user81374: Setting up a method to calculate ID3 frame sizes, but the variable frsz always returns 0. I need to pass this variable back to another method so the program can loop through the ID3 frames.
void frameInfo(File track, char frame[4], uint32_t ltwo[4], int32_t frsz) {
 uint8_t buff[4];
 track.seek(10);
 track.read((uint8_t *)frame, 4);

 track.seek(14);
 track.read((uint8_t *)buff,4); 
 ltwo[0] = buff[0];
 ltwo[1] = buff[1];
 ltwo[2] = buff[2];
 ltwo[3] = buff[3];

 ltwo[0] = ltwo[0] * 2097152;
 ltwo[1] = ltwo[1] * 16384;
 ltwo[2] = ltwo[2] * 128;

 frsz = ltwo[0] + ltwo[1] + ltwo[2] + ltwo[3];

 track.rewind();
}

Am I missing some sort of initialization for this uint32?

user10794: void frameInfo(File track, char frame[4], uint32_t ltwo[4], int32_t frsz) {

The way you did it, frsz is passed by value (ie. a copy is made, and you have changed the copy, not the original). To make it change outside the function you need to pass it by reference:
void frameInfo(File track, char frame[4], uint32_t ltwo[4], int32_t &frsz) {

Note the ampersand.

81374: <p>Setting up a method to calculate ID3 frame sizes, but the variable <em>frsz</em> always returns 0. I need to pass this variable back to another method so the program can loop through the ID3 frames.</p>
<pre><code>void frameInfo(File track, char frame[4], uint32_t ltwo[4], int32_t frsz) {
 uint8_t buff[4];
 track.seek(10);
 track.read((uint8_t *)frame, 4);

 track.seek(14);
 track.read((uint8_t *)buff,4); 
 ltwo[0] = buff[0];
 ltwo[1] = buff[1];
 ltwo[2] = buff[2];
 ltwo[3] = buff[3];

 ltwo[0] = ltwo[0] * 2097152;
 ltwo[1] = ltwo[1] * 16384;
 ltwo[2] = ltwo[2] * 128;

 frsz = ltwo[0] + ltwo[1] + ltwo[2] + ltwo[3];

 track.rewind();
}
</code></pre>
<p>Am I missing some sort of initialization for this uint32?</p>
 10794: <pre><code>void frameInfo(File track, char frame[4], uint32_t ltwo[4], int32_t frsz) {
</code></pre>
<p>The way you did it, frsz is passed by value (ie. a copy is made, and you have changed the copy, not the original). To make it change outside the function you need to pass it by reference:</p>
<pre><code>void frameInfo(File track, char frame[4], uint32_t ltwo[4], int32_t &amp;frsz) {
</code></pre>
<p>Note the ampersand.</p>
