MASTER THESIS Video Watermarking - Computer Graphics Group ...

auxiliary coded pictures),
Supplemental Enhancement Information (necessary information for
correct video playback and other data – timing information, buffer
management hints, user data, scene information, pan-scan information,
spare picture information, still frames etc.),
Slice Data Partitions, i.e. partitions of too big slices.
4.2 The Watermarking Framework
The framework is designed for easiness when implementing any particular
watermarking method in either spatial or frequency domain of H.264 video
streams. Then, implementation of a method consists in writing only two
functions, one for watermark embedding and the other for watermark detection.
4.2.1 GStreamer Multimedia Framework
In practice, a H.264 video stream is usually enveloped (multiplexed / muxed)
together with an audio stream into a multimedia container format such as Audio
Video Interleave (AVI) or Matroska (MKV). In order to avoid implementing of
unpacking (demultiplexing / demuxing) various container formats and separating
out the video stream, the watermarking framework is implemented as a plugin in
the open source multimedia framework called GStreamer [12].
GStreamer is a library that allows the construction of graphs of
media-handling components, ranging from simple audio playback to complex
audio and video processing.
A graph, also called a pipeline, of a generic audio-video player is illustrated
in Figure 8.
Figure 8: Generic audio-video player pipeline
The file source reads the input file of particular container format and
forwards its data to the demuxer. The demuxer demultiplexes the container
format resulting in audio and video data blocks. The video decoder decodes video
data and forms pictures of the video sequence. Then, pictures are displayed by
the video sink on the screen with the correct timing to be a fluently moving video.
Audio data are decoded by the audio decoder and reproduced by the audio sink on
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