get mp3 file duration when it is VBRI file

[yuyuer_007@…]

hi all!

When I used FFmpeg realease "Love" to get mp3 file duration,I found this bug in libavformat/mp3dec.c

---

    if(v == MKBETAG('V', 'B', 'R', 'I')) {
        /* Check tag version */
        if(avio_rb16(s->pb) == 1) {
            /* skip delay and quality */
            avio_skip(s->pb, 4);
            frames = avio_rb32(s->pb);//code line 1
            size = avio_rb32(s->pb);// code line 2
        }
    }

---

"code line 1" and "code line 2" should exchanged.

before I exchanged , the info is :

Metadata:

track : 1

Duration: 43:01:23.13, start: 0.000000, bitrate: 0 kb/s

after exchanged,the info is :

Metadata:

track : 1

Duration: 00:04:04.11, start: 0.000000, bitrate: 194 kb/s

[Christian Boos]

WrongTrac, please try ​https://ffmpeg.org/trac/ffmpeg instead.