Exporting Waveforms as Sigrok SR Files

Scott Prahl

Apr 2026

%config InlineBackend.figure_format = 'retina'

import shutil
import subprocess
import sys
import tempfile
import urllib.request
import zipfile
from pathlib import Path

repo = "https://raw.githubusercontent.com/scottprahl/RigolWFM/main/tests/files/"


def sample_url(relative_path: str) -> str:
    return repo + relative_path


def download_sample(relative_path: str, directory: str | Path) -> Path:
    directory = Path(directory)
    directory.mkdir(parents=True, exist_ok=True)
    out = directory / Path(relative_path).name
    urllib.request.urlretrieve(sample_url(relative_path), out)
    return out


def create_sigrok_session(relative_path: str, directory: str | Path) -> Path:
    directory = Path(directory)
    infile = download_sample(relative_path, directory)
    cmd = [
        sys.executable,
        "-m",
        "RigolWFM.wfmconvert",
        "--force",
        "--output-dir",
        str(directory),
        "sigrok",
        str(infile),
    ]
    subprocess.run(cmd, check=True, capture_output=True, text=True)
    session = directory / f"{infile.stem}.sr"
    if not session.exists():
        raise FileNotFoundError(f"Sigrok output was not created: {session}")
    return session


def read_member_text(session_path: str | Path, member: str) -> str:
    with zipfile.ZipFile(session_path) as zf:
        return zf.read(member).decode("utf-8", errors="replace")


SIGROK_AVAILABLE = shutil.which("sigrok-cli") is not None
SIGROK_AVAILABLE

Introduction

A sigrok session file (.sr) is the native archive format used by PulseView and other tools built on sigrok. In this repo, wfmconvert sigrok ... creates the session by exporting the waveform to an intermediate CSV representation and then handing that data to sigrok-cli.

If sigrok-cli is not installed in the current environment, the live export cells below print a short message instead of failing.

Analog Session Example

This first example starts from a two-channel analog capture and creates a sigrok session archive.

if not SIGROK_AVAILABLE:
    print("sigrok-cli is not installed in this environment, so the live .sr export is skipped.")
else:
    analog_dir = Path(tempfile.mkdtemp()) / "analog"
    analog_sr = create_sigrok_session("wfm/DS1102E-D.wfm", analog_dir)
    with zipfile.ZipFile(analog_sr) as zf:
        analog_members = sorted(zf.namelist())
    print(analog_sr)
    analog_members

if not SIGROK_AVAILABLE:
    print("sigrok-cli is not installed in this environment, so there is no metadata to inspect.")
else:
    print(read_member_text(analog_sr, "version"))
    print(read_member_text(analog_sr, "metadata"))

Logic Session Example

The same command can export a parsed digital trace. Here we use the DS1074Z-C.wfm fixture, which exposes D6.

if not SIGROK_AVAILABLE:
    print("sigrok-cli is not installed in this environment, so the live .sr export is skipped.")
else:
    logic_dir = Path(tempfile.mkdtemp()) / "logic"
    logic_sr = create_sigrok_session("wfm/DS1074Z-C.wfm", logic_dir)
    with zipfile.ZipFile(logic_sr) as zf:
        logic_members = sorted(zf.namelist())
    print(logic_sr)
    logic_members

if not SIGROK_AVAILABLE:
    print("sigrok-cli is not installed in this environment, so there is no metadata to inspect.")
else:
    print(read_member_text(logic_sr, "version"))
    print(read_member_text(logic_sr, "metadata"))

Command-Line Equivalent

The notebook helper above eventually runs the same CLI that you would use from a shell:

wfmconvert sigrok DS1102E-D.wfm
wfmconvert sigrok DS1074Z-C.wfm

The resulting .sr files can be opened directly in PulseView.