adding sample exporter #7627

szeli1 · 2024-12-19T20:14:26Z

This Pull request adds sample exporting to lmms that is independent from AudioEngine.

How to test:
Open lmms, load a sample into a sample clip. Open the context menu and click on the new option called "export sample buffer". A file dialog should open up. Select an audio file to export to, or create a new file by using a custom name in the file dialog. Click "open" inside the file dialog. The sample should be exported to the selected output file.

related pull request: #7557
this allows #5990 to be finished

src/gui/clips/SampleClipView.cpp

michaelgregorius · 2025-01-03T16:07:13Z

src/gui/clips/SampleClipView.cpp

+			if (outputFileName.isEmpty()) { return; }
+			if (outputFileName.endsWith(".flac") == false)
+			{
+				outputFileName = PathUtil::stripPrefix(outputFileName) + ".flac";


If I understand correctly you let the users choose different file types but then save it as a Flac anyway. This is very confusing in my opinion.

Yes, the exporter class only supports .flac and this was agreed to in discord. I can still change that, but it will add unreasonable complexity in my view.

src/gui/clips/SampleClipView.cpp

michaelgregorius · 2025-01-03T16:21:52Z

src/core/LmmsExporterSample.cpp

+		outputBuffer[i + 1] = outputBuffer[i + 1] > 1.0f ? 1.0f : outputBuffer[i + 1] < -1.0f ? -1.0f : outputBuffer[i + 1];
+		i = i + channelCount;
+	}
+	size_t count = sf_writef_float(m_fileDescriptor, outputBuffer.data(), static_cast<sf_count_t>(buffer->size()));


IMO all the sndfile related code should be moved into a helper class that is concerned with writing LMMS buffers into files in various formats using sndfile. It could be an RAII class which

takes a filename and the export format in its constructor and opens the file using sndfile

provides a method to push LMMS buffers which are then written into the file

in the destructor closes the file.

Doing so would likely also remove duplicated code in AudioFileFlac and AudioFileWave.

firewall1110 · 2025-01-03T20:19:00Z

It seems that #7627 only exports the content of sample clips into files, i.e. it will not replace the recorded data with references to the exported files.

Can this be fixed with new option to replace old reference or data with reference to exported file?

michaelgregorius · 2025-01-03T20:23:26Z

It seems that #7627 only exports the content of sample clips into files, i.e. it will not replace the recorded data with references to the exported files.

Can this be fixed with new option to replace old reference or data with reference to exported file?

We should not implement too many workflow crutches that we might never get rid of again. IMO recording to files should be implemented as fast as possible instead of some workarounds.

szeli1 · 2025-01-04T11:37:22Z

Can this be fixed with new option to replace old reference or data with reference to exported file?

Originally I couldn't do it because the exporting ran on a different thread and SampleClipView didn't wait for the exporting to be done before trying to import it.

firewall1110 · 2025-01-04T12:16:17Z

SampleClipView didn't wait for the exporting to be done

Can this exporting thread before quit trigger event connected to some SampleClip (OR ...) slot that do the same as happens when user load file to clip?

[Of course - only if user want this to happen]

szeli1 · 2025-01-04T18:13:19Z

I will need to move the FlacExporter into a new file, but it is ready for review.

Use `FileDialog::getSaveFileName` to retrieve the file name of the file into which the sample buffer is saved. This gives us lots of functionality automatically, e.g. the request if an existing file should be overwritten. Also let remove the appending of the `.flac` file extension and let the users decide using the system file dialog.

szeli1 · 2025-01-05T14:32:38Z

I realized that I would rather not touch AudioFileFlac, because I don't fully understand how it works. For example the writeBuffer() function has "integer PCM encoding" built in, while FlacExporter doesn't and it doesn't need to have it. It can certainly be used to replace most libsndfile functions for AudioFileFlac, but I'm unsure if this should be done.

szeli1 · 2025-01-05T14:58:18Z

@michaelgregorius It seems like you introduced a crash by removing the code that ensures ".flac" file extensions are there. If the name (outputFilename) doesn't contain an extension in the file dialog, then lmms will crash. I believe this happens because after exporting, the exported sample will be reimported by the clip, but the clip will try to import outputFilename without the ".flac" extension that does not exist.

Save the exported file under the name that the users have selected and do not append ".flac". This fixes an exception that was thrown because the file is saved with the appended extension but then attempted to load without it.

michaelgregorius · 2025-01-06T20:01:25Z

@michaelgregorius It seems like you introduced a crash by removing the code that ensures ".flac" file extensions are there. If the name (outputFilename) doesn't contain an extension in the file dialog, then lmms will crash. I believe this happens because after exporting, the exported sample will be reimported by the clip, but the clip will try to import outputFilename without the ".flac" extension that does not exist.

@szeli1, I have fixed this with commit 5fa60b3 by saving the file with the name that the users have selected and not appending the ".flac" extension.

michaelgregorius · 2025-01-06T20:03:54Z

include/LmmsMassExporter.h

+
+typedef void (*callbackFn)(void*);
+
+class LmmsMassExporter


Some remarks about the name of the class:

It lives in the lmms namespace so there is not need to prefix it with "Lmms".

Why is it called mass exporter? To me it seems that one of its main features is that it exports data in a thread so perhaps something like ThreadedExporter might be more fitting.

Edit: I have just noticed the vector. Perhaps something like ExportManager or ThreadedExportManager might be better as a name then.

I like ThreadedExportManager, I will rename.

szeli1 · 2025-01-06T21:44:13Z

@szeli1, I have fixed this with commit 5fa60b3 by saving the file with the name that the users have selected and not appending the ".flac" extension.

I don't know why do you prefer removing it, but sure, I approve if it works. I will remove the QFileInfo include.

szeli1 · 2025-01-08T06:07:19Z

@szeli1, I have fixed this with commit 5fa60b3 by saving the file with the name that the users have selected and not appending the ".flac" extension.

It now works, it can export files without file extension, I don't know why is this useful, because the result will be a file without an extension, so every time the user would like to open it, they will have to select a program that can open .flac files.

CorruptVoidSoul · 2025-01-09T20:53:13Z

So I tested this with a wav and an ogg file, both exported without problems and there doesn't seem to be any hearable difference.
In case it's wanted, system info is aarch64 Ubuntu running on top of Termux on a phone (samsung galaxy A25).

michaelgregorius · 2025-01-12T14:06:49Z

@szeli1, I have fixed this with commit 5fa60b3 by saving the file with the name that the users have selected and not appending the ".flac" extension.

It now works, it can export files without file extension, I don't know why is this useful, because the result will be a file without an extension, so every time the user would like to open it, they will have to select a program that can open .flac files.

The reason is that we should let users do what the want to do. The dialog already proposes the "flac" extension so this adds no extra work for the users. The default is that it is exported with the extension.

However, if the users for some reason decide that they want/need to have a file without extension then the previous implementation would make them jump through the hoops to export the file and then having to rename it manually to remove the extension. With the current implementation they simply save it without the extension and they are good.

The current implementation gives the best of both words. I guess we all have some experience with software that attempts to be clever only to do the wrong thing. So please let's not add such behavior to LMMS if it is not even necessary in some way.

michaelgregorius · 2025-01-12T14:11:40Z

src/core/SampleClip.cpp

+{
+	if (thisObject == nullptr) { return; }
+	SampleClip* castedThis = static_cast<SampleClip*>(thisObject);
+	castedThis->setSampleFile(castedThis->m_exportedSampleName);


Now that I have thought a bit more about it I do not think that replacing the sample with the one we have just exported is a good idea.

Let's say you have a project with all the samples contained in the project. You now want to export the sample to a different folder outside of the project just to save it. In this case the project file would now point to a file outside of the project folder which might not be the intended effect.

IMO the export feature should simply export the file to wherever the users want. If users want to replace the sample with the exported one it should either be an option in the export dialog (initially disabled) or they should explicitly replace the samples themselves after the export.

Doing it as it is currently done will likely lead to "chaos".

firewall1110 · 2025-01-12T16:39:39Z

If users want to replace the sample with the exported one it should either be an option in the export dialog (initially disabled)

Something like this I mean when wrote:

Can this be fixed with new option to replace old reference or data with reference to exported file?

szeli1 added 9 commits December 19, 2024 21:35

LmmsExporterSample_adding_class

1be7bb8

CMakeLists_adding_new_class_target

318d8b4

LmmsExporterSample_fixing_printf

a9248c4

SampleClip_implementing_static_exporter

50d20a7

SampleClipView_implementing_exporting_context_menu_option

3d98c77

LmmsExporterSample_fixing_typo

0c630d0

SamleClipView_fixing_typo

baab754

LmmsExporterSample_removing_blank_line

77cfaae

LmmsExporterSample_removing_LMMS_EXPORT

58f4e15

szeli1 force-pushed the sample_export branch from db25510 to 58f4e15 Compare December 19, 2024 20:36

szeli1 added 2 commits December 19, 2024 21:46

LmmsExporterSample_removing_ifdef

b25142f

LmmsExporterSample_removing_more_blank_lines

61e7ca9

qnebra mentioned this pull request Jan 2, 2025

Sample Track Recording Stage One #5990

Draft