CDDA streams assume that the first track number is zero.

[vext01]

mpv version and platform

At least 0.22.0 and master.

Reproduction steps

Play a CD whose start track is not one.

Expected behavior

Reports playing the correct track number.

Actual behavior

This CD starts with track 7:

$ cd-info
...
CD-ROM Track List (7 - 11)
  #: MSF       LSN    Type   Green? Copy? Channels Premphasis?
  7: 00:02:00  000000 audio  false  no    0        no
  8: 03:07:72  013947 audio  false  no    0        no
  9: 05:46:12  025812 audio  false  no    0        no
 10: 07:24:74  033224 audio  false  no    0        no
 11: 09:41:34  043459 audio  false  no    0        no
170: 12:48:10  057460 leadout (128 MB raw, 128 MB formatted)

fremen:edd> mpv cdda://
Playing: cdda://
[cdda] Switched to track 1 <------------------------------------ !
 (+) Audio --aid=1 (pcm_s16le)
AO: [sdl] 44100Hz stereo 2ch s16
A: 00:00:02 / 00:12:46 (0%) Cache: 10s+3MB
...

Track 7 is heard playing.

Sample files

Here's how to make a CD with a start track number of 7:

cdrskin -v dev=/dev/rcd0d cd_start_tno=7 trackA.wav trackB.wav trackC.wav

Obviously switch out the device node for your CD drive.

[vext01]

Here's the problem code:

static int fill_buffer(stream_t *s, char *buffer, int max_len)
{
    cdda_priv *p = (cdda_priv *)s->priv;
    int16_t *buf;
    int i;

    if (max_len < CDIO_CD_FRAMESIZE_RAW)
        return -1;

    if ((p->sector < p->start_sector) || (p->sector > p->end_sector)) {
        return 0;
    }

    buf = paranoia_read(p->cdp, cdparanoia_callback);
    if (!buf)
        return 0;

    p->sector++;
    memcpy(buffer, buf, CDIO_CD_FRAMESIZE_RAW);

    for (i = 0; i < p->cd->tracks; i++) {
        if (p->cd->disc_toc[i].dwStartSector == p->sector - 1) {
            print_track_info(s, i + 1); <-------------------------- !
            break;
        }
    }

    return CDIO_CD_FRAMESIZE_RAW;
}

i+1 is the wrong track number to report if the first track is not one.

[ghost]

Feel free to provide patches; they probably have a good chance of getting in. I don't think anyone else is going to look at this. Closing.