change the speed of video

change the speed of video

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

@@ -99,7 +99,8 @@ public class VideoHandleActivity extends BaseActivity {
                 R.id.btn_denoise_video,
                 R.id.btn_to_image,
                 R.id.btn_pip,
-                R.id.btn_moov
+                R.id.btn_moov,
+                R.id.btn_speed
         );
     }
 
@@ -271,6 +272,10 @@ public class VideoHandleActivity extends BaseActivity {
                     Log.e(TAG, "move moov use time=" + (System.currentTimeMillis() - start));
                 }
                 break;
+            case R.id.btn_speed://playing speed of video
+                String speed = PATH + File.separator + "speed.mp4";
+                commandLine = FFmpegUtil.changeSpeed(srcFile, speed, 2f, false);
+                break;
             default:
                 break;
         }

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

@@ -478,11 +478,36 @@ public class FFmpegUtil {
         return ffprobeCmd.split(" ");
     }
 
-    public static String[] changeSpeed(String inputFile, String outputFile, float speed) {
+    /**
+     * Changing the speed of playing, speed range at 0.5-2 in audio-video mode.
+     * However, in pure video mode, the speed range at 0.25-4
+     * @param inputFile the inputFile of normal speed
+     * @param outputFile the outputFile which you want to change speed
+     * @param speed speed of playing
+     * @param pureVideo whether pure video or not, default false
+     * @return change speed success or not
+     */
+    public static String[] changeSpeed(String inputFile, String outputFile, float speed, boolean pureVideo) {
         //audio atempo: 0.5--2
+        //video pts:0.25--4
+        if (pureVideo) {
+            if (speed > 4 || speed < 0.25) {
+                throw new IllegalArgumentException("speed range is 0.25--4");
+            }
+        } else {
+            if (speed > 2 || speed < 0.5) {
+                throw new IllegalArgumentException("speed range is 0.5--2");
+            }
+        }
         float ptsFactor = 1/speed;
-        String speedCmd = "ffmpeg -i %s -filter_complex [0:v]setpts=%.2f*PTS[v];[0:a]atempo=%.2f[a] -map [v] -map [a] %s";
+        String speedCmd;
+        if (pureVideo) {
+            speedCmd = "ffmpeg -i %s -filter_complex [0:v]setpts=%.2f*PTS[v] -map [v] %s";
+            speedCmd = String.format(Locale.getDefault(), speedCmd, inputFile, ptsFactor, outputFile);
+        } else {
+            speedCmd = "ffmpeg -i %s -filter_complex [0:v]setpts=%.2f*PTS[v];[0:a]atempo=%.2f[a] -map [v] -map [a] %s";
             speedCmd = String.format(Locale.getDefault(), speedCmd, inputFile, ptsFactor, speed, outputFile);
+        }
         return speedCmd.split(" ");
     }
 

app/src/main/res/layout/activity_video_handle.xml

@@ -122,6 +122,13 @@
                 android:layout_marginTop="4dp"
                 android:text="@string/video_moov"/>
 
+            <Button
+                android:id="@+id/btn_speed"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="4dp"
+                android:text="@string/video_speed"/>
+
         </LinearLayout>
     </ScrollView>
 

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

@@ -42,6 +42,7 @@
     <string name="video_pip">Video Pip</string>
     <string name="video_preview">Video preview</string>
     <string name="video_moov">MOOV move ahead</string>
+    <string name="video_speed">Playing speed</string>
 
     <string name="swap">Swap</string>
     <string name="start">Start</string>

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

@@ -42,6 +42,7 @@
     <string name="video_pip">视频画中画</string>
     <string name="video_preview">播放预览</string>
     <string name="video_moov">MOOV前移</string>
+    <string name="video_speed">播放倍率</string>
 
     <string name="swap">切换</string>
     <string name="start">开始</string>