Guides, tips and comparisons on processing PDFs, images, audio and video.
The steps for turning document photos taken with your phone camera into a clean PDF that looks like it came out of a scanner, how to choose a filter, and the mistakes people commonly make.
9 min read
ComparisonThree ways of turning a document into a PDF compared: the document scanner with automatic correction, dropping the raw photo straight into a PDF, and a hardware scanner. A decision guide, scenario by scenario.
10 min read
GuideThe three image processing steps that turn a phone photo into a scanned document: contour-based edge detection, the four-point perspective transform, and shadow removal via a background map.
11 min read
How-ToConverting a web address or HTML code to PDF: page size and margins, print styles, the dynamic content problem, and background and link behavior.
7 min read
How-ToEmbedding or burning SRT/VTT subtitles into a video: the difference between the two methods, fixing timing, the character encoding problem, style settings and platform requirements.
8 min read
How-ToSeparating a video's audio track: the difference between stream copy and re-encoding, choosing a target format, multiple audio tracks, the bitrate decision, and the factors determining the resulting file's quality.
7 min read
ComparisonA format comparison for audio extracted from video: the stream-copy opportunity, compatibility, editing needs and file size — which wins in which scenario.
7 min read
How-ToTurning a section of video into an animated GIF: the duration limit, choosing a frame rate, resolution, the 256-color limit, and ways to control file size.
7 min read
GuideSeparating tracks inside a container (demuxing), audio codec container compatibility, timestamps, and the technical difference between stream copy and re-encoding.
8 min read
GuideThe difference between the MP4, MKV and AVI containers and the H.264, H.265 and VP9 codecs; frame types, GOP structure, bitrate modes, and why some videos won't open.
8 min read
How-ToConverting between video formats: the container/codec distinction, the difference between remuxing and re-encoding, choosing resolution and bitrate, and audio track and subtitle behavior.
7 min read
GuideThe background of the concat operation: the conditions for stream copy, GOP structure and cut points, timestamp rewriting, the VFR/CFR problem, and why parameter compatibility is essential.
7 min read
How-ToMerging multiple videos into one file: resolution and frame rate compatibility, codec matching, audio sync, transitions, and post-merge checks.
7 min read
ComparisonThree ways to merge videos compared: an online merging tool, a video editing program and the command line. Which is right when, in terms of time, quality and flexibility.
7 min read
ComparisonThe ways of producing PDF from a URL compared: an online converter, the browser's print feature, reader mode and screenshots. Differences in sessions, dynamic content and control.
7 min read
How-ToThe problem of two pages ending up on one sheet in book and magazine scans: choosing vertical or horizontal splitting, where the cut line falls, skewed scans, and page order after splitting.
7 min read
ComparisonThree methods for producing PDF from SVG compared: a conversion tool, Illustrator/Inkscape, and 'Print to PDF' in a browser. Differences in size control, fonts and print preparation.
7 min read
How-ToConverting an SVG file to PDF: setting the page size, the relationship between viewBox and physical dimensions, the font embedding problem, and print preparation checks.
7 min read
GuideThe shared vector origins of SVG and PDF: path definitions, coordinate systems, the font problem, the CMYK/RGB distinction, and what gets lost in conversion.
7 min read
GuideThe difference between SVG's flexible coordinate system and PDF's fixed page logic: how viewBox is interpreted, unit conversion, font embedding, and freezing dynamic content.
8 min read
GuideThe logic behind lossy audio compression: psychoacoustic masking, frequency transforms, the relationship between bitrate and quality, and why transcoding loss accumulates.
8 min read
How-ToConverting audio files between formats: the lossy/lossless distinction, choosing a bitrate, limiting transcoding loss, and which target format suits which use.
7 min read
How-ToMerging multiple audio files into one: file order, format compatibility, level differences, sample rate mismatch, and post-merge checks.
7 min read
GuideThe technical background of gapless playback: encoder delay, padding samples, sample rate mismatch, zero-crossing points, and what crossfading solves.
8 min read