static int mov_read_tkhd(MOVContext *c, AVIOContext *pb, MOVAtom atom)
{
    int i;
    int width;
    int height;
    int64_t disp_transform[2];
    int display_matrix[3][2];
    AVStream *st;
    MOVStreamContext *sc;
    int version;

    if (c->fc->nb_streams < 1)
        return 0;
    st = c->fc->streams[c->fc->nb_streams-1];
    sc = st->priv_data;

    version = avio_r8(pb);
    avio_rb24(pb); /* flags */
    /*
    MOV_TRACK_ENABLED 0x0001
    MOV_TRACK_IN_MOVIE 0x0002
    MOV_TRACK_IN_PREVIEW 0x0004
    MOV_TRACK_IN_POSTER 0x0008
    */

    if (version == 1) {
        avio_rb64(pb);
        avio_rb64(pb);
    } else {
        avio_rb32(pb); /* creation time */
        avio_rb32(pb); /* modification time */
    }
    st->id = (int)avio_rb32(pb); /* track id (NOT 0 !)*/
    avio_rb32(pb); /* reserved */

    /* highlevel (considering edits) duration in movie timebase */
    (version == 1) ? avio_rb64(pb) : avio_rb32(pb);
    avio_rb32(pb); /* reserved */
    avio_rb32(pb); /* reserved */

    avio_rb16(pb); /* layer */
    avio_rb16(pb); /* alternate group */
    avio_rb16(pb); /* volume */
    avio_rb16(pb); /* reserved */

    for (i = 0; i < 3; i++) {
        display_matrix[i][0] = avio_rb32(pb);   // 16.16 fixed point
        display_matrix[i][1] = avio_rb32(pb);   // 16.16 fixed point
        avio_rb32(pb);           // 2.30 fixed point (not used)
    }

    width = avio_rb32(pb);       // 16.16 fixed point track width
    height = avio_rb32(pb);      // 16.16 fixed point track height
    sc->width = width >> 16;
    sc->height = height >> 16;


    if (display_matrix[1][0] == -65536 && display_matrix[0][1] == 65536) {
         av_dict_set(&st->metadata, "rotate", "90", 0);
    }

    if (display_matrix[0][0] == -65536 && display_matrix[1][1] == -65536) {
         av_dict_set(&st->metadata, "rotate", "180", 0);
    }

    if (display_matrix[1][0] == 65536 && display_matrix[0][1] == -65536) {
         av_dict_set(&st->metadata, "rotate", "270", 0);
    }

    if (width && height &&
        ((display_matrix[0][0] != 65536  ||
          display_matrix[1][1] != 65536) &&
         !display_matrix[0][1] &&
         !display_matrix[1][0] &&
         !display_matrix[2][0] && !display_matrix[2][1])) {
        for (i = 0; i < 2; i++)
            disp_transform[i] =
                (int64_t)  width  * display_matrix[0][i] +
                (int64_t)  height * display_matrix[1][i] +
                ((int64_t) display_matrix[2][i] << 16);

        st->sample_aspect_ratio = av_d2q(
            ((double) disp_transform[0] * height) /
            ((double) disp_transform[1] * width), INT_MAX);
    }
    return 0;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.