Bagsy

my_app_root = Path.join(__DIR__, ".")

Mix.install(
  [
    {:bagsy, path: my_app_root, env: :dev},
    {:kino, "~> 0.7"}
  ],
  # config_path: Path.join(my_app_root, "config/config.exs"),
  lockfile: Path.join(my_app_root, "mix.lock")
)

Section

file = "/path/to/bag.db3"
conn = Bagsy.Conn.new(file)

bag = Bagsy.Bag.new(conn)

{:ok, statement} =
  Exqlite.Sqlite3.prepare(conn.db, "SELECT topic_id, data FROM messages WHERE id == 84")

{:row, [topic_id, data]} = Exqlite.Sqlite3.step(conn.db, statement)

parser = Bagsy.Parser.new(bag.topics)
{:ok, img} = Bagsy.Parser.parse_message(parser, topic_id, data)

mat = img.data |> Nx.to_binary() |> Evision.imdecode(Evision.cv_IMREAD_GRAYSCALE())

{2, [y, x]} = Evision.Mat.size(mat)
y = trunc(y / 5)
x = trunc(x / 5)
Evision.resize(mat, {_width = x, _height = y})

{:ok, statement} =
  Exqlite.Sqlite3.prepare(conn.db, "SELECT topic_id, data FROM messages WHERE id == 60")

{:row, [topic_id, data]} = Exqlite.Sqlite3.step(conn.db, statement)

parser = Bagsy.Parser.new(bag.topics)
{:ok, speed} = Bagsy.Parser.parse_message(parser, topic_id, data)