.TBC Format Wikipedia Page Backup - harrypm/vhs-decode GitHub Wiki

[[File:Screenshot at 2022-11-13 18-42-52.png|thumb|Y+C (Luma + Chroma) Chroma, VHS-C SP ([[Pixel aspect ratio|SAR]] 1:1)|484x484px]] The TBC format is a lossless and headerless, 4fsc digital file format not dissembler to [[D-2 (video)|D-2]] & [[D-3 (video)|D-3]] video tape, storing time base corrected [[Composite video|composite]]/[[S-Video|s-video]] (combined or luminance/chrominance separated) analogue video signals in 16-bit unsigned grey scale values allowing signals to be stored and processed on affordable [[Hard disk drive|HDD]]/[[Solid-state drive|SSD]] and archived to [[Optical disc|Optical]] disks or [[Linear Tape-Open|LTO]] data tapes.

These can be inspected inside the open source tool ld-analyse for frame by frame and signal analysis on Windows, Linux & MacOS then files can easily be encoded to a video file via [[FFmpeg|FFMPEG]] typically to a lossless [[10-bit H.264|10-bit]] [[Chroma subsampling|4:2:2]] file using the [[Matroska|.mkv]] container then [[Deinterlacing|de-interlaced]] via W3FDIF<ref>{{Cite web |title=w3fdif - FFmpeg |url=http://underpop.online.fr/f/ffmpeg/help/w3fdif.htm.gz |access-date=2022-11-30 |website=underpop.online.fr}}</ref> or more modern de-intelracers like Avisynths QTGMC<ref>{{Cite web |title=QTGMC - Avisynth wiki |url=http://avisynth.nl/index.php/QTGMC |access-date=2022-11-30 |website=avisynth.nl |language=en}}</ref> ,

As the base export is interlaced these files can be played via composite/s-video/RGB for usage on a analogue [[Cathode-ray tube|CRT]] display.

Composite sources like [[LaserDisc|LaserDisk]] are stored in one single TBC file and colour under tape formats such as ([[S-VHS|S]]), [[Betamax|BetaMax]], [[U-matic|Umatic]], , [[8 mm video format|Video8]], [[8 mm video format|High8]], [[Video 2000|Video2000]] have luminance/chrominance separated into two TBC files allowing for cleaner direct image processing for black and white but especially colour images.

While originally developed for LD-Decode<ref>{{Cite web |title=Home · happycube/ld-decode Wiki |url=https://github.com/happycube/ld-decode |access-date=2022-11-21 |website=GitHub |language=en}}</ref> due to being opensorce it has subsquently gained wide usage and development expansion by the VHS-Decode<ref>{{Citation |last=oyvindln |title=VHS-Decode (It does more than VHS now!) |date=2022-11-24 |url=https://github.com/oyvindln/vhs-decode |access-date=2022-11-24}}</ref> (colour-under tape decoding, not limited to just VHS) & CVBS-Decode<ref>{{Cite web |title=CVBS Composite Decode · oyvindln/vhs-decode Wiki |url=https://github.com/oyvindln/vhs-decode |access-date=2022-11-24 |website=GitHub |language=en}}</ref> projects, under the domesday86 community creating a modern archival ecosystem, consisting of directly digitizing the original modulated or even baseband composite signals off analogue mediums to be preserved and de-modulated later, skipping the immediate and optional processing of dedicated internal and or external hardware entirely removing the need for physical time base correctors.

As the format allows for composite/s-video streams to be stored with sync signals, the files contents be streamed directly to an [[Digital-to-analog converter|Digital to Analogue Converter]] (DAC) for live real time playback to an [[Cathode-ray tube|CRT]] or outer analogue equipment currently this is achieved with low cost USB 2.0/3.0 VGA adaptors that use the Frisco Logic 2000 (FL2K) chipset and a modified driver for Windows & Linux available on GitHub<ref>{{Citation |last=vrunk11 |title=FL2K TBC Player |date=2022-10-25 |url=https://github.com/vrunk11/fl2k_2 |access-date=2022-11-21}}</ref>. [[File:DdD-SMPTE-Colour-Bar-PAL-VHS-SP - 2021.png|thumb|485x485px|VHS SP - Full Signal Frame [[SMPTE color bars|SMPTE Colour Bars]] Decoded in 2021 - VHS-Decode

Note: Image brightness levels may not be displayed correctly on your computer display.]]

Linux & Windows supported, ld-tools is a set of tools to handle and process TBC files.

• ld-process-vbi processes information such as closed captioning into the .JSON metadata file.

• ld-process-vits processes information such as VITS test signals into the .JSON metadata file.

• ld-process-efm

• ld-export-metadata

• ld-chroma-decoder

• ld-chroma-encoder

• ld-disc-stacker

• ld-ldf-cut allows for cutting of RF data files

• ld-compress compresses RF data to FLAC

• ld-dropout-correct does dropout correction on a single TBC file or stacks data from multiple files to composite a cleaner file.

[[File:LD-Analyse-202—​11-13-18-46-18.png|thumb|Black Signal to Noise Ratio Graph|419x419px]] [[File:LD-Analyse-2022-11-13 18-45-38.png|thumb|LD-Analyse Dropout Loss Analysis Graphing Output|420x420px]] <gallery> File:Screenshot at 2022-11-13 18-42-52.png|Y+C (Luma + Chroma) Chroma, VHS-C SP File:Screenshot at 2022-11-13 18-42-08.png|Y (Luma) Source Mode, VHS-C SP File:Screenshot at 2022-11-13 18-41-44.png|Y (Chroma) Source, VHS-C SP File:Screenshot at 2022-11-13 18-42-30.png|C (Chroma) Source Mode, VHS-C SP File:LD-Analyse Vector Scope.png|LD-Analyse Vector Scope </gallery>LD-Analyse the primary application for viewing the TBC files directly allows for frame by frame inspection of the whole active image area and vertical blanking area, simmer to a H/V shift capable [[Cathode-ray tube|broadcast CRT’s]] (Sony PVM/BVM etc) the whole signal area is available, and aspect ratios such as 1:1 [[Pixel aspect ratio|SAR]], DAR 4:3 & 16:9 can be defined, with dropouts being visually displayed with an overlay using red/blue colours on the effected lines of analogue video.

As shown with the set of images above and to the right side there is visual information and its relating graphing data of white and black signal to noise ratio and dropouts can be also viewed, there is also a vector-scope and scan-line oscilloscope Chroma colour decoding and video levels data can be changed on the fly inside ld-analyse to then be adjusted on the single command encoding to a final video file.

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