Acoustica Premium 7.1.8 - loudness measurement and file statistics

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Paulo-Brazil
KVRist
113 posts since 1 Oct, 2017

Post Wed Dec 26, 2018 3:20 am

Mr. Stian,

I refer to Acoustica Premium 7.1.8, running on Windows 10 Professional 64-bit.

This is a long post, with some interrelated questions and suggestions about loudness measurement and file statistics, for your consideration.

--- 1. I would like to suggest that the Maximum True Peak Level be included in the Loudness Meter, and consequently that a reference to the Maximum True Peak Level be included in the Help page about that Meter.

The EBU R-128 recommendations establish a limit for the Maximum True Peak Level of a programme, this is one of the key audio measurements that should be controlled under those recommendations. So it seems to me that this level should be easily and readily monitored, which doesn't happen today in Acoustica.

In the Help files, in the section about the Loudness Meter, it is stated: "There are four different loudness measures defined by the EBU R128". In fact, there aren't four, but five measurements defined by the EBU R128: the four ones mentioned in the Help page plus the Maximum True Peak Level.

The Level Meter can measure the True Peak Level, but it does not record its maximum value across the file. In the Analysis > Show Statistics window, for each channel of an audio file there is a "Maximum True Peak Level" and "Minimum True Peak Level", so there are four True Peak Level measurements in all for a stereo file, and more for a multichannel file. What is the relation between these True Peak parameters and the EBU R-128 Maximum True Peak Level, which is a single measurement? Possibly, this is the maximum of all the True Peak measurements, but I cannot be sure. At this moment, how could one obtain the EBU R-128 Maximum True Peak Level from the True Peak measurements in the different channels? Some clarification about that could maybe be included in the Help files.

Several loudness meters include the Maximum True Peak Level in their main windows, for example the iZotope's RX6 loudness/normalization module in EBU R-128 mode (a picture is attached), and the free plugin TBProAudio dpMeter 3 in EBU mode (a picture is also attached) - there are many other meters by different software developers.

--- 2. In the Loudness Meter, when the audio playing stops, the Momentary Loudness and the Short-Term Loudness should possibly be turned off, possibly go to minus infinity (as it happens with the Level Meter). Only the integrated, whole-file parameters should possibly be displayed when the audio is stopped, namely the five EBU R-128 measurements: the Integrated Loudness, Loudness Range, Maximum Short-Term Loudness, Maximum Momentary Loudness and (if it is included in the Loudness Meter) the Maximum True Peak Level. It seems to me that the running Momentary Loudness and the running Short-Term Loudness are "local" measurements, not integrated, whole-file ones, they do not pertain to the whole file so they make no sense when the audio playing has stopped. Please take a look at the attached picture of the TBProAudio dpMeter 3, where these two measurements went to minus infinity when the audio playing stopped.

--- 3. In the Analysis > Show Statistics window, I would like to suggest that, at the bottom of the window, the full set of five EBU R-128 audio parameters be displayed: Loudness and Loudness Range (these two do exist now), and Maximum Short-Term Loudness, Maximum Momentary Loudness and Maximum True Peak Level (these three would be added). The display of the five EBU R-128 parameters could be important for archiving and documentation purposes, under the idea that, in some future version, Acoustica will allow one to save the Statistics Window.

Incidentally, for archiving and documentation purposes, possibly some basic file information should be included in the Statistics window, e.g., file size, total duration, number of channels, sampling rate, resolution (bit depth) - others? The name of the file is currently displayed at the top bar of the Statistics window, but it's not clear to me whether it would be saved together with the other information, so maybe that name should be included among the information in the main part of the window to be saved. If we think about documentation, maybe some or all of the information in the "File tag information" in File > Edit Properties could also be saved together with the audio statistics, but I am not sure.

--- 4. In the Analysis > Show Statistics window, this is not absolutely necessary, but could be handy: where the time position, say, of the Maximum True Peak Level is shown, the time value could be clickable, and a click on the time position would send the audio cursor to the corresponding point of the file. As things are today, to go to the point where a maximum or minimum occurs one should either manually type the displayed time position on the small cursor position window under the clip editor or use the cursor position marker (the cursor head) to take the cursor approximately to the point. Clicking on the time position value would be faster and less work, I think.

--- 5. In the Volume > Normalize module, there seems to exist some inconsistency regarding the EBU R-128 setting. As stated in the Help files: "The EBU recommendation refers to the ITU standard and specifies specific values for the absolute gate (-70 LUFS) and the relative gate (-10 LU)". The two levels of gating are fixed in the EBU recommendations, but in Normalize's EBU R-128 setting the two gating sliders are active and can be used to change the gating levels - in that case, the modified gatings would fall outside the EBU recommendations, despite the fact that the Normalize setting is the EBU R-128. Possibly, the gating sliders should not be active while one is under the EBU R-128 setting of Normalize. A further setting, "User defined", should maybe be created in that module, where the two sliders would indeed be active and the levels of gating could be changed at will by the user, who would know that he or she is outside the EBU R-128 rules.

--- 6. This is just an observation: In iZotope RX6, under the EBU R-128 setting, one can normalize both the integrated loudness and the peak level in one pass (please see the attached figure), while in Acoustica two operations are required, each with a different setting of the Normalize module. Would a one-pass double operation be of interest to Acoustica?

--- 7. As far as I understand, there is possibly some issue with the way Acoustica handles plugins, when it comes to external loudness meter plugins like the free plugin TBProAudio dpMeter 3 (figure attached). This has to do with the looping of the audio file.

When one opens an Acoustica module like the Equalize module and presses the Play button on the preview transport control of the module, Acoustica plays the audio file in loop mode, even when the Play Looped Toggle on the main toolbar is not selected. For a module like Equalize, which acts (or so it seems) locally on the file, this is not a problem: when the cursor reaches the end of the file it goes right back to the beginning, and at each moment the module is acting locally on the file, in this case modifying the equalization at each moment.

But this automatic looping seems to present a problem for a loudness meter plugin, which acts not only (nearly) locally on the file, e.g. by calculating the Momentary Loudness, but which also produces results like the Integrated Loudness or the Loudness Range which integrate information from the whole file, results that belong to the audio file as a whole. In this last situation, looping through the file, as the plugin continues to be active, destroys the integrated measurement that was initially taken for the whole file. One could at some point press the Stop button on the preview transport control, but one could possibly never be sure that both the file was totally read and no looping occurred. If there are plugins other than loudness meters that also perform integrated actions on an audio file, the same issue would arise.

I have tried the TBProAudio dpMeter 3 loudness plugin, and also Acon's Equalize 2, in Magix's Sound Forge Audio Studio 12.6 - in both cases the audio does not loop.

In relation to these observations, I have three questions:

7.1 - Acoustica of course has its own Loudness Meter. Are we allowed, for any reason, to use an external plugin for loudness measurements? Would it exist any kind of interference between Acoustica's Loudness Meter and an external loudness plugin, so that the results of any of these meters would be distorted in any way? Or should the use of an external meter be avoided altogether?

7.2 - When using the Play button in the preview transport control of modules and plugins, shouldn't the default behaviour of Acoustica be to play the file in one pass, without the looping? Is there any special reason for the automatic looping that we observe today? My own feeling is that there should exist no automatic looping.

7.3 - When I use the TBProAudio dpMeter 3 plugin in Acoustica, the Process button at the bottom of the plugin window does nothing. There is a run of the yellow processing horizontal bar at the bottom-right of the clip editor, but no results are produced by the plugin. I cannot know whether there is some issue with the plugin itself, but the same thing happened with another free external loudness meter that I have tried, the Youlean Loudness Meter 2. If the Process button worked, and if "Process" means a one-pass through the file, could this be another solution to the use of the plugin in one pass, without looping?

With wishes of a happy and peaceful 2019,

Paulo
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Paulo-Brazil
KVRist
113 posts since 1 Oct, 2017

Re: Acoustica Premium 7.1.8 - loudness measurement and file statistics

Post Thu Dec 27, 2018 7:37 pm

Mr. Stian, please disregard item 6, it makes no sense.

Thank you. Paulo

User avatar
stian
KVRian
934 posts since 1 Jan, 2005 from Norway

Re: Acoustica Premium 7.1.8 - loudness measurement and file statistics

Post Tue Mar 26, 2019 1:33 am

Hi Paulo,
Paulo-Brazil wrote:
Wed Dec 26, 2018 3:20 am
--- 1. I would like to suggest that the Maximum True Peak Level be included in the Loudness Meter, and consequently that a reference to the Maximum True Peak Level be included in the Help page about that Meter.

The EBU R-128 recommendations establish a limit for the Maximum True Peak Level of a programme, this is one of the key audio measurements that should be controlled under those recommendations. So it seems to me that this level should be easily and readily monitored, which doesn't happen today in Acoustica.

In the Help files, in the section about the Loudness Meter, it is stated: "There are four different loudness measures defined by the EBU R128". In fact, there aren't four, but five measurements defined by the EBU R128: the four ones mentioned in the Help page plus the Maximum True Peak Level.

The Level Meter can measure the True Peak Level, but it does not record its maximum value across the file. In the Analysis > Show Statistics window, for each channel of an audio file there is a "Maximum True Peak Level" and "Minimum True Peak Level", so there are four True Peak Level measurements in all for a stereo file, and more for a multichannel file. What is the relation between these True Peak parameters and the EBU R-128 Maximum True Peak Level, which is a single measurement? Possibly, this is the maximum of all the True Peak measurements, but I cannot be sure. At this moment, how could one obtain the EBU R-128 Maximum True Peak Level from the True Peak measurements in the different channels? Some clarification about that could maybe be included in the Help files.

Several loudness meters include the Maximum True Peak Level in their main windows, for example the iZotope's RX6 loudness/normalization module in EBU R-128 mode (a picture is attached), and the free plugin TBProAudio dpMeter 3 in EBU mode (a picture is also attached) - there are many other meters by different software developers.
The reason for not adding the true peak read-out to the loudness meter is that the same functionality is duplicated in the level meter (which is set to true peak per default). I know the EBU R 128 standard requires true peak read-out as well, we didn't want to have too much duplicated information on screen and Acoustica adheres to the standard with the default window pane setup.
Paulo-Brazil wrote:
Wed Dec 26, 2018 3:20 am
--- 2. In the Loudness Meter, when the audio playing stops, the Momentary Loudness and the Short-Term Loudness should possibly be turned off, possibly go to minus infinity (as it happens with the Level Meter). Only the integrated, whole-file parameters should possibly be displayed when the audio is stopped, namely the five EBU R-128 measurements: the Integrated Loudness, Loudness Range, Maximum Short-Term Loudness, Maximum Momentary Loudness and (if it is included in the Loudness Meter) the Maximum True Peak Level. It seems to me that the running Momentary Loudness and the running Short-Term Loudness are "local" measurements, not integrated, whole-file ones, they do not pertain to the whole file so they make no sense when the audio playing has stopped. Please take a look at the attached picture of the TBProAudio dpMeter 3, where these two measurements went to minus infinity when the audio playing stopped.
We didn't want to reset the information when the playback is stopped because some of the information could be useful to have even after stopping the playback, such as gain range etc.
Paulo-Brazil wrote:
Wed Dec 26, 2018 3:20 am
--- 3. In the Analysis > Show Statistics window, I would like to suggest that, at the bottom of the window, the full set of five EBU R-128 audio parameters be displayed: Loudness and Loudness Range (these two do exist now), and Maximum Short-Term Loudness, Maximum Momentary Loudness and Maximum True Peak Level (these three would be added). The display of the five EBU R-128 parameters could be important for archiving and documentation purposes, under the idea that, in some future version, Acoustica will allow one to save the Statistics Window.

Incidentally, for archiving and documentation purposes, possibly some basic file information should be included in the Statistics window, e.g., file size, total duration, number of channels, sampling rate, resolution (bit depth) - others? The name of the file is currently displayed at the top bar of the Statistics window, but it's not clear to me whether it would be saved together with the other information, so maybe that name should be included among the information in the main part of the window to be saved. If we think about documentation, maybe some or all of the information in the "File tag information" in File > Edit Properties could also be saved together with the audio statistics, but I am not sure.
Yes, we could add the additional maximum momentary and short-term values. True peak is already there, but per channel and split into positive and negative max values. I guess we could add the maximum absolute value as well. I think the other information is so visible elsewhere in Acoustica that I don't really see the point in duplicating it in Statistics.
Paulo-Brazil wrote:
Wed Dec 26, 2018 3:20 am
--- 4. In the Analysis > Show Statistics window, this is not absolutely necessary, but could be handy: where the time position, say, of the Maximum True Peak Level is shown, the time value could be clickable, and a click on the time position would send the audio cursor to the corresponding point of the file. As things are today, to go to the point where a maximum or minimum occurs one should either manually type the displayed time position on the small cursor position window under the clip editor or use the cursor position marker (the cursor head) to take the cursor approximately to the point. Clicking on the time position value would be faster and less work, I think.
Yes, that would be a nice feature!
Paulo-Brazil wrote:
Wed Dec 26, 2018 3:20 am
--- 5. In the Volume > Normalize module, there seems to exist some inconsistency regarding the EBU R-128 setting. As stated in the Help files: "The EBU recommendation refers to the ITU standard and specifies specific values for the absolute gate (-70 LUFS) and the relative gate (-10 LU)". The two levels of gating are fixed in the EBU recommendations, but in Normalize's EBU R-128 setting the two gating sliders are active and can be used to change the gating levels - in that case, the modified gatings would fall outside the EBU recommendations, despite the fact that the Normalize setting is the EBU R-128. Possibly, the gating sliders should not be active while one is under the EBU R-128 setting of Normalize. A further setting, "User defined", should maybe be created in that module, where the two sliders would indeed be active and the levels of gating could be changed at will by the user, who would know that he or she is outside the EBU R-128 rules.
Not really, the EBU R-128 setting is just a preset, so if you modify the values, it no longer adheres to the standard.
Paulo-Brazil wrote:
Wed Dec 26, 2018 3:20 am
--- 7. As far as I understand, there is possibly some issue with the way Acoustica handles plugins, when it comes to external loudness meter plugins like the free plugin TBProAudio dpMeter 3 (figure attached). This has to do with the looping of the audio file.

When one opens an Acoustica module like the Equalize module and presses the Play button on the preview transport control of the module, Acoustica plays the audio file in loop mode, even when the Play Looped Toggle on the main toolbar is not selected. For a module like Equalize, which acts (or so it seems) locally on the file, this is not a problem: when the cursor reaches the end of the file it goes right back to the beginning, and at each moment the module is acting locally on the file, in this case modifying the equalization at each moment.

But this automatic looping seems to present a problem for a loudness meter plugin, which acts not only (nearly) locally on the file, e.g. by calculating the Momentary Loudness, but which also produces results like the Integrated Loudness or the Loudness Range which integrate information from the whole file, results that belong to the audio file as a whole. In this last situation, looping through the file, as the plugin continues to be active, destroys the integrated measurement that was initially taken for the whole file. One could at some point press the Stop button on the preview transport control, but one could possibly never be sure that both the file was totally read and no looping occurred. If there are plugins other than loudness meters that also perform integrated actions on an audio file, the same issue would arise.

I have tried the TBProAudio dpMeter 3 loudness plugin, and also Acon's Equalize 2, in Magix's Sound Forge Audio Studio 12.6 - in both cases the audio does not loop.

In relation to these observations, I have three questions:

7.1 - Acoustica of course has its own Loudness Meter. Are we allowed, for any reason, to use an external plugin for loudness measurements? Would it exist any kind of interference between Acoustica's Loudness Meter and an external loudness plugin, so that the results of any of these meters would be distorted in any way? Or should the use of an external meter be avoided altogether?

7.2 - When using the Play button in the preview transport control of modules and plugins, shouldn't the default behaviour of Acoustica be to play the file in one pass, without the looping? Is there any special reason for the automatic looping that we observe today? My own feeling is that there should exist no automatic looping.

7.3 - When I use the TBProAudio dpMeter 3 plugin in Acoustica, the Process button at the bottom of the plugin window does nothing. There is a run of the yellow processing horizontal bar at the bottom-right of the clip editor, but no results are produced by the plugin. I cannot know whether there is some issue with the plugin itself, but the same thing happened with another free external loudness meter that I have tried, the Youlean Loudness Meter 2. If the Process button worked, and if "Process" means a one-pass through the file, could this be another solution to the use of the plugin in one pass, without looping
The automatic looping is there for convenience only. Usually, you would want the audio to loop so that you can adjust parameters and apply when you're done. It would be tiresome to restart the playback if the selection is short. However, you can use the Chain Processor if you don't want the looping. You can just add your metering tool there and the chain follows the loop toggle in Acoustica.

Best,
Stian

Paulo-Brazil
KVRist
113 posts since 1 Oct, 2017

Re: Acoustica Premium 7.1.8 - loudness measurement and file statistics

Post Fri Mar 29, 2019 4:42 am

Mr. Stian,

Thank you very much for your reply. You have said:

[Mr. Stian] "The reason for not adding the true peak read-out to the loudness meter is that the same functionality is duplicated in the level meter (which is set to true peak per default). I know the EBU R 128 standard requires true peak read-out as well, we didn't want to have too much duplicated information on screen and Acoustica adheres to the standard with the default window pane setup."

The point is: the level meter provides a momentary reading, a running reading, of the true peak, and even so for each channel separately, it does not provide a single measurement of the maximum true peak since the start of playing, valid for all channels. What is missing in Acoustica is an integrated measurement of the maximum true peak, that is, the maximum true peak since the start of the playing - an integrated measurement like the integrated loudness or the (integrated) loudness range, not momentary true peak measurements.

Nowhere in Acoustica we can find the maximum true peak for the whole file. Not in the loudness meter (after playing the whole file), not in the Statistics window, and certainly not in the level meter. In the Statistics window we find a set of maximum and minimum true peak measurements, separately by channel, but there is not a single maximum true peak value for the whole file.

My interpretation is that, at the moment, Acoustica does not provide us with an easily read maximum true peak for the whole file (or a part of a file that has been played), as required by the EBU recommendations.

-------------------

With regard to information about the file that could be included in the Statistics window, like file name, size, total duration, number of channels, sampling rate, resolution (bit depth), you have said:

[Mr. Stian] "I think the other information is so visible elsewhere in Acoustica that I don't really see the point in duplicating it in Statistics."

The point is: My suggestion to include that kind of information in the Statistics window was due to the possible use of that window for archiving purposes. Hopefully, some day we will be able to save the Statistics window as a text file, and when reading later this text file, that information (file name, size, etc.) would not be "visible elsewhere in Acoustica", as you have said. This is why I think there is a need to include some file information in the Statistics window. Of course, if you have no intention of allowing in the future the Statistics window to be saved, there would be no need for that information.

-------------------

I take the liberty of repeating this question:

Acoustica of course has its own Loudness Meter. Are we allowed, for any reason, to use an external plugin for loudness measurements? Would it exist any kind of interference between Acoustica's Loudness Meter and an external loudness plugin, so that the results of any of these meters would be distorted in any way? Or should the use of an external meter be avoided altogether?

Best regards,

Paulo

User avatar
stian
KVRian
934 posts since 1 Jan, 2005 from Norway

Re: Acoustica Premium 7.1.8 - loudness measurement and file statistics

Post Fri Apr 12, 2019 4:55 am

Paulo-Brazil wrote:
Fri Mar 29, 2019 4:42 am
The point is: the level meter provides a momentary reading, a running reading, of the true peak, and even so for each channel separately, it does not provide a single measurement of the maximum true peak since the start of playing, valid for all channels. What is missing in Acoustica is an integrated measurement of the maximum true peak, that is, the maximum true peak since the start of the playing - an integrated measurement like the integrated loudness or the (integrated) loudness range, not momentary true peak measurements.

Nowhere in Acoustica we can find the maximum true peak for the whole file. Not in the loudness meter (after playing the whole file), not in the Statistics window, and certainly not in the level meter. In the Statistics window we find a set of maximum and minimum true peak measurements, separately by channel, but there is not a single maximum true peak value for the whole file.

My interpretation is that, at the moment, Acoustica does not provide us with an easily read maximum true peak for the whole file (or a part of a file that has been played), as required by the EBU recommendations.
I see your point. We'll add the global maximum true peak across all channels in the Statistics window (at the end where the other EBU R 128 values are listed). This is merely the maximum value of what's listed per channel, but it's of course convenient to have it written out.
Paulo-Brazil wrote:
Fri Mar 29, 2019 4:42 am
Acoustica of course has its own Loudness Meter. Are we allowed, for any reason, to use an external plugin for loudness measurements? Would it exist any kind of interference between Acoustica's Loudness Meter and an external loudness plugin, so that the results of any of these meters would be distorted in any way? Or should the use of an external meter be avoided altogether?
I'm not sure what you mean with the question. We don't intentionally restrict any third party tools. On the contrary, we try to keep Acoustica as open as possible. However, there's no specialized interface beyond VST, VST3 or AU at the time being that allows you to embed 3rd. party tools for loudness metering.

Best,
Stian

Paulo-Brazil
KVRist
113 posts since 1 Oct, 2017

Re: Acoustica Premium 7.1.8 - loudness measurement and file statistics

Post Sun Apr 14, 2019 5:45 pm

Mr. Stian,

The reason for my question about the use of external loudness plugins in Acoustica: given that Acoustica at the moment does not show the global true peak of a file, I thought that one would need to use an external loudness plugin to get that measurement. But now you have said that the global maximum true peak will be included in some future version of Acoustica, so from that future moment on an external loudness plugin will not be necessary in order to obtain the maximum true peak value.

Thank you.

Paulo

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