Musings

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About The New Site

Folks, I just put up this new site.  It is WordPress and chosen because it is responsive design, accessible from anywhere and simply mega easy to style, modify and maintain.  Expect to see more details as I add all sorts of techno babble, skills and projects on the site.

 

For the moment I am a consultant who works remotely.   I have strong expertise in audio signal processing, compression standards, in particular ISO/IEC MPEG, as well as ITU G.7xx speech codecs.  I also am an optimization expert and live to write cryptic assembly that I actually comment so one can follow along at home. C is my best language with my Kernighan and Ritchie still with me in tatters.   I do have many other languages, including the antiquated Fortran and the obligatory C++.

I have a strong hardware background and have implemented projects on all sorts of embedded architectures. Yes, I do run a popular economics site, based in Drupal 7.x, where I did all of the coding modifications.  The site currently resides on a CentOS 6.x, unmanaged VPS that I configured and maintain.

I build my own systems too.  They will have to pry my Wiha T4 Torx from my cold dead hands, I am that geeky.

Other skills will be added to the site and overall I’m out to be more chatty.  I am a notorious lurker who posts little, yet  knows a lot.  We’re out to change that.

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H.264 in WebRTC

Cisco just did a solid and released H.264 into open source for use in WebRTC. Cisco is absorbing the estimated $13 million in licensing fees from MPEG-LA. The reason Cisco did this was to avoid transcoding of H.264 streams from other video clients, a wise choice. The IETF is determining which video compression algorithm will be the baseline for webRTC this week.

Mozilla will incorporate webRTC, including H.264, into the Firefox browser and Chrome already has it. Google is sticking with VP8 and is a major developer and contributor to webRTC. The IETF vote is in Atlanta this week and we’ll update this post with who won out in the video codec selection. We hope both are supported, yet Cisco is right, the last thing one wants to be doing in a real time stream is transcoding H.264 to VP8. It does seem that stand alone proprietary video conferencing and streaming solutions are going the way of the dinosaur, although webRTC as the meteor which killed the beast is yet to be determined.

Real-time communications in the browser utilizing native codecs and javascript sounds too good to be true and that is becuase it is. Underneath the hood are the typical real time streaming issues such as NAT transversal, firewalls, latency, QoS and synchronization, to name just a few. WebRTC latency was reported to be 150ms with a mininimum of 100ms. While that mets ITU QoS, it is pretty much the crappy out of sync video conferencing most of us experience daily.

It appears at the IETF meeting there was no consensus on which video compression algorithm to make mandatory for webRTC.   It also appears both is not an option, so far and Nexus has hardware implementations of VP8 while hardware acceleration for H.264 is available in many chipsets.

On a technical note, I am downloading the source for webRTC, focus on Opus, (Xiph), since supposedly it is not ported, never mind optimized, on many embedded platforms.    I’ll write up what I find in another post.

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Tools Which Make Remote Consulting Work

Telecommuting saves the environment, allows those with disabilities to more easily perform tasks,  increases productivity and removes distractions that are common in an office environment.    Yet, many employers still do not take advantage of new technologies which enable working remotely.

Here at Musemagic we utilize Skype, ftp, servers,  remote access, chat clients, and our personal favorite, VMware Workstation.   We can create VMware images with not just the deliverables, but the entire development system and test bench.  One can see exactly every step of development and the results by this method.  All one has to do is pull up the image in their VMware player and hit go.    VMware can convert physical machines into virtual ones and vice versa in minutes and enables remote access to a virtual machine.

For embedded projects where JTAG USB drivers are not compatible with VMware (we’ve yet to see this happen), we can also configure a laptop with all development tools for that particular embedded environment.  Evaluation kits are cheap, custom boards are also easy to transport and one can mirror development as well as burn the flash ROM with the latest code drops in minutes.  Of course being able to set up systems, solder daughter boards, design circuitry and other skills one must have to bootstrap a project are a given.

We also can set up Mantis, a bug database, and a code repository of your choice.    With today’s video conferencing and  on-line meeting tools, literally we can be present on your desktop anytime you wish.          This is just a short list of technologies which make remote consulting of all types work.

Our Skype ID is musemagic.  Give us a buzz, even for casual queries.

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HEVC Video

The ISO/IEC JTC 1/SC 29/WG 11, a.k.a. MPEG video – ITU video, a.k.a. JCT-VC,  has issued a committee draft of H.265, or HEVC.    HEVC stands for High Efficiency Video Coding and is the next generation video coding standard.     The algorithm’s main goal is to achieve the same video quality at half the bitrates of H.264.     More resolutions are also offered.     The final standardization approval date is scheduled for January 2013, with a standardization draft due in July 2012.

The Fraunhofer site is maintaining the source and some documentation.

We’re following HEVC as it develops.     Here is a pdf of the  HEVC requirements document, w11872.      The requirements document does specify video conferencing.      This implies a low algorithmic delay and overall  low latency HEVC profile, at minimum.     The fundamental trade off of the standard is increased computational complexity to achieve higher compression efficiency.     Below is the HEVC application list from the MPEG  requirements document.

• Home cinema
• Digital Cinema
• Surveillance
• Broadcast
• Realtime communications, video chat, video conferencing
• Mobile streaming, broadcast and communications
• Storage and playback of video
• Camcorders
• Video On Demand
• Internet streaming, download and play
• Remote video presentation and remote computer graphics display
• 3D video
• Telepresence
• Content production and distribution
• Medical imaging

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3D Video

There have been recent queries on 3D video technologies.    Currently the MPEG standards body has created an amendment to the H.264 (AVC) video standard, approved June 2009, called Multiview Video Coding.

The amendment covers:

  • Stereoscopy
  • Multi-view
  • Free viewpoint

The MPEG H.264/AVC MVC amendment is backwards compatible to older technologies & MPEG-4/H.264 implementations that do not support 3D display capabilities.

Nokia Research is hosting the reference source code and corresponding standards drafts.

I am currently working with the above references, Fedora 13 OS platform. To date, the open source x264 project, part of VideoLan, emulating H.264 streams, does not support the MVC amendment.