The website "FFmpeg by Example" provides a practical, example-driven guide to utilizing the FFmpeg command-line tool for various multimedia manipulation tasks. It eschews extensive theoretical explanations in favor of presenting concrete, real-world use cases and the corresponding FFmpeg commands to achieve them. The site is structured around a collection of specific examples, each demonstrating a particular FFmpeg operation. These examples cover a broad range of functionalities, including but not limited to:
Basic manipulations: These cover fundamental operations like converting between different multimedia formats (e.g., MP4 to WebM), changing the resolution of a video, extracting audio from a video file, and creating animated GIFs from video segments. The examples demonstrate the precise command-line syntax required for each task, often highlighting specific FFmpeg options and their effects.
Audio processing: The examples delve into audio-specific manipulations, such as normalizing audio levels, converting between audio formats (e.g., WAV to MP3), mixing multiple audio tracks, and applying audio filters like fade-in and fade-out effects. The provided commands clearly illustrate how to control audio parameters and apply various audio processing techniques using FFmpeg.
Video editing: The site explores more advanced video editing techniques using FFmpeg. This encompasses tasks such as concatenating video clips, adding watermarks or overlays to videos, creating slideshows from images, and applying complex video filters for effects like blurring or sharpening. The examples showcase the flexibility of FFmpeg for performing non-linear video editing operations directly from the command line.
Streaming and broadcasting: Examples related to streaming and broadcasting demonstrate how to utilize FFmpeg for encoding video and audio streams in real-time, suitable for platforms like YouTube Live or Twitch. These examples cover aspects like setting bitrates, choosing appropriate codecs, and configuring streaming protocols.
Subtitle manipulation: The guide includes examples demonstrating how to add, remove, or manipulate subtitles in video files. This encompasses burning subtitles directly into the video stream, as well as working with external subtitle files in various formats.
For each example, the site provides not only the FFmpeg command itself but also a clear description of the task being performed, the purpose of the various command-line options used, and the expected output. This approach allows users to learn by directly applying the examples and modifying them to suit their specific needs. The site focuses on practicality and immediate application, making it a valuable resource for both beginners seeking a quick introduction to FFmpeg and experienced users looking for specific command examples for common tasks. It emphasizes learning through practical application and avoids overwhelming the reader with unnecessary theoretical details.
The GitHub repository introduces KEON, a serialization and deserialization (serde) format designed for human readability and writability, drawing heavy syntactic inspiration from the Rust programming language. KEON aims to provide a user-friendly alternative to existing formats like JSON, TOML, and YAML, particularly for configurations and data representation within Rust projects. The format emphasizes clarity and ease of use, making it simpler for developers to both create and understand serialized data.
KEON's syntax closely mirrors Rust's struct definitions, employing familiar keywords like struct, enum, and tuple. This allows Rust developers to transition seamlessly between code and data representation, reducing the cognitive overhead associated with working with different syntaxes. The format supports various data types, including integers, floating-point numbers, booleans, strings, arrays, tuples, structs, enums, and even more complex structures like nested structs and enums. This comprehensive type support ensures KEON can handle a wide range of data structures encountered in real-world applications.
A key feature of KEON is its ability to represent complex data structures in a concise and organized manner. The Rust-like syntax allows for nested structures, providing a natural way to express hierarchical data. This makes it well-suited for configuration files, where settings are often organized into logical groups and sub-groups. The human-readable nature of KEON further enhances its suitability for configuration files, allowing developers to easily modify and maintain these files without needing specialized tools or parsers.
The repository provides Rust implementations for both serialization and deserialization of KEON data. This allows developers to integrate KEON directly into their Rust projects, streamlining the process of reading and writing data in this format. The project aims to offer a robust and performant serde solution for Rust, leveraging the language's features and ecosystem. While the primary focus is on Rust, the creators envision KEON as a potentially language-agnostic format, with the possibility of implementations in other programming languages in the future. This would expand its applicability and make it a versatile option for cross-platform data exchange.
The Hacker News post titled "KEON is a human-readable serde format that syntactic similar to Rust" generated a moderate amount of discussion, with several commenters expressing interest and raising pertinent questions.
A prominent theme in the comments was the comparison of KEON to other serialization formats, particularly JSON, TOML, and YAML. Some users questioned the need for another format, wondering what advantages KEON offers over existing solutions. One commenter specifically asked about the performance characteristics of KEON compared to JSON. Another user pointed out the potential benefits of KEON's Rust-like syntax for developers already familiar with Rust, suggesting it could reduce the cognitive load when working with configuration files or data serialization.
The discussion also touched on the practical aspects of using KEON. One commenter inquired about the editor support for the format, highlighting the importance of syntax highlighting and autocompletion for developer productivity. Another user expressed concern about the potential ambiguity of KEON's syntax, especially concerning the use of unquoted keys, and how this might affect parsing and error handling.
There was a brief exchange about the use of Rust enums in KEON, with one commenter mentioning the potential benefits of this feature for representing structured data. However, the discussion didn't delve deeply into the specifics of how enums are handled.
Some commenters focused on the project's maturity and tooling. Questions were raised about the availability of a specification for the format, the existence of a parser implementation, and the overall stability of the project.
While some commenters expressed skepticism about the need for another serialization format, others seemed genuinely interested in KEON, appreciating its Rust-like syntax and potential for integration with Rust projects. Overall, the comments reflected a mix of curiosity, cautious optimism, and pragmatic concerns about the format's practicality and long-term viability.
Summary of Comments ( 209 )
https://news.ycombinator.com/item?id=42695547
Hacker News users generally praised "FFmpeg by Example" for its clear explanations and practical approach. Several commenters pointed out its usefulness for beginners, highlighting the simple, reproducible examples and the focus on solving specific problems rather than exhaustive documentation. Some suggested additional topics, like hardware acceleration and subtitles, while others shared their own FFmpeg struggles and appreciated the resource. One commenter specifically praised the explanation of filters, a notoriously complex aspect of FFmpeg. The overall sentiment was positive, with many finding the resource valuable and readily applicable to their own projects.
The Hacker News post for "FFmpeg by Example" has several comments discussing the utility of the resource, alternative learning approaches, and specific FFmpeg commands.
Many commenters praise the resource. One user calls it a "great starting point" and highlights the practicality of learning through examples. Another appreciates the clear explanations and the well-chosen examples which address common use cases. A third commenter emphasizes the value of the site for its concise and focused approach, contrasting it favorably with the official documentation, which they find overwhelming. The sentiment is echoed by another who found the official documentation difficult to navigate and appreciates the example-driven learning offered by the site.
Several comments discuss alternative or supplementary resources. One commenter recommends the book "FFmpeg Basics" by Frantisek Korbel, suggesting it pairs well with the website. Another points to a different online resource, "Modern FFmpeg Wiki," which they find to be more comprehensive. A third user mentions their preference for learning through man pages and flags, reflecting a more command-line centric approach.
Some commenters delve into specific FFmpeg functionalities and commands. One user discusses the complexities of hardware acceleration and how it interacts with different FFmpeg builds. They suggest static builds are generally more reliable in this regard. Another commenter provides a specific command for extracting frames from a video, demonstrating the practical application of FFmpeg. A different user shares a command for losslessly cutting videos, a common task for video editing. This sparks a small discussion about the nuances of lossless cutting and alternative approaches using keyframes. Someone also recommends using
-avoid_negative_ts make_zerofor generating output suitable for concatenation, highlighting a lesser-known but useful flag combination.Finally, there's a comment advising caution against blindly copying and pasting commands from the internet, emphasizing the importance of understanding the implications of each command and flag used.