way of making -V0 more defensive is to add the options '--ns-bass -8 --ns-alto -8 --ns-treble -5 --ns-sfb21 5' apart from '-b 320'. This results in an usually unnecessary increase of signal to noise ratio but improves upon problem samples.Current 3.99 alpha is about to improve on problem samples, but with a release version above options are the only way I can see to make -V0 more defensive.
-F ? strictly enforce the -b option This is mainly for use with hardware players that do not support low bitrate mp3. Without this option, the minimum bitrate will be ignored for passages of analog silence, ie when the music level is below the absolute threshold of human hearing (ATH).