Characteristics
Applications
When developing
professional and consumer equipment, particularly encoders and set-top
boxes, the characteristics of the test streams being either generated
or used as stimulus need to be ascertained. Of critical importance
amongst these characteristics is adherence to the buffer model. That
is, when the stream is processed by a receiver, will any of the internal
buffers be caused to either under- or overflow. Consequences of these
conditions will be freeze frames and receiver resets.
There
are two types of buffer model; the one to use by the receiver is signaled
within the Elementary Stream itself. The T-STD method is based upon
the DTS values within the PES header and can be used for any contained
CODEC type. Additionally, certain video CODECs such as MPEG-2 and
H.264/AVC may contain buffer parameters within the ES itself. The
Buffer Analyzer verifies conformance of a stream to the T-STD model.
Verification of the H.264/AVC HRD method is covered by the MTS4EA
product.
Feature Details
The Buffer Analyzer accepts
any recorded Transport Stream as an input source. The TS is then demultiplexed
into its component PES, grouped by Program. The user can select one
or more PES to analyze for conformance to the T-STD model according
to the buffer parameters for the CODEC type in question. General information
such as profile and level together with any buffer errors are recorded
in a log.
The user may manually set buffer sizes and other
parameters prior to analysis, rather than use those specified by the
standard or signaled within the stream.
Buffer Graphs
The occupancy level for each buffer within the model (3
for video, 2 for audio, and 2 for PSI) is plotted on a graph for each
PES being analyzed. Graphs may be zoomed for ease of use. A Synchronization
feature allows for comparisons at a particular point in time between
each of the graphs and individual log entries.
Trace View
Version 8.0 enhancements have integrated the previously
separate Tracer utility into the Buffer Analyzer application. The
Trace view provides details of the buffer movements for in-depth analysis
of the results. Trace entries are included in the Synchronization
feature for ease of diagnosis.
Buffer Model Results (BMR
files)
The analysis results will be stored in a .bmr file
to save having to reanalyze the same file. Results files may be opened
directly in the Buffer Analyzer, whereby logs, graphs, and Trace contents
(max 7000 entries) are repopulated. They are far smaller than the
original TS files and thus useful to add as e-mail attachments.
Supported CODECs
- MPEG-2 Video
- H.264/AVC (MPEG-4 part 10)
- MPEG-2 Audio
- MPEG-2 AAC
Audio
- MPEG-4 AAC Audio, including High Efficiency and 5.1
channels
- AC-3 Audio
- PSI (ISO/IEC 13818 parts 1)
Standalone Software System Requirements (MTS4SA)
- PC with Genuine Intel Pentium class 1.2 GHz processor
- Intel or 100% compatible motherboard chipset
- Windows 2000
or Windows XP Operating System
- Internet Explorer 5.0 or above
- 256 MB of RAM
- 50 MB of available hard disk space for
the application and documentation
- SVGA (800 × 600) resolution
video adapter and monitor (XVGA (1024 × 768) or higher resolution
recommended)
- CD-ROM or DVD drive
- Keyboard and Microsoft
Mouse or compatible pointing device
