change video from rgb to gray

app/src/main/java/com/frank/ffmpeg/activity/VideoHandleActivity.kt

@@ -123,7 +123,8 @@ class VideoHandleActivity : BaseActivity() {
                 getString(R.string.video_thumbnail),
                 getString(R.string.video_subtitle),
                 getString(R.string.video_rotate),
-                getString(R.string.video_gop))
+                getString(R.string.video_gop),
+                getString(R.string.video_gray))
 
         layoutVideoHandle = findViewById(R.id.list_video_item)
         val layoutManager = StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL)
@@ -316,17 +317,14 @@ class VideoHandleActivity : BaseActivity() {
                 }
                 val filePath = FileUtil.getFilePath(srcFile)
                 var fileName = FileUtil.getFileName(srcFile)
-                Log.e(TAG, "moov filePath=$filePath--fileName=$fileName")
                 fileName = "moov_" + fileName!!
                 val moovPath = filePath + File.separator + fileName
                 if (useFFmpegCmd) {
                     commandLine = FFmpegUtil.moveMoovAhead(srcFile, moovPath)
                 } else {
-                    val start = System.currentTimeMillis()
                     val ffmpegCmd = FFmpegCmd()
                     val result = ffmpegCmd.moveMoovAhead(srcFile, moovPath)
                     Log.e(TAG, "result=" + (result == 0))
-                    Log.e(TAG, "move moov use time=" + (System.currentTimeMillis() - start))
                 }
             }
             14 //playing speed of video
@@ -367,6 +365,11 @@ class VideoHandleActivity : BaseActivity() {
                 val gopPath = PATH + File.separator + "gop" + gop + suffix
                 commandLine = FFmpegUtil.changeGOP(srcFile, gop, gopPath)
             }
+            20 // change video from RGB to gray
+            -> {
+                val grayPath = PATH + File.separator + "gray" + suffix
+                commandLine = FFmpegUtil.toGrayVideo(srcFile, grayPath)
+            }
             else -> {
             }
         }

app/src/main/java/com/frank/ffmpeg/util/FFmpegUtil.java

@@ -612,6 +612,18 @@ public class FFmpegUtil {
         return moovCmd.split(" ");
     }
 
+    /**
+     * Change Video from RGB to gray(black & white)
+     * @param inputPath inputPath
+     * @param outputPath outputPath
+     * @return grayCmd
+     */
+    public static String[] toGrayVideo(String inputPath, String outputPath) {
+        String grayCmd = "ffmpeg -i %s -vf lutyuv='u=128:v=128' %s";
+        grayCmd = String.format(Locale.getDefault(), grayCmd, inputPath, outputPath);
+        return grayCmd.split(" ");
+    }
+
     /**
      * using FFprobe to parse the media format
      *

app/src/main/res/values-en/strings.xml

@@ -67,6 +67,7 @@
     <string name="video_thumbnail">Insert thumbnail</string>
     <string name="video_subtitle">add subtitle</string>
     <string name="video_gop">KeyFrame interval</string>
+    <string name="video_gray">Gray video</string>
 
     <string name="swap">Swap</string>
     <string name="start">Start</string>

app/src/main/res/values/strings.xml

@@ -67,6 +67,7 @@
     <string name="video_thumbnail">插入封面</string>
     <string name="video_subtitle">添加字幕</string>
     <string name="video_gop">关键帧间隔</string>
+    <string name="video_gray">黑白视频</string>
 
     <string name="swap">切换</string>
     <string name="start">开始</string>

doc/FFmpeg_command_line.md

@@ -183,8 +183,8 @@ ffmpeg -ss 20 -accurate_seek -t 10 -i input.mp4 -an -r 5 %3d.jpg<br>
 使用setpts设置视频速度，atempo设置音频速度：<br>
 ffmpeg -i in.mp4 -filter_complex [0:v]setpts=%.2f*PTS[v];[0:a]atempo=%.2f[a] -map [v] -map [a] out.mp4<br>
 
-### 3.12 旋转视频
-ffmpeg -i in.mp4 -c copy -metadata:s\:v:0 rotate=90 out.mp4<br>
+### 3.12 黑白视频
+ffmpeg -i in.mp4 -vf lutyuv='u=128:v=128' out.mp4
 
 # 二、ffplay命令行
 ffplay主要用于播放视频，也可以播放网络流，示例如下：<br>

doc/FFmpeg_compile_shell.md

@@ -47,7 +47,7 @@ swscale提供图像缩放与像素格式转换，swresample提供音频重采样
  | --disable-all           | disable components, libs    |
  | --disable-autodetect    | disable detect external libs|
 
- | Program options:        |                             |
+ | Program options:        | Description                 |
  |:------------------------|:----------------------------|
  | --disable-programs      | don't build command line    |
  | --disable-ffmpeg        | disable ffmpeg build        |