Gonzalo Martin's List: Television y contenidos en movilidad

• Keyes told the Reuters Media Summit he started watching movies on his BlackBerry after some help from a technical expert at Blockbuster and from Jim Balsillie, the co-chief executive of Blackberry maker Research in Motion.
• "The challenge is how do I make this convenient for everybody," Keyes said.
• "It is a rare treat for me to sit at home with my family and watch a DVD," he said.

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• Reducing -3dB to -6dB down from full-scale audio will give the audio codec enough headroom to prevent clipping
• ou may choose to convert stereo to mono audio. Mono is half the amount of data as stereo since the audio bitrate is not divided between two channels
• Some content, usually music videos and movie trailers, may require stereo audio, but if you don’t need to use stereo, don’t.
• You should crop video edges. Clean, well-defined edges encode best,
• Since handsets do not use interlaced displays, you should deinterlace content shot on interlaced video, which will convert the video scanning from interlaced to progressive. This will result in smoother motion and smoother edges.
• Also, remove letterboxes where possible. If you cannot remove it, make sure it is Super Black
• For content shot on 24 fps film and delivered on 30 fps videotape, apply an inverse telecine filter, which will remove the 3:2 pulldown added in the telecine process. This will return the video to 24 fps, which, when frame rate subsampled for mobile delivery, will result in better image quality.
• Establish Super Black as the reference, but do not push midtones and greys into black
• hen subsampling, calculate frame rate using whole numbers: -30 fps —> 15 fps; -24 fps —> 12 fps. The linear reduction in file size is 30 to 15 fps = .5 file size
• ideo noise is very inefficient to encode. It eats up a huge amount of bits, which are diverted from the subject. Reducing noise makes the codec’s job easier to create higher visual quality content.

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• n order to effectively deliver video content to wireless and mobile users, content providers must move from an “MTV” mind-set to a narrowband mind-set. Every aspect of production needs to be examined from this viewpoint. Not all content will work well in narrowband. Preprocessing repurposed content for mobile delivery will reap significant benefits. The best scenario is to deliver content purposely designed to encode well for narrowband delivery. Whether repurposing or creating new content, be sure to return to the fundamentals of production:
   • Rely on strong storytelling and well-composed shots.
   • Place less emphasis on visual eye candy.
   • Pace edits less frenetically.
• The narrowband mind-set requires a shift in production values. First, the rate and amount of change should be carefully controlled. Both contribute significantly to higher bandwidth requirements. Second, a jump to a higher visual quality level is difficult to achieve. Instead, one must accumulate small improvements in each step of production. Therefore, no opportunity to improve quality is too small. Always choose the quality option. Do not fall for the “it’s so small it doesn’t matter” trap. Minimized video requires maximized quality. The encoding process magnifies shortcuts on quality.
• Preprocessing Audio
   Before encoding, preprocess audio and video tracks in order to maximize the post-encoding video quality. Preprocessing audio and video can be done within the timeline of an editor using available plug-ins. Alternately, preprocess audio separately from video using an audio mastering application. Then recombine the audio and video to build your master clip. If you process outside of a nonlinear editor, import the audio to the timeline and edit to picture, replacing original nonprocessed audio.
  ,br>  Perform low-pass and high-pass filtering on your audio. This will reduce frequencies not reproducible in handsets due to the limited frequency response of miniature speakers
• It is important, therefore, to reduce the low and high frequencies prior to encoding.
• Higher signal levels keep the codec working in the range where it sounds the best, with smoother sound quality.

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• Producing video content for wireless networks can be as complicated as delivering it successfully. Here are some guideline and best practices for optimizing video for playback on handheld devices.
• Wireless video delivery is complicated
• Codecs use a number of techniques to compress the size of digital video content:
   • Spatial Compression: Each pixel within a frame is compared to neighboring pixels. Based on a given threshold, pixels are evaluated as similar or different and are discarded if considered redundant.
   • Temporal Compression: Successive frames of video are compared to one another, and a series of keyframes (I frames)—containing all the data that comprises the image—are created to establish a baseline quality. Delta frames (P and B frames) fall between I frames and are more highly compressed, holding only the pixel information that has changed from the previous frame and requiring a decoder to reference other frames to present a complete image.
   • Color Space Subsampling: This process exploits the fact that human eyes are more sensitive to brightness than to color, so it reduces the amount of color information.
   • One-Pass: One-pass encoding is speed-optimized, whereby the codec analyzes the need for bitrate slightly ahead of the actual encoding. It is used in applications requiring real-time encoding, such as live streaming.
   • Two-Pass: Primarily used in nonreal-time applications such as video-on-demand, two-pass encoding analyzes the bitrate requirement in a complete pass through the video, and then it applies the bitrate map to the video in a second pass.
   • Constant Bitrate (CBR): Video is encoded at a bitrate below a ceiling, usually specified by the mobile network operator. Video bitrates above the ceiling would cause interruptions in delivery.
   • Variable Bitrate (VBR): Bitrate varies with demand of the content, producing higher-quality output. Dynamic, high-motion scenes require more bitrate than talking heads. Spikes in encoded video bitrate are acceptable depending on the

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• What we mean by 'mobile 2.0' is another (r)evolution, already started, that will dramatically change the web and the mobility landscape that we currently know. The idea is that the mobile web will become the dominant access method in many countries of the world, with devices that become more hybrid and networks that become more powerful - everywhere in the next decade to come.
• Non-carrier projects like Google Wi-Fi and FON aim to make cities completely Wi-Fi accessible. From personal experience I can tell you that people are going to use these alternative options to connect to the internet, once it's available on their mobile devices.