Diagnostic Instrumentation

Table of Contents | Overview: Diagnostic output | Overview: Intra frames

Overview

Operation

This diagnostics tool has been developed as a standalone executable for ease of development outside of the main Dirac codec. Specific code structure and internal operation is detailed here.

The executable is compile as part of the Dirac software suite and can be found under the util/instrumentation diractory. The following command is used to execute the program:

util/instrumentation/dirac_instrumentation -flag [flag val] input output

Input and output is in the form of raw format YUV picture files. Instrumentation data must also be present in a file named [input_file].imt. Further details on motion data transfer is given here.

The following options dictate the mode of instrumentation:

Flag Default value Description

-motion_colour

True

Display motion vectors using a colour wheel

-motion_arrows False Display motion vectors using white arrows
-motion_colour_arrows False Display motion vectors using coloured arrows
-global false Display global motion vectors using above mechanism
-global_diff false Display difference between global motion vectors and block motion vectors using above mechanism
-global_inliers false Display motion vectors used to approximate global motion
-sad False Display sum of absolute difference
-split_mode False Display macroblock splitting mode
-pred_mode False Display motion prediction mode
-no_bg False Display overlay on mid-grey luminance
-no_legend False Do not display colour legend information
-verbose False Output progress information

Table 1. Diagnostics command line flag options

Parameter Default value Description
-ref 1 Set reference frame for motion and SAD
-clip 25* Clip value for motion vectors
10000 Clip value for SAD
-start 0 First frame to be processed
-stop end of sequence Last frame to be processed
-buffer 50 Size of internal motion data buffer

Table 2. Diagnostics command line parameter options

For example, the following syntax requesting colour arrow motion vectors for second reference on a grey background with the legend turned off:

dirac_instrumentation -motion_colour_arrows -ref 2 -no_bg -no_legend


* This value means 25 1/8th pixel increments, the fixed motion vector resolution at the time of writing

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