What could cause Audacity 2.0.3 with lam_enc.dll 3.98.2 not to retain Edit->Preferences->Quality->Sampling Rate setting to Project rate and for the next Audacity session?
On my one Windows 7 Notebook the Audacity 2.0.3 preference Quality Sampling Rate change is reflected immediately in Project Rate and is retained for subsequent sessions. For example if I set Sampling Rate to 22050 in preferences, it is automatically updating Project rate to 22050 and retains this setting for subsequent session. In my thoughts this is a normal and I am happy
But on a Windows 7 Desktop machine the change in Preference Quality Sampling Rate to 22050 does not reflect in Project Rate window and need to be manually set to correspond to Preference Quality change 22050. The exported file retain this Sampling rate for the current session but for the next Audacity session it is not retained and Project rate revert back to default setting of 44100. This is uncomfortable and painful.
Is it a known problem? I have reinstalled Audacity a couple of time to resolve but with no success. What one can do rectify this situation? Thanks.
Note that if you import a file into a fresh project then the project rate changes to reflect the sample rate of that file (but does not change for further imported files).
I understand the Project Rate will correspond to file imported or opened.
I will appreciate your suggestions for a working solution for the following scenario.
We always have input file Sampling rate 41100 Hz at 256 bitrate
And after Audacity editing we always export MP3 with Sampling Rate 22050 Sampling Format 32 bit and Quality 64 kbps
In Edit-> Preferences-> Quality, we have set Sampling Rate 22050 Format 32 and hoped that it will apply all the time without any further manual intervention. But the export MP3 coming as 44.1 KHz unless we do Project Rate Menu - manual selection.
Would the process Edit-> Preference-> Quality OR selection 22050 Hz from the Project Rate menu Drop list necessary each time for desired Sampling rate export MP3 output?
If it is done from Project Export Menu Drop list, how Audacity apply Sampling Format 32/24/16 bits.
How can MP3 Export to a 22050 Hz without the need of reselect be automated?
We process three 41100 Hz at 256 bitrate MP3 to edit and export with Sampling rate 22050 Hz Sampling Format 32 bit, 64 kbps.
Any help suggestions will be much appreciated. Thanks.
Assuming the input file is MP3, 41100 Hz is not a valid MP3 sample rate. I assume you meant 44100 Hz.
Do you need to destroy the sound quality by re-encoding at such a low bit rate?
Do you need to re-encode it at all? If you can keep the bit rate at 256 then you will be able to perform lossless cuts, pastes and volume edits in other direct MP3 editors Missing features - Audacity Support .
As already explained, importing a file for the first time into an empty project changes the project rate to the rate of the file (if different).
Would you like to vote for a preference to be added to maintain the current project rate when importing files?
There is no easy workaround, because the Chains “batch processing” feature (under the “File” Menu) does not currently allow the sample rate to be set as a parameter in the export command. Therefore although the processing is automated, the MP3 will be exported at the same sample rate that it originally had. This is quite a high priority to fix but it is not ready yet.
I would suggest a couple of workarounds. Launch Audacity, Tracks > Add New > Audio Track. That will create an empty 22050 Hz track, then imported files will not change the project rate. Save that empty track as an AUP project file, and launch Audacity by opening that AUP.
Alternatively, import a group of files into the same project. Change the project rate to 22050 Hz (you only need to do that once in this session). Then File > Export Multiple. Each track will export as a separate 22050 Hz MP3.
32/24/16 bit depth does not apply to MP3 files - the MP3 format does not allow it to be changed.
If you have not yet done so, you can change the MP3 export bit rate to 64 kbps by clicking the “Options…” button when you export (if you Export Multiple, it has the same button). That setting will then remain at 64 kbps until you change it.
I appreciate prompt help at such a depth and valuable suggestions - Many thanks.
And yes, I strongly vote for a preference to be added to maintain the current project rate when importing files?
As you said sampling Format 32/24/16 does not apply to MP3 files, I will appreciate your confirming that simplest way possible for us is to select 22050 from Project Rate (Hz) Menu Drop list for each file just prior to doing Export as MP3.
I also wish to know an important fact - if a 44100 Hz, 256 kbps MP3 is Audacity exported as 44100 Hz, 64 kbps, AND then open again in Audacity to export as 22050 Hz , would the quality of second stage MP3 file will be same as if exported as 22050 Hz 64 kbps in the first stage.
Yes, I have selected MP3 Export Quality 64 and because this retains until changed, and this lead me to believe that same will hold good for Preference Quality Sampling Rate.
I definitely will explore the suggested workarounds -
(a) Launch Audacity, Tracks > Add New > Audio Track. That will create an empty 22050 Hz track, and then imported files will not change the project rate. Save that empty track as an AUP project file, and launch Audacity by opening that AUP.
And alternatively,
(b) Import a group of files into the same project. Change the project rate to 22050 Hz (you only need to do that once in this session). Then File > Export Multiple. Each track will export as a separate 22050 Hz MP3. Thanks.
I read your reference http://wiki.audacityteam.org/wiki/Lame_ … tion#lossy . Now I am clear in that the each pass of Audacity edit MP3 will cost loss in quality.
However I will appreciate your confirming that selecting 22050 selection from Project Rate (Hz) Menu Drop list has same effect as doing **Edit>Preferences>Quality>Sampling Rate>**22050 AND that Sampling Format 32/24/16 is inapplicable for MP3 exports. Thanks.
If you don’t use the workarounds, yes. And change “Options…” to 64 kbps one time only if you wish to degrade the MP3 quality further in exchange for smaller file size.
No, as I think you now realise, every single MP3 re-encoding is lossy, even if you increase the bit rate and sample rate. Exporting as MP3 twice will always lose quality as against exporting it once.
It won’t hold good for project rate.
If you or Audacity changes the project rate to 22050 Hz, the effect is the same for the audio.
It’s inapplicable. As I understand it (I am no expert) the exported MP3 is a stream of floating point data in the frequency domain (amplitude against frequency) - as opposed to WAV which is amplitude against time. But the bit depth represented in the MP3 stream is not fixed, but actually varies according to the demands of which parts of the audio are retained and which are discarded. Otherwise, the files would never be small enough.
It’s completely up the MP3 decoder (player) whether it decodes the MP3 stream as 16-bit, 24-bit, 32-bit or whatever. See for example MAD: Winamp Plug-in .
