zoukankan      html  css  js  c++  java
  • 《Pro Android Graphics》读书笔记之第二节

    Android Digital Video: Formats, Concepts and Optimization

           Android Digital Video Formats: MPEG4 H.264 and WebM VP8

       H.263 支持老显示器
    MPEG4 SP  
    supported for commercial video(支持商业视频)
    3GP
    Google在2.3.3中增加对WebM的支持
    video Stream 4.0以后版本号
    recommend using MPEG-4 H.264 AVC
    WebM 直播流

            

    Android VideoView and MediaPlayer Class: Video Players

              

    MediaPlayer:在包android.media中。

                    

    VideoView:在包android.widget中,direct subclass of the Android SurfaceView(详细介绍请參考书)。


    The Foundation of Digital Video: Motion, Frames and FPS

    pixels, resolution, aspect ratios, color depth, alpha channels, pixel blending, image compositing, and even data footprint optimization(相似于图片的概念)。

    计算影片大小:每帧的大小*帧率*时间


    Digital Video Conventions: Bit Rates, Streams, SD, and HD

      Internet 2.0 IP infrastructure is 1536 kbits/second (1.5 MBPS, or megabits per second)。

    A faster data pipe is at least 2048 kbits/s, or 2 mbits/s or 2 MBPS, and video compressed at this higher bit rate exhibits a higher visual quality level. More modern 4G networks claim to be between 3 and 6 mbits/s(3G networks deliver between 600 kbits/s and 1.5 mbits/s, so, on average, these will be 1.5 mbits/s and classified as a medium data pipe)。


    Digital Video Files for Android: Resolution Density Targets

    DPI:density pixel imagery

    For digital video, this also includes different target bit rates, so that you can try to fit all of the different device screen densities and the different processing power capabilities of single-core through quad-core CPU product offerings。


    Optimizing Digital Video: Codecs and Compression

    decode  codec

    professional solution(专业解决方式(不到1000刀))

    EditShare Lightworks 11(open source)

    Creating Your Video Assets: Using Terragen 3 3D Software

    Planetside 


    Creating Uncompressed Video: Using VirtualDub Software

    VirtualDub Video(须要花费大量时间)


    Compressing Your Video Assets: Using Sorenson Squeeze

    从AVI到MP4(H264)(文中样例:压缩比达到120:1)

    Installing a Video Asset in Android: Using the Raw Folder


    Referencing the Video Asset in Your Android Application

    Uri splashScreenUri = Uri.parse("android.resource://"+getPackageName()+"/"+R.raw.pag480portrait);
    (VideoView)splashScreen.setVideoURI(splashScreenUri);
    MediaController splashScreenMediaController = new MediaController(this); 


  • 相关阅读:
    详解Go变量类型的内存布局
    saltstack手册(含官方pdf)
    Linux之《荒岛余生》(三)内存篇
    linux之网络
    Linux之IO
    【WPF】提高InkAnalyer手写汉字识别的准确率
    mssql 小技巧
    WCF Data Service
    jQuery基础之选择器
    Window程序的安装与部署
  • 原文地址:https://www.cnblogs.com/wzjhoutai/p/6917596.html
Copyright © 2011-2022 走看看