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Check out our Usage Guide
14 | 15 | --- 16 | ## What is FFMPEG? 17 | [FFMPEG](https://ffmpeg.org/ffmpeg.html) is a very popular, longstanding tool for reading, writing, and streaming audio and video content. Most developers use FFMPEG through its command-line interface (CLI), because that's much easier than interfacing with the C code upon which FFMPEG is built. 18 | 19 | ## What is `ffmpeg_cli` 20 | This package allows you to configure FFMPEG CLI commands with Dart code. 21 | 22 | `ffmpeg_cli` purposefully retains the complexity of FFMPEG commands so that anything the FFMPEG CLI can do, the `ffmpeg_cli` package can do. 23 | 24 | ## Quickstart 25 | First, make sure that `ffmpeg` is installed on your device, and is available on your system path. 26 | 27 | Compose an FFMPEG command with Dart: 28 | 29 | ```dart 30 | // Define an output stream, which will map the filter 31 | // graph to the video file. The ID names can be whatever 32 | // you'd like. 33 | const outputStream = FfmpegStream( 34 | videoId: "[final_v]", 35 | audioId: "[final_a]", 36 | ); 37 | 38 | // Compose your desired FFMPEG command, with inputs, filters, arguments, 39 | // and an output location. 40 | final command = FfmpegCommand( 41 | inputs: [ 42 | FfmpegInput.asset("assets/intro.mp4"), 43 | FfmpegInput.asset("assets/content.mp4"), 44 | FfmpegInput.asset("assets/outro.mov"), 45 | ], 46 | args: [ 47 | // Map the filter graph to the video file output. 48 | CliArg(name: 'map', value: outputStream.videoId!), 49 | CliArg(name: 'map', value: outputStream.audioId!), 50 | const CliArg(name: 'vsync', value: '2'), 51 | ], 52 | filterGraph: FilterGraph( 53 | chains: [ 54 | FilterChain( 55 | inputs: [ 56 | // Send all 3 video assets into the concat filter. 57 | const FfmpegStream(videoId: "[0:v]", audioId: "[0:a]"), 58 | const FfmpegStream(videoId: "[1:v]", audioId: "[1:a]"), 59 | const FfmpegStream(videoId: "[2:v]", audioId: "[2:a]"), 60 | ], 61 | filters: [ 62 | // Concatenate 3 segments. 63 | ConcatFilter( 64 | segmentCount: 3, 65 | outputVideoStreamCount: 1, 66 | outputAudioStreamCount: 1, 67 | ), 68 | ], 69 | outputs: [ 70 | // Give the output stream the given audio/video IDs 71 | outputStream, 72 | ], 73 | ), 74 | ], 75 | ), 76 | outputFilepath: "/my/output/file.mp4", 77 | ); 78 | 79 | // Execute command 80 | final process = await Ffmpeg().run(command: command); 81 | ``` 82 | 83 | ## How ffprobe support is managed 84 | There are a lot of properties in `ffprobe`. Many of these properties can present in 85 | varying formats, which are not effectively documented. 86 | 87 | The approach to `ffprobe` is to add missing result parameters as they are discovered 88 | and to add parsing functionality per property as the various possible formats are 89 | discovered. In other words, only do what is necessary in the given moment because 90 | the overall scope is too large and difficult to discover. 91 | -------------------------------------------------------------------------------- /README_FRAME_TIMES.md: -------------------------------------------------------------------------------- 1 | ### How videos encode frame times 2 | Modern video containers do not store a constant frame rate. They store a timestamp for each frame: 3 | 4 | **Conceptual frame times (not quite accurate, read further):** 5 | Frame Frame Time 6 | 0 0.00 7 | 1 0.04 8 | 2 0.08 9 | 3 0.12 10 | 11 | In practice, rather than store the explicit timestamp of a given frame, two numbers are taken together to synthesize a frame time: the **Presentation TimeStamp (pts)**, and the **timebase (tb)**. 12 | 13 | **The timebase is a fundamental unit of time**, such that every frame appears on a multiple of the timebase. Or, said differently, the timebase is the greatest common denominator of all frame times. 14 | 15 | **The presentation timestamp refers to a specific frame's time as a multiple of the timebase**. Therefore, a given frame's actual time is: **pst * tb**. 16 | 17 | **Example:** 18 | 19 | Timebase = 1/75; Timescale = 75 20 | 21 | Frame pts pts_time 22 | 0 0 0 x 1/75 = 0.00 23 | 1 3 3 x 1/75 = 0.04 24 | 2 6 6 x 1/75 = 0.08 25 | 3 9 9 x 1/75 = 0.12 26 | 27 | **Using a timebase and presentation timestamp allows videos to encode variable frame rates, rather than limiting the entire video to a static frame rate.** 28 | -------------------------------------------------------------------------------- /analysis_options.yaml: -------------------------------------------------------------------------------- 1 | include: package:flutter_lints/flutter.yaml 2 | 3 | analyzer: 4 | exclude: 5 | - doc/** 6 | -------------------------------------------------------------------------------- /doc/website/.gitignore: -------------------------------------------------------------------------------- 1 | # Build output 2 | /build 3 | 4 | # https://dart.dev/guides/libraries/private-files 5 | # Created by `dart pub` 6 | .dart_tool/ 7 | 8 | # Android Studio and IntelliJ IDEA 9 | .idea 10 | 11 | .DS_Store 12 | -------------------------------------------------------------------------------- /doc/website/analysis_options.yaml: -------------------------------------------------------------------------------- 1 | # This file configures the static analysis results for your project (errors, 2 | # warnings, and lints). 3 | # 4 | # This enables the 'recommended' set of lints from `package:lints`. 5 | # This set helps identify many issues that may lead to problems when running 6 | # or consuming Dart code, and enforces writing Dart using a single, idiomatic 7 | # style and format. 8 | # 9 | # If you want a smaller set of lints you can change this to specify 10 | # 'package:lints/core.yaml'. These are just the most critical lints 11 | # (the recommended set includes the core lints). 12 | # The core lints are also what is used by pub.dev for scoring packages. 13 | 14 | include: package:lints/recommended.yaml 15 | 16 | # Uncomment the following section to specify additional rules. 17 | 18 | # linter: 19 | # rules: 20 | # - camel_case_types 21 | 22 | # analyzer: 23 | # exclude: 24 | # - path/to/excluded/files/** 25 | 26 | # For more information about the core and recommended set of lints, see 27 | # https://dart.dev/go/core-lints 28 | 29 | # For additional information about configuring this file, see 30 | # https://dart.dev/guides/language/analysis-options 31 | -------------------------------------------------------------------------------- /doc/website/bin/ffmpeg_cli_docs.dart: -------------------------------------------------------------------------------- 1 | import 'dart:io'; 2 | 3 | import 'package:static_shock/static_shock.dart'; 4 | 5 | FuturetestWidgets((tester) async {
6 | // Setup the test.
7 |
8 | // Press CMD+V (like for a paste).
9 | await tester.pressCmdV();
10 |
11 | // Press CMD+ALT+LEFT (jump to start).
12 | await tester.pressCmdAltLeftArrow();
13 |
14 | // Verify expectations.
15 | });
16 | testWidgets((tester) async {
21 | // Setup the test.
22 |
23 | // Press CMD+V (like for a paste).
24 | await tester.sendKeyDownEvent(
25 | LogicalKeyboardKey.meta,
26 | );
27 | await tester.sendKeyEvent(
28 | LogicalKeyboardKey.keyV,
29 | );
30 | await tester.sendKeyUpEvent(
31 | LogicalKeyboardKey.meta,
32 | );
33 |
34 | // Press CMD+ALT+LEFT (jump to start).
35 | await tester.sendKeyDownEvent(
36 | LogicalKeyboardKey.meta,
37 | );
38 | await tester.sendKeyDownEvent(
39 | LogicalKeyboardKey.alt,
40 | );
41 | await tester.sendKeyEvent(
42 | LogicalKeyboardKey.left,
43 | );
44 | await tester.sendKeyUpEvent(
45 | LogicalKeyboardKey.left,
46 | );
47 | await tester.sendKeyUpEvent(
48 | LogicalKeyboardKey.meta,
49 | );
50 |
51 | // Verify expectations.
52 | });
53 |