Merge pull request #469 from MobyGamer/deinterlace_updates

Update deinterlacing methods to current best practices

.github/pull_request_template.md

@@ -0,0 +1,3 @@
+## Checklist
+
+* [ ] I've referred to the [Guidelines for contributing](https://github.com/amiaopensource/ffmprovisr/blob/gh-pages/readme.md#guidelines-for-contributing)

code_of_conduct.md

@@ -1,50 +1,133 @@
-# Contributor Code of Conduct
+# Contributor Covenant Code of Conduct
 
-As contributors and maintainers of this project, and in the interest of
-fostering an open and welcoming community, we pledge to respect all people who
-contribute through reporting issues, posting feature requests, updating
-documentation, submitting pull requests or patches, and other activities.
+## Our Pledge
 
-We are committed to making participation in this project a harassment-free
-experience for everyone, regardless of level of experience, gender, gender
-identity and expression, sexual orientation, disability, personal appearance,
-body size, race, ethnicity, age, religion, or nationality.
+We as members, contributors, and leaders pledge to make participation in our
+community a harassment-free experience for everyone, regardless of age, body
+size, visible or invisible disability, ethnicity, sex characteristics, gender
+identity and expression, level of experience, education, socio-economic status,
+nationality, personal appearance, race, religion, or sexual identity
+and orientation.
 
-Examples of unacceptable behavior by participants include:
+We pledge to act and interact in ways that contribute to an open, welcoming,
+diverse, inclusive, and healthy community.
 
-* The use of sexualized language or imagery
-* Personal attacks
-* Trolling or insulting/derogatory comments
+## Our Standards
+
+Examples of behavior that contributes to a positive environment for our
+community include:
+
+* Demonstrating empathy and kindness toward other people
+* Being respectful of differing opinions, viewpoints, and experiences
+* Giving and gracefully accepting constructive feedback
+* Accepting responsibility and apologizing to those affected by our mistakes,
+  and learning from the experience
+* Focusing on what is best not just for us as individuals, but for the
+  overall community
+
+Examples of unacceptable behavior include:
+
+* The use of sexualized language or imagery, and sexual attention or
+  advances of any kind
+* Trolling, insulting or derogatory comments, and personal or political attacks
 * Public or private harassment
-* Publishing other's private information, such as physical or electronic
-  addresses, without explicit permission
-* Other unethical or unprofessional conduct
+* Publishing others’ private information, such as a physical or email
+  address, without their explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
 
-Project maintainers have the right and responsibility to remove, edit, or
-reject comments, commits, code, wiki edits, issues, and other contributions
-that are not aligned to this Code of Conduct, or to ban temporarily or
-permanently any contributor for other behaviors that they deem inappropriate,
-threatening, offensive, or harmful.
+## Enforcement Responsibilities
 
-By adopting this Code of Conduct, project maintainers commit themselves to
-fairly and consistently applying these principles to every aspect of managing
-this project. Project maintainers who do not follow or enforce the Code of
-Conduct may be permanently removed from the project team.
+Community leaders are responsible for clarifying and enforcing our standards of
+acceptable behavior and will take appropriate and fair corrective action in
+response to any behavior that they deem inappropriate, threatening, offensive,
+or harmful.
 
-This Code of Conduct applies both within project spaces and in public spaces
-when an individual is representing the project or its community.
+Community leaders have the right and responsibility to remove, edit, or reject
+comments, commits, code, wiki edits, issues, and other contributions that are
+not aligned to this Code of Conduct, and will communicate reasons for moderation
+decisions when appropriate.
+
+## Scope
+
+This Code of Conduct applies within all community spaces, and also applies when
+an individual is officially representing the community in public spaces.
+Examples of representing our community include using an official e-mail address,
+posting via an official social media account, or acting as an appointed
+representative at an online or offline event.
+
+## Enforcement
 
 Instances of abusive, harassing, or otherwise unacceptable behavior may be
-reported by contacting a project maintainer. All
-complaints will be reviewed and investigated and will result in a response that
-is deemed necessary and appropriate to the circumstances. Maintainers are
-obligated to maintain confidentiality with regard to the reporter of an
-incident.
+reported to the community leaders responsible for enforcement, who are the
+ffmprovisr maintainers:
+* Ashley Blewer (ashley.blewer@gmail.com)
+* Katherine Frances Nagels (kfnagels@gmail.com)
+* Kieran O'Leary (kieran.o.leary@gmail.com)
+* Andrew Weaver (theandrewjw@gmail.com)
 
+All complaints will be reviewed and investigated promptly and fairly.
+
+All community leaders are obligated to respect the privacy and security of the
+reporter of any incident.
+
+## Enforcement Guidelines
+
+Community leaders will follow these Community Impact Guidelines in determining
+the consequences for any action they deem in violation of this Code of Conduct:
+
+### 1. Correction
+
+**Community Impact**: Use of inappropriate language or other behavior deemed
+unprofessional or unwelcome in the community.
+
+**Consequence**: A private, written warning from community leaders, providing
+clarity around the nature of the violation and an explanation of why the
+behavior was inappropriate. A public apology may be requested.
+
+### 2. Warning
+
+**Community Impact**: A violation through a single incident or series
+of actions.
+
+**Consequence**: A warning with consequences for continued behavior. No
+interaction with the people involved, including unsolicited interaction with
+those enforcing the Code of Conduct, for a specified period of time. This
+includes avoiding interactions in community spaces as well as external channels
+like social media. Violating these terms may lead to a temporary or
+permanent ban.
+
+### 3. Temporary Ban
+
+**Community Impact**: A serious violation of community standards, including
+sustained inappropriate behavior.
+
+**Consequence**: A temporary ban from any sort of interaction or public
+communication with the community for a specified period of time. No public or
+private interaction with the people involved, including unsolicited interaction
+with those enforcing the Code of Conduct, is allowed during this period.
+Violating these terms may lead to a permanent ban.
+
+### 4. Permanent Ban
+
+**Community Impact**: Demonstrating a pattern of violation of community
+standards, including sustained inappropriate behavior,  harassment of an
+individual, or aggression toward or disparagement of classes of individuals.
+
+**Consequence**: A permanent ban from any sort of public interaction within
+the community.
+
+## Attribution
 
 This Code of Conduct is adapted from the [Contributor Covenant][homepage],
-version 1.4.1, available at
-[https://www.contributor-covenant.org/version/1/4/code-of-conduct.html][version]
+version 2.0, available at
+https://www.contributor-covenant.org/version/2/0/code_of_conduct.html.
 
-[homepage]: https://www.contributor-covenant.org/
-[version]: https://www.contributor-covenant.org/version/1/4/code-of-conduct.html
+Community Impact Guidelines were inspired by [Mozilla’s code of conduct
+enforcement ladder](https://github.com/mozilla/diversity).
+
+[homepage]: https://www.contributor-covenant.org
+
+For answers to common questions about this code of conduct, see the FAQ at
+https://www.contributor-covenant.org/faq. Translations are available at
+https://www.contributor-covenant.org/translations.

css/css.css

@@ -85,7 +85,7 @@ a:visited {
 }
 
 .license img {
-  max-width: 10em;
+  max-width: 6em;
   display: inline;
 }
 
@@ -113,10 +113,6 @@ h4 {
   font-size: 1.2em;
 }
 
-.intro-lead {
-  font-size: 1em;
-}
-
 code {
   padding: 2px 4px;
   color: #c7254e;

index.html

@@ -45,25 +45,26 @@
   <div class="content">
     <div class="well">
       <h2 class="heading" id="about">About ffmprovisr</h2>
-      <span class="intro-lead">Making FFmpeg Easier</span>
+      <h3>Making FFmpeg Easier</h3>
       <p>FFmpeg is a powerful tool for manipulating audiovisual files. Unfortunately, it also has a steep learning curve, especially for users unfamiliar with a command line interface. This app helps users through the command generation process so that more people can reap the benefits of FFmpeg.</p>
       <p>Each button displays helpful information about how to perform a wide variety of tasks using FFmpeg. To use this site, click on the task you would like to perform. A new window will open up with a sample command and a description of how that command works. You can copy this command and understand how the command works with a breakdown of each of the flags.</p>
       <p>This page does not have search functionality, but you can open all recipes (second option in the sidebar) and use your browser's search tool (often ctrl+f or cmd+f) to perform a keyword search through all recipes.</p>
-      <span class="intro-lead">Tutorials</span>
+      <h3>Tutorials</h3>
       <p>For FFmpeg basics, check out the program’s <a href="https://ffmpeg.org/" target="_blank">official website</a>.</p>
       <p>For instructions on how to install FFmpeg on Mac, Linux, and Windows, refer to Reto Kromer’s <a href="https://avpres.net/FFmpeg/#ch1" target="_blank">installation instructions</a>.</p>
       <p>For Bash and command line basics, try the <a href="https://learnpythonthehardway.org/book/appendixa.html" target="_blank">Command Line Crash Course</a>. For a little more context presented in an ffmprovisr style, try <a href="https://explainshell.com/" target="_blank">explainshell.com</a>!</p>
-      <span class="intro-lead">License</span>
+      <h3>License</h3>
       <p class="license">
         <a href="https://creativecommons.org/licenses/by/4.0/" target="_blank"><img alt="Creative Commons License" src="img/cc.png"></a><br>
         This work is licensed under a <a href="https://creativecommons.org/licenses/by/4.0/" target="_blank">Creative Commons Attribution 4.0 International License</a>.
       </p>
-      <span class="intro-lead">Sister projects</span>
+      <h3>Sibling projects</h3>
       <p><a href="https://dd388.github.io/crals/" target="_blank">Script Ahoy</a>: Community Resource for Archivists and Librarians Scripting</p>
       <p><a href="https://datapraxis.github.io/sourcecaster/" target="_blank">The Sourcecaster</a>: an app that helps you use the command line to work through common challenges that come up when working with digital primary sources.</p>
       <p><a href="https://pugetsoundandvision.github.io/micropops/" target="_blank">Micropops</a>: One liners and automation tools from Moving Image Preservation of Puget Sound</p>
       <p><a href="https://amiaopensource.github.io/cable-bible/" target="_blank">Cable Bible</a>: A Guide to Cables and Connectors Used for Audiovisual Tech</p>
-      <p><a href="https://eaasi.gitlab.io/qemu-qed/" target="_blank">QEMU QED</a>: instructions for using QEMU (Quick EMUlator), a command line application for computer emulation and virtualization</p>
+      <p><a href="https://eaasi.gitlab.io/program_docs/qemu-qed/" target="_blank">QEMU QED</a>: instructions for using QEMU (Quick EMUlator), a command line application for computer emulation and virtualization</p>
+      <p><a href="https://amiaopensource.github.io/ffmpeg-artschool/" target="_blank">ffmpeg-artschool</a>: An AMIA workshop featuring scripts, exercises, and activities to make art using FFmpeg</p>
     </div>
 
     <div class="well">
@@ -107,6 +108,18 @@
     <div class="well">
 
     <h2 id="concepts">Learn about more advanced FFmpeg concepts</h2>
+    <!-- Loop usage explanation -->
+    <label class="recipe" for="batch-loop">Batch and Loop script usage</label>
+    <input type="checkbox" id="batch-loop">
+    <div class="hiding">
+      <h5>Batch and Loop script usage</h5>
+      <p><code>ffmpeg -nostdin -i <em>input_file</em> ...</code></p>
+      <p>One of the frequent uses of FFmpeg is to run batch commands within loops to, for example, generate access files for an entire collection at once.</p>
+      <p>When running an FFmpeg command within a loop it is often necessary to use the <code>-nostdin</code> flag prior to the input in order to ensure successful execution of the commands. This is needed to override FFmpeg's default behavior of enabling interaction on standard input which can result in errors as loop inputs are fed to the ongoing command.</p>
+      <p class="link"></p>
+    </div>
+    <!-- End loop usage explanation -->
+
     <!-- Codec Defaults explanation -->
     <label class="recipe" for="codec-defaults">Codec defaults</label>
     <input type="checkbox" id="codec-defaults">
@@ -116,9 +129,9 @@
       <p>When creating or transcoding files with FFmpeg, it is important to consider codec settings for both audio and video, as the default options may not be desirable in your particular context. The following is a brief list of codec defaults for some common file types:</p>
       <ul>
         <li><code>.avi</code>: Audio Codec: mp3, Video Codec: mpeg4</li>
-        <li><code>.mkv</code>: Audio Codec: ac3, Video Codec: h.264</li>
-        <li><code>.mov</code>: Audio Codec: aac, Video Codec: h.264</li>
-        <li><code>.mp4</code>: Audio Codec: aac, Video Codec: h.264</li>
+        <li><code>.mkv</code>: Audio Codec: ac3, Video Codec: H.264</li>
+        <li><code>.mov</code>: Audio Codec: AAC, Video Codec: H.264</li>
+        <li><code>.mp4</code>: Audio Codec: AAC, Video Codec: H.264</li>
         <li><code>.mpg</code>: Audio Codec: mp2, Video Codec: mpeg1video</li>
         <li><code>.mxf</code>: Audio Codec: pcm_s16le, Video Codec: mpeg2video</li>
         <li><code>.wav</code>: Audio Codec: pcm_s16le (16 bit PCM)</li>
@@ -183,7 +196,7 @@
       <p>To map <em>all</em> streams in the input file to the output file, use <code>-map 0</code>. However, note that not all container formats can include all stream types: for example, .mp4 cannot contain timecode.</p>
       <h4>Mapping with a failsafe</h4>
       <p>To safely process files that may or may not contain given a type of stream, you can add a trailing <code>?</code> to your map commands: for example, <code>-map 0:a?</code> instead of <code>-map 0:a</code>.</p>
-      <p>This makes the map optional: audio streams will be mapped over if they are present in the file—but if the file contains no audio streams, the transcode will precede as usual, minus the audio stream mapping. Without adding the trailing <code>?</code>, FFmpeg will exit with an error on that file.</p>
+      <p>This makes the map optional: audio streams will be mapped over if they are present in the file—but if the file contains no audio streams, the transcode will proceed as usual, minus the audio stream mapping. Without adding the trailing <code>?</code>, FFmpeg will exit with an error on that file.</p>
       <p>This is especially recommended when batch processing video files: it ensures that all files in your batch will be transcoded, whether or not they contain audio streams.</p>
       <p>For more information, check out the FFmpeg wiki <a href="https://trac.ffmpeg.org/wiki/Map" target="_blank">Map</a> page, and the official FFmpeg <a href="https://ffmpeg.org/ffmpeg.html#Advanced-options" target="_blank">documentation on <code>-map</code></a>.</p>
       <p class="link"></p>
@@ -212,7 +225,7 @@
         The new container you are rewrapping to is defined by the filename extension used here, e.g. .mkv, .mp4, .mov.</dd>
       </dl>
       <h4>Important caveat</h4>
-      <p>It may not be possible to rewrap a file's contents to a new container without re-encoding one or more of the streams within (that is, the video, audio, and subtitle tracks). Some containers can only contain streams of a certain encoding type: for example, the .mp4 container does not support uncompressed audio tracks. (In practice .mp4 goes hand-in-hand with a H.264-encoded video stream and an AAC-encoded video stream, although other types of video and audio streams are possible). Another example is that the Matroska container does not allow data tracks; see the <a href="#mkv-to-mp4">MKV to MP4 recipe</a>.</p>
+      <p>It may not be possible to rewrap a file's contents to a new container without re-encoding one or more of the streams within (that is, the video, audio, and subtitle tracks). Some containers can only contain streams of a certain encoding type: for example, the .mp4 container does not support uncompressed audio tracks. (In practice .mp4 goes hand-in-hand with a H.264-encoded video stream and an AAC-encoded video stream, although other types of video and audio streams are possible). Another example is that the Matroska container does not allow data tracks.</p>
       <p>In such cases, FFmpeg will throw an error. If you encounter errors of this kind, you may wish to consult the <a href="#transcode">list of transcoding recipes</a>.</p>
       <p class="link"></p>
     </div>
@@ -331,11 +344,44 @@
         <dt>-crf <em>18</em></dt><dd>Specifying a lower CRF will make a larger file with better visual quality. For H.264 files being encoded with a 4:2:0 chroma subsampling scheme (i.e., using <code>-pix_fmt yuv420p</code>), the scale ranges between 0-51 for 8-bit content, with 0 being lossless and 51 the worst possible quality.<br>
           If no crf is specified, <code>libx264</code> will use a default value of 23. 18 is often considered a “visually lossless” compression.</dd>
       </dl>
+      <p>By default, this recipe will include one track of each type (e.g. audio, video) in the output file. If you wish to include more tracks, consult the <a href="#stream-mapping">entry on stream mapping</a>.</p>
       <p>For more information, see the <a href="https://trac.ffmpeg.org/wiki/Encode/H.264" target="_blank">FFmpeg and H.264 Encoding Guide</a> on the FFmpeg wiki.</p>
       <p class="link"></p>
     </div>
     <!-- ends Transcode to H.264 -->
 
+    <!-- Transcode to H.264 or H.265 using the GPU -->
+    <label class="recipe" for="transcode_gpu">Transcode to H.264/H.265 using the GPU</label>
+    <input type="checkbox" id="transcode_gpu">
+    <div class="hiding">
+      <h5>Transcode to H.264/H.265 using the GPU</h5>
+      <p><code>ffmpeg -i <em>input_file</em> -c:v h264_nvenc -preset llhq -rc:v vbr_hq -cq:v 19 -b:v 8000k -maxrate:v 12000k -profile:v high -c:a copy <em>output_file</em></code></p>
+      <p>This command takes an input file and transcodes it to H.264 using the encoding functionality of an Nvidia GPU (without transcoding the audio). If you're using H.264 with AAC or AC3 audio, you can output to an .mp4 file; if you're using HEVC and/or more exotic audio, you should output to .mkv. While Nvidia's fixed-function hardware can be 10x as performant as encoding on the CPU, it requires a few more parameters in order to optimize quality at lower bitrates.</p>
+      <dl>
+        <dt>ffmpeg</dt><dd>starts the command</dd>
+        <dt>-i <em>input_file</em></dt><dd>path, name and extension of the input file</dd>
+        <dt>-c:v <em>h264_nvenc</em></dt><dd>tells FFmpeg to encode the video stream as H.264 using Nvidia's encoder.</dd>
+        <dt>-preset <em>llhq</em></dt><dd>uses the "low latency, high quality" encoding preset, a good default when working with nvenc.</dd>
+        <dt>-rc:v <em>vbr_hq</em></dt><dd>means "variable bitrate, high quality," allowing you to set a minimum and maximum bitrate for the encode.</dd>
+        <dt>-cq:v <em>19</em></dt><dd>is the same as the CRF quality level specified using x264 or other CPU-based encoders, where 0 is lossless, 51 is the worst possible quality, and values from 18-23 are typical.</dd>
+        <dt>-b:v <em>8000k -maxrate:v 12000k</em></dt><dd>corresponds to a minimum bitrate of 8 megabits (8000k) per second, and a maximum of 12 megabits per second. nvenc is not as good at estimating bitrates as CPU-based encoders, and without this data, will occasionally choose a visibly lower bitrate. The 8-12 mbit range is generally a good one for high-quality 1080p h264.</dd>
+        <dt>-profile:v <em>high</em></dt><dd>uses the "high quality" profile of h264, something that's been baked in to the spec for a long time so that older players can declare compatibility; almost all h264 video now uses high.</dd>
+        <dt>-c:a <em>copy</em></dt><dd>will skip reencoding the audio stream, and copy the audio from the source file.</dd>
+        <dt><em>output_file</em></dt><dd>path, name and extension of the output file</dd>
+      </dl>
+      <p>In order to encode to HEVC instead, and optionally transcode the audio, you can try changing the command like this:</p>
+      <p><code>ffmpeg -i <em>input_file</em> -c:v hevc_nvenc -preset llhq -rc:v vbr_hq -cq:v 19 -b:v 5000k -maxrate:v 8000k -profile:v main10 -c:a aac <em>output_file</em></code></p>
+      <dl>
+        <dt>-c:v <em>hevc_nvenc</em></dt><dd>encodes to HEVC (also called H.265), a more efficient codec supported on GPUs from approximately 2015 and newer.</dd>
+        <dt>-b:v <em>5000k -maxrate:v 8000k</em></dt><dd>specifies a slightly lower bitrate than when using h264, per HEVC's greater efficiency.</dd>
+        <dt>-profile:v <em>main10</em></dt><dd>declares the "main10" profile for working with HEVC; one of the primary advantages of this codec is better support for 10-bit video, enabling consumer HDR.</dd>
+        <dt>-c:a <em>aac</em></dt><dd>reencodes the audio to AAC with default parameters, a very common and widely supported format for access copies.</dd>
+      </dl>
+      <p>Much of the information in this entry was taken from <a href="https://superuser.com/a/1236387" target="_blank">this superuser.com post</a> provided by an Nvidia developer, one of the best sources of information on the ffmpeg Nvidia encoders.</p>
+      <p class="link"></p>
+    </div>
+    <!-- ends Transcode to H.264 or H.265 using the GPU -->
+
     <!-- H.264 from DCP -->
     <label class="recipe" for="dcp_to_h264">Transcode from DCP to an H.264 access file</label>
     <input type="checkbox" id="dcp_to_h264">
@@ -431,7 +477,6 @@
       <h5>Transcode to H.265/HEVC</h5>
       <p><code>ffmpeg -i <em>input_file</em> -c:v libx265 -pix_fmt yuv420p -c:a copy <em>output_file</em></code></p>
       <p>This command takes an input file and transcodes it to H.265/HEVC in an .mp4 wrapper, keeping the audio codec the same as in the original file.</p>
-      <p><strong>Note:</strong> FFmpeg must be compiled with libx265, the library of the H.265 codec, for this script to work. (Add the flag <code>--with-x265</code> if using the <code>brew install ffmpeg</code> method).</p>
       <dl>
         <dt>ffmpeg</dt><dd>starts the command</dd>
         <dt>-i <em>input file</em></dt><dd>path, name and extension of the input file</dd>
@@ -459,7 +504,6 @@
       <h5>Transcode to Ogg/Theora</h5>
       <p><code>ffmpeg -i <em>input_file</em> -acodec libvorbis -b:v 690k <em>output_file</em></code></p>
       <p>This command takes an input file and transcodes it to Ogg/Theora in an .ogv wrapper with 690k video bitrate.</p>
-      <p><strong>Note:</strong> FFmpeg must be installed with support for Ogg Theora. If you are using Homebrew, you can check with <code>brew info ffmpeg</code> and then update it with <code>brew upgrade ffmpeg --with-theora --with-libvorbis</code> if necessary.</p>
       <dl>
         <dt>ffmpeg</dt><dd>starts the command</dd>
         <dt>-i <em>input file</em></dt><dd>path, name and extension of the input file</dd>
@@ -629,6 +673,9 @@
         For silent videos you can replace <code>-c:a copy</code> with <code>-an</code>.</dd>
         <dt><em>output_file</em></dt><dd>path, name and extension of the output file</dd>
       </dl>
+      <p>If your source is interlaced, you will want to deinterlace prior to scaling. In that case, your command would look like this:</p>
+      <p><code>ffmpeg -i <em>input_file</em> -c:v libx264 -filter:v "yadif, colormatrix=bt601:bt709, scale=1440:1080:flags=lanczos, pad=1920:1080:240:0" -c:a copy <em>output_file</em></code></p>
+      <p>See the <a href="#ntsc_to_h264">Interlaced NTSC to MP4 recipe</a> for a fuller explanation of the deinterlacing step.</p>
       <p class="link"></p>
     </div>
     <!-- ends SD to HD -->
@@ -720,7 +767,7 @@
           <li>In the sound filter <code>atempo</code> the numerator <code>output_fps</code> sets the output speed and the denominator <code>input_fps</code> sets the input speed; both values are given in frames per second.</li>
         </ul>
         The different filters in a complex filter can be divided either by comma or semicolon. The quotation marks allow to insert a space between the filters for readability.</dd>
-        <dt>-map "[v]"</dt><dd>maps the video stream and:</dd>
+        <dt>-map "[v]"</dt><dd>maps the video stream and</dd>
         <dt>-map "[a]"</dt><dd>maps the audio stream together into:</dd>
         <dt><em>output_file</em></dt><dd>path, name and extension of the output file</dd>
       </dl>
@@ -733,13 +780,13 @@
     <input type="checkbox" id="fade_streams">
     <div class="hiding">
       <h5>Fade both video and audio streams</h5>
-      <p><code>ffmpeg -i <em>input_file</em> -filter:v "fade=in:st=0:d=1, fade=out:st=59:d=1" -filter:a "afade=in:st=0:d=1, afade=out:st=59:d=1" -c:v libx264 -c:a aac <em>output_file</em></code></p>
-      <p>This command fades in and out the first and last 30 video frames and 44100 audio samples on a video</p>
+      <p><code>ffmpeg -i <em>input_file</em> -filter:v "fade=in:st=IN_POINT:d=DURATION, fade=out:st=OUT_POINT:d=DURATION" -filter:a "afade=in:st=OUT_POINT:d=DURATION, afade=out:st=IN_POINT:d=DURATION" -c:v libx264 -c:a aac <em>output_file</em></code></p>
+      <p>This command fades your video in and out. Change IN_POINT, OUT_POINT, and DURATION to the time in seconds (expressed as integers).</p>
       <dl>
           <dt>ffmpeg</dt><dd>starts the command</dd>
           <dt>-i <em>input_file</em></dt><dd>path, name and extension of the input file</dd>
-          <dt>-filter:v "fade=in:st=0:d=1, fade=out:st=59:d=1"</dt><dd>applies a video filter that fades in the first and last 30 video frames</dd>
-          <dt>-filter:a "afade=in:st=0:d=1, afade=out:st=59:d=1"</dt><dd>applies an audio filter that fades in the first and last 30 video frames. <code>st</code> sets the start and <code>d</code> sets the duration.</dd>
+          <dt>-filter:v "fade=in:st=IN_POINT:d=DURATION, fade=out:st=OUT_POINT:d=DURATION"</dt><dd>applies a video filter that fades your video in and out. <code>st</code> sets the start and <code>d</code> sets the duration.</dd>
+          <dt>-filter:a "afade=in:st=IN_POINT:d=DURATION, afade=out:st=OUT_POINT:d=DURATION"</dt><dd>applies an audio filter that fades your video in and out. <code>st</code> sets the start and <code>d</code> sets the duration.</dd>
           <dt>-c:v <em>video_codec</em></dt><dd>as a video filter is used, it is not possible to use <code>-c copy</code>. The video must be re-encoded with whatever video codec is chosen, e.g. <code>ffv1</code>, <code>v210</code> or <code>prores</code>.</dd>
           <dt>-c:a <em>audio_codec</em></dt><dd>as an audio filter is used, it is not possible to use <code>-c copy</code>. The audio must be re-encoded with whatever audio codec is chosen, e.g. <code>aac</code>.</dd>
           <dt><em>output_file</em></dt><dd>path, name and extension of the output_file</dd>
@@ -937,7 +984,7 @@
       <p><code>ffmpeg -i <em>input_file</em> -af loudnorm=print_format=json -f null -</code></p>
       <p>This filter calculates and outputs loudness information in json about an input file (labeled input) as well as what the levels would be if loudnorm were applied in its one pass mode (labeled output). The values generated can be used as inputs for a 'second pass' of the loudnorm filter allowing more accurate loudness normalization than if it is used in a single pass.</p>
       <p>These instructions use the loudnorm defaults, which align well with PBS recommendations for target loudness. More information can be found at the <a href="https://ffmpeg.org/ffmpeg-filters.html#loudnorm" target="_blank">loudnorm documentation</a>.</p>
-      <p>Information about PBS loudness standards can be found in the <a href="https://www-tc.pbs.org/capt/Producing/TOS-2012-Pt2-Distribution.pdf" target="_blank">PBS Technical Operating Specifications</a> document. Information about EBU loudness standards can be found in the <a href="https://tech.ebu.ch/docs/r/r128-2014.pdf" target="_blank">EBU R 128</a> recommendation document.</p>
+      <p>Information about PBS loudness standards can be found in the <a href="http://bento.cdn.pbs.org/hostedbento-prod/filer_public/PBS_About/Producing/Red%20Book/TOS%20Pt%201%20Submission%202016.pdf" target="_blank">PBS Technical Operating Specifications</a> document. Information about EBU loudness standards can be found in the <a href="https://tech.ebu.ch/docs/r/r128-2014.pdf" target="_blank">EBU R 128</a> recommendation document.</p>
       <dl>
         <dt>ffmpeg</dt><dd>starts the command</dd>
         <dt><em>input_file</em></dt><dd>path, name and extension of the input file</dd>
@@ -1057,16 +1104,18 @@
     <div class="hiding">
       <h5>Join files together</h5>
       <p><code>ffmpeg -f concat -i mylist.txt -c copy <em>output_file</em></code></p>
-      <p>This command takes two or more files of the same file type and joins them together to make a single file. All that the program needs is a text file with a list specifying the files that should be joined. However, it only works properly if the files to be combined have the exact same codec and technical specifications. Be careful, FFmpeg may appear to have successfully joined two video files with different codecs, but may only bring over the audio from the second file or have other weird behaviors. Don’t use this command for joining files with different codecs and technical specs and always preview your resulting video file!</p>
+      <p>This command takes two or more files of the same file type and joins them together to make a single file. All that the program needs is a text file with a list specifying the files that should be joined. If possible, run the command from the same directory where the files and the text file reside. Otherwise you'll have to use <code>-safe 0</code>, see below for more information. However, it only works properly if the files to be combined have the exact same codec and technical specifications. Be careful, FFmpeg may appear to have successfully joined two video files with different codecs, but may only bring over the audio from the second file or have other weird behaviors. Don’t use this command for joining files with different codecs and technical specs and always preview your resulting video file!</p>
       <dl>
         <dt>ffmpeg</dt><dd>starts the command</dd>
         <dt>-f concat</dt><dd>forces ffmpeg to concatenate the files and to keep the same file format</dd>
         <dt>-i <em>mylist.txt</em></dt><dd>path, name and extension of the input file. Per the <a href="https://ffmpeg.org/ffmpeg-formats.html#Options" target="_blank">FFmpeg documentation</a>, it is preferable to specify relative rather than absolute file paths, as allowing absolute file paths may pose a security risk.<br>
-        This text file contains the list of files to be concatenated and should be formatted as follows:
-        <pre>file '<em>./first_file.ext</em>'
-  file '<em>./second_file.ext</em>'
+        This text file contains the list of files (without their absolute path) to be concatenated and should be formatted as follows:
+<pre>
+  file '<em>first_file.ext</em>'
+  file '<em>second_file.ext</em>'
   . . .
-  file '<em>./last_file.ext</em>'</pre>
+  file '<em>last_file.ext</em>'
+</pre>
   In the above, <strong>file</strong> is simply the word "file". Straight apostrophes ('like this') rather than curved quotation marks (‘like this’) must be used to enclose the file paths.<br>
   <strong>Note:</strong> If specifying absolute file paths in the .txt file, add <code>-safe 0</code> before the input file.<br>
   e.g.: <code>ffmpeg -f concat -safe 0 -i mylist.txt -c copy <em>output_file</em></code></dd>
@@ -1360,6 +1409,43 @@
     </div>
     <!-- ends Deinterlace video -->
 
+    <!-- Deinterlace video fields -->
+    <label class="recipe" for="deinterlace_fields">Deinterlace video fields to frames</label>
+    <input type="checkbox" id="deinterlace_fields">
+    <div class="hiding">
+      <h5>Deinterlace video fields to frames</h5>
+      <p><code>ffmpeg -i <em>input_file</em> -c:v libx264 -vf "idet,bwdif,format=yuv420p" <em>output_file</em></code></p>
+      <p>This command takes an interlaced input file and outputs a deinterlaced H.264 MP4, with each field separated into its own frame.  This is preferred for interlaced video that contains a lot of motion, as the double-rate output preserves the visual cadence of the source material.</p>
+      <dl>
+        <dt>ffmpeg</dt><dd>starts the command</dd>
+        <dt>-i <em>input file</em></dt><dd>path, name and extension of the input file</dd>
+        <dt>-c:v libx264</dt><dd>tells FFmpeg to encode the video stream as H.264</dd>
+        <dt>-vf</dt><dd>video filtering will be used (<code>-vf</code> is an alias of <code>-filter:v</code>)</dd>
+        <dt>"</dt><dd>start of filtergraph (see below)</dd>
+        <dt>idet</dt><dd>detect interlaced video field order<br>
+         <a href="https://ffmpeg.org/ffmpeg-filters.html#idet" target="_blank">idet</a> will try to detect if the video is interlaced, and if so, what the order of the fields are (top-field-first, or bottom-field-first).  This is done to ensure the output of the deinterlacing filter is correct.</dd>
+        <dt>bwdif</dt><dd>deinterlacing filter (‘Bob Weaver Deinterlacing Filter’)<br>
+         By default, <a href="https://ffmpeg.org/ffmpeg-filters.html#bwdif-1" target="_blank">bwdif</a> will output one frame for each field, matching the visual cadence of interlaced video. </dd>
+        <dt>,</dt><dd>separates filters</dd>
+        <dt>format=yuv420p</dt><dd>chroma subsampling set to 4:2:0<br>
+        By default, <code>libx264</code> will use a chroma subsampling scheme that is the closest match to that of the input. This can result in Y′C<sub>B</sub>C<sub>R</sub> 4:2:0, 4:2:2, or 4:4:4 chroma subsampling. QuickTime and most other non-FFmpeg based players can’t decode H.264 files that are not 4:2:0, therefore it’s advisable to specify 4:2:0 chroma subsampling.</dd>
+        <dt>"</dt><dd>end of filtergraph</dd>
+        <dt><em>output file</em></dt><dd>path, name and extension of the output file</dd>
+      </dl>
+      <p><code>"idet,bwdif,format=yuv420p"</code> is an FFmpeg <a href="https://trac.ffmpeg.org/wiki/FilteringGuide#FiltergraphChainFilterrelationship" target="_blank">filtergraph</a>. Here the filtergraph is made up of one filter chain, which is itself made up of the three filters (separated by the comma).<br>
+      The enclosing quote marks are necessary when you use spaces within the filtergraph, e.g. <code>-vf "idet, bwdif, format=yuv420p"</code>, and are included above as an example of good practice.</p>
+      <p><strong>Note:</strong> bwdif also supports the older method of outputting one frame for each frame (thereby halving the number of output frames per second) with the syntax <code>bwdif=mode=send_frame</code>.  This can be used when the presentation device is not capable of reproducing 50 (PAL) or 60 (NTSC) frames per second.</p>
+      <p>For more H.264 encoding options, see the latter section of the <a href="#transcode_h264">encode H.264 command</a>.</p>
+      <div class="sample-image">
+        <h2>Example</h2>
+        <p>Before and after deinterlacing with bwdif:</p>
+        <img src="img/interlaced_video_fields.png" alt="VLC screenshot of original interlaced video">
+        <img src="img/deinterlaced_video_frames.png" alt="VLC screenshot of deinterlaced video">
+      </div>
+      <p class="link"></p>
+    </div>
+    <!-- ends Deinterlace video fields -->
+
     <!-- Inverse telecine -->
     <label class="recipe" for="inverse-telecine">Inverse telecine</label>
     <input type="checkbox" id="inverse-telecine">
@@ -1503,7 +1589,7 @@
     <label class="recipe" for="embed_subtitles">Embed subtitles</label>
     <input type="checkbox" id="embed_subtitles">
     <div class="hiding">
-      <h5>Embed a subtitle file into a movie file </h5>
+      <h5>Embed a subtitle file into a movie file</h5>
       <p><code>ffmpeg -i <em>input_file</em> -i <em>subtitles_file</em> -c copy -c:s mov_text <em>output_file</em></code></p>
       <dl>
         <dt>ffmpeg</dt><dd>starts the command</dd>
@@ -2332,7 +2418,6 @@
     <input type="checkbox" id="ocr_on_top">
     <div class="hiding">
       <h5>Plays video with OCR on top</h5>
-      <p>Note: ffmpeg must be compiled with the tesseract library for this script to work (<code>--with-tesseract</code> if using the <code>brew install ffmpeg</code> method).</p>
       <p><code>ffplay input_file -vf "ocr,drawtext=fontfile=/Library/Fonts/Andale Mono.ttf:text=%{metadata\\\:lavfi.ocr.text}:fontcolor=white"</code></p>
       <dl>
         <dt>ffplay</dt><dd>starts the command</dd>
@@ -2356,7 +2441,6 @@
     <input type="checkbox" id="ffprobe_ocr">
     <div class="hiding">
       <h5>Exports OCR data to screen</h5>
-      <p>Note: FFmpeg must be compiled with the tesseract library for this script to work (<code>--with-tesseract</code> if using the <code>brew install ffmpeg</code> method)</p>
       <p><code>ffprobe -show_entries frame_tags=lavfi.ocr.text -f lavfi -i "movie=<em>input_file</em>,ocr"</code></p>
       <dl>
         <dt>ffprobe</dt><dd>starts the command</dd>
@@ -2564,7 +2648,7 @@
            <dt>-flags +global_header</dt><dd>Don't place extra data in every keyframe</dd>
            <dt>-vf scale="1280:-1"</dt><dd>Scale to 1280 width, maintain aspect ratio.</dd>
            <dt>-pix_fmt yuv420p</dt><dd>convert to 4:2:0 chroma subsampling scheme</dd>
-           <dt>-level 3.1</dt><dd>H264 Level (defines some thresholds for bitrate)</dd>
+           <dt>-level 3.1</dt><dd>H.264 Level (defines some thresholds for bitrate)</dd>
            <dt>-vsync passthrough</dt><dd>Each frame is passed with its timestamp from the demuxer to the muxer.</dd>
            <dt>-crf 26</dt><dd>Constant rate factor - basically the quality</dd>
            <dt>-g 50</dt><dd>GOP size.</dd>

readme.md

@@ -5,6 +5,7 @@ Repository of useful FFmpeg command lines for archivists!
 * [What is this?](#what-is-this)
 * [How do I see it?](#how-do-i-see-it)
 * [How do I contribute?](#how-do-i-contribute)
+  * [Guidelines for contributing](#guidelines-for-contributing)
 * [Code of conduct](#code-of-conduct)
 * [Maintainers](#maintainers)
 * [Contributors](#contributors)
@@ -15,7 +16,7 @@ Repository of useful FFmpeg command lines for archivists!
 
 ## What is this?
 
-#### Project Objective
+### Project Objective
 
 To facilitate better understanding of FFmpeg through collaborative sharing of useful scripts and detailed flag-level description of how each script works, so archivists can copy-paste and produce their own scripts, but also understand how and why they work.
 
@@ -34,7 +35,7 @@ ffmprovisr
 ```
 This works currently under macOS, Linux and the Linux apps on Windows (Ubuntu and Debian tested). On classic Windows you can install the last [release](https://github.com/amiaopensource/ffmprovisr/releases) manually and the open `index.html` in a browser.
 
-#### Parseable list of the commands
+### Parseable list of the commands
 
 A list of all recipes in an easily parseable [ASCII text](recipes.txt) format is provided as well. It contains for each recipe its title and command in the following format:
 
@@ -58,15 +59,30 @@ The used [one-liner](scripts/get_recipe_list) is in the `scripts` folder.
 
 You are welcome to edit the codebase yourself, or just supply the information and ask it to be added to the site.
 
-#### Edit codebase
+### Edit codebase
 
-To contribute to this project directly (and more quickly), clone this repository and create a new branch (`git checkout -b your-branch-name`) and add or modify a new block in `index.html`. Then [submit a pull request](https://github.com/amiaopensource/ffmprovisr/pulls) and the maintainers will review and integrate your code. There is a commented-out sample block available at the bottom of `index.html` that can be as a guideline for your command.
+To contribute to this project directly (and more quickly), clone this repository and create a new branch (`git checkout -b your-branch-name`) and add or modify a new block in `index.html`. Then [submit a pull request](https://github.com/amiaopensource/ffmprovisr/pulls) and the maintainers will review and integrate your code. There is a commented-out sample block available at the bottom of `index.html` that can be a guideline for your command.
 
-#### Make a request
+#### Guidelines for contributing
+
+* Recipes should ideally do just one thing or solve one problem, to keep things as user-friendly as possible and to avoid unintended side-effects
+* Explanations and examples for recipes should be as generic as possible, to allow users to alter the command for their own use-case.
+  * This may involve the use of `VARIABLE_NAMES`
+  * Example: [Fade video and audio streams](https://amiaopensource.github.io/ffmprovisr/#fade_streams)
+* Some recipes may benefit from including a GIF that shows the output
+  * Example: [Plays a graphical output showing decibel levels of an input file](https://amiaopensource.github.io/ffmprovisr/#astats)
+* Some recipes require an explanatory section which may not fit gracefully into the recipe itself
+  * Example: [Rewrap a file](https://amiaopensource.github.io/ffmprovisr/#basic-rewrap)
+* Recipes involving `-filter_complex` can be some of the most verbose and difficult to understand, so breaking these down as much as possible into their relevant sections is ideal
+  * Example: [Generate two access MP3s from input](https://amiaopensource.github.io/ffmprovisr/#append_mp3)
+* Some recipes may refer to a specific standard or vocabulary, and it's useful to link to these so that the user can scale the recipe to their use case
+  * Example: [Generate Broadcast WAV](https://amiaopensource.github.io/ffmprovisr/#bwf)
+
+### Make a request
 
 If you are having trouble with coding it yourself or with GitHub, feel free to [submit an issue](https://github.com/amiaopensource/ffmprovisr/issues) with the kind of command you would like to see added to the site.
 
-#### General help
+### General help
 
 If you want to help but don't have a new script to add, you can help us by testing out the scripts available, by refining or clarifying the documentation, or [creating an issue](https://github.com/amiaopensource/ffmprovisr/issues) for anything that sounds confusing and requires clarification.
 
@@ -156,7 +172,8 @@ Last updated: 2019-12-11
 ## Sister projects
 
 [The Cable Bible](https://amiaopensource.github.io/cable-bible/): A Guide to Cables and Connectors Used for Audiovisual Tech  
-[QEMU QED](https://eaasi.gitlab.io/qemu-qed): instructions for using QEMU (Quick EMUlator), a command line application for computer emulation and virtualization  
+[FFCommand_Engine](https://github.com/ColorlabMD/FFCommand_Engine): a tool for easier use of FFmpeg binaries  
+[QEMU QED](https://eaasi.gitlab.io/program_docs/qemu-qed/): instructions for using QEMU (Quick EMUlator), a command line application for computer emulation and virtualization  
 [Script Ahoy](http://dd388.github.io/crals/): Community Resource for Archivists and Librarians Scripting  
 [sourcecaster](https://datapraxis.github.io/sourcecaster/): helps you use the command line to work through common challenges that come up when working with digital primary sources.
 

recipes.txt

@@ -16,6 +16,10 @@ ffmpeg -i input_file -map 0 -dn -c:v ffv1 -level 3 -g 1 -slicecrc 1 -slices 16 -
 ffmpeg -i concat:input_file_1\|input_file_2\|input_file_3 -c:v libx264 -c:a aac output_file.mp4
 # Transcode to an H.265/HEVC MP4
 ffmpeg -i input_file -c:v libx265 -pix_fmt yuv420p -c:a copy output_file
+# Transcode to H.264 using the GPU
+ffmpeg -i input_file -c:v h264_nvenc -preset llhq -rc:v vbr_hq -cq:v 19 -b:v 8000k -maxrate:v 12000k -profile:v high -c:a copy output_file
+# Transcode to H.265 using the GPU
+ffmpeg -i input_file -c:v hevc_nvenc -preset llhq -rc:v vbr_hq -cq:v 19 -b:v 5000k -maxrate:v 8000k -profile:v main10 -c:a copy output_file
 # Transcode to an Ogg Theora
 ffmpeg -i input_file -acodec libvorbis -b:v 690k output_file
 # Convert WAV to MP3
@@ -108,7 +112,7 @@ ffmpeg -i input_file -ss 00:00:20 -vframes 1 thumb.png
 ffmpeg -i input_file -vf fps=1/60 out%d.png
 # Create GIF from still images
 ffmpeg -f image2 -framerate 9 -pattern_type glob -i "input_image_*.jpg" -vf scale=250x250 output_file.gif
-# Create GIF from a video
+# Create GIF from a video
 ffmpeg -ss HH:MM:SS -i input_file -filter_complex "fps=10,scale=500:-1:flags=lanczos,palettegen" -t 3 palette.png
 ffmpeg -ss HH:MM:SS -i input_file -i palette.png -filter_complex "[0:v]fps=10, scale=500:-1:flags=lanczos[v], [v][1:v]paletteuse" -t 3 -loop 6 output_file
 # Transcode an image sequence into uncompressed 10-bit video
@@ -161,7 +165,7 @@ ffmpeg -f lavfi -i smptebars=size=720x576:rate=25 -c:v prores -t 10 output_file
 ffmpeg -f lavfi -i testsrc=size=720x576:rate=25 -c:v v210 -t 10 output_file
 # Play HD SMPTE bars
 ffplay -f lavfi -i smptehdbars=size=1920x1080
-# Play VGA SMPTE bars
+# Play VGA SMPTE bars
 ffplay -f lavfi -i smptebars=size=640x480
 # Generate a sine wave test audio file
 ffmpeg -f lavfi -i "sine=frequency=1000:sample_rate=48000:duration=5" -c:a pcm_s16le output_file.wav
@@ -181,7 +185,7 @@ ffmpeg -i input_one -i input_two -filter_complex signature=detectmode=full:nb_in
 ffmpeg -i input -vf signature=format=xml:filename="output.xml" -an -f null -
 # Play an image sequence
 ffplay -framerate 5 input_file_%06d.ext
-# Split audio and video tracks
+# Split audio and video tracks
 ffmpeg -i input_file -map 0:v:0 video_output_file -map 0:a:0 audio_output_file
 # Merge audio and video tracks
 ffmpeg -i video_file -i audio_file -map 0:v -map 1:a -c copy output_file
@@ -195,22 +199,3 @@ ffmpeg -i input_file -filter:v drawbox=w=iw:h=7:y=ih-h:t=max output_file
 ffmpeg -re -i ${INPUTFILE} -map 0 -flags +global_header -vf scale="1280:-1,format=yuv420p" -pix_fmt yuv420p -level 3.1 -vsync passthrough -crf 26 -g 50 -bufsize 3500k -maxrate 1800k -c:v libx264 -c:a aac -b:a 128000 -r:a 44100 -ac 2 -t ${STREAMDURATION} -f tee "[movflags=+faststart]${TARGETFILE}|[f=flv]${STREAMTARGET}"
 # View FFmpeg subprogram information
 ffmpeg -h type=name
-# Rip a CD with CD Paranoia
-cdparanoia -L -B -O [Drive Offset] [Starting Track Number]-[Ending Track Number] output_file.wav
-# Rip a CD with Cdda2wav
-cdda2wav -L0 -t all -cuefile -paranoia paraopts=retries=200,readahead=600,minoverlap=sectors-per-request-1 -verbose-level all output.wav
-# Compare two images
-compare -metric ae image1.ext image2.ext null:
-# Create thumbnails of images
-mogrify -resize 80x80 -format jpg -quality 75 -path thumbs *.jpg
-# Creates grid of images from text file
-montage @list.txt -tile 6x12 -geometry +0+0 output_grid.jpg
-# Get file signature data
-convert -verbose input_file.ext | grep -i signature
-# Removes exif metadata
-mogrify -path ./stripped/ -strip *.jpg
-# Resizes image to specific pixel width
-convert input_file.ext -resize 750 output_file.ext
-# Transcoding to/from FLAC
-flac --best --keep-foreign-metadata --preserve-modtime --verify input.wav
-flac --decode --keep-foreign-metadata --preserve-modtime --verify input.flac

scripts/ffmprovisr

@@ -4,17 +4,12 @@
 # connected to the Web, and the local version otherwise.
 
 if [[ "$(uname -s)" = "Darwin" ]] ; then
-    default_browser=$(plutil -convert json ~/Library/Preferences/com.apple.LaunchServices/com.apple.launchservices.secure.plist -r -o - | grep https -b1 | tail -n1 | cut -d'"' -f4)
     if ping -c 1 amiaopensource.github.io >/dev/null 2>&1 ; then
         ffmprovisr_path='https://amiaopensource.github.io/ffmprovisr/'
     else
         ffmprovisr_path=$(find /usr/local/Cellar/ffmprovisr -iname 'index.html' | sort -M | tail -n1)
     fi
-    if [[ -n "${default_browser}" ]] ; then
-        open -b "${default_browser}" "${ffmprovisr_path}"
-    else
     open "${ffmprovisr_path}"
-    fi
 elif [[ "$(uname -s)" = "Linux" ]] ; then
     if ping -c 1 amiaopensource.github.io >/dev/null 2>&1 ; then
         ffmprovisr_path='https://amiaopensource.github.io/ffmprovisr/'