Betamax:

“Is a consumer-level analog-recording and cassette format of magnetic tape for video. It was developed by Sony and was released in Japan on May 10, 1975. The first Betamax introduced in the United States was the LV-1901 console, which included a 19-inch (48 cm) color monitor, and appeared in stores in early November, 1975. The cassettes contain 0.50-inch-wide (12.7 mm) videotape in a design similar to that of the earlier, professional 0.75-inch-wide (19 mm), U-matic format.” (https://en.wikipedia.org/wiki/Betamax)

VHS:

“VHS (Video Home System) is a widely-adopted videocassette recording ( VCR ) technology that was developed by Japan Victor Company (JVC) and put on the market in 1976. It uses magnetic tape 1/2 inch (1.27 cm) in width. Originally, the abbreviation VHS stood for Vertical Helical Scan, and was later changed as the technology gained in popularity.” (http://whatis.techtarget.com/definition/VHS-Video-Home-System)  

Role of adult film industry in the formats wars Between Betamax and VHS.

Before the battle between HD- DVD and Blu-ray, it exist the war of Betamax and VHS. On 1980´s it was really common to use VHS or Betamax formats to watch a movie in home. The war that these two formats had was similar to the war between IPhone and Samsung, or the war between Xbox and PlayStation.   

Usually, Betamax was better than VHS it had a better quality, starting with more lines of image, 

the capacity of Betamax was better; in conclusion they were different (duration of the tapes,

 the size, etc.). The competition between this two formats was very hard-fought and Sony was 

leading the competition, but not for too longer, and pornography was the reason. 

Today is very easy get pornography content for the audience.The biggest source of 

pornography is on the Internet, and for people is very easy to get it. There are millions of 

webpages that have pornography content. On the 70´s and 80´s it wasn’t that easy to obtain

 pornography content. 

Sony refused to use pornography on his Betamax format but VHS accept to use it. 

So as I mentioned people don’t have such extensive access branch in that time, and the 

unique way to have porn in video vas with the VHS format.       

“During the 1970s, Betamax and VHS battled over which home viewing technology would reign supreme. While the wide format of Sony's Betamax made for better quality recordings, each tape only held 60 minutes of footage, as compared to the three hours of footage VHS held. That meant people couldn't tape their favorite movies on TV or experience three full hours of pornographic movies. 

Sony toiled over the pornography issue, but ultimately decided against allowing smutty movies to be recorded onto the Betamax format. By the end of the 1970s, erotic films accounted for over half of all videotape sales in the United States, which meant people wanted to get their hands on VCRs, regardless of the fact they cost $800 back then.” (https://www.thrillist.com/vice/how-porn-influenced-technology-8-ways-porn-influenced-tech-supercompressor-com)

As I was saying, the fact of accessibility was the principal reason of the VHS victory. Also VHS won millions of dollars with selling huge quantities of pornography content in the United States. On the Latin-American countries happen the same story, people prefer VHS because of the good experience that the cassette brings (good sound, three hours of duration, good quality, etc.)

“One oft-recalled explanation for the failure of Sony's Betamax videocassette format in the 1980s was the Japanese company's ambivalence towards producers of pornographic videos. By contrast, proponents of VHS, Betamax's rival, welcomed adult content with open arms and, the legend goes, caused Betamax's demise.”  (http://skeptics.stackexchange.com/questions/3089/vhs-vs-betamax-how-influential-was-the-pornography-industry-in-the-format-war)

Blue-Ray VS HD-DVD

The war continues but the formats change. Blue Ray and HD-DVD are now in a continuous fight. Toshiba was one company who support the production of the HD-DVD consoles. Both formats where very good designed and give good experiences to the consumers. One fact that supports these formats were the video games consoles, Xbox and PlayStation, in both consoles the formats are aviable. These formats produced a lot of consoles that reproduced the movies and videos in High definition.

In 2008 the end of the war takes place when several companies and industries change their teams to the Blue-Ray one.  After this event, Toshiba Company decided to stop the production of the consoles of HD-DVD, announcing Blue Ray as the wining format.

Pornography in HD-DVD and Blue-Ray  

“The adult industries have a number of reasons for preferring HD DVD, with lower production costs being the main reason and better technology support being the next.  At the start, neither HD DVD or Blu-ray were willing to help the adult industry with mass producing their high definition films, but eventually some members of the HD DVD camp finally decided to help out.  According to Wicked Pictures, they had no success in getting any company to mass-produce its films on Blu-ray, but still hopes to work with the Blu-ray format eventually.” (http://www.myce.com/news/Adult-film-industry-gets-no-help-from-Blu-ray-so-far-12862/)

General conclusion:

The movie formats have being changing and the formats too. First it was the Betamax vs the VHS, then it passes to Blue-Ray vs HD-DVD, and now what?  Maybe in some years the 4k resolution will be fighting with other format, but we don’t know.  Pornography was present in both wars, but today it is very easy to get porn content, so in my opinion porn will not be resent in a future war.   

Bibliography:
http://skeptics.stackexchange.com/questions/3089/vhs-vs-betamax-how-influential-was-the-pornography-industry-in-the-format-war
http://www.myce.com/news/Adult-film-industry-gets-no-help-from-Blu-ray-so-far-12862/
https://www.thrillist.com/vice/how-porn-influenced-technology-8-ways-porn-influenced-tech-supercompressor-com
https://en.wikipedia.org/wiki/Betamax
http://whatis.techtarget.com/definition/VHS-Video-Home-System