scripts: rewrite append_signals.py for linescan scrolling video

Complete rewrite to properly handle linescan image sequences:
- Stitches linescan images horizontally into wide panorama
- Creates scrolling video that pans left-to-right
- Configurable scroll speed based on capture rate (750 lines/sec)
- Output saved one folder up from image source
- Uses Pillow for image stitching, ffmpeg for video creation

Features:
- --scroll-speed: multiplier for playback speed (1.0 = real-time)
- --lines-per-second: linescan capture rate (default: 750)
- --max-frames: limit frames for testing
- --fps: output video framerate (default: 30)
- --width: viewport width (default: 1920)
- Automatic cleanup of temporary stitched image

Example usage:
  # Real-time playback
  uv run scripts\append_signals.py results\20251122\bumpy-filter

  # 2x speed
  uv run scripts\append_signals.py results\20251122\bumpy-filter --scroll-speed 2.0

  # Test with 10 frames
  uv run scripts\append_signals.py results\20251122\bumpy-filter --max-frames 10
This commit is contained in:
yair
2025-11-22 16:59:26 +02:00
parent 411310e4f1
commit 11b279cb08

View File

@@ -1,12 +1,14 @@
#!/usr/bin/env -S uv run
# /// script
# requires-python = ">=3.10"
# dependencies = []
# dependencies = [
# "pillow",
# ]
# ///
"""
Concatenate a sequence of frames into a video using ffmpeg.
Scales to 1920 width and allows control of video speed via fps.
Stitch linescan frame sequences horizontally and create scrolling video.
Linescan images are concatenated side-by-side and played as a scrolling video.
"""
import argparse
@@ -15,6 +17,7 @@ import sys
import time
from pathlib import Path
from typing import List
from PIL import Image
def find_frames(directory: Path, pattern: str = "*.jpeg") -> List[Path]:
@@ -27,83 +30,105 @@ def find_frames(directory: Path, pattern: str = "*.jpeg") -> List[Path]:
return frames
def create_video_ffmpeg(
input_dir: Path,
def stitch_images_horizontally(
frames: List[Path],
output_file: Path,
fps: int = 30,
width: int = 1920,
crf: int = 18,
pattern: str = "*.jpeg",
max_frames: int = None
) -> None:
) -> tuple[int, int]:
"""
Create video from image sequence using ffmpeg.
Args:
input_dir: Directory containing the frames
output_file: Output video file path
fps: Frames per second (controls playback speed)
width: Output video width in pixels (height auto-scales)
crf: Constant Rate Factor for quality (lower = better, 18-23 recommended)
pattern: File pattern to match frame files
Stitch images horizontally into a single wide image.
Returns (width, height) of stitched image.
"""
frames = find_frames(input_dir, pattern)
if not frames:
print(f"Error: No frames found in {input_dir} matching pattern {pattern}")
sys.exit(1)
total_frames = len(frames)
# Limit frames if max_frames is specified
if max_frames is not None and max_frames > 0:
frames = frames[:max_frames]
print(f"Found {total_frames} frames in {input_dir}, processing first {len(frames)} frames")
else:
print(f"Found {len(frames)} frames in {input_dir}")
print(f"First frame: {frames[0].name}")
print(f"Last frame: {frames[-1].name}")
# Check if frames are sequential (no gaps)
first_frame = frames[0]
is_sequential = True
print(f"Loading {len(frames)} images for stitching...")
# Extract frame numbers and check for gaps
name_parts = first_frame.stem.rsplit('_', 1)
if len(name_parts) == 2 and name_parts[1].isdigit():
frame_numbers = []
for frame in frames:
parts = frame.stem.rsplit('_', 1)
if len(parts) == 2 and parts[1].isdigit():
frame_numbers.append(int(parts[1]))
else:
is_sequential = False
break
# Load first image to get dimensions
first_img = Image.open(frames[0])
img_width, img_height = first_img.size
# Check if there are gaps in the sequence
if is_sequential and frame_numbers:
expected_count = frame_numbers[-1] - frame_numbers[0] + 1
if len(frame_numbers) != expected_count:
is_sequential = False
print(f"Warning: Detected gaps in frame sequence (have {len(frame_numbers)} frames, expected {expected_count})")
else:
is_sequential = False
# Calculate total width
total_width = img_width * len(frames)
# Use concat method for reliability (works with gaps, non-sequential naming, etc.)
# Create concat file
concat_file = input_dir / "concat_list.txt"
with open(concat_file, 'w') as f:
for frame in frames:
# Use absolute paths to avoid issues
f.write(f"file '{frame.absolute()}'\n")
print(f"Creating stitched image: {total_width}x{img_height} pixels")
print(f" Individual frame size: {img_width}x{img_height}")
print(f" Total frames: {len(frames)}")
# Create large canvas
stitched = Image.new('RGB', (total_width, img_height))
# Paste images
x_offset = 0
for i, frame_path in enumerate(frames):
if i % 50 == 0:
print(f" Stitching frame {i+1}/{len(frames)}...")
img = Image.open(frame_path)
stitched.paste(img, (x_offset, 0))
x_offset += img_width
print(f"Saving stitched image to {output_file}...")
stitched.save(output_file, quality=95)
return total_width, img_height
def create_scrolling_video(
stitched_image: Path,
output_file: Path,
total_width: int,
height: int,
output_width: int = 1920,
scroll_speed: float = 750.0,
fps: int = 30,
crf: int = 18,
lines_per_second: float = 750.0
) -> None:
"""
Create scrolling video from stitched image.
Args:
stitched_image: Path to stitched horizontal image
output_file: Output video file
total_width: Total width of stitched image
height: Height of image
output_width: Width of output video viewport
scroll_speed: Scroll speed multiplier (1.0 = real-time @ 750 lines/sec)
fps: Output video framerate
crf: Quality (lower = better)
lines_per_second: Linescan capture rate (pixels per second)
"""
# Calculate scroll parameters
# At scroll_speed=1.0, we scroll at the actual capture rate
pixels_per_second = lines_per_second * scroll_speed
pixels_per_frame = pixels_per_second / fps
# Calculate video duration
scrollable_width = total_width - output_width
duration = scrollable_width / pixels_per_second
total_frames = int(duration * fps)
print(f"\nScrolling video parameters:")
print(f" Output viewport: {output_width}x{height}")
print(f" Scroll speed: {scroll_speed}x real-time ({pixels_per_second:.1f} pixels/sec)")
print(f" Pixels per frame: {pixels_per_frame:.2f}")
print(f" Video duration: {duration:.2f} seconds")
print(f" Total frames: {total_frames}")
print(f" Output FPS: {fps}")
# FFmpeg crop filter with horizontal scrolling
# crop=w:h:x:y where x moves from 0 to (total_width - output_width)
# The 't' variable represents time in seconds
crop_expr = f"crop={output_width}:{height}:min({pixels_per_second}*t\\,{total_width-output_width}):0"
cmd = [
"ffmpeg",
"-y",
"-f", "concat",
"-safe", "0",
"-i", str(concat_file),
"-vf", f"scale={width}:-2,fps={fps}",
"-loop", "1",
"-i", str(stitched_image),
"-vf", crop_expr,
"-t", str(duration),
"-r", str(fps),
"-c:v", "libx264",
"-crf", str(crf),
"-pix_fmt", "yuv420p",
@@ -111,20 +136,17 @@ def create_video_ffmpeg(
str(output_file)
]
print(f"\nCreating video with:")
print(f" FPS: {fps}")
print(f" Width: {width}px")
print(f" CRF (quality): {crf}")
print(f" Output: {output_file}")
print(f"\nRunning: {' '.join(cmd)}\n")
print(f"\nRunning ffmpeg...")
print(f"Command: {' '.join(cmd)}\n")
try:
result = subprocess.run(cmd, check=True)
print(f"\nVideo created successfully: {output_file}")
subprocess.run(cmd, check=True)
print(f"\nScrolling video created successfully: {output_file}")
# Show file size
size_mb = output_file.stat().st_size / (1024 * 1024)
print(f" File size: {size_mb:.2f} MB")
print(f" Duration: {duration:.2f} seconds")
except subprocess.CalledProcessError as e:
print(f"Error: ffmpeg command failed with return code {e.returncode}")
@@ -136,54 +158,68 @@ def create_video_ffmpeg(
def main():
parser = argparse.ArgumentParser(
description="Concatenate frame sequences into a video using ffmpeg",
description="Stitch linescan images horizontally and create scrolling video",
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog="""
Examples:
# Basic usage with default settings (30 fps, 1920 width)
python append_signals.py C:\\dev\\gst-plugins-vision\\results\\20251122\\bumpy-filter
# Real-time playback (1.0x speed, 750 lines/second)
python append_signals.py results/20251122/bumpy-filter
# Slow motion (10 fps)
python append_signals.py C:\\dev\\gst-plugins-vision\\results\\20251122\\bumpy-filter --fps 10
# Slow motion (0.5x speed)
python append_signals.py results/20251122/bumpy-filter --scroll-speed 0.5
# Fast playback (60 fps) with custom output name
python append_signals.py results/20251122/bumpy-filter --fps 60 -o timelapse.mp4
# Fast playback (2x speed)
python append_signals.py results/20251122/bumpy-filter --scroll-speed 2.0
# Higher quality (lower CRF)
python append_signals.py results/20251122/bumpy-filter --crf 15
# Custom width
python append_signals.py results/20251122/bumpy-filter --width 3840
# Process only first 100 frames for testing
# Process only first 100 frames
python append_signals.py results/20251122/bumpy-filter --max-frames 100
# Higher FPS for smoother scrolling
python append_signals.py results/20251122/bumpy-filter --fps 60
# Custom output width (4K)
python append_signals.py results/20251122/bumpy-filter --width 3840
"""
)
parser.add_argument(
"input_dir",
type=Path,
help="Directory containing the frame sequence"
help="Directory containing the linescan frame sequence"
)
parser.add_argument(
"-o", "--output",
type=Path,
help="Output video file (default: output.mp4 in input directory)"
help="Output video file (default: {folder_name}_{timestamp}.mp4 in input dir)"
)
parser.add_argument(
"--scroll-speed",
type=float,
default=1.0,
help="Scroll speed multiplier (1.0 = real-time at 750 lines/sec, default: 1.0)"
)
parser.add_argument(
"--lines-per-second",
type=float,
default=750.0,
help="Linescan capture rate in lines/pixels per second (default: 750)"
)
parser.add_argument(
"--fps",
type=int,
default=30,
help="Output video framerate/playback speed (default: 30)"
help="Output video framerate (default: 30)"
)
parser.add_argument(
"--width",
type=int,
default=1920,
help="Output video width in pixels (default: 1920)"
help="Output video viewport width in pixels (default: 1920)"
)
parser.add_argument(
@@ -218,13 +254,26 @@ Examples:
print(f"Error: Input path is not a directory: {args.input_dir}")
sys.exit(1)
# Set output file
# Find frames
frames = find_frames(args.input_dir, args.pattern)
if not frames:
print(f"Error: No frames found in {args.input_dir} matching pattern {args.pattern}")
sys.exit(1)
total_frames = len(frames)
if args.max_frames is not None and args.max_frames > 0:
frames = frames[:args.max_frames]
print(f"Found {total_frames} frames, processing first {len(frames)} frames")
else:
print(f"Found {len(frames)} frames in {args.input_dir}")
# Set output file (one folder up from input directory)
if args.output is None:
# Generate filename: input_folder_name_unixtime.mp4
unix_time = int(time.time())
folder_name = args.input_dir.name
output_filename = f"{folder_name}_{unix_time}.mp4"
output_file = args.input_dir / output_filename
output_filename = f"{folder_name}_scroll_{unix_time}.mp4"
output_file = args.input_dir.parent / output_filename
else:
output_file = args.output
@@ -233,15 +282,36 @@ Examples:
print("Error: CRF must be between 0 and 51")
sys.exit(1)
create_video_ffmpeg(
input_dir=args.input_dir,
output_file=output_file,
fps=args.fps,
width=args.width,
crf=args.crf,
pattern=args.pattern,
max_frames=args.max_frames
)
# Create temporary stitched image
stitched_filename = f"stitched_temp_{int(time.time())}.jpg"
stitched_path = args.input_dir / stitched_filename
try:
# Stitch images
total_width, img_height = stitch_images_horizontally(
frames=frames,
output_file=stitched_path,
max_frames=args.max_frames
)
# Create scrolling video
create_scrolling_video(
stitched_image=stitched_path,
output_file=output_file,
total_width=total_width,
height=img_height,
output_width=args.width,
scroll_speed=args.scroll_speed,
fps=args.fps,
crf=args.crf,
lines_per_second=args.lines_per_second
)
finally:
# Clean up temporary stitched image
if stitched_path.exists():
print(f"\nCleaning up temporary file: {stitched_filename}")
stitched_path.unlink()
if __name__ == "__main__":