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Abstract
The Wide-Band Code Division Multiple Access
(WCDMA) is the technology of the third generation mobile
systems. It has many advantages over the second generation
mobile systems. It has better bandwidth efficiency. In
addition, wide-band services such as videophone and Internet
services are provided including video streaming.
In this thesis we will concentrate on wideband services.
This is done by making a deep study on video codecs in
general and concentrating on H.264 video codec. H.264 video
codec is capable of providing good video quality at
substantially lower bit rates than previous standards without
increasing the complexity of design so much that it would be
impractical or excessively expensive to implement. H.264
also provides enough flexibility to allow the standard to be
applied to a wide variety of applications on a wide variety of
networks and systems.
To do that, H.264 uses some mechanisms that are
specified in the international standards (ITU-T
Recommendation H.264 and ISO/IEC 14496-part 10).
The video frame is divided into some macroblocks, and
then motion estimation takes place allowing the residual data
to be transferred to the transformer. The transformer applies
the DCT to the frame then the frame is quantized and entropy
encoded to be ready to be sent to the decoder.
The decoder passes data to the Entropy decoder, then to
the inverse quantizer and then to the IDCT. The resulted data
will then represent the original frame using the motion
estimation data.
XI
We used H.264 Reference software to implement the
decoder and develop it into a digital signal processor. This
includes the study of Linux OS and the Digital Video
Evaluation Module. International Standards were followed to
insure conformance to the standard specifications.
The H.264 decoder was first implemented on Windows
platform. The initial encoding speed was 200 fps. Secondly,
the decoder software was implemented on Linux platform.
The encoding speed was 136.364 fps. This is due to the
difference between Windows and Linux and their memory
management techniques.
After that, the software was implemented on the ARM
processor and the result was 9.524 fps. The reason for this
low speed is that the ARM processor is not manufactured to
perform DSP functions.