feat: Argument override

README.md

@@ -115,6 +115,12 @@ Type: `String`
 
 Seeks the video to the provided time. The time must be in the following form: `hh:mm:ss[.ms]`, eg. `00:00:42.23`. If omitted, the video time will be set to `00:00:00` (ie. the first frame).
 
+#### config.args
+
+Type: `Array<String>`
+
+FFmpeg arguments that override the synthetic arguments created by `simple-thumbnail`; you'll likely need to pass include your own `-i` flag, `-y` flag, etc.
+
 ## Contributors
 
 <!-- ALL-CONTRIBUTORS-LIST:START - Do not remove or modify this section -->

index.js

@@ -160,15 +160,21 @@ function genThumbnail (input, output, size, config = {}) {
   const rstream = typeof input === 'string' ? null : input
   const wstream = typeof output === 'string' ? null : output
 
-  const parsedSize = parseSize(size)
-  const args = buildArgs(
-    typeof input === 'string' ? `"${input}"` : 'pipe:0',
-    typeof output === 'string' ? `"${output}"` : '-f singlejpeg pipe:1',
-    parsedSize,
-    seek
-  )
-
-  if (input === null && output === null) {
+  let args = ''
+  if (config.args) {
+    args = config.args
+  } else {
+    const parsedSize = parseSize(size)
+
+    args = buildArgs(
+      typeof input === 'string' ? `"${input}"` : 'pipe:0',
+      typeof output === 'string' ? `"${output}"` : '-f singlejpeg pipe:1',
+      parsedSize,
+      seek
+    )
+  }
+
+  if ((input === null && output === null) || config.args) {
     return ffmpegDuplexExecute(ffmpegPath, args)
   }
   if (output === null) {

test/data/text.txt

@@ -0,0 +1 @@
+this is text

test/test.js

@@ -74,6 +74,14 @@ async function httpMediaTestMacro (t, { url, title }) {
   t.true(isSame)
 }
 
+async function withArgsMacro (t, { config, output }) {
+  await genThumbnail(null, null, null, config)
+
+  const textImageIsSame = await looksSame(absPath('./expected/args-text.png'), output, { tolerance: 5 })
+
+  t.true(textImageIsSame)
+}
+
 function streamReturnMacro (t, { input, title }) {
   const output = absPath(`./out/${title}.png`)
   const write = fs.createWriteStream(output)
@@ -115,6 +123,27 @@ test('creates thumbnails for streams', imageTestMacro, {
   title: 'stream'
 })
 
+;(function () {
+  const title = 'args'
+  const text = absPath('./data/text.txt')
+  const output = absPath(`./out/${title}.png`)
+  const fontPath = absPath('./utils/opensans.ttf')
+
+  test('can pass args to ffmpeg via config', withArgsMacro, {
+    config: {
+      args: [
+        '-f lavfi',
+        '-i color=c=white:s=640x480:d=5.396',
+        `-filter_complex "drawtext=textfile='${text}':x=0:y=0:fontsize=30:fontcolor=ff00ff:fontfile=${fontPath}"`,
+        '-y',
+        output
+      ],
+      path: ffmpeg.path
+    },
+    output
+  })
+})()
+
 test('creates thumbnails for http', httpMediaTestMacro, {
   url: 'http://www.w3schools.com/html/mov_bbb.webm',
   title: 'http'