Audio Clip (#314)

* add missing headers
* add audio clip filter and improve timecode
* php 5.4 :(
* prevent audio from being reencoded
* php 5.x: Really?
* fix tests... I need to concentrate...

tests/Unit/Filters/Audio/AudioClipTest.php

@@ -0,0 +1,47 @@
+<?php
+
+namespace Tests\FFMpeg\Unit\Filters\Audio;
+
+use FFMpeg\Filters\Audio\AudioFilters;
+use FFMpeg\Coordinate\TimeCode;
+use Tests\FFMpeg\Unit\TestCase;
+
+class AudioClipTest extends TestCase {
+
+    public function testClipping() {
+        $capturedFilter = null;
+
+        $audio = $this->getAudioMock();
+        $audio->expects($this->once())
+            ->method('addFilter')
+            ->with($this->isInstanceOf('FFMpeg\Filters\Audio\AudioClipFilter'))
+            ->will($this->returnCallback(function ($filter) use (&$capturedFilter) {
+                $capturedFilter = $filter;
+        }));
+        $format = $this->getMock('FFMpeg\Format\AudioInterface');
+
+        $filters = new AudioFilters($audio);
+
+        $filters->clip(TimeCode::fromSeconds(5));
+        $this->assertEquals(array(0 => '-ss', 1 => '00:00:05.00', 2 => '-acodec', 3 => 'copy'), $capturedFilter->apply($audio, $format));
+    }
+
+    public function testClippingWithDuration() {
+        $capturedFilter = null;
+
+        $audio = $this->getAudioMock();
+        $audio->expects($this->once())
+            ->method('addFilter')
+            ->with($this->isInstanceOf('FFMpeg\Filters\Audio\AudioClipFilter'))
+            ->will($this->returnCallback(function ($filter) use (&$capturedFilter) {
+                $capturedFilter = $filter;
+        }));
+        $format = $this->getMock('FFMpeg\Format\AudioInterface');
+
+        $filters = new AudioFilters($audio);
+
+        $filters->clip(TimeCode::fromSeconds(5), TimeCode::fromSeconds(5));
+        $this->assertEquals(array(0 => '-ss', 1 => '00:00:05.00', 2 => '-t', 3 => '00:00:05.00', 4 => '-acodec', 5 => 'copy'), $capturedFilter->apply($audio, $format));
+    }
+
+}