ld decode tools

ld-decode-tools

ld-decode-tools is a suite of applications for processing the .tbc output from ld-decode. The tools enable various processing of the LaserDisc including VBI, 40-bit FM code, White-Flag, dropout detection/correction and comb filtering. The ld-decode-tools use a JSON based metadata file to store and communicate information about the .tbc. Details of the JSON format can be found on the ld-decode wiki pages.

Installation

From the tools directory (of the ld-decode repo) type 'qmake' followed by 'make all'. Once all of the applications are compiled use 'sudo make install' to install and 'sudo make uninstall' to remove.

Note: The ld-decode-tools.pro qmake project file is designed only for command line compilation with Ubuntu. The individual application .pro files can be used within the Qt Creator IDE (you should build ld-decode-shared first in order to make a local copy of the required shared libraries).

So if, for example, your .tbc output file is test_video.tbc (and is NTSC):

ld-process-vbi test_video.tbc (add in the VBI data and determine the field order)

ld-dropout-correct test_video.tbc test_video_doc.tbc (correct the dropouts and create a new .tbc)

ld-analyse test_video_doc.tbc & (view the corrected .tbc)

ld-comb-ntsc test_video_doc.tbc test_video_doc.rgb (convert the .tbc to RGB 16-16-16 frames)

For a PAL .tbc output file a typical sequence would be:

ld-process-vbi test_video.tbc (add in the VBI data and determine the field order)

ld-dropout-correct test_video.tbc test_video_doc.tbc (correct the dropouts and create a new .tbc)

ld-analyse test_video_doc.tbc & (view the corrected .tbc)

ld-comb-pal test_video_doc.tbc test_video_doc.rgb (convert the .tbc to RGB 16-16-16 frames)

Note that the VBI processing, NTSC processing, drop-out detection and correction are optional.

ld-process-vbi

This application examines the input TBC file and determines the available VBI data for each available frame. The VBI data is stored as both the raw data value for the 3 VBI lines as well as a full decode of the VBI according to the IEC specifications. The resulting information is written back into the JSON metadata file for the TBC output.

For NTSC sources this application also processes items from the IEC NTSC specification that are specific to NTSC LaserDiscs such as 40-bit FM codes, white flags, etc.

Syntax:

ld-process-vbi <options> <input TBC file name>

Available options are:

--debug - Show full debug output

--help - show help text

--version - show version text

--correction - Perform automatic VBI frame number, time-code and sound mode correction (experimental). Note: this will not function correctly on NTSC pull-down sources. You must run ld-process-vbi on the TBC file without this option first to populate the required metadata.

ld-dropout-correct

This application uses the drop-out information in the JSON metadata file to perform dropout correction on the input TBC file and produces a new output file. The current version of the corrector uses framing in order to provide inter-field correction. Note that inter-field correction may not function correctly for NTSC pull-down sources.

Syntax:

ld-dropout-correct <options> <input TBC file name> <output TBC file name>

Available options are:

--debug - Show full debug output

--help - show help text

--version - show version text

--reverse - Reverse the field order to second/first (default first/second)

ld-comb-pal

This application takes the PAL TBC input video and colourises it. Output is a sequence of RGB 16-16-16 video frames.

Syntax:

ld-comb-pal <options> <input TBC file name> <output RGB file name>

Available options are:

--debug - Show full debug output

--start - Specify the start frame

--length - Specify the maximum number of frames to process

--reverse - Reverse the field order to second/first (default first/second)

--blackandwhite - Output in black and white (only outputs Y and ignores UV)

--help - show help text

--version - show version text

ld-analyse

This GUI application provides a range of features for examining TBC output including drop-out detection, video extent, line scope and VBI data. The application works with NTSC and PAL TBC output files.

Note: The input file name is optional (you can either specify it from the command line or using the GUI once the application is running).

Syntax:

ld-analyse <options> <input TBC file name>

Available options are:

--debug - Show full debug output

--help - show help text

--version - show version text

ld-comb-ntsc

This application takes the NTSC TBC input video and colourises it. Output is a sequence of RGB 16-16-16 video frames.

Syntax:

ld-comb-ntsc <options> <input TBC file name> <output RGB file name>

Available options are:

--debug - Show full debug output

--3d - Use 3D filtering (default is 2D)

--blackandwhite - Output video frames in black and white

--reverse - Reverse the field order to second/first (default first/second)

--white - Use a 75% white-point (default is 100%)

--oftest - Superimpose the optical flow map (generated for 3D processing) over the output RGB image (Note: this option is for testing purposes)

--start - Specify the start frame

--length - Specify the maximum number of frames to process

--help - show help text

--version - show version text

ld-combine

This application combines two TBC source files using quality and drop-out metadata to decide which source contains the best image data. For lines containing dropouts the application will replace the whole line (if a perfect replacement is available) or the individual dropouts where replacement data is available in the secondary source. Output is a new TBC file with dropout metadata for any dropouts that could not be replaced.

Syntax:

ld-combine <options> <primary TBC file name> <secondary TBC file name> <output TBC file name>

Available options are:

--debug - Show full debug output

--help - show help text

--version - show version text

--reverse - Reverse the field order to second/first (default first/second)

ld-process-audio

This application attempts to correct analogue audio data based on the video dropout metadata. The processing averages the audio data over dropouts to remove clicks and pops in the .pcm file generated by ld-decode.

Syntax:

ld-process-audio <options> <input TBC file name>

Available options are:

--label - Output Audacity label metadata file (this can be used to annotate the .pcm file in Audacity)

--silence - Silence audio according to VBI data (removes PCM audio data for sections where the VBI sound mode field indicates audio should not be present)

--debug - Show full debug output

--help - show help text

--version - show version text