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Posts Tagged ‘standard’

Samsung & Amazon Introduce HDR10+ Standard with Dynamic Metadata & Tone Mapping

April 20th, 2017 7 comments

Most recent 4K Ultra HD televisions support high dynamic range (HDR) through standards such as HDR10, Dolby Vision, or Hybrid Log-Gamma (HLG). Samsung and Amazon have jointly introduced an update to HDR10 with HDR10+ that adds dynamic tone mapping & metadata.

The companies describe the issues for HDR10′ static metadata as follows:

The current HDR10 standard utilizes static metadata that does not change during playback despite scene specific brightness levels. As a result, image quality may not be optimal in some scenes. For example, when a movie’s overall color scheme is very bright but has a few scenes filmed in relatively dim lighting, those scenes will appear significantly darker than what was originally envisioned by the director.

HDR10+ will be able to adjust metadata for each scene, and even for each frame, hence solving the issue of darker scenes. If you already own a Samsung TV with HDR10,  it’s not already outdated, as all 2017 UHD TVs already support HDR10+, and 2016 UHD TVs will support HDR10+ through a firmware update.

Amazon Video will be the first streaming service to deliver HDR10+ content, and Samsung also collaborated with other companies to integrate HDR10+ into products such as Colorfront’s Transkoder for post-production master, and MulticoreWare x265 video encoder.

HDR10 – and HDR10+ – is also said to be an open standard, but it could not find the specifications online, and only managed to find that HDR10 Media Profile main  must support EOTF: SMPTE ST 2084, 4:2:0 color Sub-sampling, 10-bit color depth, ITU-R BT.2020 color primaries, and SMPTE ST2086, MaxFALL and MaxCLL metadata defined in CTA 861.3-A standard (free preview) which you can purchase for $67. There must be some sort of CTA Standard for HDR dynamic metadata extensions for HDR10+, but I could not find anything [Update: Maybe SMPTE ST 2094-20-2016?]

Samsung showcased a static vs dynamic tone mapping demo at NAB 2016 last year, but it’s quite hard to see any differences in the video.

Categories: Hardware Tags: amazon, hdr, HDR10, samsung, standard

MIPI I3C Sensor Interface is a Faster, Better, Backward Compatible Update to I2C Protocol

January 11th, 2017 6 comments

I2C (Inter-Integrated Circuit) is one of the most commonly used serial bus for interfacing sensors and other chips, and use two signals (Clock and Data) to control up to 128 chips thanks to its 7-bi address scheme. After announcing it was working of a new I3C standard in 2014, the MIPI Alliance has now formally introduced the MIPI I3C (Improved Inter Integrated Circuit) Standardized Sensor Interface, a backward compatible update to I2C with lower power consumption, and higher bitrate allowing it to be used for applications typically relying on SPI too.

mipi-i3cI3C offers four data transfer modes that, on maximum base clock of 12.5MHz, provide a raw bitrate of 12.5 Mbps in the baseline SDR default mode, and 25, 27.5 and 39.5 Mbps, respectively in the HDR modes. After excluding transaction control bytes, the effective data bitrates achieved are 11.1,20, 23.5 and 33.3 Mbps.

MIPI I3C vs I2C Energy Consumption and Bitrate - Click to Enlarge

MIPI I3C vs I2C Energy Consumption and Bitrate – Click to Enlarge

The MIPI Alliance has also provided a tablet comparing I3C, I2C, and SPI features, advantages and disadvantages.

Parameter MIPI I3C I2C SPI
Number of Lines 2-wire 2-wire (plus separate wires for each required interrupt signal) 4-wire (plus separate wires for each required    interrupt signal)
Effective Data Bitrate 33.3 Mbps max at 12.5 MHz
(Typically: 10.6 Mbps at 12 MHz SDR)
3 Mbps max at 3.4 MHz (Hs)
0.8 Mbps max at 1 MHz (Fm+)
0.35 Mbps max at 400 KHz (Fm)
Approx. 60 Mbps max at 60 MHz for conventional implementations (Typically: 10 Mbps at 10 MHz)
 Advantages
  • Only two signal lines
  • Legacy I2C devices co-exist on the same bus (with some limitations)
  • Dynamic addressing and supports
    static addressing for legacy I2C
    devices
  • I2C-like data rate messaging  (SDR)
  • Optional high data rate messaging
    modes (HDR)
  • Multi-drop capability and dynamic
    addressing avoids collisions
  • Multi-master capability
  • In-band Interrupt support
  • Hot-join support
  • A clear master ownership and
    handover mechanism is defined
  • In-band integrated commands
    (CCC) support
  • Only two signal lines
  • Flexible data transmission rates
  • Each device on the bus is
    independently addressable
  • Devices have a simple master/slave relationship
  • Simple implementation
  • Widely adopted in sensor
    applications and beyond
  • Supports multi-master and multi-drop capability features
  • Full duplex communication
  • Push-pull drivers
  • Good signal integrity and high speed below   20MHz (higher speed are challenging)
  • Higher throughput than I2C and SMBus
  • Not limited to 8-bit words
  • Arbitrary choice of message size, content and purpose
  • Simple hardware interfacing
  • Lower power than I2C
  • No arbitration or associated failure modes
  • Slaves use the master’s clock
  • Slaves do not need a unique address
  • Not limited by a standard to any maximum  clock speed (can vary between SPI devices)
 Disadvantages
  • Only 7-bits are available for device addressing
  • Slower than SPI (i.e. 20Mbps)
  • New standard, adoption needs to be proven
  • Limited number of devices on a
    bus to around a dozen devices
  • Only 7-bits (or 10-bits) are available for static device addressing
  • Limited communication speed rates and many devices do not support the higher speeds
  • Slaves can hang the bus; will require
    system restart
  • Slower devices can delay the
    operation of faster speed devices
  • Uses more power than SPI
  • Limited number of devices on a bus
    to around a dozen devices
  • No clear master ownership and
    handover mechanism.
  • Requires separate support signals for
    interrupts
  • Need more pins than I2C/MIPI I3C
  • Need dedicated pin per slave for
    slave select (SS)
  • No in-band addressing
  • No slave hardware flow control
  • No hardware slave acknowledgment
  • Supports only one master device
  • No error-checking protocol is
    defined
  • No formal standard, validating
    conformance is  not possible
  • SPI does not support hot swapping
  • Requires separate support signals
    for interrupts

You’ll find more technical details by downloading MIPI I3C specifications and/or whitepaper (free email registration required). Note that only MIPI member can have access to the complete specifications.

Via Electronics Weekly

Categories: Hardware Tags: i3c, mipi, sensor, standard

Adding Plus Sign and Tag to Email Address May Help Identify Source of (Spam/Junk) Emails

November 27th, 2016 15 comments

I’ve noticed several commenters using email formatted as [email protected] or [email protected] while posting comments on CNX Software blog, but I just thought they were using some specific emails account or some forwarding techniques to receive emails, but I did not investigate further, and by chance I came across the reason on reddit this morning:

It’s just another character that can be in an email address. For example, [email protected], [email protected], [email protected], and [email protected] are all completely different email addresses.

However, Gmail will ignore a + and everything after it in the username portion of an email address, so [email protected], [email protected], and [email protected] will all go to [email protected]‘s inbox. This is acceptable because Google does not allow + in its login names. Many people use this property to identify the source of an email.

So I could not resist trying by sending myself an email by adding +source1 to my username, and I did receive the email to my inbox as if I had not added the plus sign and “source1” tag/string.

email-address-plus-sign

I’m using gmail for cnx-software.com emails, but I also tried with hotmail, and it worked too. Another reddit commenter mentioned that it’s actually part of RFC5233 standard, but not all email providers support it.

This can be used to trace the source of email. For example, if you’ve commented on this blog only with “[email protected]”, and some day you receive a email entitled “Nose Enlargement Program”  with that exact email address, that will either mean that the whole purpose of CNX Software blog was always to gather email addresses for nefarious purposes, or that the blog was somehow hacked and others took the opportunity. It’s not exactly 100% reliable as spammers who want to hide their source could easily remove any “+tag” string from their email database(s).

Categories: Testing Tags: standard

Wi-Fi CERTIFIED ac Wave 2 Products Support MU-MIMO, 160 MHz Channels, and More

July 5th, 2016 1 comment

802.11ac WiFi is now found in many routers and devices, and the Wi-Fi alliance has so far certified close to 3,000 “Wi-Fi CERTIFIED ac” products. I understand that certification is not mandatory, but if you want to make sure a device works well, the certification at least means the devices have been tested for interoperability, security and application specific protocols, and found to work in a satisfactory manner.

WiFi_Certified_AC_Wave_2

Now the Wi-Fi alliance has announced Wi-Fi CERTIFIED ac Wave 2 certification program with the following new requirements:

  • MU-MIMO (Multi-user Multiple Input Multiple Output) in order to send data to multiple devices at once to improve overall  network efficiency and throughput
  • 160 MHz channels support (not only 80 MHz) potentially doubling transmission speeds
  • Four spatial streams instead of just three spatial streams.
  • Extended 5 GHz channel support by adding more channels in the 5 GHz to reduce interference and congestion.

Currently the following WiFi SoCs, routers, and reference designs are said to be certified with Wave 2 features:

  • Broadcom BCM94709R4366AC
  • Marvell Avastar 88W8964
  • MediaTek MT7615 AP Reference Design and MT6632 STA Reference Design
  • Qualcomm IPQ8065 802.11ac 4-stream Dual-band, Dual-concurrent Router
  • Quantenna QSR1000 4×4 802.11ac Wave 2 Chipset Family

WiFi_CERTIFIED_ac_Wave_2_featuresAccording to Wi-Fi alliance website, You can check “Wi-Fi CERTIFIED™ ac (with wave 2 features)” products by following this link, and at the time of writing there are 9 products listed. However, if you show “advanced filters” in that link, only “DL MU-MIMO” is selected, and if you  start selecting “160 MHz channels” and “Extended 5 GHz Channel Support”, the number drops to two items: Broadcom BCM94709R4366AC and Mediatek MT6632. So either there’s a temporary issue with the website, or the certification does not guarantee all features are included, only MU-MIMO.

AOMedia AV1 is a Royalty-free, Open Source Video Codec Aiming to Replace VP9 and Compete with H.265

July 3rd, 2016 22 comments

The Alliance for Open Media, or AOMedia, is a new non-profit organization founded in 2015 by Amazon, Cisco, Google, Intel Corporation, Microsoft, Mozilla, and Netflix, and more recently joined by AMD, ARM, and NVIDIA, whose first project is to develop AV1 royalty-free and open video codec and format to provide an alternative to H.265 / HEVC, and a successor to VP9.

Alliance_For_Open_Media_AOMedia

The project is a team effort combining teams working on Daala, Thor, and VP10 video codecs, and while AFAIK, AV1 specifications have not been released yet (target: Q1 2017), the organization has already released an early implementation of AV1 video decoder and encoder under the combination of an BSD-2 clause license and the Alliance for Open Media Patent License 1.0 , which can be found on googlesource.com.

So I’ve had a quick my myself following the instructions, by first downloading one uncompressed YUV4MPEG sample:

and the source code:

before building it:

The last command will install the headers, and aomdec video decoder and aomenc encoder.

We also need some scripts to be placed in the path:

Now we can run the script in the directory for the sample(s):

The command will encode all y4m files in the directory at 200 kbps up to 500 kbps at a 50 kbps increment. Encoding only uses one core, my machine is powered by AMD FX8350 processor, and you can see encoding is currently very slow well under 0.5 fps for a CIF video (352 x 288 resolution), but that should be expected because VP9 encoding is already slow (its successor is expected to require even more processing power), and first software implementations are usually not optimized for speed, they are just meant to show the encoding works.

The test scripts will create a bunch of AV1 video files in baseline directory: husky_cif.y4m-200.av1.webm, husky_cif.y4m-250.av1.webm, etc… as well as husky_cif.y4m.stt with some statistics.

Decoding is much faster as it should be:

You can play back the videos with mpv using aomdec for decoding. For example:

AOmedia_AV1_Video_MPV

New video codecs normally take years to replace old ones, but if it gains traction AV1 will likely be used along side VP9, H.265 and H.264 for several years. Considering software and silicon vendors, and content providers (Google/YouTube, Amazon, and Netflix) are involved in the project, I’m quite confident the AOMedia AV1 codec will become popular, and hardware decoder are likely to be implemented in ARM, Intel and  AMD SoCs in a few years.

Thanks to Ohmohm for the tip.

Bluetooth 5 Promises Four times the Speed, Twice the range of Bluetooth 4.0 LE Transmissions

June 10th, 2016 7 comments

The Bluetooth SIG is about to officially unveil Bluetooth 5 on June 16 during a media event in London. One change on the marketing side is that they dropped the point number, so it won’t be called Bluetooth 5.0 like in Bluetooth 4.0, but just Bluetooth 5. The decision has been made allegedly to “simplifying marketing, and communicating user benefits more effectively”.

Bluetooth_5On the technical side, Bluetooth 5 will double the range and quadruple the speed of low energy Bluetooth transmissions compared to Bluetooth 4.x, which could be important for IoT applications where nodes are connected throughout the house.

Bluetooth 5 will also allow connectionless services to add location-relevant information and navigation. The specifications have not been publicly released yet, and made they will be on June 16. Eventually, you’ll be able to download them on Bluetooth “adopted specifications” page.

Via XDA developers

Categories: Uncategorized Tags: ble, bluetooth, standard

802.11ax WiFi Aims to Deliver Higher Throughput (Up to 10 Gbps), Better Handle High Density Scenarios

May 27th, 2016 1 comment

802.11ax WiFi, also known as High-Efficiency Wireless (HEW), aims to improve the average throughput per user by a factor of at least 4 times in dense user environments, with a total bandwidth of 10 Gbps over 2.4 and 5.0 GHz . The new standard is still work in progress and is expected to be published in 2019.

802.11ac_vs_802.11ax

802.11ax WiFi key features include:

  • Backwards compatible with 802.11a/b/g/n/ac
  • Increase 4x the average throughput per user in high-density scenarios, such as train stations, airports and stadiums.
  • Data rates and channel widths similar to 802.11ac, with the exception of new Modulation and Coding Sets (MCS 10 and 11) with 1024-QAM.
  • Specified for downlink and uplink multi-user operation by means of MU-MIMO and Orthogonal Frequency Division Multiple Access (OFDMA) technology.
  • Larger OFDM FFT sizes (4x larger), narrower subcarrier spacing (4x closer), and longer symbol time (4x) for improved robustness and performance in multipath fading environments and outdoors.
  • Improved traffic flow and channel access
  • Better power management for longer battery life

802.11ax_vs_802.11ac_subcarrier_spacing

So 802.11ax looks particularly suited to public space and WiFi in buildings, but if you live in the countryside or other low population density areas, it may not bring that much benefit over 802.11ac. You can read more about 802.11ax in National Instruments’ white paper, where they also mention software and equipment that can be used to work with the upcoming 802.11ax such as WLAN Measurement Suite and PXI RF Vector Signal Transmitter (VST). You can also visit IEEE 802.11ax page.

OpenThread is an Open Source Implementation of Thread IoT Networking Protocol

May 12th, 2016 4 comments

Thread was announced about two years ago, as a new IP-based wireless protocol based on 6LoWPAN and 802.15.4 standards and targeting IoT applications. Nest Labs,  an Alphabet company, has now released OpenThread open source implementation of the networking protocol under a BSD license.

OpenThread

The source code (C++)  includes supports for End Device, Router, Leader & Border Router roles, and  can be found on Github. The implementation is said to be OS and platform agnostic with a radio abstraction layer, have a small footprint, and implement all Thread networking layers, namely IPv6, 6LoWPAN, IEEE 802.15.4 with MAC security, Mesh Link Establishment, and Mesh Routing. To quickly get started you can may to read the Examples README which explains how to build the code, start two nodes, and ping them.

Interestingly, while the code is there for everybody to use, only paid members ($2,500 to $100,00) of the Thread group can access the full specifications.

Thanks to Nanik for the tip.

Categories: Hardware Tags: IoT, ipv6, nest, open source, standard, thread