barcode in vb.net Video and Audio Compression in Software

Making Code 128A in Software Video and Audio Compression

Appendix E
Scan Code 128 In None
Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications.
Generating Code 128 Code Set A In None
Using Barcode printer for Software Control to generate, create Code 128 Code Set B image in Software applications.
high-frequency coefficients, but most of the coefficients typically have been quantized to zero. To exploit this phenomenon, the two-dimensional array of transform coefficients is reformatted and prioritized into a one-dimensional sequence through either a zigzag or alternate scanning process. This results in most of the important non-zero coefficients (in terms of energy and visual perception) being grouped together early in the sequence. They will be followed by long runs of coefficients that are quantized to zero. These zero-value coefficients can be efficiently represented through run length encoding. In run length encoding, the number (run) of consecutive zero coefficients before a non-zero coefficient is encoded, followed by the non-zero coefficient value. The run length and the coefficient value can be entropy-coded, either separately or jointly. The scanning separates most of the zero and the non-zero coefficients into groups, thereby enhancing the efficiency of the run length encoding process. Also, a special end-ofblock (EOB) marker is used to signify when all the remaining coefficients in the sequence are equal to zero. This approach can be extremely efficient, yielding a significant degree of compression. In the alternate- or zigzag-scan technique, the array of 64 DCT coefficients is arranged in a one-dimensional vector before run length/amplitude code word assignment. Two different one-dimensional arrangements, or scan types, are allowed, generally referred to as zigzag scan (shown in Figure E.11a) and alternate scan (shown in Figure E.11b). The scan type is specified before coding each picture and is permitted to vary from picture to picture. Channel Buffer. Whenever entropy coding is employed, the bit rate produced by the encoder is variable and is a function of the video statistics [10]. Because the bit rate permitted by the transmission system is less than the peak bit rate that may be produced by the variable length coder, a channel buffer is necessary at the decoder. This buffering system must be carefully designed. The buffer controller must allow the efficient allocation of bits to encode the video and also ensure that no overflow or underflow occurs. Buffer control typically involves a feedback mechanism to the compression algorithm whereby the amplitude resolution (quantization) and/or spatial, temporal, and color resolution may be varied in accordance with the instantaneous bit rate requirements. If the bit rate decreases significantly, a finer quantization can be performed to increase it.
Code 128 Code Set C Decoder In None
Using Barcode decoder for Software Control to read, scan read, scan image in Software applications.
Create Code-128 In Visual C#.NET
Using Barcode generation for .NET Control to generate, create Code128 image in .NET applications.
Video and Audio Compression
Printing Code 128C In VS .NET
Using Barcode generation for ASP.NET Control to generate, create ANSI/AIM Code 128 image in ASP.NET applications.
ANSI/AIM Code 128 Encoder In .NET
Using Barcode generation for Visual Studio .NET Control to generate, create Code 128 image in .NET applications.
Figure E.11 Scanning of coefficient blocks: (a) alternate scanning of coefficients and (b) zigzag scanning of coefficients. (From [10]. Used with permission.)
Draw Code 128 Code Set A In VB.NET
Using Barcode drawer for .NET framework Control to generate, create Code 128 image in .NET framework applications.
GTIN - 128 Creator In None
Using Barcode drawer for Software Control to generate, create GS1 128 image in Software applications.
As an example, the ATSC DTV standard specifies a channel buffer size of 8 megabits. The model buffer is defined in the DTV video coding system as a reference for manufacturers of both encoders and decoders to ensure interoperability. To prevent overflow or underflow of the model buffer, an encoder may maintain measures of buffer occupancy and scene complexity. When the encoder needs to reduce the number of bits produced, it can do so by increasing the general value of the quantizer scale, which will increase picture degradation. When it is able to produce more bits, it can decrease the quantizer scale, thereby decreasing picture degradation. Decoder Block Diagram. As shown in Figure E.12, the ATSC DTV video decoder contains elements that invert, or undo, the processing performed in the encoder [10]. The incoming coded video bit stream is placed in the channel buffer and a variable length decoder (VLD) removes bits. The VLD reconstructs 8 8 arrays of quantized DCT coefficients by decoding run length/amplitude codes and appropriately distributing the coefficients according to the scan type used. These coefficients are dequantized and transformed by the IDCT to obtain pixel values or prediction errors.
Painting Bar Code In None
Using Barcode maker for Software Control to generate, create barcode image in Software applications.
Drawing UPC Code In None
Using Barcode encoder for Software Control to generate, create UPC-A Supplement 5 image in Software applications.
Figure E.12 ATSC DTV video system decoder functional block diagram. (From [10]. Used with permission.)
Barcode Generation In None
Using Barcode maker for Software Control to generate, create barcode image in Software applications.
DataMatrix Creator In None
Using Barcode maker for Software Control to generate, create DataMatrix image in Software applications.
GS1 - 12 Creator In None
Using Barcode generation for Software Control to generate, create UPCE image in Software applications.
Create Code 128 Code Set A In None
Using Barcode creation for Microsoft Excel Control to generate, create Code128 image in Office Excel applications.
Painting GS1 - 12 In Objective-C
Using Barcode drawer for iPad Control to generate, create UPCA image in iPad applications.
Barcode Generator In Java
Using Barcode generator for Android Control to generate, create bar code image in Android applications.
Universal Product Code Version A Recognizer In Java
Using Barcode decoder for Java Control to read, scan read, scan image in Java applications.
Recognize GS1 128 In VB.NET
Using Barcode decoder for .NET Control to read, scan read, scan image in VS .NET applications.
UCC - 12 Encoder In VB.NET
Using Barcode generation for Visual Studio .NET Control to generate, create USS-128 image in VS .NET applications.
Bar Code Generator In None
Using Barcode creator for Microsoft Word Control to generate, create bar code image in Office Word applications.
Copyright © OnBarcode.com . All rights reserved.