WarpEngineer · June 7, 2018 12:56 · Jun 3, 2018 · Jun 3, 2018 · Jun 3, 2018 · Jun 3, 2018
diff --git a/gif-from-tweet.md b/gif-from-tweet.md
@@ -5,8 +5,8 @@ There are so many great GIFs out there and I want to have copies of them. Twitte
 ## Dependencies
 
 - ffmpeg
- - macOS: `brew install ffmpeg`
- - Ubuntu/Debian: `apt install ffmpeg`
+  - macOS: `brew install ffmpeg`
+  - Ubuntu/Debian: `apt install ffmpeg`
 
 ## Install
 

diff --git a/gif-from-tweet.md b/gif-from-tweet.md
@@ -4,7 +4,9 @@ There are so many great GIFs out there and I want to have copies of them. Twitte
 
 ## Dependencies
 
-- ffmpeg: `brew install ffmpeg`
+- ffmpeg
+ - macOS: `brew install ffmpeg`
+ - Ubuntu/Debian: `apt install ffmpeg`
 
 ## Install
 

diff --git a/gif-from-tweet.md b/gif-from-tweet.md
@@ -2,6 +2,10 @@
 
 There are so many great GIFs out there and I want to have copies of them. Twitter makes that harder than it should be by converting them to MP4 and not providing access to the source material. To make it easier, I made a bash pipeline that takes a tweet URL and a filename, extracts the MP4 from that tweet and uses ffmpeg to convert back to GIF.
 
+## Dependencies
+
+- ffmpeg: `brew install ffmpeg`
+
 ## Install
 
 Stick this in your `~/.profile`:

diff --git a/gif-from-tweet.md b/gif-from-tweet.md
@@ -0,0 +1,91 @@
+# gif-from-tweet
+
+There are so many great GIFs out there and I want to have copies of them. Twitter makes that harder than it should be by converting them to MP4 and not providing access to the source material. To make it easier, I made a bash pipeline that takes a tweet URL and a filename, extracts the MP4 from that tweet and uses ffmpeg to convert back to GIF.
+
+## Install
+
+Stick this in your `~/.profile`:
+
+```bash
+video-url-from-tweet() {
+    if [ "$1" ]; then
+        url=$1
+    else
+        echo "Must provide a url"
+        return 1
+    fi
+
+    curl --silent $url |\
+        # should find the <meta> tag with content="<thumbnail url>"
+        (grep -m1 "tweet_video_thumb" ||\
+          echo "Could not find video" && return 1) |\
+
+        # from: <meta property="og:image" content="https://pbs.twimg.com/tweet_video_thumb/xxxxxxxxxx.jpg">
+        # to: https://pbs.twimg.com/tweet_video_thumb/xxxxxxxxxx.jpg
+        cut -d '"' -f 4 |\
+
+        # from: https://pbs.twimg.com/tweet_video_thumb/xxxxxxxxxx.jpg
+        # to: https://video.twimg.com/tweet_video/xxxxxxxxxx.mp4
+        sed 's/.jpg/.mp4/g' |\
+        sed 's/pbs.twimg.com\/tweet_video_thumb/video.twimg.com\/tweet_video/g'
+}
+video-from-tweet() {
+    if [ "$1" ]; then
+        url=$1
+    else
+        echo "Must provide a url"
+        return 1
+    fi
+    curl $(video-url-from-tweet $url)
+}
+video-to-gif() {
+    # derived from https://engineering.giphy.com/how-to-make-gifs-with-ffmpeg/
+    if [ "$2" ]; then
+        input=$1
+        output=$2
+    else
+        echo "Must provide an input file and output file"
+        return 1
+    fi
+
+    ffmpeg -i $input \
+           -filter_complex "[0:v] split [a][b];[a] palettegen [p];[b][p] paletteuse" \
+           -f gif \
+           $output
+}
+gif-from-tweet() {
+    if [ "$2" ]; then
+        url=$1
+        output=$2
+    else
+        echo "Must provide a url and an output filename"
+        return 1
+    fi
+    video-from-tweet $url | video-to-gif - $output
+}
+
+```
+
+## Usage
+
+- `video-url-from-tweet <url>`: takes a tweet URL and returns the MP4 embedded in that tweet, or fails if no video is found.
+- `video-from-tweet <url>`: returns the raw data of the video that is embedded in the tweet
+- `video-to-gif <input> <output>`: converts a video to a GIF
+- `gif-from-tweet <url> <output>`: takes a tweet URL and an output filename and saves the MP4 embedded in that tweet as a GIF.
+
+### Example
+
+```bash
+$ video-url-from-tweet https://twitter.com/tsunamino/status/1003318804619804672
+https://video.twimg.com/tweet_video/DeyBINOUwAAbuif.mp4
+
+# creates `wink.mp4'
+$ video-from-tweet https://twitter.com/tsunamino/status/1003318804619804672 > wink.mp4
+
+# creates `wink.gif' from `wink.mp4'
+$ video-to-gif wink.mp4 wink.gif
+<...a bunch of ffmpeg output...>
+
+# or use this, which pipelines the above and doesn't create intermediate MP4
+$ gif-from-tweet https://twitter.com/tsunamino/status/1003318804619804672 wink.gif
+