Propagate FFmpegError through FFmpegException on FFprobe failures

Author: James Barnett

src/main/java/net/bramp/ffmpeg/FFcommon.java

@@ -5,6 +5,8 @@
 import com.google.common.collect.ImmutableList;
 import com.google.common.io.CharStreams;
 import net.bramp.ffmpeg.io.ProcessUtils;
+import net.bramp.ffmpeg.probe.FFmpegError;
+import net.bramp.ffmpeg.probe.FFmpegProbeResult;
 
 import javax.annotation.Nonnull;
 import java.io.BufferedReader;
@@ -55,6 +57,20 @@ protected void throwOnError(Process p) throws IOException {
     }
   }
 
+  protected void throwOnError(Process p, FFmpegProbeResult result) throws IOException {
+    try {
+      // TODO In java 8 use waitFor(long timeout, TimeUnit unit)
+      if (ProcessUtils.waitForWithTimeout(p, 1, TimeUnit.SECONDS) != 0) {
+        // TODO Parse the error
+        final FFmpegError ffmpegError = null == result ? null : result.getError();
+        throw new FFmpegException(
+                path + " returned non-zero exit status. Check stdout.", ffmpegError);
+      }
+    } catch (TimeoutException e) {
+      throw new IOException("Timed out waiting for " + path + " to finish.");
+    }
+  }
+
   /**
    * Returns the version string for this binary.
    *

src/main/java/net/bramp/ffmpeg/FFmpegException.java

@@ -0,0 +1,20 @@
+package net.bramp.ffmpeg;
+
+import net.bramp.ffmpeg.probe.FFmpegError;
+
+import java.io.IOException;
+
+public class FFmpegException extends IOException {
+
+    private static final long serialVersionUID = 3048288225568984942L;
+    private FFmpegError error;
+
+    public FFmpegException(String message, FFmpegError error) {
+        super(message);
+        this.error = error;
+    }
+
+    public FFmpegError getError() {
+        return error;
+    }
+}

src/main/java/net/bramp/ffmpeg/FFprobe.java

@@ -110,7 +110,7 @@ public FFmpegProbeResult probe(String mediaPath, @Nullable String userAgent) thr
 
       FFmpegProbeResult result = gson.fromJson(reader, FFmpegProbeResult.class);
 
-      throwOnError(p);
+      throwOnError(p, result);
 
       if (result == null) {
         throw new IllegalStateException("Gson returned null, which shouldn't happen :(");

src/test/java/net/bramp/ffmpeg/FFprobeTest.java

@@ -4,13 +4,15 @@
 import net.bramp.ffmpeg.fixtures.Samples;
 import net.bramp.ffmpeg.lang.NewProcessAnswer;
 import net.bramp.ffmpeg.probe.FFmpegChapter;
+import net.bramp.ffmpeg.probe.FFmpegError;
 import net.bramp.ffmpeg.probe.FFmpegProbeResult;
 import net.bramp.ffmpeg.probe.FFmpegStream;
 import org.apache.commons.lang3.math.Fraction;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
+import org.mockito.Mockito;
 import org.mockito.junit.MockitoJUnitRunner;
 
 import java.io.IOException;
@@ -25,6 +27,7 @@
 public class FFprobeTest {
 
   @Mock ProcessFunction runFunc;
+  @Mock Process mockProcess;
 
   FFprobe ffprobe;
 
@@ -143,4 +146,17 @@ public void testProbeDivideByZero() throws IOException {
 
     // System.out.println(FFmpegUtils.getGson().toJson(info));
   }
+
+  @Test
+  public void shouldThrowOnErrorWithFFmpegProbeResult() throws IOException, InterruptedException {
+    Mockito.when(mockProcess.waitFor()).thenReturn(-1);
+    final FFmpegError error = new FFmpegError();
+    final FFmpegProbeResult result = new FFmpegProbeResult();
+    result.error = error;
+    try {
+      ffprobe.throwOnError(mockProcess, result);
+    } catch (FFmpegException e) {
+      assertEquals(error, e.getError());
+    }
+  }
 }