Since more than a year now, we at ulango.tv are engaged in the screening, review and presentation of streams whose URLs are to be found all over the internet. Some Urls just work for years, many don’t work at all, and many are showing poor quality. In this article I would like to take a look at the different factors a little more closely. There are basically three areas that need our attention: Player, Network and Server.
Players have been constantly enhanced to deal with new streaming protocols and hardware over time. In a future article I will have a closer look on the various protocols relevant to live streaming.
There is always the principal problem, to find a compromise between the best possible resolution, refresh rate, and the required network bandwidth for video transmission with limited transmission capacity. The stronger a stream is compressed the more intelligence must be used in the coding and decoding of the signal. Higher compression techniques require more computing power for decoding and even special hardware support (GPU) to deal with. If an older model does not have the appropriate power, then there is no chance to watch those streams. Of course, the pixel size of the image plays a huge role.
In our app UlangoTV – both on Samsung SmartTVs and on Android devices – we detect the hardware/firmware version of the client and therefore can control the selection of a stream representing a TV channel depending on the model number. Some streams are so called Multi streams. They contain a variety of resolutions and protocol variants in an index (m3u8 file) and the player has the opportunity to pick out the best, depending on the currently available bandwidth.
For Ulango TV we maintain a database with potentially many streams to a single TV channel and can select the most suitable for the user’s hardware. And there are already millions of them.
In general it can be said that newer players can cope better with complex protocols, or allow to view them in the first place. So, for example looking at the Samsung SmartHub SmartTV devices, we found that many streams didn’t run well until Series H and J. This also applies to newer Android devices. So we have, for example, found a significant improvement from the Amazon Fire TV 2014 Box and the Amazon Fire TV Stick which still run with Android 4.2.2, towards the newer Amazon Fire TV mit 4K Ultra HD Box with Android 5.1.
[Update Januar 2017
Strategy “Freezing” of Streams and Time Shift
Just recently we discovered a very interesting behavior of the VLC Player following a hint of one of our users. It made very bad streams to the best performers. With many streams we saw the problem, that the server declined to serve the 2nd or 3rd data block. The reason is that the servers need some time to compute the data blocks and the computation time may vary. So a very good strategy of the player is to wait some time before asking for the next block. This way the probability to get the block is much bigger without stressing the server with failing requests which finally would result in a complete disconnect with the problem of a failing reconnect as a result of missing ports on a loaded server. So the freezing ist nothing else than a time-shift. The player will continue without any data loss.
Of cause the time shift must not be too large, because then it could happen, that a block is no longer available from the server. That would imply a data loss and the user would see a gap.
The time shift can be up to 40 Seconds. So users occasionally have to be patient before seeing an uninterrupted stream!
Fast networks are actually available almost everywhere today. Because of good compression techniques, the required bandwidth consumption for IPTV is lower than is assumed in common way. Problems arise mostly only when the TV or set-top box is connected via a wireless home network. Degradation in the WLAN performance can have various reasons. Even in situations where the unit is not far from the wireless router, network faults from the outside can reduce the transmission rate significantly.
For many of the international stream servers, the transport from the international networks to the provider’s network plays an important role. Here, the bandwidths are limited and are controlled individually by the provider. Cable providers generally have much better international connections.
On the performance of the stream sources we have no influence at all. And there are huge differences.
Many small suppliers of streams have their own setup, with which they receive satellite data, decode and redistribute. Whether this is legal in detail, you cannot judge simply by looking at the Urls or the content. But users who view such Urls on TV or with their set-top box do commit legally speaking no wrong, as long as they do not store and redistribute the content.
Our UlangoTV application is only designed to be an mediator of stream Urls, assign the best quality stream to TV channels and possibly organize them into playlists. Once the user starts a stream, there is a direct connection to the sender of the stream.
The stream Urls of providers are often thought only to be consumed by specific users. Nevertheless, many of them are available on the web. You cannot know just by looking at the Urls if it is a single user stream or suitable to be watched by many simultaneous users. In Ulango TV we continuously monitor the quality of the streams and summarize the results in a so-called “usability” value. This is the average availability of a stream in percent. At values below 50 frequent buffering, interruption or even stalling of the stream is very likely. Again devices with fast and intelligent buffering clients are at an advantage because they are much less affected by disturbances on the server side.
The best performing streams are those running as so-called Multi-Cast streams. The data streams in the network are multiplied hierarchically towards the end users. This means that more and more users can view the stream without affecting the performance of the source server. Such stations at Ulango TV almost always have usability near 100%, which is also independent of load situations.
In summary, it must be said, that working with freely accessible IPTV streams is a very complex and often frustrating task. Anyone can go on the net himself in search of m3u lists and view streams. He will realize very quickly that these lists usually have only a very short life, because streams that work fine at the moment, will no longer be valid in a few days.
With our screening technology at Ulango TV we can take as much burden from the user’s shoulders as possible. With the help of our users, we constantly monitor and optimize the coverage of TV channels. Thus the user always has a good chance to see well-running streams. But he also needs to understand that occasionally coverage with runnable streams is simply not sufficient. That is not a problem of Ulango TV alone, but of all people who are looking after runnable streams world wide! Because of the large number of our active users, it is very likely that every functioning stream is already in the Ulango TV database!
Dieser Beitrag ist auch verfügbar auf: German