The first question: Genuine nero aac does use MPEG-4 AAC. So the extension uses m4a.

Second question: It seems that brother, you have never learned coding. MPEG-2 AAC is also the vast majority of MPEG-4 AAC. For example, the used Huffman coding, correlated stereo, channel coupling, inverse adaptive prediction, temporal noise shaping, modified discrete cosine transform (MDCT), and hybrid filter banks are all very the same. So it contains MPEG-2 AAC. AAC is just an extension, not an encoding.

The third question: The software does not have this option.

The fourth question: To use Qianqianjingting conversion, first install Qianqianjingting, then install the neroaac component (you need to use the Qianqianjingting version), and check the export ISO 13818 in the configuration file. -7 aac track. Then the conversion is done.

In addition, I would like to say a few additional words. Your question is very strange. MPEG-4 AAC integrates MPEG-2 AAC and adds features for better sound quality. If you can drool looking at a suffix like aac, then use the extension of aac.

And if you rename the m4a file to aac or mp4, it can also be played.

It can be understood that mp4 is the highest level of encapsulation. m4a is part of mp4. And aac is only part of m4a.

Of course, using the extension m4a is the way to go, for authentic high-quality aac audio.

In addition, I am a moderator of the 51AAC High-Quality Music Forum. Welcome to the forum.