SER.Lib

A pure-managed reader and writer for the SER planetary-imaging video format (the Lucam Recorder format, spec v3).

SER is the de-facto container for lunar / planetary / solar lucky-imaging captures: thousands of raw mono, Bayer, or RGB frames in one file, with optional per-frame UTC timestamps. SER.Lib decodes and encodes it with memory-mapped, frame-accurate random access (seek to any frame in O(1), even in multi-gigabyte files), and is AOT- and trim-friendly with zero external dependencies.

Part of the SharpAstro family (alongside FITS.Lib). It is consumed by TianWen, whose tianwen-fits viewer opens SER captures as a frame sequence.

dotnet add package SER.Lib

using SharpAstro.Ser;

using var ser = SerReader.Open("jupiter.ser");

Console.WriteLine($"{ser.Width}x{ser.Height}  {ser.ColorId}  " +
                  $"{ser.PixelDepthPerPlane}-bit  {ser.FrameCount} frames");

// Random access: decode frame 1000 into a reusable buffer (no per-frame allocation).
var frame = new ushort[ser.Width * ser.Height * ser.ColorId.PlaneCount];
ser.ReadFrame16(index: 1000, frame);

// Per-frame UTC timestamps (when the file carries the optional trailer).
if (ser.HasTimestamps)
    Console.WriteLine(ser.Timestamps[1000].ToString("u"));

Writing:

using var w = new SerWriter("out.ser", width: 640, height: 480,
    colorId: SerColorId.BayerRGGB, pixelDepthPerPlane: 8);

foreach (var (bytes, time) in frames)
    w.AppendFrame(bytes, time);   // timestamps -> the v3 trailer on Close()

Slicing a frame range out of a (possibly multi-gigabyte) capture, e.g. to carve a small shareable clip. Frame bytes are copied verbatim -- no decode -- so the slice is loss-free for any bit depth or endianness, and the matching timestamps come along:

// 200 frames starting at frame 15000 -> a new, self-contained .ser
SerReader.Cut("jupiter.ser", "clip.ser", startFrame: 15000, count: 200);

// or from an already-open reader:
using var ser = SerReader.Open("jupiter.ser");
ser.CutTo("clip.ser", startFrame: 15000, count: 200);

Cropping every frame to a window, e.g. a small planet tracked across a whole-sensor capture. The crop is verbatim: the source's own header bytes with only the width and height changed (its padded strings and both start times as they were), each window as its bytes are stored, and the timestamp trailer plus anything after it byte for byte, so nothing is re-encoded. The callback places each frame's window as it is written; a Bayer mosaic's origin must be even, or the pattern would re-phase:

using var ser = SerReader.Open("jupiter.ser");
ser.CropTo("jupiter-crop.ser", width: 288, height: 304, originOf: i => TrackedOrigin(i));

The on-disk format is a fixed 178-byte little-endian header, the frame data, and an optional per-frame timestamp trailer. A few real-world subtleties SER.Lib handles for you:

• The LittleEndian header flag is interpreted the way SER Player / PIPP do (the de-facto reference): for 16-bit data, LittleEndian == 0 means little-endian samples and LittleEndian == 1 means big-endian — the opposite of what the field name suggests. This is a well-known wart in the ecosystem; matching the reference players is what makes real captures display correctly. The header's own integers are always little-endian regardless of this flag.
• Timestamps are .NET DateTime ticks (100 ns since 0001-01-01). SER.Lib surfaces them as UTC DateTimeOffsets, applying the same UTC-vs-local detection the reference player uses.
• Frames are stored top-row-first (the first pixel is the upper-left); SER.Lib does not flip rows.
• v2 vs v3: RGB/BGR true colour, arbitrary bit depths (1-16 with MSB/LSB alignment), and the timestamp trailer + UTC start time are v3 additions. SER.Lib reads v2 files (mono/Bayer, 8/16-bit, no trailer) transparently.

MIT - see LICENSE.