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The history of streaming media is largely rooted in the advancement of much older technology. There would be nothing to stream if the media didn’t exist in the first place. The first form of media would be the captured media; the ability to take a photograph was developed in the late 1820’s by using light and transferring that radiation from the light into a sensitive material. With this innovation, the next step in the evolution of picture media was the moving picture first introduced by Thomas Edison in the 1890’s. The motion picture is created by presenting multiple photos in sequence with slight changes creating the illusion of movement. Edison’s film projection device successfully did this through the projection of light through a moving film strip flashing once each time a single frame from the film crosses the lens.
Around the same time, the first audio recording and playback device was created. The sound was recorded by talking into a diaphragm directly connecting to a sensitive needle vibrating it while it is cutting into a waxy cylinder to be played back by the same or similar needle resonating through a horn and thus creating playback. The two medias only existed as separate media types for quite awhile, until about 1910 when Edison introduced his new projection device that would have a phonograph attached to it to have sound played conjointly with a film.
Due to unreliability to synch up to the film and the occasional needle skip, voice overlay was rarely attempted but this set the groundwork to create new devices that will be able to improve the ability to synch up sound correctly to a film. Some of the ways they have done this is by embedding the sound signal into the film itself and with the improvement of digital technology, they have also been able to have multi-channel high definition surround sound on a separate optical disk synched up to the film by some sort of embedded time code. The creation of media was great, thousands gathered into packed rooms and special theaters to watch these films and very few people had an audio playback device because they were so expensive. These technologies were restrictive in how many people it can reach, they can only be played through one device at a time. What was needed was a way for many people to be entertained, informed, or contacted in any other way transmitted to many places from a single source.
The existence of the radio wave existed in the late 1880’s but was never used to transmit full messages until the next decade where the message was used to transmit telegraph signals over the airwaves. This was used to create transmission and communication over vast waters like the English Channel and some ships had started carrying these devices to communicate to each other. Voice was soon introduced into the airwaves and the first official radio broadcast station to transmit voice which was established 1917 in Wisconsin. In 1928, the first televisions were sold as well as the first television broadcast permits were distributed by the government. Not all of the televisions were run by cathode ray tubes (which are still used today), but using a scanning disk and lamp system which created a blurry orange color picture and created an image that was roughly the size of half a business card. These devices quickly became a huge part of American culture, entire buildings would gather into a single room to marvel at these devices and companies knew this. Now, almost every household in the world have a television set in their homes.
The relevance of all this previous technology to telecommunications and streaming do not occur until the early 90’s when the World Wide Web was first made commercially available to the public. Through the web, many people were able to connect and share information with hundreds of thousands of other computers around the world. But the bandwidth for consumers was so small that bits of text were the only things that could feasibly be transmitted and downloaded. Audio and video media has also been digitized at this time but a one minute sample of audio would take up roughly 10MB of space which if transmitted through the consumer’s modem lines would take most of the day to download, not worth the download at all. At this same time, companies are working on implementing even higher definition audio and video which would further reduce the potential of streaming over the internet. Another branch of digital media development was developed apart from the hi-definition developers, their purpose was to create a way to get more media into the net. Many protocols of file compression were created around this time and many failed.
What gave the consumer the greatest interest in what the internet can do for media is the use of MPEG-1 layer 3, or MP3 for short. The MP3 is an audio compression format that had the ability to take that minute long 10MB file and reduce the file size to one sixth of that original size and reproduce the sound with virtually unnoticeable degradation. The use MP3 is also the sole reason for the creation of the monstrously popular distribution software known as file sharing today. With the popularity of MP3, people realized how important compression can be to the internet and greater amounts of money had been allocated to do more research and development of it. Many formats had been developed and eventually bought out by two giant companies, Real and Microsoft. Microsoft had even managed to legally steal the Real player’s RTSP streaming protocol in which Microsoft had invested over eighty million dollars into before releasing their own streaming media player in 1997. Today, both companies still exist and are huge competitors rivaling each other with many smaller programs available as well.
Older technology such as the ability to record audio, capture photographs, broadcast radio and television were much needed stepping stones that paved the way for streaming content. With the creation of TCP/IP, the internet was born-but solely for military and governmental use. It was not until the 90’s when the internet or World Wide Web was accessible to consumers-bringing about new inventions created for users such as file sharing. If it were not for file sharing, the need for smaller file sizes for sharing would not be as great as it is. This gave way to compression techniques such as MP3, AVI, WMA, and MPEG, bringing about the creation of Hi-Definition for better visual quality. Corporations were eager to control the growing market of media players which was here to stay. This sparked the media player wars which was an all out attempt to dominate the online media content viewer of choice. The winner would also dominate streaming media content as the future of the media delivery business. A very lucrative one, considering billions of billions of people will be future customers.
Streaming content is never downloaded. It is in essence “channeled” or broadcasted to your computer. This is what makes it so attractive; users do not need to download large files in order to play their content. It’s a great way of delivering huge amounts of media without actually downloading it. Could you imagine downloading a thirty minute news segment before actually playing it? This would take up a lot of time to download, plus it wouldn’t be live if it were downloaded. In other words, streaming also opens up new frontiers such as live content. Users can tune in to a live broadcast as its happening without downloading a thing. This technology is widely used in financial markets where they use live streaming quotes to make decisions. It is a great example to show you the need for streaming. Investors cannot make decisions on data that is 30 minutes old. They need up to the minute or second data.
The underlying workings of streaming files involve the use of metafiles. These are very small text files that contain the address of the file and location of the streaming media server. The web server sends the metafile to the client machine, the user in turn opens the metafile which opens the correct application to view the stream which opens the streaming content, stores it in the buffer and begins playing the file. The reason why we use metafiles is very simple. Since we don’t want users to spend their time downloading content, we use metafiles to tell them where the content is stored instead of initiating a download. Metafiles contain information about the stream such as the IP address of the server it is located on and the type of file (.mp3, .wmv, .rm).
Real Time Streaming Protocol is the actual blueprint for streaming media. RTSP defines how media will be streamed between the server and client. It defines the different types of connections that will be used in different types of situations to deliver the content best. RTSP is designed to work with time sensitive media like streaming audio and video, as well as any application where time based delivery is essential. It is pretty much the code for streaming. All streams follow the same rules on how to work and RTSP it that rule. Another way to look at RTSP is like looking at TCP/IP. TCP/IP defines how the internet will work. It specifies how the packet will go from one computer to the next reliably and how to check for errors. The internet is dependant on TCP/IP to function and streaming is dependant on RTSP to function as well. So without RTSP there would be no such thing as streaming.
With the advent of streaming, it has brought with it efficiency. Internet users of different speeds can all view the same clip even though one person is on a 28.8 modem and another is on cable. This is possible thanks to RTSP’s ability to handle multiple bandwidths on one stream. For example, you can encode a single audio music clip for 28.8 Kbps modems, 56 Kbps modems, 112 Kbps dual ISDN, and T1 connections. Your Web page links to this single clip, and when a visitor clicks the link, RTSP determines which encoding to use based on the available bandwidth. RTSP can even adjust this choice to compensate for network conditions. If a fast connection becomes bogged down because of high network traffic, RTSP seamlessly switches to a lower bandwidth encoding to prevent the presentation from stalling. When the congestion clears, RTSP switches back to the higher bandwidth encoding.
Despite its advantages, streaming in general has been off to a slow start. It’s still not as common on the internet as it should be. Reasons for the slow growth of streaming media may have to do with the slow implementation of it. The technology is still fairly new and web designers must learn how to implement it in their websites. This is fairly common with new technology as it must first be learned before it can be implemented. Thanks to larger bandwidth, powerful computers, and better video compression algorithms, today’s internet is capable of delivering streaming media such as news, radio, and even live television with unsurpassed quality and speed.
Some issues with bandwidth needed to be resolved before streaming in general could take off. Speed barriers of traditional 56k modems were broken with the adoption of broadband such as cable, DSL, and satellite internet service which promise speeds up to 3 mbps. A common problem for streaming on slow connections such as modems was its inability to download the content fast enough for it to play smoothly. With the wide adoption of broadband such as cable and DSL, this resolved problems of the files playing faster than they were being downloaded and enabled higher quality playback thanks to larger bandwidth. In order to successfully stream media on the web you need to have enough bandwidth. Everything contained on a web page including text, graphics, animation, audio and video requires a certain amount of bandwidth to move across a network. Bandwidth is similar to the width or capacity of a pipe. For example, a high capacity water pipe might allow a maximum of twenty gallons of water per second to stream through it.
On the other side, a low capacity water pipe might only allow 1.5 gallons of water per second to stream through it. However, on the web we’re pumping packets of data measured in bits, kilobits and megabits per second. The term called data rate refers to the rate per second at which data is electronically transmitted across a network line. On the internet data rate is measured based on kilobits per second. For example, a 28.8 modem has a bandwidth capacity of about 28 kilobit’s per second.
The cost for streaming is now mainly associated with server cap which is the limit or cost of server space and bandwidth. Prices can range anywhere from hundreds of dollars a month for a very small amount of bandwidth all the way up to hundreds of thousands of dollars for huge websites like google, yahoo, msn and other websites that have streaming content. In their case, these huge companies don’t just have one streaming server for their content. They have many streaming servers situated at strategic and geographic locations in order to accommodate the largest audience at the best speed and quality. It seems that no matter how much technology advances, space is still a challenge that has not been able to be conquered. This “limit” on bandwidth is what makes it expensive. If we had no limits on bandwidth, we would never pay for it.
Sometimes we fail to give credit to the basic developments in technology. After all, many of the advancements in today’s streaming content in largely due to the advancement of much older technology. Older technology such as TCP/IP and many other advances is what streaming rests its foundation on. If it wasn’t for these basic underlying advances, streaming would not exist today. Thanks to larger bandwidth, powerful computers, and better video compression algorithms, today’s internet is capable of delivering streaming media such as news, radio, and even live television with unsurpassed quality and speed. The prospect for the future is good. We are still in the very early stages of streaming implementation. It will be interesting as we see how this technology will develop itself in the future to accommodate our ever so changing needs. One thing will remain for sure. Live content delivery over the internet is here to stay. This market has no choice but to grow. You can bet your last dollar on that.
In order to send an audio or video over the internet, and because of the bandwidth consuming nature of streaming, more efficient ways of content delivery was needed. File compression is the main technique that is used to keep file sizes down to a minimum. It allows for transmitting the maximum amount of data through a limited amount of bandwidth while keeping the integrity of the file as intact as it is possible. Compression in its very nature introduces additional obstacles in the streaming world itself. Also, we shouldn’t forget that the disadvantage of compressing files makes us lose precious quality but the advantage is that it offer smaller file sizes, which makes it faster to download a file. In file compression we should differentiate audio file compression from video file compression since the processes are different for each type.
To facilitate the compression of audio files, whether these are in the form of speech or music two different techniques are used. These two techniques are predictive encoding and perceptual encoding. However, we shouldn’t forget that there are a few differences in the compression of the audio files depending on what type it is. The main difference is how much we need to compress, for instance for speech audio files, we need to compress a 64-Khz digitized signal. In the other hand, for music audio files we need to compress a 1.411-Mhz signal. The differences between the techniques tell us what type of audio files we can compress with each one. For example, in predicting encoding, we encode the differences between the samples (which means differences within the samples), instead of encoding the samples values. We will usually use this technique to compress speech audio files instead of music audio files. There are a number of standards defined for this technique, for example GSM, G.729, and G.723.3, among others; these range from 5.3 Kbps to about 13 Kbps.
In the perceptual encoding technique, the study of how people perceive sound or psychoacoustics is used. The main idea is to use the flaws present in our auditory system, such as masking a sound with another. Masking sounds can happen not only in frequency, but also in time. The difference is that in frequency masking, a loud sound in a frequency range can mask a softer sound in another frequency range. And in temporal (time) masking, a loud sound can deaden our ears for a short period of time, even when the sound has stopped already. This technique is mostly use in compressing music audio files because it needs at least 1.411 Mbps and is the most conventional or most common compression technique used to create CD-quality audio. MP3, which is part of MPEG is one of the standards using this technique. MP3, in this technique, analyzes and divides the spectrum into several groups. The frequency ranges that are totally masked have zero bits allocated to them, and the frequency ranges that are not masked have allocated to them the largest number of bits. As it is obvious, the frequency ranges that are partially masked will have allocated to them a small number of bits. In MP3 three data ranges are possible: 96 Kbps, 128 Kbps and 160 Kbps.
Another type of file compression is video files compression, which is extremely different from that of audio files. In video file compression, a video is composed of (or divided into) multiple frames, where each frame is an image. So, in video files compression, we first compress these images. Video file compressions also have standards established in the market such as JPEG (Joint Photographic Experts Group) and MPEG (Moving Picture Experts Group). The processes in JPEG are different from the ones in MPEG. In JPEG, a picture is divided into blocks of pixels - this depends on whether the picture is in gray scale or in color. The purpose of this is to decrease the number of calculations for each picture, since the number of mathematical operations needed for each picture is the square of the number of its units. The main idea in JPEG is to alter the picture into a linear set of numbers that reveal the redundancies or lack of changes in the picture, so this can then be removed by using a text compression method.
One of the steps in JPEG is called Discrete Cosine Transform (DCT), where each block of 64 pixels undergo an alteration which changes the 64 values in order to keep the relative relationships between the pixels, but where the redundancies are not exposed. Another step is known as quantization, where the values are quantized to decrease the number of bits needed for encoding. In quantization, we have to divide the number by a constant and drop the fraction, which in the end will reduce the number of bits even more. However, one of the disadvantages of JPEG comes to sight in this phase because this is the only step that is not reversible, and in this step or phase, we lose some information that we cannot recover later. Also, another step after quantization is compression, where values are read from a table - created before - and redundancies are removed completely.
The other type of video file compression mentioned was MPEG, in which a motion picture is defined as a rapid flow of a set of frames, and where each frame is considered an image. MPEG defines a frame to be a spatial combination of pixels, and a video as a temporal combination of frames sent one after the other. These two types of combination create two different types of compression, which are spatial compression and temporal compression. However, for MPEG video file compression is spatially compressing each frame and temporally compressing a set of frames. In spatial compression, each frame is a picture that can be compressed independently from the others. In temporal compression, redundant frames - frames that don’t show too much changes - are removed. In addition, and in order to compress data temporally, MPEG divides frames into three classes: I-frames, P-frames and B-frames. The differences among these classes of frames are very simple.
I-frames are intracoded frames; these are independent frames not related to any other frames. These are only present at regular intervals to deal with sudden changes that cannot be shown in neither previous frames nor in the future frames. These also cannot be assembled from other frames. The P-frames are predicted frames; these are related to the preceding I-frame or P-frame. These contain small segment of changes from the preceding frame, therefore, P-frames can be build only from previous I-frames or P-frames. An advantage is that these carry fewer information than other frames types and so, they carry fewer bits after being compressed. Finally, B-frames are bidirectional frames; these are related to the preceding and following I-frame or P-frame, so they are related to the preceding and the future frame. However, these are not related to another B-frame. One advantage of MPEG as a whole is that it already has gone though two versions, one known as MPEG1 and the other as MPEG2. The differences between these versions rely mostly upon what was designed for and the data rates. MPEG1 was designed for CD-ROM with a data rate of 1.5 Mbps and MPEG2 was designed for high-quality DVD with a data rate of 3 to 6 Mbps, which is twice to even four times the data rate of MPEG1.
Nonetheless, the streaming industry is currently a very common place for lossy compression, which is when a stream (or file) is compressed to decrease it’s size, but as a tradeoff, it decreases in quality. Also, in lossy compression, parts of the file information are removed and then the player place in predicted information based on the last frame played and the next frame known. An example of this - regarding video compression - is JPEG, which is called lossy compression because of the quantization phase, since in this phase - as we said before - we will lose some of the file information that cannot be recovered later on. However, the stream or file will still be recognizable to the user but so will the lower quality. Also, streaming audio and video, whether it is stored or live, are sensitive to delay and neither of these can accept retransmission, which makes us see that there is still much progress to be done in the streaming industry as a whole.
One of the main concerns that experts have in mind or issues that they are striving for today is lossless compression, which is simply compressing files without degrading the quality of those. Also, multicast services and the use of some protocols, such as UDP and RTP needs to be developed a lot more, since today in the streaming media, whether it is stored audio/video files or live audio/video files, we use only unicasting services or multiple unicasting services and the TCP protocol. However, all we can say is that thanks to advancements in compression algorithms, lossy compression is beginning to be less common in streaming media today, but more as mentioned before there is still a lot of development needed in the streaming industry.
Since in steaming, the file never actually exists in the user’s computer at any one time, the user receives the file via streaming and either views or listens to it. Live steaming allows you to build the stream very quickly from the source, either a camera or microphone and record the event. This is then sent to the users as soon as the stream is built instead of it actually saving it as a file.
Live streaming radio resembles the traditional radio but instead of using frequencies to deliver the live content, you access the material via an IP address. Nearly every radio station in the country now has a presence on the internet. Internet radio has been around since the late 1990’s and has grown popular year by year. Nearly every radio station now has a presence on the web where they still broadcast the traditional way via frequencies but simultaneously send their content via broadband.
Although this may seem difficult from the person who is unaware about it but quite frankly it is not. From the disc jockeys mike, the audio enters the Internet broadcaster’s computer for encoding via a sound card. The sound card changes the wave sound to 1 and 0’s so the computer can understand it. After the sound card, it is then sent to the encoder system in the computer. Encoding programs like SimpleCast provides a simple way of taking audio from your sound card or line in and encode it ready for streaming. SimpleCast allows the option of encoding the sound in the most popular streaming formats like mp3, real and wma9. All this is done in real-time.
After the encoding process has completed, the audio is compressed and sent to the server. Instead of the file residing in the server in the same way a streaming file may be saved in a server, it is sent there to be delivered via the internet. The server has a high bandwidth connection to the internet. When a user clicks on a link on a webpage, lets say the radio stations, a meta file referencing an IP Address and in turn the meta file opens the correct player and the player opens the stream. The same happens when the source is actually live.
Now there are even stations that don’t even broadcast via sound waves but have and exclusive presence online. So the only way a user can hear their content is when they are connected on the internet. An example of such a station is www.di.fm .
Radio live streaming is well known but TV is now making waves in the way it uses the internet to stream its programs. In the United States, it may not be as popular but in other countries like Germany, there are TV stations that are broadcasted via broadband. An example of such a station is www.viva.tv and another popular one not exclusive to Germany is bbc.co.uk.
The amount of people using the internet daily is increasing year by year. And with the availability of fast internet connection, more interactive websites are becoming more and more popular. Just a static website is no longer acceptable, websites using flash and video and audio material is what makes a website more appealing. The statistics obtained by www.itfacts.biz prove that 74% of Web users have viewed online video at least once and 51% do so a minimum of once a month. More data collected show that 27% watch streaming video at least once a week; and 5% view Web video streams daily, according to Online Publishers Association.
The primary users of streaming video can be broken down to 4 main groups. The Brokers, Students, Businesses and the regular consumer.
Brokers use methods where by a java script will update every number of times and display quotes of a certain stock. A company called Datek is about to change all that. It is the first company to actually use streaming quotes online for brokers to use. It is an idea that will catch on as big fortune 500 companies realize that there is a market for it. A new company called esignal.com is also joining the Datek in providing live streaming quotes.
Students are also experiencing the benefits of streaming in their education. Lectures can now be streamed online and one of the biggest benefits of this is that students who want to review material can re-watch the lecture at their leisure which is a bigger benefit then using the traditional voice recorder. UCLA is a very good example of a university that has adopted streaming lectures. It has a live and on-demand program for streaming lectures. Some students oppose this because they claim that posting lectures online robs the student of the incentive to attend class, and puts too much emphasis on presenting information rather than on the instructional interactions between students and instructor.
Businesses are now catching on the big potential of using streaming in their organizations advertisements. Streaming Media can be a highly efficient way of advertisement for branding campaigns but also to announce new products like film releases. A recent study commissioned by Measurecast, a streaming audio measurement firm, polled 100 ad agency executives and found that nearly two-thirds of the agencies have recommended streaming media advertising to their clients in the last 12 months and will continue to do so in the future. When you go to sites like nissandriven.com and sony.com, you will notice that these websites are filled with flash and various interactive technologies. There are even small videos you can view of the performance of lets say Nissan’s 350Z and majority of them are streamed.
Consumers are by far the largest users of streaming content on the internet. After all, it is because of them that the technology really exists in the first place. Live shows can now be viewed online without having to actually go the concert. If you have AOL, they often have their Concert Series which allows users to be able to view a live band on the internet and the content is live. Video on demand is another niche in the market that is booming. Being able to watch a video of your favorite artist at will is very attractive and an example of a service that offers this is Yahoo. Yahoo has their launch.yahoo.com site that anyone can register and listen and watch the video of their favorite artist. If you can’t watch the news, you can log onto abc7.com and watch the news there, right in your office and still be up to date with the news happening in the world.
The future for streaming is still uncertain. The technology behind streaming has had positive effects on other media fields as a feasible way to save space in broadcast and Hi-Definition media. In television, re-run shows are compressed to the point of much lower quality to save money on broadcasts to increase profits from sponsors and save money from using less bandwidth. In the Hi-Definition realm, companies are beginning to approve certain lossless compression codecs in order to fit more precious information onto available optical disks. Optical disks have also improved with shorter wavelength lasers allowing for even more information to be stored onto a disk and the ability to read multiple layers multiplies that amount. There have also been discussions of placing fluorescent lower layers to counteract the problem of lower layers being more difficult to read allowing for many more multiples of layers to be able to fit onto a single optical disk. What about advancements for actual streaming over the internet? Better compression codecs will most likely be developed to fit even more information into the limited consumer bandwidths. Surround sound over the internet will be available as well. Bandwidth is also getting cheaper. Pretty soon, every house in the world will have the ability to get onto the internet and many will have available speeds many times faster than current broadband lines which will help make streaming that much more accessible to the consumers. In the end, it is all about satisfying the consumers, and the consumers will always want more than whatever is available.
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