Name: 4 / 8 / 16 / 24 HDMI IPTV Streaming H.264 Encoder - UDP, RTP/RTSP - SPTS & MPTS - Multicast & Unicast
Brand: Thorbroadcast
Price: 10049.5 USD
Availability: InStock

8 HDMI model description

Thor Broadcast High Density H264 Encoder H-HDPerformux, specifically designed and made to handle up to 24 HDMI inputs and output via 1MPTS or 24SPTS.

Description

Thor Broadcast High Density H.264 Encoder H-HDPerformux-XX, specifically designed and made to handle up to 24 HDMI inputs and output via 1MPTS or 24SPTS. This unit has a full functioning GUI (Graphical User Interface) that Thor has designed to help navigate creating all of your H.264 Streams with MPEG 1 Layer 2 Audio or AC3 Audio Passthrough. Additionally you have a single ASI output that will mirror the MPTS output. Specifically featuring the QR code, Logo, and OSD insertion for cable operators that require this feature. Furthermore it has PID remapping, PCR and PSDI adjusting and editing as well. This 1RU unit can replace an entire headend with the high density 24 HDMI input chassis with easy operation and Thor Broadcast's leading warranty and free tech support from our lab in Los Angeles.

Tags: HDMI over IP

Features

4 / 8 / 16 / 24 HDMI inputs
MPEG-4 AVC/H.264 Video encoding
1 Gigabit Output for UDP and RTP/RTSP protocols
1-20Mbps output data per IP Stream
MPEG1 Layer II Audio encoding and support audio gain adjustment
MPEG-1 Layer 2, LC-AAC, HE-AAC, AC3 Passthrough audio encoding
Control via web management, and easy updates via RJ45
1ASI output, copy of MPTS output
CBR / VBR
QR Code, Logo, OSD insertion
Null Packet Filter
PID Remapping (180 inputs per channel)
PCR Adjusting
PSI/SI Editing and Insertion
Exceptional Price Per Channel

Drawings

Video

Quick configuration Guide for H-HDPerformux- 8/16/24

H-HDPerformux-XX is an affordable high density H.264 Multi-channel IP encoder. The HDMI HDCP enabled IPTV Streaming HD encoder & integrated multiplexer is a 1RU platform. Outputs up to 24 SMPTS' UDP or RTP(RTSP), 1MPTS, encodes HD video from any HDMI source into IPTV streams. The encoding video rate is adjustable from 1-20Mbps

Model Selection

Model Numbers

H-HDPerformux-4 4 channel HDMI to IP H.264 Encoder Streamer

H-HDPerformux-8 8 channel HDMI to IP H.264 Encoder Streamer

H-HDPerformux-16 16 channel HDMI to IP H.264 Encoder Streamer

H-HDPerformux-24 24 channel HDMI to IP H.264 Encoder Streamer

IPTV encoders are a valuable piece of infrastructure to transmit multiple channels or programs over a LAN easily, and generally in H264. However, it is essential that you use a decoding apparatus like an IP-STB here that can receive those programs via IP addresses in H264 and output that signal via HDMI so a television or screen can receive them.

Our Encoders can be used with our IP STB's ( set-top Boxes ) - IP to HDMI decoders

Example H-STB-IP

Specification

Input	4/8/16/24 HDMI inputs
Video	Resolution	Input		1920×1080_60P, 1920×1080_60i, 1920×1080_50P, 1920×1080_50i, 1280×720_60P, 1280×720_50P
		Output		1920×1080_30P, 1920×1080_25P, 1280×720_30P, 1280×720_25P
	Encoding	MPEG-4 AVC/H.264
	Bit-rate	0.5Mbps~20Mbps each channel
	Rate Control	CBR/VBR
	GOP Structure	25-50
Audio	Encoding	MPEG-1 Layer 2, LC-AAC, HE-AAC, AC3 Passthrough
	Sampling rate	32, 44.1, 48KHz
	Resolution	24-bit
	Audio Gain	0-255 Adjustable
	Bit-rate	48/56/64/80/96/112/128/160/192/224/256/320/384Kbps
Multiplexing	Maximum PID Remapping	180 output PIDs per channel
	Function	PID remapping (automatically or manually)
		Accurate PCR adjusting
Stream output	ASI output(optional) as copy of MPTS IP output thru Data1 (GE) or Data2 (FE) over UDP and RTP protocol (8 HDMI inputs with 8 SPTS and 1MPTS output; 16/24 HDMI inputs with 16/24 SPTS or 1MPTS output)
System function	Network management (WEB)
	English
	Ethernet software upgrade
Miscellaneous	Dimension (W×L×H)		482mm×440mm×44mm (1RU)
	Approx weight		8kg
	Environment		0~45C(operating) -20~80C Storage
	Power requirements		AC 110V± 10%, 50/60Hz, AC 220 ± 10%, 50/60Hz

Question and Answers

Question:
1) Good day, I'm interested in this solution for a hotel, the TVs (476 units) are Samsung Hospitality type without an Ethernet port, some IP to HDMI needs to be in place also. Thank you in advance 2)They want to have at least HD definition, they want to use the HMDI input of the TV, there's a Giga ethernet LAN in a site intended for the distribution of the content (copper and fiber). All receivers in their headend have HDMI output, they are thinking on 24 channels + 1 hotel channel (hotel information, schedule, tourism). The image below pretty much describes what I'm looking for, they have the content, the network, and the TVs, the missing part is the Encoding/Streaming/Decoding part. 3) Yes, exactly. IP to Hdmi on each TV and H.264 compression.

Answer:
1)So the TV's all require RF coaxial cable correct? How many channels total? What is going to be the source of those channels, commercial set-top boxes? 2) We have various formats and options for RF modulation. Please let me know what is the standard that you require: QAM, ATSC, ISDBT, DVBT, etc Mpeg 2 or H264? 3) So you plan on putting an IPTV set-top box on every television? For IP input and HDMI output correct? For 24 channels you plan on using H264 compression? So, in this case the best product would be 24 HDMI H.264 MPEG4 Encoder H-HDPerformux-24, it encodes 24 HDMI sources for 24 SMPT's Multicast TS UDP streams. The IP STB will receive the streams and display them as an HDMI Video output, Those channels will be programmed into the IP STB and using the remote control you will access all your 24 TV programs on each STB on the network. This is the link to the IP-STB https://thorbroadcast.com/es/producto/compacto-ip-del-decodificador-set-top-box.html

Question:

I'm looking for 4 channel HEVC encoder with SDI input

Answer:

Hello, we only have HEVC H.265 with HDMI inputs right now

would you use something like this with converters?

https://thorbroadcast.com/product/4-8-16-24-hdmi-iptv-streaming-8230.html/214

H-HDPerformux-4+ 4 channel HDMI to IP HEVC H.264&H.265 Encoder Streamer

You could potentially use converters so long that they would be compatible with all the needs of transmitting data.

I assume you have 3GSDI feeds?

yes

so you'd have to make sure the converter can do 3G and HDMI to 1080p60

Even then, no telling if that would effect the unit

as far as timing? frame loss?

yeah all that. because a lot of those 3rd party converters will take short cuts to work, but not exactly a professional solution

so its a coin flip honestly.

so buy the cheapest converter I can find

so no encoders with native SDI input?

There might be some on the market, but we only have HDMI input models avaialble

They work really well, we just sold a ton of 24 HDMI input models, super high density

Question:

Our clients have questions that seem to be around the system being able to work via their existing distribution network. They advised they had CAT 6 cabling to all cabins earlier but there appears to be some mix messaging at the moment with the offshore team talking about a coax network.This is a prestigious project for us and I would assume it is for you too. The Kwame Nkrumah FPSO is a landmark project for Ghana and it’s good PR to be providing your solution on that vessel.

2)

Basically they have 2 distribution networks on the vessel:

An existing coax network they used in distributing the existing TV system signals to all cabins and common rooms

An cat 5 ethernet network they use in providing ethernet connectivity to all cabins and common rooms

The Engineer onboard wasn’t too sure of which network we intended to use but we clarified it was the CAT 5 network today. He however flagged up another concern we agreed to take away as an action to check with Thor Broadcasting.

Concern

Some of the existing CAT 5 cables are over 100m on a single run. The existing coax network appears to be amplified at certain points to avoid signal degeneration and so borrowing from the reason for this amplification on the coax network, they are asking how we plan to overcome potential signal issues on the long cat 5 runs.

Does the encoder compensate for this in any way? I proposed getting a switch with PoE ports is the usual solution for these sorts of problems but wanted to check if you are in agreement and if this conflicts with any protocols on your system? Please let me know what you think. I have attached a drawing with our proposed solution for context.

Answer:

So, if I understand correctly, your consumer would like to use the Coaxial network, not the IP network to distribute the video?

We will be happy to talk about all the technical aspects of the project and advise the best solution, we can provide modulators if needed.

please check those units :

4 channel HDMI to COAX

https://thorbroadcast.com/product/1-4-or-8-hdmi-digital-rf-encoder-modulator-8230.html/238

8 channel HDMI to Coax

https://thorbroadcast.com/product/1-8-hdmi-digital-rf-modulator-cc-closed-captioning.html/95

or both

4Channel HDMI to COAX and IP at the same time :

https://thorbroadcast.com/product/4-hdmi-component-hd-to-coax-and-iptv-hd-8230.html/21

We will be happy to talk about all the technical aspects of the project and advise the best solution, we can provide modulators if needed.

2)Cat 5 is passing Ethernet, the ethernet is a digital signal, Ethernet devices always re-clocks the signal, it is easy to determine if the 100m is an issue or not, you would have a link on the switch or not.

The 100m is a maximum CAT5 that can run.

If you do not have a link then you need to put an ethernet switch somewhere in between, or you can use point to point optical transceivers like those below, by using them you can extend Ethenet of many Km:

https://thorbroadcast.com/product/10-100-1000-mbps-fast-and-gigabit-ethernet-over-1-fiber-media-8230.html

There is no CAT 5 amplifier, the ethernet doesn't have power like CATV RF

No, As I mentioned the Ethernet can not be stronger and weaker, it is a data stream signal

POE Switch does not do anything for this, POE switch can send DC power over the CAT 5 to power POE device like Camera, so you do not have to use external DC power supply, but it doesn't extend the range of the ethernet signal.

Question:

I have few questions about your IP Encoder product line

Answer:

I want to implement IPTV, we will be a small ISP that will start soon

We will reach our clients through fiber optics to their homes

We want to mount the necessary equipment on our node to offer IPTV service.

But we don't know at all what equipment we need

We want to contract legal channels such as FOX, HBO, Discovery, etc. to be able to offer our clients these packages.

But first we need the equipment.

What equipment could they offer us?

Could we have a small meeting by videoconference?

I could send you the invitation is through Microsoft Teams, you can access it from the web browser of your cell phone or computer.

We only want to know about the IPTV equipment solutions that they could offer us.

Do you have your own headend? Where are the sources coming from?

We have lot of encoders for IPTV, but distribution is another process.

https://thorbroadcast.com/product/8-hdmi-broadcast-encoder-iptv-streamer-and-asi-out-h-264-8230.html

We have HDMI or SDI, but we need to know the protocol fro video, MPEG2 or H264; then the streaming protocol like RTP UDP RTMP etc there are many variations in the resolution and audio codecs as well we need to know more information about

ok currently we don't have the headend ready, we are under construction.

We want to search for sources, but we want our sources completely legal so as not to have problems of transmission by content, but we do not know with whom we can talk about it.

Well that starts with which country you are in, you need to speak with somebody in the government who can help you a little, or contact the cable TV companies

Essentially you will have several issues, from building the headend, getting access to those channels, and then distribution. Of which you will need make some sort of encryption effort, supply customer with set top boxes, and also lease the fiber. If this is all in one location or building then it is easier.

I do not want to retransmit a signal from cable companies.

I want to buy my own signal and pass it right to my clients.

Oh I see, then you will have to contact those companies directly, setup agreements and lease out those channels like any other cable company

Very good chance that they can let you access those channels direct from satellites, so you would pay a fee, get an access card, or code, and then you can use an IRD with CAS to get that data from satellites.

However I will mention our company does not get involved in any of that. We make and sell headend equipment.

Question:

H-HDPerformux-16 unit. What is the best software to decode the encoded stream on a laptop or PC?

Answer:

You can use any program that can decode the protocol that you plan on using.

If its a more common protocol like UDP/ RTP/ RTSP then you can use something like VLC that is freeware.

Something like RTMP is commonly used with YouTube for live streaming.

There's no shortage of programs that can decode; really depends on how you plan on encoding the signal, then identifying that protocol in a software.

As for the best? That's more of personal preference. OBS is another Free program that plenty of people use.

If you want to pay for one, there are dozens of professional studio decoding options available.

So I would start with which protocol you plan on using to stream; then go from there.

Question:

Am in Africa(Uganda),i have 8 inputs that are to be distributed to 50 rooms. which equipment would you recommend for me to use, we used CAT 6 cables for all the rooms

Answer:

If you have cat6 then you would need an IPTV encoder; something like this:

https://thorbroadcast.com/product/8-hdmi-broadcast-encoder-iptv-streamer-and-asi-out-h-264-8230.html

This will intake 8 inputs HDMI then convert to IPTV streams.

At every room you will need a decoder to convert IP to HDMI for input into the televisions.

https://thorbroadcast.com/product/compact-ip-decoder-set-top-box.html

So if there is one TV in every room, then you will need 50 decoders.

Question:

Do you have equipment like "HDHomeRun "? input: DVT antenna ..(Inside your box multiple tuners (2, 4, or more) and then transform them in IPTV format for diffusion thru fast ethernet .. connected to our personal box ? the client will be android APP, installed on a smart TV or tv box with IPTV client.. your device will be remotely manageable to select the DVT sources on the 4 tuners

Answer:

Yes, we do RF to IP IPTV gateways, In the USA, CANADA, and MEXICO, you use the ATSC modulation standard.

The gateways have 8 or 16 DVB-T tuners and they can output UDP unicast or multicast stream for all TS's ( programs ) multiplexed on those Channels.

So, for example, if ATSC ch 50 has 4 Video/ Audio TS programs, we can output all of them, and as a TS

We do not re-encode the video audio we are just passing it from RF to IP

You can use any decoder supporting UDP multicast or unicast to decode those streams

so any of those devices would work for you

H-8ATSC-IP-RF

https://thorbroadcast.com/product/atsc-or-qam-to-ip-gateway-atsc-qam-iptv-broadcast-8230.html/70

H-16ATSC-IP-RF

https://thorbroadcast.com/product/16-rf-tuners-to-iptv-ts-qam-output.html/116

You can watch this video:

https://youtu.be/zMDsT0aua3g

Question:

How to set up and test HDMI IP encoder and your IP Set-top-box H-STB-IP. I am using a cisco switch. Does it need any special configuration?

We have 120 STB's on the network , this is the STB we are using:

https://thorbroadcast.com/product/compact-ip-decoder-set-top-box.html

Answer:

1) the switch needs to have the ability for DHCP, the STB needs to get the IP address from the network router DHCP server.

2) Also, the IGMP protocol needs to be enabled.

The Encoder has a Gigabit Ethernet interface, the STB has 100base T

The STB needs to be connected to the switch, it will not communicate directly with the encoder because of the Ethernet speed interface difference.

Troubolsuting :

Please connect the encoder to the switch, connect The PC to the switch, and verify if the Lulicast streams are being sent out using VLC

the VLC syntax is udp://@224.2.2.2:10002 , udp://@224.2.2.4:10004 .. and on

You can also use TS reader very handy tool :

Please download the TS reader, it is a really good tool for analyzing streams,

TS reader accepts udp multicast

Whence you verify the multicast stream, please concentrate on the STB,

Please verify if the IP STB received is own IP Adress

Check the switch port and see if the traffic on the port doesn't exude 100mbps , the switch when the IGMP is enabled should send only the stream which was requested by IP STB, so the data rate on the switch port should be = 1 encoded stream about 8mbps

Question:

We are setting up an H-HDPerformux 8 hdmi port unit. This is on
a ship and just used to stream TV throughout our wifi. We are having
issues though and it appears to be with the multicast over WiFi. We
have tested the streams on a wired connection and it worked great. In
reading it seems like this is an inherrent issue with multicast over
wifi. what is the best method to configure for unicast. I have used
other similar products from other vendors and would point stream to an
individual IP and or port. we have set the stream output to the data
IP address and port but are unable to view the video. I would
appreciate any assistance you can offer on helping to resolve this. We
are viewing with VLC. This is a very robust network with gigabit to
all switch ports and approximately 20 Access points

Answer:

Unfortunately, it is impossible to distribute multicast streams over
Wifi reliably, Wifi doesn't have that ability and doesn't support it.
It needs to be distributed over a copper LAN network
You can set up a unicast stream and instead of the multicast IP
address, place the destination (decoder/receiver / PC ) IP address )
but the encoder Data IP address needs to be on the same Subnet as a
receiving device.

So for example, if the receiving PC address is 192.168.2.100, the data
IP also needs to be on 192.168.2.XX network.

Please note the NMS and Data IP Must be on the different subnets

Question:

I’m looking at your systems here… https://thorbroadcast.com/products/pro-dvb-encoders#

And trying to get a sense of what we would need to make our office video distribution work.

We’d like 16 (or more) discreet video channels (a mix of HDMI and SDI) to transmit through the office to 10-12 individual desks – where the user at the desk can change the channel to whatever source they would like to watch.

KInda need an inhouse cable system over IP.

Can the encoders be combined? A 4 HDMI encoder working along side of a 4 SDI encoder?

Can this system run on a standard switch configuration? Or does it need its own network?

How would I get a quote for a system?

Answer:

This is a relatively simple application. Yes, the encoders can be combined.

It is possible to use a mix of HDMI and SDI encoders to transmit 16 or more discreet video channels. The encoder would create its decreased UDP multicast stream which can be decoded anywhere on the LAN by any PC or IP Set-top Box. On the PC, you could use a simple VLC player to decode, the IP STB is a stand-alone small device for receiving and decoding those streams to HDMI.

Regarding the network, it can be run on a standard switch configuration, but the IGMP protocol needs to be enabled for the multicast to work.

"UDP (User Datagram Protocol) multicast is a type of IP multicast that uses UDP as the transport protocol. It allows for the efficient one-to-many distribution of data to multiple receivers on a network. This is achieved by sending a single copy of the data to a special IP address called a "multicast group" that represents the group of receivers that should receive the data.

To use UDP multicast, a sender sends data to the multicast group IP address, and any device that has joined that group will receive the data. The sender does not need to know the individual IP addresses of the receivers, only the multicast group address.

Receivers can join and leave a multicast group at any time using a process called "multicast group membership". This is typically done using the Internet Group Management Protocol (IGMP) or the Multicast Listener Discovery (MLD) protocol.

UDP multicast is widely used in a variety of applications such as streaming video, online gaming, and software updates. "

The 16 streams would require approximately 160Mbps of bandwidth

You could use the following encoders:

8ch- 24ch HDMI H-HDPerformux-8 - H-HDPerformux-24

https://thorbroadcast.com/product/4-8-16-24-hdmi-iptv-streaming-8230.html/214

for the SDI we do have only 2 models :

4ch - H-4HD-EMS

https://thorbroadcast.com/product/4-hd-sdi-broadcast-encoder-iptv-and-asi-out-mpeg2-8230.html

12 CH H-12SDI-QAM-IPLL

https://thorbroadcast.com/product/12-hd-sd-3g-sdi-with-608-708cc-closed-captioning-catv-rf-modulator.html/41

This is link to the H-STB-IP IP to HDMI decoders you could use for decoding

H-STB-IP

https://thorbroadcast.com/product/compact-ip-decoder-set-top-box.html

Please review and let me know if that is clear, please let me know how many HDMI channels and SDI channels you will need.

Question:

what are the H.264 MPEG Profiles and what is the adventuresses from one to another

Answer:

H.264, also known as MPEG-4 AVC (Advanced Video Coding), is a video compression standard that is used to encode video data in a digital format. It is widely used in video compression for a variety of applications, including streaming video, television broadcasting, and video conferencing.

H.264 has several different "profiles" that determine the set of features that are supported by the codec. The most commonly used profiles are:

Baseline Profile (BP): This profile is designed for low-complexity devices such as cell phones and is the most widely supported profile by consumer devices.
Main Profile (MP): This profile is designed for standard-definition (SD) video and provides a higher level of compression than the Baseline Profile.
High Profile (HiP): This profile is designed for high-definition (HD) video and provides a higher level of compression than the Main Profile.
High 10 Profile (Hi10P): This profile is designed for high-definition (HD) video with 10-bit color depth and provides a higher level of compression than the High Profile.
High 4:2:2 Profile (Hi422P): This profile is designed for high-definition (HD) video with 4:2:2 chroma subsampling and provides a higher level of compression than the High Profile.

Each profile is designed to address specific use cases and requirements, therefore the main advantage of one profile over another is the level of compression, video quality and the specific features and capabilities it supports.

Question:

I have the H-HDPerformux-8, please which mobile application I can use to
receive channels from my IP encoder streamer to my phone ?

-----------------

Thank you for this information. I don’t have a problem with receiving channels from the encoder streamer on VLC from my PC. Indeed I have about 30 Android TVs on which I have installed an IPTV application. I also create a m3u8 file based on the address and port numbers of my streamer, file I copy to all my TVs for the app to use.

Answer:

Are you familiar with the difference between multicast and unicast streaming?

The unit outputs UDP/RTP multicast streams, which means that any devices on the network with IGMP protocol enabled can receive the streams.

For example, the syntax for VLC players is udp://@(multicast IP address):(port number), for instance, udp://@224.2.2.2:2234.

For mobile applications, you would need a video server and encoder to stream UDP to the server.

The server then streams HLS streams to the devices which requested the streams like cell phones.

This can be a hardware server or software, with many consumers using Wawza.

---

You mentioned that you want to stream from an IP encoder to my phone, which you cannot do without the video server since multicast UDP does not support it.

Please do the following test: output a UDP multicast with the example 224.2.2.2 port 2234 and connect the data port to the switch.

Then, on the VLC media player, type the following syntax udp://@224.2.2.2:2234 and let's check.

You need to enable the IGMP protocol on the switches in order to send multicast

You can test it directly, without the switch , connect the PC directly to the Data port , thank use VLC

I do not have a recommendation on the Video serves because we do not make it.

Some customers are using Wowza servers , andy video server witch inputs UDP multicast and outputs HLS would work.

UDP multicast streaming is a method of transmitting data packets from
one source to multiple destinations simultaneously over a network. In
this type of communication, the sender sends a single copy of the data
to the multicast group IP address, and the network ensures that it is
delivered to all interested receivers who have joined the multicast
group.

To set up a network for IGMP protocol, you need to configure your
network devices like routers, switches, and firewalls to support
multicast traffic. Here are the basic steps to set up a network for
IGMP protocol:

Configure the multicast source: Configure the source device (e.g.,
server) to send multicast traffic with a specific IP address range.

Enable multicast routing: Enable multicast routing on your network
devices. Multicast routing enables the network devices to send
multicast traffic to the correct network segment.

Configure IGMP snooping: Configure IGMP snooping on your switches to
ensure that multicast traffic is forwarded only to those ports that
are interested in receiving the traffic.

Enable PIM: Enable Protocol Independent Multicast (PIM) on your
routers. PIM is a protocol used to route multicast traffic across
multiple networks.

By following these steps, you can set up a network that supports IGMP
protocol and UDP multicast streaming.

Question:

I have a request that has never crossed my desk before, so I was wondering if you would have some wisdom –

I have a medical facility that uses televisions in their waiting and employee areas. These TVs strictly show cable TV programming. The customer wants to keep the cable television, but they want to overlay lower 3rd banners with information for the patients or employees. I know how to create a digital signage template, but what I don’t know is how to take a cable TV feed and turn it into a live IP stream. That might not even be the best way to do this, but that is where my head is taking me.There are services that specifically cater to medical facilities, but I can’t find any that can work as an overlay across a television feed. There are some that will send network video clips, but those are typically Vimeo video segments, not true network television. The customer is very adamant that they want to keep the cable television, thus my quandary.Do you have a suggestion as to how I can handle this request?

Answer:

It is possible to achieve that, but it can be a bit complex. Each channel would need to be re-encoded, which means we would first need to decode each program to HDMI video format using separate Cable TV STBs. Then, we would use HDMI encoders to produce IP streams. HDMI encoders have the ability to inject text or images and incorporate them into the IP streams. The IP streams would then be converted back to HDMI using IP STBs.

Please let me know how many channels you would like to process in this manner.

We have 8 to 24-channel HDMI encoders available. The 8-channel HDMI encoder is priced at $4,295, while the 24-channel HDMI encoder is priced at $5,995.Additionally, we have the H-STB-IP available for $169 each, which is the compact IP decoder set-top box.

Question:

What is GOP in the TS stream, and how does it affect the encoded stream? If the setting is 25-50, which is better to use?

Answer:

In video encoding and streaming, GOP stands for "Group of Pictures." It's a term used in video compression to describe a collection of successive frames within a coded video stream. The GOP structure significantly influences the efficiency and quality of the video compression process.

Understanding GOP in TS Stream

Structure:
- I-frames (Intra-coded frames): These are keyframes that are self-contained and can be decoded independently of other frames. They are typically larger in size.
- P-frames (Predicted frames): These frames depend on previous I-frames or P-frames for decoding. They are more compressed than I-frames.
- B-frames (Bidirectional frames): These frames depend on both previous and future frames for decoding, offering the highest compression.
GOP Size:
- GOP Length: It refers to the number of frames between two I-frames. For example, a GOP size of 25-50 means the encoder might use a structure where an I-frame is followed by a mix of P-frames and B-frames, up to 50 frames total.
- Open vs. Closed GOP:
  - Open GOP: B-frames can reference frames outside the GOP.
  - Closed GOP: All frames in the GOP are self-contained.

Effects on Encoded Stream

Compression Efficiency:
- Larger GOP (e.g., 50): Generally results in better compression efficiency because fewer I-frames are used, and more frames are compressed using the more efficient P- and B-frames.
- Smaller GOP (e.g., 25): Can lead to less efficient compression but might provide better error resilience and faster seeking.
Video Quality:
- Larger GOP: Potentially better overall quality at a given bitrate, but with possible artifacts if the connection is unstable.
- Smaller GOP: May maintain more consistent quality across different network conditions, but might require a higher bitrate to achieve the same quality.
Latency:
- Larger GOP: Could introduce more latency in live streaming scenarios because of the increased processing time for B-frames.
- Smaller GOP: Usually results in lower latency, making it more suitable for live streaming.

Choosing Between 25 and 50

The choice between a GOP size of 25 and 50 depends on your specific use case:

If you prioritize compression efficiency and can handle higher latency: Use a larger GOP size (50). This is suitable for pre-recorded content where buffering is less of an issue.
If you prioritize lower latency and error resilience: Use a smaller GOP size (25). This is preferable for live streaming or situations where fast seeking and lower latency are important.

Conclusion

Ultimately, the best GOP setting depends on your specific needs regarding video quality, compression efficiency, and latency. For most general use cases, a GOP size of 25 is a safe and balanced choice, while a GOP size of 50 might be better for high-quality, pre-recorded videos where compression efficiency is a higher priority.