Hello ... Nice to be here!!
the quality of a video depends by the bitrate and the encoder...
I don't know where you are living and witch tv services do you have...
here in italy we have satellite and standard tv...
I would like to compare the x264 encoder with the encoders used on the tv channels...
because the bitrate is not sufficient to compare....
more important is even the fact that the tv channels need to do on the fly/ online compression, compared to the others streaming services like netflix that do it offline....
so for example right now in Italy sky dish company is using a particular encoder produced by NTT DATA called ntr https://emea.nttdata.com/fileadmin/web_data/country/it/encoding_print.pdf
THEY SAY THAT IT SAVES 40 % OF SPACE
OTHERWISE NETFLIX USES OTHER ENCODER...
I DON'T KNOW HOW TO COMPARE A X264 FILE WITH THIS OTHER ENCODERS...
ACCORDING TO YOUR EXPERINCE IN THE COUNTRY YOU ARE LIVING ... WHAT ARE THE DIFFERENCES BEETWEEN A X264 FILES AND A STANDARD DISH TV MOVIES FILE...?
THANK YOU VERY MUCH....
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Bitrate reduction can be achieved in many ways - video preprocessing is one of them and any encoder can be beneficial.
the question is about the quality of the encoding... free encoding vs paid encoding... so basically could a mkv x264 file achieve the quality of a dish tv channel?
I'm here to improve my knowledge...
so i know that the bitrate is not sufficient to determine the quality of a video because it depends also on the quality of the encoder... so the question I repeat the x264 encoder is good enought compared to the ones used to the dish tv channel??
x264 is far better than all the GPU based encoders encoders available for Windows. So I think it's a fair bet that x264 is better than any real time hardware encoder used by broadcasters.
LOOK AT THIS ENCODER https://emea.nttdata.com/fileadmin/web_data/country/it/encoding_print.pdf
IT IS USED BY ITALIAN DISH TV SKY TV , THEY CLAIM TO SAVE UP 40% SPACE...
NRT 2.0 is able to offer, at 4.5 Mbit/s, the same
perceptual quality which is usually delivered at 8Mbit/s by a traditional live encoder (H.264
NRT Encoding focuses on broadcasters that operate on Cable, DVB-S/T, IPTV and intend
WHAT DO YOU THINK ABOUT THIS ENCODER AND THE FREE VERSION OF X264?....
MOREOVER ONE IS ONFLY ENCODER AND THE OTHER IS OFFLINE SO OFFLINE SHOULD WIN IN QUALITY....
As you see first you need to define quality meaning - everyone has own unique quality perception - for example i've tried to encode 1080p with x264 and i could say that with 3 - 4Mbps average (dual pass slowest settings etc) it can deliver acceptable quality - for some people on this forum this will be unacceptable quality...
There are some effort to create objective metrics for subjective quality measurements but IMHO all of them are not complete solution.
You can give a chance to https://github.com/Netflix/vmaf - created by Netflix - there is some theory there so you can start reading.
Real time encoders (and most of broadcast encoders) are different beasts than offline encoder such as x264 - encoding for broadcast is full of compromises due of way how bitrate can be allocated for content. IMHO it is not difficult by decent offline encoder to beat broadcast encoder as offline encoder is able to perform multipass and can distribute bitrate with more optimal way (in broadcast limitation is transponder bitrate capacity and how other services present in transponder affect your channel as statistical multiplexing is vital for HQ broadcast encoding).
I've just checked paper provided by you - this is not realtime encoder - it is mostly for offline content - x264 should be able to deliver high quality in such case.
thank ya very much for your replies, I appreciate so much...
let's say that I don't have so many notions to make a judgment, so that's the reason why I was asking...
according to me quality is a matter of definition... and colours... this is my first priorities.
other than check the bitrate are there other parameters to focus on in order to find a good mkv files?
bad encoders have problems with moving sceneries... for example... so a not good quality could means less definition artificials... even more some files seem with fake colours that I don't know if this depends upon the master (even the filter used by the filmmaker )or by the file or IS JUST MY SUGGESTION
how colours could be influenced by the encoder?
thank ya again....
Last edited by air0s; 3rd Jan 2017 at 11:29.
NTT Data provides encoding solution to Sky Italia
By: Roberto Landini, Italian Correspondent
Monday, July 29, 2013 - 3:43 pm
Italian company NTT DATA has developed a solution, NRT Encoding, for Sky Italy that by applying innovative processes to the compression of linear channels broadcast via satellite can reduce bandwidth consumption by up to 40% whilst retaining the same quality.
Since bandwidth consumption is fundamental to the overall cost of a channel, it is clear that such a solution is potentially able to bring major savings for a broadcaster which has nearly two hundred satellite channels, such as Sky Italy.
NTT DATA provides professional value, from consulting to systems development to outsourcing, combining global approach and local attention with a long-term commitment to its customers. Sky Italy, for its part, is an Italian pay TV operator 100% controlled by News Corporation.
Riccardo Ferrari, senior manager, NTT DATA in Italy says: “The debut of NRT Encoding – with the first channel on the Sky platform transmitted thanks to new technology – was achieved by June and by December 2013, the solution will be extended to other channels.
“We have been partners of Sky Italy for several years and, just based on the experience made in the development of VoD encoding used to offer Sky On Demand on all screens (PCs, smartphones, tablets and TV), came the idea of exploiting the latest encoding techniques to process an offline linear signal.”
The basic idea is very simple: in fact, NTT Data had in the past developed and provided to Sky Video On Demand a system of encoding/transcoding offline input files supplied on different formats, generating an encoded version in various forms for various devices.
The system core is the same, based on AVC H264, with two different codes that share a large part of the initial encoding process, then depending on the device that requests them there are slight differences in the end-result.
This product encoding on-demand for tits services has proved extremely effective for Sky, and after selecting it in the face of competition from some other major names, Sky asked NTT Data to develop a different coding system that could also be used in linear systems.
Note that the file transmission for non-linear VOD has a physical beginning and an end well-defined, it is captured in full batch mode, and processed offline. The new encoding solution, meanwhile, us able to handle a continuous channel entry in linear mode and create an encoded version in output.
The linear flow input is segmented into small segments, each encoded in single mode, while a final component of the software makes a ‘merge’ of these segments in the correct way, then manages the output signal.
The process causes an important delay in the process of linear encoding from the moment the incoming stream arrives to that in when it is streamed in output. This delay is configurable, however, and preset by the broadcaster so they can establish a near real time of 5 to 10 minutes, or as required, and so everything is manageable in a concrete way by the playout systems.
The basis of this system of linear encoding by NTT Data uses very advanced techniques for encoding in H264, which also integrates open source libraries mixed with advanced techniques of adaptive encoding, rather than psycho-visual techniques.
The ‘core’ of the system of encoding works in terms of multi-step process even with very small segments. In fact, with a first passage are identified the complexity of the file and a number of useful features to better describe it, while the second coding operates on the basis of the data that the first passage has provided. The result is that you can manage a trade-off between the quality and the size of the stream. The above-mentioned basic segment is a configurable value; nell’NRT for SKY has been set to 10/15 seconds so at the end of the process, the transmission of a full HD Sky channel is accompanied by a bandwidth saving of as much as 40%.