LIVESHOT IP VIDEO CODEC I. Introduction 7 A Word about 3G/4G Networks 8 QuickStart in Loopback 9 II.
IV. Getting Started with LiveShot Portable 30 Connecting to a Network 30 Ethernet 30 wireless devices 30 Connecting Input Audio/Video 31 Connecting Output Audio/Video 31 V. Getting Started with Crosslock 32 VI.
Preserve After Reset 49 Use with crosslock 50 broadcast config 50 VIII. Peers tab details 51 editing peers 53 IX. Media Link Tab Details 54 utilization graph 55 packet loss graph 55 Delay slider 56 media link detailed view 57 X.
advanced config options 73 auto-connect 73 Session modes 75 System Clock 76 switchboard settings 77 crosslock VPN 78 XI.
About Comrex Comrex has been building reliable, high quality broadcast equipment since 1961. Our products are used daily in every part of the world by networks, stations and program producers. Every product we manufacture has been carefully designed to function flawlessly, under the harshest conditions, over many years of use. Each unit we ship has been individually and thoroughly tested. Comrex stands behind its products.
I. Introduction The Comrex LiveShot is a hardware video codec system designed for real-time video and audio transmission over IP networks, including the Internet. Some of the benefits of the LiveShot system are: Quality - LiveShot uses a highly optimized version of H.264 video coding and AAC-ELD audio coding for the best possible quality. Delay - LiveShot’s video and audio processing is highly optimized to reduce delay. End-to-end delays of 200mS are possible on good networks.
A Word about 3G/4G Networks Summary - Default coding is 2.2Mbps (or lower) up, 400Kbps (or lower) down. The default video encoders will throttle based on network performance. This works well with LTE or a pair of 3G modems. Many users are excited to get started using LiveShot in 3G and 4G networks. Here’s some advice and suggestions for use on these networks: The default mode (or “sweet spot”) for LiveShot delivers a video feed coded to 2Mbps, along with an audio feed coded to 48Kbps.
QuickStart in Loopback We’ll dive into all the LiveShot connections, interfaces and modes soon, but if you want to do a quick check of how LiveShot works in “Loopback” (a single LiveShot encoding and decoding the same media), it’s fairly simple to do. Since the LiveShot Portable offers only composite video output, you’ll need to use the rack to experience the full quality. Here are the steps: 1 Connect a video source (camera) to LiveShot. On the Portable you can use HD-SDI, HDMI, or Composite.
II. LiveShot Connections, Controls, Indicators Liveshot portable connections, controls, indicators 1 2 3 5 6 7 4 8 Figure 1 Liveshot Portable front Figure 1 shows the front panel of the LiveShot Portable: 1 Power Button - Press this for two seconds to power the device on and off. 2 Store/Forward Status Indicator - For future use.
7 F1 & F2 keys - Used for special functions. In current firmware, these are “hot connect” keys that are programmed to make outgoing connections. As shipped from factory, “Long Press” of F2 establishes a loopback connection for testing (internal encoder - internal decoder). Three other functions are available (short press F1, F2, long press F1). Each of these can be assigned to trigger an outgoing connection.
1 5 6 2 7 8 3 4 9 Figure 3 LiveShot Portable rear panel Figure 3 shows the rear panel of LiveShot Portable: 1 Wi-Fi On/Off switch - Enables or disables the internal Wi-Fi access point (associate a laptop or smartphone to this signal for control of the unit). 2 Composite Video/Audio Output - This port presents the return video/audio signal from the far end (if enabled in the connection profile). 3 Ethernet Port - For use on wired networks. 4 Power Jack - Plug in the supplied external power supply here.
Portable Connector pinout Power in - 5 pin mini-DIN Accepts 15V DC @ 1A 1) unconnected 2) & 4) Ground 3) & 5) +15V DC Analog Audio in - 5 Pin XLR-F Input level is 0dBu nominal Ground Pin 1 GROUND Pin 2 Balanced Left audio + Pin 3 Balanced Left audio - Pin 4 Balanced Right audio + Pin 5 Balanced Right audio - For unbalanced input connections, connect Pins 1, 2 and 4 together and apply L & R + signal to Pins 3 and 5 respectively.
Portable Power Details The LiveShot Portable is designed to be powered from either its external desktop-style supply or via an Anton Bauer Gold-Mount (also known as 3-stud) compatible battery. The Portable may also be mounted to the back of a camera that uses a Gold-Mount battery. In this case, the LiveShot is “sandwiched” between the battery and the camera, and the LiveShot draws power from the battery and passes it through to the camera.
LiveShot Rackmount Connections, Controls, Indicators 1 2 3 4 5 6 Figure 4 liveshot Rackmount front panel Figure 4 shows the front panel of LiveShot Rackmount: 1 & 2 Display/Control buttons - Allows basic configuration and operation. LiveShot is designed to be driven from its web interface, but the front panel controls provide an alternate means for some basic functions. 3 Send Audio Indicators - Measures audio level of incoming audio. Green means good, Orange means approaching clipping.
1 2 3 4 5 6 AUDIO OUT AUDIO IN 7 11 AES3 SERIAL HD SDI GEN LOCK LEFT RIGHT CUE AUDIO LEFT RIGHT CUE AUDIO IN OUT COMP IN IN 8 OUT 9 COMP OUT HDMI 10 12 Figure 5 liveshot Rackmount rear panel Figure 5 shows the rear panel of LiveShot Rackmount: 1 Mains AC Power - Universal IEC connector accepts 110-240VAC 50/60Hz. 2 Analog Audio In L/R - When using composite input, these balanced XLR-3F ports accept analog audio.
Rackmount Connector Pinout Analog XLR pinning (L&R in, L&R out) 0dBu nominal level (+20dBu clip) Cue Audio In/Out pinning -10dBu nominal level (+6dBu clip) Pin 1 Ground Pin 2 Balanced Audio + Pin 3 Balanced Audio - To use unbalanced sources, connect Pins 1 and 3 to Ground, and connect the audio + signal to Pin 2. This is valid for outputs, as the output stage can detect an unbalanced connection and adapt.
About LiveShot Video I/O Summary - LiveShot will adapt to most I/O resolutions automatically and use default coding resolutions which may be different still. On digital video inputs and outputs, LiveShot supports 1080i50/60, 720p50/60, and all SD modes. On Composite In/Out, LiveShot supports SD modes. LiveShot video inputs are automatic; an active video input is automatically selected and the resolution and frame rate are adapted to by the encoder.
Figure 6 Also referring to Figure 6, frame rates typically remain constant throughout the system, except that the LiveShot encoder can be set to reduce the input video frame rate by a value of 2, 4, etc. But even though the encode/decode process is happening at a reduced frame rate, the decoder output frame rate will be increased to automatically match that of the native input video. Again, the exception is the Portable output, which will adapt to an SD frame rate.
ABOUT LIVESHOT VIDEO CODING Before we begin discussing video coding, let’s define the term “video quality”. Obviously, quality is a highly subjective topic. When we use the term quality here, we use it as a substitute for the more technical term “encoding efficiency”. This means relative to a certain encoding bitrate (note: everything is relative to bitrate in LiveShot), the encoder will produce a certain amount of video artifacts or “noise” based on some of the other options chosen.
quality, delay etc). In general, simple video (few acute details and colors without motion) will require a smaller bandwidth than what is specified as the target. When specifying a target bitrate, you should take care to stay below the maximum specified speed of your network. E.g., if your 4G network claims upload speeds of 5Mbps, it’s a good idea to start by using network streams that utilize less than half that bandwidth.
LiveShot Encode/Decode limits The codec engine within LiveShot has a lot of responsibility, including maintaining a consistent video encode and decode stream (if a full-duplex profile is chosen). There are many options involving bitrates and resolutions that can make this engine work very hard. Here are some general limits to what you can expect from LiveShot. 1 The aggregate video bitrate (send and receive) in a LiveShot profile should be 15Mbps or less. E.g.
About LiveShot Networking and Protocols LiveShots connect together using a variety of protocols that are layered on top of each other. This concept is illustrated in Figure 7. Figure 7 LiveShot layers The lowest layer protocol is called a Stream, and consists of a one-way or bi-directional video or audio stream. Along with the stream definitions, we define a “Session Mode” as a group of protocols used by the LiveShots to establish and translate how the streams work.
CrossLock is the outermost layer and gets established between LiveShot first. Crosslock handles the ability to aggregate multiple network devices on each end of a link. It also provides statistics to the far end and determines the rate at which each network applied is capable of working, throttling the encoders if necessary to fit within the available bandwidth.
CrossLock works in conjunction with Switchboard server (maintained by Comrex) to allow for the IP address of LiveShots to change (as they move around) without any reconfiguration of dialing destinations. This is shown in Figure 9. LiveShots will ping the Switchboard server with their IP address information, and will run some tests against the server to determine whether there are router or firewall issues that might impair peer-to-peer connections.
Here’s another advantage of CrossLock--Normally in this scenario (one LiveShot on Private IP, one on Public IP), connections could only be made in the direction of the Public unit. Connections attempted toward the Private unit would be blocked by the NAT router. CrossLock maintains a VPN connection “tunnel” through the NAT router and allows media connections to be established from either end. One of the key features of CrossLock is the ability to “bond” multiple network channels in a single device.
III. Getting Started with liveshot rackmount Connecting To a network Summary: Connect LiveShot Rackmount to a Public IP, or a Private IP with UDP 9001 forwarded. LiveShot Rackmount connects to your network via 100BaseT Ethernet. Factory default is DHCP, so LiveShot will get an address from your network and display it on the front panel display. Since LiveShot Rackmount is controlled from the web page served from the unit, it is often useful to assign it a static IP address in your network.
Figure 11 Device manager Staying on the Device tab, look for the button labeled Network Settings on the right side as shown in Figure 11. You will see a timer that shows how much longer the LiveShot has before IP configuration function is disabled for security purposes. After the timer expires, the button will be disabled and it will read IP config locked.
As an alternative to using the Device Manager to view and set the IP address information, the LiveShot Rackmount front panel interface can perform this function. See the section on Using the LiveShot Rackmount Front Panel. Connecting Input Audio/Video Summary - Choose in and out connections. LiveShot will detect them. Choose which type of input video (if any) to apply to LiveShot Rackmount. Input A/V is only required if you plan to stream media back to LiveShot Portable.
IV. Getting Started with liveshot portable connecting to a Network Ethernet Summary - Ethernet on Portable is usually plug-and-play. In most circumstances, it won’t be important to set the Portable to a static IP address. This is because the connection is usually initiated from LiveShot Portable, so it’s not important for the Portable to have unsolicited incoming connectivity from the Internet.
Connecting Input Audio/Video Choose the type of input video you plan to connect to LiveShot Portable. It’s important to have the video input connected and active before a connection is made. “Hot swapping” video inputs while a stream is active is not supported. The LiveShot Portable offers inputs via HD-SDI (with embedded audio), HDMI (with embedded audio) and Composite (with analog audio input). Once an input is attached, it is selected automatically and an indicator lights beside the input.
V. Getting Started with crosslock One of the most important elements of LiveShot operation is CrossLock. See the above section titled About LiveShot Networking and Protocols for theory of CrossLock operation. One of the key elements of the Comrex LiveShot system is its ability to create a “tunnel” (much like a VPN) between two units. We call this CrossLock VPN. CrossLock is established between two LiveShot peers in advance of any audio or video streams.
CrossLock’s primary function is to provide stability over poor networks. To this end, it will have control over video data rate, frame rate and other functions that will affect media quality. There may be circumstances where CrossLock is not desired. This may be when running over known good managed IP connections. In this case, connections can be made directly without engaging CrossLock at all. See the section on non-CrossLock connections to configure LiveShot for this mode.
VI. getting started with the LiveShot Web Interface The LiveShot Web Interface is provided by an internal web server in LiveShot and delivered via any of the active network ports. On LiveShot Rackmount, the only network port is Ethernet, so the main LiveShot IP address is used in a browser. On LiveShot Portable, any device associated with the internal Wi-Fi Access Point can view it at a special address. In order to deliver useful real-time statistics, moving graphs are employed.
Whether via web or app, the interface is identical and will attempt to log into LiveShot using the default password at the default address. The system will look for the web interface at port 80. If that fails, it will prompt you to enter a new interface port number. The system will next attempt to log in using the default password (comrex) or the last one used. If that fails, it will prompt you for the correct password.
After logging in, the main web interface appears as shown in Figure 13. The interface is laid out in four main sections: Network, Peers, Media Link, and Config. Figure 13 When one of these tabs is chosen, the area above the tabs fills with the options for that particular section. The area below the tabs is reserved for status and remains always visible. Due to space constraints on mobile devices, the status section is moved to a fifth tab. Here is a quick summary of what’s on each section.
Status Section The bottom section of the interface (fifth tab on the app) is reserved for the unit’s status information. Figure 14 As shown in Figure 14, a thumbnail of any video that is applied to the input of the LiveShot is available in the lower left corner, along with the detected input resolution. To the right of the thumbnail is a status bar giving some other critical LiveShot information.
Network tab When this tab is chosen, as in Figure 15, the top section is populated with a list of network connected devices that have, at one point, been attached to LiveShot. The first device is always the internal Ethernet port, and on LiveShot Portable the second device is always the internal Wi-Fi access point. Figure 15 This is the section where, if necessary, you will configure your network devices. Often, this isn’t necessary, because many configurations are saved in LiveShot.
Under each entry in the device list you’ll see relevant status for that device. This information includes private IP address extracted from the network device. In addition, LiveShot does a sync with a server maintained by Comrex and displays two other pieces of information: The public IP address (this could be the public address of the entire LAN), and the type of Network Address Translation (if any) that is detected on the network. Network devices are active on LiveShot if they show a valid IP address.
Media Link Tab Figure 17 shows the Media Link Tab. All the statistics relevant to connections that are active are presented here. Graphs show network utilization and packet loss, as well as delay and error correction information. These graphs are available for both the local transmit and local receive paths. In addition, each network device can be selected on the right side, and statistics relevant only to that network are available.
Config Tab Figure 18 shows the Config tab, which is used to set all global configuration for the LiveShot. Options here are available to define audio and video profiles, configure A/V hardware ports, and set up CrossLock and administration functions. Details are in the Config section.
VII. network tab details Many devices in the network tab will be “plug and play”, meaning that if drivers are included in the LiveShot’s firmware, and no special configuration is needed, the device should just attach to the network, and CrossLock should become enabled. Devices can be “hot plugged” into the LiveShot’s USB ports, and if supported, will appear in the network tab list as shown in Figure 19.
Locations LiveShot implements a feature called Locations, which allows the user to store several profiles for each network interface. This way, several different configurations can be stored for the same network interface and switched easily when LiveShot is moved between networks. Examples are Ethernet networks that require specific static settings (that are used variably in conjunction with DHCP-based Ethernet networks) or Wi-Fi networks that are mixed and matched regularly.
Ethernet Settings Unless your LiveShot will always be used on the same network, we recommend that new Locations be created for custom Ethernet settings, leaving the Default Location as DHCP. This will allow quick reversion to DHCP where necessary. Figure 21 shows the creation of a new Ethernet Location. Once the default setting of DHCP is set to Static, new entries will appear to allow setting of all the vital static Ethernet fields. These include IP address, Gateway Address, and DNS entries.
Changing the active network location is shown in Figure 22. It’s important to remember that if you choose a new active Location, and are configuring LiveShot via that network, you will lose web connectivity when the new Location is chosen. Figure 22 It is always recommended that LiveShot be manually rebooted whenever the Ethernet settings have been changed.
WLAN Settings Once the included Wi-Fi adapter is attached to LiveShot, an entry will appear for WLAN network. Because users tend to change Wi-Fi networks often, a special function is offered under the Locations feature. The Default Location of the WLAN adapter has a network choice of “Auto”. In this mode, LiveShot will scan for all other previous Locations that have been configured. It will attach and use the first Wi-Fi signal found to match any previous Location configured.
If you need to set the APN value manually, this process is shown in Figure 23. Figure 23 Select the device in the interface to open the configuration settings. Search for an entry marked “SIM”, which contains all the carrier-specific values for that modem. Under “APN”, a menu will be offered to select the region and country of use, then a list of available carriers. Selecting a carrier should add the correct APN.
Internal Access Point On LiveShot Portable only, an additional entry appears in the Network list for the internal WLAN access point. This is the Wi-Fi host used to communicate with wireless devices like phones, tablets and laptops, allowing field configuration. By default, this access point is open and has no security. It is recommended to apply WPA security to this feature by adding password protection here. Advanced Network Features Gateway Mode Gateway mode allows you to share one network with another.
Figure 25 illustrates how data is bridged to external devices in Gateway mode. Figure 25 Preserve After Reset When LiveShot is reset to factory settings, it removes all configuration files resident to the hardware. Factory Reset can be performed by the Device Manager utility or can be done from the control buttons on the LiveShot hardware. Factory reset erases all internal settings that contain user profiles and destinations, and all network information. In some environments (e.g.
Use With CrossLock By default, CrossLock (and therefore media streams) will use any available network deemed to be worthy of media transport (except for the internal access point on LiveShot Portable). There may be circumstances where one network is desired for remote control only and is not intended to move media streams. An example of this is troubleshooting wireless connections remotely.
VIII. Peers tab details The Peers tab lists your destination addresses. Incoming calls are reflected here as well. The list contains three default values, which will be edited by the user. Many users will need no more than this, but it is possible to create others. A Peer entry consists of several pieces of information, as shown in Figure 26. Figure 26 1 Descriptive Name - The name you’ve assigned to this outgoing connection so you can remember it (e.g.
Peers do not need to go to unique destinations. It’s OK to set several Peer entries to the same destination, with different names and profiles chosen. The default peers are designed to be the main ones you will use. These are: 1 Program - This entry is designed to be the way to make audio/video connections between LiveShots using the CrossLock VPN feature. You will need to edit this entry and choose a destination (and perhaps give it a friendlier name) before using it.
Editing Peers Peers are edited by highlighting one and choosing the pull-down options menu in the upper left corner, and selecting “Edit”. The four parameters described above are displayed as shown in Figure 27, and may be individually selected, changed and saved. Figure 27 Before you can use any of your outgoing peers, you need to select a peer by choosing the “Remote unit” option here.
IX. Media Link tab details The Media Link tab is the one designed to have all the graphs and controls necessary for the user while a media stream is active. It contains a wealth of information about network performance in each direction. All graphical data in the Media Link tab is updated once every second. The main Media Link graph is shown in Figure 28, and contains two main displays.
Utilization graph The top section contains a graph of the outgoing (or incoming) utilization of the network. The bars indicate the average data rate used by the system during each one second window. It is expected that the size of these bars will vary due to a variety of factors including: 1 H.264 video is a variable bitrate system, and source material will affect the data rate. Static, simple images require much less network throughput that complex, moving images.
Delay Slider The most powerful way to stabilize a LiveShot connection is to have the decoder add a delay buffer to the CrossLock connection. This compensates for changes in the rate packets are received - known as jitter in Internet speak. LiveShot uses a combination of decode delay buffering and error correction to keep connections stable. The activity of the delay buffer is illustrated and controlled via the delay slider on the Media Link tab. Figure 29 shows the Delay Slider.
Media Link Detailed View A powerful feature of the Media Link tab is to allow the user to “drill down” to the statistics for each network interface, and view the performance of that network alone. By clicking the button that appears for each interface on the right side of the tab, a new window opens that shows graphs similar to the “overview” graph, but limited to the performance of that particular network. This is shown in Figure 31 R1 - R3.
The differences with these graphs are: 1 Encoder target rate is not shown on these graphs, since it might be an order of magnitude larger than the information shown. 2 The rate of error correction applied to this interface is shown in the top graph overlaid on the utilization data. This is shown as FEC rate (violet) and Retransmit rate (Green). 3 The Packet Loss graph (middle) shows only truly lost packets, as opposed to late and recovered.
X.
A/V Ports Figure 33 shows the LiveShot A/V Ports page. Each of the available inputs can be clicked to open a configuration page. Figure 33 The Composite Input config page is shown in Figure 34.
Inputs have a setting where the aspect ratio can be manually set between 4:3 and 16:9. The “auto” setting usually works best. In addition, inputs provide options to crop undesired input video lines from the top and bottom and undesired pixel columns from left and right. These values are all set to zero by default. As shown in Figure 33, the last three (two on LiveShot Portable) options are global outputs settings.
Alternatively, you can set a “Primary Output” via the pull-down menu, and that output will always be active regardless of coding resolution. The other outputs will be active if they can be supported alongside the current encode/decode resolution and primary output choice. Also, you can choose an output format (regardless of input format) by setting it discretely in the pull-down menu. Note that some formats won’t be supported (e.g.
Connection Profiles Profiles define all the media parameters of a LiveShot connection. Profiles define audio and video coding parameters for each direction of a connection, along with parameters used to control decoder receive buffer management. In this way, the initiator of a LiveShot stream (the only one who can assign a profile) is master of all media streams in both directions.
When you choose to create or edit a profile, you’ll be presented with the page shown in Figure 36. Figure 36 First, you’ll give the profile a descriptive name (e.g., 1Mbps full duplex). Then you will proceed to “build” individual streams into your profile with the bitrates and other parameters you desire. A separate audio and video stream must be created for each direction one is desired.
Video Streams Entries for a sample video stream are shown in Figure 37. The relevant entries are: Name - A descriptive name (e.g., duplex video, tx video etc). Media Type - Choose H.264 video. Media Direction - Relative to the unit making the outgoing call, the choices here are Bidirectional, Transmit Only (outgoing from this LiveShot), or Receive Only (incoming to this LiveShot). Video Lines - 1080 or 720 (HD), 576 or 480 (SD), or lower resolutions are selectable.
VIdeo Advanced Options By clicking “Show Advanced Options” (upper left menu button) several other encoding options are presented: Bitrate Optimization - This option is set to “Low” for the typical bitrates used by LiveShot. It balances the choices made by the encoding algorithm between total network bandwidth and quality. In some cases, users may want to experiment with setting this parameter manually. Not recommended for casual users.
Field encoding is chosen as the default because PAFF and MBAFF, although higher efficiency, have been shown to produce visual artifacts in some instances. The options are there for experimentation on certain video sources. Intra-Refresh (IR)* - Thiss setting (normally disabled) allows a special mode that alters how reference frames are sent from encoder to decoder over the network.
2 Low Latency - Latency is considered to be an overriding factor over quality in this mode. Use only in environments where the lowest possible latency is important. For most users, the amount of latency reduced in this mode is a poor tradeoff for quality. 3 Constrained Bitrate - This mode limits the “burstiness” of the encoder to 1.5x the target bitrate over a one second window. It’s useful for networks that perform poorly when bursty data is applied.
Audio Streams LiveShot by default encodes audio using the AAC-ELD algorithm, which is a highly regarded codec designed to balance low delay and high quality audio. It is a variant of the AAC-LC algorithm, popularized by Portable media players. AAC-ELD adds to AAC-LC in two ways: 1 Low Delay (LD) Operation - Using a shorter framesize, overall processing delay is reduced to a fraction of AAC-LC. This is important because of LiveShot’s extremely low delay video codec.
Figure 38 shows the options in setting up an audio stream: Figure 38 Name - A descriptive name (e.g., duplex audio, tx audio etc). Media Type - Choose AAC Audio. Media Direction - Relative to the unit making the outgoing call, the choices here are Bidirectional, Transmit Only (outgoing from this LiveShot) or Receive Only (incoming to this LiveShot). Channels - Choices are mono or stereo. Low Delay - Chooses a low audio coding frame size, lessening delay.
Audio Advanced Options Buffer Parameters - These options are common for all types of streams, so they are treated in their own separate section below. Stream Optional - This option determines whether a connection will fail in the absence of a source for this particular stream. For example, if an audio input set to embedded SDI or HDMI, and a stream is defined to use it but it is not present, the system can be set to fail or complete the connection anyway.
Buffer Delay Deadband - The Deadband setting applies some hysteresis to the jitter calculation. The Manager will not react to changes in jitter above and below the Deadband setting. This is a way to “dampen” the Manager’s buffer adjustments, causing it to move less. This can result in fewer video or audio frame adjustments. Loss Cushion - This is another way to “dampen” the effects of the Manager, by specifying a percentage of packet loss that is tolerable before adjustments kick in.
Admin Advanced Options Clicking Show Advanced under Admin Settings opens a few more options for the advanced user. The Diagnostics setting allows use of an SSH port on LiveShot so Comrex tech support personnel can access it remotely. Use of this port requires a key code that Comrex does not provide to customers, so it is secure when turned on, but some users may still have security concerns. Setting this value to No disables the diagnostic port.
As shown in Figure 39, the system allows you to designate which defined connection(s) are activated on Auto-connect #1-4. By default, a media connection to the Default Peer (the first entry in the peer list, 3G/4G profile) is active on #1, and a cue channel connection to the same destination unit is on #2. #3 is tied to an HD video connection (entry #4 in the peer list) and a Loopback test connection is active on #4.
Session Modes The Session Modes layer remains invisible to most users, but offers some options to the power Liveshot user. Session Modes describe the protocols used to transfer data between LiveShots, and other Session Modes besides the default are available to allow advanced functions. Figure 40 shows the Session Modes list that appears when the option is selected.
The last entry under LiveShot Normal Session mode is important. By default, this protocol is only enabled for use over CrossLock VPN. If you need to make LiveShot connections without this feature (by dialing a LiveShot’s “real” IP address, or accepting a call from a “real” address) you will need to change this setting to No to turn this restriction off. This special setting must be changed on both LiveShots in the link. See Figure 41.
Switchboard Settings The LiveShot Switchboard server is maintained by Comrex on the public Internet at the address of switchboard.comrex.com. Organizations with larger fleets of products, and those who simply need to host their own server, can change the address of the server in this section. Normally, LiveShots can only make CrossLock connections to other LiveShots in their Switchboard accounts. The list of other LiveShots detected within your account appears in the Switchboard Settings.
CrossLock VPN This section determines settings for the CrossLock reliability layer. Use of CrossLock is optional but highly recommended. Theory of operation of CrossLock is described in the section “About LiveShot Networking and Protocols” (page 21). Previous versions of LiveShot firmware operated CrossLock in a “client-server” mode, but firmware 1.4 and higher changes this to a “peer-peer” model. For this reason, CrossLock firmware below 1.4 is incompatible with connections to 1.4 and higher.
FEC Delay - Controls both how much delay is introduced into the system by FEC , and also to an extent how effective the recovery is (which is dependent greatly on the packet rate). The default of 100mS should only be altered on recommendation of Comrex support. Base FEC - This parameter applies a constant rate of FEC targeting recovery of the specified expected loss rate. It is measured in percent packet loss to be corrected. This is useful when retransmission is not effective (e.g.
XI. Making and Receiving LiveShot Connections After all the configuration is done, it’s time to actually use LiveShot. Before you make any connections, you’ll need to at least choose your destination on the outgoing LiveShot in the Peer menu. You can create a new Peer with the steps outlined in the Peers Tab section, or you can edit the default Peers presented in the factory configuration. If you are using Switchboard, this process is simple.
Making Connections via the Web Interface Once the peer is created or edited to choose the proper destination (and a proper connection profile is selected) you can select “Connect” to make that connection. LiveShot will take several seconds to establish CrossLock with the Peer, then set up encoding and decoding parameters on each end. Finally it should enter the “Connected” state and you should have an active media connection.
Making CrossLock Connections without using Switchboard About Crosslock Security LiveShot’s default mode is to use CrossLock, which has many advantages in media stability on poor networks. CrossLock does more than add an enhanced media layer - It creates an actual VPN between your LiveShots, capable exchanging lots of different data. At the same time, LiveShot is connected to your LAN - possibly your station’s main corporate LAN. This may raise security concerns.
The change is made in the Config tab under Advanced Settings->Switchboard menu. As shown in Figure 44, there’s a Peer List in this menu, with the option to add a new peer at the bottom. Select the Add Peer option and you’ll see a series of fields that need to be filled in for the opposite LiveShot.
Permissive Mode There may be situations (e.g. LiveShot is on an isolated network, or one on which security is less of a concern) where you want to disable all restrictions regarding who can establish CrossLock connections to your LiveShot. Note that only Comrex products with valid certificates can make these connections, but Permissive Mode opens LiveShot to all other LiveShots. The Permissive mode setting is under the Config Tab-> Advanced->CrossLock VPN->Permissive->On.
Making non-CrossLock Connections LiveShot may be compatible with other hardware and software capable of H.264 video and AAC audio encoding and decoding. Since these systems will not support the CrossLock VPN layer, in these instances you may want to make or receive connections without CrossLock applied. Enabling connections without CrossLock is done in the Config tab under Adavanced Settings->Session Modes->LiveShot Normal (SIP) entry.
In addition to this, to make outgoing connections without CrossLock you’ll need to create a peer in the Peers tab in a special way. This is shown in Figure 47. Figure 47 Under the “Remote Unit” choice, where you’ll normally see your list of Switchboard peers, you’ll choose “Manual Destination”. This choice will enable another field labeled “Destination”. Here you will enter the public IP address of the unit you want to connect to.
XII. Using the LiveShot Rack Front Panel Interface The LiveShot Rackmount, via its front panel buttons and display, allows setting of some of the basic features of LiveShot. The Interface can: • • Change Ethernet IP settings on the LiveShot. Make and break connections to the two Hot-key auto-connect destinations programmed into the LiveShot. • Adjust settings in the LiveShot’s A/V I/O ports. • Restart LiveShot and reset it to factory defaults.
Figure 48 and Figure 49 show a map of the various menu options on the Rackmount front panel interface.
Figure 49 These options mirror options available via the LiveShot Web Interface. See details in that section (page 32) for more on these options. Navigation is done through the arrow buttons and enter keys. To the farthest most side of the top line, cursor icons appear to offer which cursors are active. Most menus are browsed using the to the previous menu. and buttons.
On menus that offer the ability to change a setting, the will offer an option to cancel. Each digit of a numerical value (e.g., IP addresses) can be altered with the buttons, and digits can be selected with the and and buttons. Scrolling all the way to the right on a numeric entry will offer an option to cancel your setting. The legend on the right side of the bottom line of the display gives hints as to whether: This item is purely informational and non-editable.
The current value can be saved by pressing Enter. The current operation can be cancelled by pressing Enter.
XIII. Information for IT Managers - Liveshot The purpose of this document is to describe all open ports and services available on the Comrex LiveShot. The Comrex LiveShot is a device designed to move real-time, wideband audio and video over IP networks. The main network interface is 100BaseT-Ethernet. The device contains an optimized version of Linux kernel. The IP parameters are set by a PC on the local LAN using a proprietary broadcast UDP protocol.
XIV. Advanced Topics Multiple CrossLock Connections A single LiveShot is capable of connecting to multiple others simultaneously. We call this function “MultiStreaming”. This is shown in Figure 50. This is generally for the purpose of distributing media from one location to several. Three simultaneous CrossLock connections can be maintained from a LiveShot. Figure 50 There are several limitations in this scenario.
The simplest way to acheive Multistreaming is to build a single “TX only” profile on the MultiStreamer, and initiate connections from that LiveShot to all the peers. Connections can be achieved from the receiving peers, but because the connecting unit control parameters in both directions, it requires much more coordination regarding throttling and profile settings on each LiveShot. It is actually possible for the MultiStreaming LiveShot to receive a media stream from one of the units in the group.
Each of the two supported Streaming modes outlined below can be enabled by choosing the appropriate entry and changing the “disabled” setting to “enabled”. RTSP sessions are initiated from the player software by addressing the IP address of the LiveShot as described below. Streaming Server Mode When this mode is enabled, LiveShot will deliver an A/V stream of the media presented to its encoder. So the player will receive the LiveShot’s input media stream.
Network Bandwidth is usually a concern in RTSP modes for several reasons. First, the total bandwidth available on the network connected to LiveShot must be able to support the sum of all streams pulled from it, along with any LiveShot normal connection present. This may require a network connection many times the size of a typical LiveShot network. Secondly, mobile players used in either mode have definite limitations to their processing power.
XV. Licenses LiveShot License Disclosures THIS PRODUCT IS LICENSE UNDER THE AVC PATENT PORTFOLIO LICNESE FOR THE PERSONAL USE OF A CONSUMER OR OTHER USES IN WHICH IT DOES NOT RECEIVE RENUMERATION TO (i) ENCODE VIDEO IN COMPIANCE WITH THE AVC STANDARD (“AVC VIDEO”) AND/OR (ii) DECODE AVC VIDEO THAT HAS BEEN ENCODED BY A CONSUMER ENGAGED IN A PERSONAL ACTIVITY AND/OR WAS OBTAINED FROM A VIDEO PROVIDER LICENSED TO PROVIDE AVC VIDEO. NO LICENSE IS GRANTED OR SHALL BE IMPLIED FOR ANY OTHER USE.
glib libusb-compat libnl2 The use of Boost software is licensed under the Boost License Boost Software License - Version 1.
Except as contained in this notice, the name of the X Consortium shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization from the X Consortium. zlib is licensed under the zlib license Copyright (C) 1995-2012 Jean-loup Gailly and Mark Adler This software is provided ‘as-is’, without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software.
