Category Archive: Articles

Now it’s easy to set processor affinity for decoder and encoder (Stanley posted on December 16th, 2009 )

In the build 4560, you can easily set processor affinity for audio/video decoder and encoder. By clicking the check boxes which represent each core of your processor. If you have a quad-core processor, you will se 4 check boxes enabled and selected by default. Unticking a checkbox will cause a core not to be used by chosen decoder or encoder.  If you processor has many cores, this will be useful, as you can allocate different cores for different use, or preserve some cores free for your other tasks. Some tips:

  • Even if all cores are selected, they are not necessarily be 100% utilized during transocidng. This depends on the multi-threading support in decoder or encoder.
  • A started job will not be affected by the change of the affinity option, unlike the change of the prioirty option.

Processor affinity settings in MediaCoder在最新的Build 4560中新增了设置影音编解码器的处理器亲和度(Processor Affinity)参数。通过设置代表所有处理器或处理器核心的复选框,可以控制哪些处理器或者核心被使用,哪些不被使用。例如,在一个四核处理器的系统上,你会看到有四个复选框是可选的,如果一个复选框没有被选中,那相应的处理器或者核心就不会被使用。当你的处理器有很多核心时,这个功能就比较有用了。你可以自行分配解码器和编码器所使用的核心,也可以预留一些核心供其他应用使用。


  • 即使所有的复选框被选中,这也不意味着你的多核处理器能被100%使用。这还取决于编解码器的多线程支持程度。
  • 和优先级设置不同,多核分配设置在下一个任务开始后才会生效。

Processor affinity settings in MediaCoder


Benchmarks: CUDA H.264 vs x264 (Stanley posted on July 3rd, 2009 )

Hardware platform:

  • CPU: Intel Core2 Quad Q6600 (2.4Ghz/4 cores)
  • GPU: nVidia GTX 275 (896M/448bit/240 SP)
  • Memory: 4GB

Software platform:

  • OS: Windows XP x64
  • Transcoder: MediaCoder
  • x264 command line options:  –no-psnr –no-ssim –keyint 250 –min-keyint 25 –me hex –merange 16    –non-deterministic –aq-mode 1 –aq-strength 1.0 –b-adapt 1 –ref 1 –subme 6 –psy-rd 1:0 –bframes 3  –trellis 1 –weightb –direct auto –bitrate $(VideoBitrate) –qcomp 0.6  -o “$(DestFile)”

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CUDA H.264 transcoding test report in MediaCoderMediaCoder的CUDA H.264编码技术预览及测试报告 (zoominla posted on June 9th, 2009 )

NVIDIA’s cutting-edge CUDA tech is cool, and it’s been talking about throughout the internet. Also it’s attractive to us, we started cuda working from the start of the year. After a period of hard working, we finally successfully integrated it into MediaCoder, it’s very awsome. We can’t wait to annouce it and publish the test report.

The report mainly compares transcoding performance between CUDA-accelerated H.264 and X264. There are two parts, one is performance on HD encoding, the other is on low resolution encoding.
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H.264 profiles and levels (Stanley posted on April 28th, 2008 )

H.264 Profiles

The standard includes the following seven sets of capabilities, which are referred to as profiles, targeting specific classes of applications:

  • Baseline Profile (BP): Primarily for lower-cost applications with limited computing resources, this profile is used widely in videoconferencing and mobile applications.
  • Main Profile (MP): Originally intended as the mainstream consumer profile for broadcast and storage applications, the importance of this profile faded when the High profile was developed for those applications.
  • Extended Profile (XP): Intended as the streaming video profile, this profile has relatively high compression capability and some extra tricks for robustness to data losses and server stream switching.
  • High Profile (HiP): The primary profile for broadcast and disc storage applications, particularly for high-definition television applications (this is the profile adopted into HD DVD and Blu-ray Disc, for example).
  • High 10 Profile (Hi10P): Going beyond today’s mainstream consumer product capabilities, this profile builds on top of the High Profile—adding support for up to 10 bits per sample of decoded picture precision.
  • High 4:2:2 Profile (Hi422P): Primarily targeting professional applications that use interlaced video, this profile builds on top of the High 10 Profile—adding support for the 4:2:2 chroma subsampling format while using up to 10 bits per sample of decoded picture precision.
  • High 4:4:4 Predictive Profile (Hi444PP): This profile builds on top of the High 4:2:2 Profile—supporting up to 4:4:4 chroma sampling, up to 14 bits per sample, and additionally supporting efficient lossless region coding and the coding of each picture as three separate color planes.

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Some video tutorials of MediaCoder on YouTube (Stanley posted on March 11th, 2008 )

I found these tutorials on YouTube by a random search. Some seems weel-done and useful. Thanks to the makers of these videos.

MediaCoder Tutorial

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Adding RSS feed entries just like adding a folder (Stanley posted on March 11th, 2008 )

Since build 4075, MediaCoder is able to load a RSS feed and queue up all its entries, just like adding a disk folder. For example, we can easily find a RSS feed button on YouTube like this:

Simply drag the RSS feed button or link into MediaCoder, and you will see this: Read the rest of this entry >>