It looks like that you cannot convert PNG graphics files to MP3 audio files directly, which is essentially what png to mp3 conversion would be. But it should be possible to use .png files as pictures to albums or music collections, something that can be do with various music managers.
This conversion entry was verified by us and conversion was flagged as wrong or not possible.
Usually this happens when the conversion would try to convert different types of data between each other, such as audio to image, or it is not possible because incompatibility between programs, caused by closed file formats, very limited support etc.
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