O'Reilly logo

Visual Media Coding and Transmission by Ahmet Kondoz

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

5.5 Optimal Rate Allocation for H.264/AVC Joint MVS Transcoding

(Portions reprinted, with permission, from “Joint bit-allocation for multi-sequence H.264/AVC video coding rate control”, Picture Coding Symposium, Lisbon, November 2007. ©2007. EURASIP)

5.5.1 Problem Definition and Objectives

Let us consider the scenario depicted in Figure 5.5, where the input is represented by a set of pre-encoded H.264/AVC sequences, each encoded in either VBR or CBR mode. The sequences are multiplexed into a single channel, characterized by a global rate constraint Rtot. Therefore, the problem is twofold:

images

Figure 5.5 Proposed transcoding architecture for multi-sequence rate control. Reproduced by permission of ©2007 EURASIP

  • The rate controller module is responsible for optimally allocating the bit budget to the output sequences.
  • Transcoding needs to be performed in order to meet a more stringent rate constraint and adjust the output bit rate of the sequences.

In this work, the focus is on defining novel solutions for the rate control module, while a very simple transcoding algorithm is envisaged in order to serve as a “proof of concept”. Specifically, in order to avoid issues related to drift propagation, an explicit transcoder that decodes the sequence in the pixel domain and re-encodes it subject to the new, more stringent, rate constraint is adopted. In order to speed up the transcoding process, ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required