The preliminary numbers are in for consumer spending in the U.S. home entertainment business for 2015, and all is not what it may seem.

What the DEG: Digital Entertainment Group refers to as “total U.S. home entertainment spending” is up almost 1% to just over $18 billion last year, reversing a 1.8% decline registered in 2014. The industry’s trade org collects the numbers from studios and retailers on a quarterly basis.

But dig deeper into the numbers, and what looks up is actually down–and in more ways than one.

The $18 billion figure is an amalgam of several key revenue streams including sales and rentals of DVDs and Blurays; digital distribution options like VOD and electronic-sell-through options including iTunes, and subscription VOD options including Netflix.

That third category is where the problem lies: SVOD is truly a very different business than the other two. While all are essentially viewing options in the home that occur after the first theatrical window, lumping Netflix together with iTunes and disc revenues is a head-scratcher for several reasons.

The primary problem is the secular decline of the disc revenues that is the studios’ most important revenue stream is precisely because the easy, lower-margin distribution in subscription streaming is what is hurting that core business.

Even odder is the logic of including SVOD revenues but excluding from the total another aftermarket window for movies: premium channels like HBO, Showtime and Starz. Then there’s the fact that Netflix has evolved into a more TV-centric business while home video is primarily driven by movies.

In 2015, subscription streaming delivered over $5 billion to the bottom line for the studios; pull out that number and what was a 1% increase is actually just over a 6% decrease for the year, to just under $13 billion. The 2014 total sans subscription streaming is $13.8 billion, down from $15 billion in 2013.

The studios’ primary home entertainment revenue stream continues to be the sale of discs, which dropped from $6.9 billion in 2014 to $6.1 billion in 2015. The rate of decline accelerated from 10.9% in 2014 to 12% last year.

Considering subscription streaming increased by a whopping 25% year over year for two consecutive years, 2016 might be the year that disc sales actually become the second biggest revenue driver in home entertainment given the current trajectory of both categories.

Disc rentals also continue to decrease, now just over $3 billion. Rate of decline isn’t as steep as disc sales, which is somewhat surprising given the troubles its biggest driver–Redbox–experienced as of late in the kiosk business.

On the digital side of the home entertainment business, both VOD and EST are contributing nearly $2 billion each to the bottom line. Propelled by the push of the early window known as Digital HD, EST registered healthy 18% growth but the rate of growth is actually down from the 30% rate from 2014.

Another digital indicator showing moderating growth for home entertainment: the number of Ultraviolet accounts grew by nearly 20%, to over 25 million. But that growth was over 30% in 2014.

The home entertainment sector is hoping that the first deployment of Ultra HD discs with HDR later this year will put new fuel in the tank of the flagging disc business’, noting that penetration of 4K TVs now stands at 5 million in the U.S.

If anything, the surging subscription streaming category is actually significantly lower than its true total considering DEG doesn’t count Amazon Prime in its numbers, which is probably second only among SVOD players like Hulu to Netflix in that category.

A potential silver lining in the 2015 data that bodes well for next year: “Star Wars: The Force Awakens” drove a big 17% fourth-quarter year-over-year surge at the box office after many consecutive quarters of decline, which could soon boost disc sales. DEG doesn’t break out the revenue totals of specific titles but noted that “Star Wars Collection,” “Big Hero 6” and “Jurassic World” were among the top performing movies on home video for the year.