starting work on Waveform component

split Video class out of Video component for reuse in Waveform

7 files changed, 605 insertions, 160 deletions

diff --git a/src/component.py b/src/component.py
index 03023e7..fc8fbd3 100644
--- a/src/component.py
+++ b/src/component.py
@@ -197,7 +197,7 @@ class Component(QtCore.QObject, metaclass=ComponentMetaclass):
         '''
             Must call super() when subclassing
             Triggered only before a video is exported (video_thread.py)
-                self.worker = the video thread worker
+                self.audioFile = filepath to the main input audio file
                 self.completeAudioArray = a list of audio samples
                 self.sampleSize = number of audio samples per video frame
                 self.progressBarUpdate = signal to set progress bar number
@@ -436,7 +436,7 @@ class ComponentError(RuntimeError):
         import sys
         if sys.exc_info()[0] is not None:
             string = (
-                "%s component's %s encountered %s %s." % (
+                "%s component's %s encountered %s %s: %s" % (
                     caller.__class__.name,
                     name,
                     'an' if any([
@@ -444,12 +444,13 @@ class ComponentError(RuntimeError):
                         for vowel in ('A', 'I')
                     ]) else 'a',
                     sys.exc_info()[0].__name__,
+                    str(sys.exc_info()[1])
                 )
             )
             detail = formatTraceback(sys.exc_info()[2])
         else:
             string = name
-            detail = "Methods:\n%s" % (
+            detail = "Attributes:\n%s" % (
                 "\n".join(
                     [m for m in dir(caller) if not m.startswith('_')]
                 )
diff --git a/src/components/video.py b/src/components/video.py
index b2487c1..d3460ff 100644
--- a/src/components/video.py
+++ b/src/components/video.py
@@ -1,103 +1,13 @@
-from PIL import Image, ImageDraw
+from PIL import Image
 from PyQt5 import QtGui, QtCore, QtWidgets
 import os
 import math
 import subprocess
-import signal
-import threading
-from queue import PriorityQueue
 
 from component import Component, ComponentError
 from toolkit.frame import BlankFrame
-from toolkit.ffmpeg import testAudioStream
-from toolkit import openPipe, checkOutput
-
-
-class Video:
-    '''Opens a pipe to ffmpeg and stores a buffer of raw video frames.'''
-
-    # error from the thread used to fill the buffer
-    threadError = None
-
-    def __init__(self, **kwargs):
-        mandatoryArgs = [
-            'ffmpeg',     # path to ffmpeg, usually self.core.FFMPEG_BIN
-            'videoPath',
-            'width',
-            'height',
-            'scale',      # percentage scale
-            'frameRate',  # frames per second
-            'chunkSize',  # number of bytes in one frame
-            'parent',     # mainwindow object
-            'component',  # component object
-        ]
-        for arg in mandatoryArgs:
-            setattr(self, arg, kwargs[arg])
-
-        self.frameNo = -1
-        self.currentFrame = 'None'
-        if 'loopVideo' in kwargs and kwargs['loopVideo']:
-            self.loopValue = '-1'
-        else:
-            self.loopValue = '0'
-        self.command = [
-            self.ffmpeg,
-            '-thread_queue_size', '512',
-            '-r', str(self.frameRate),
-            '-stream_loop', self.loopValue,
-            '-i', self.videoPath,
-            '-f', 'image2pipe',
-            '-pix_fmt', 'rgba',
-            '-filter_complex', '[0:v] scale=%s:%s' % scale(
-                self.scale, self.width, self.height, str),
-            '-vcodec', 'rawvideo', '-',
-        ]
-
-        self.frameBuffer = PriorityQueue()
-        self.frameBuffer.maxsize = self.frameRate
-        self.finishedFrames = {}
-
-        self.thread = threading.Thread(
-            target=self.fillBuffer,
-            name='Video Frame-Fetcher'
-        )
-        self.thread.daemon = True
-        self.thread.start()
-
-    def frame(self, num):
-        while True:
-            if num in self.finishedFrames:
-                image = self.finishedFrames.pop(num)
-                return finalizeFrame(
-                    self.component, image, self.width, self.height)
-
-            i, image = self.frameBuffer.get()
-            self.finishedFrames[i] = image
-            self.frameBuffer.task_done()
-
-    def fillBuffer(self):
-        self.pipe = openPipe(
-            self.command, stdin=subprocess.DEVNULL, stdout=subprocess.PIPE,
-            stderr=subprocess.DEVNULL, bufsize=10**8
-        )
-        while True:
-            if self.parent.canceled:
-                break
-            self.frameNo += 1
-
-            # If we run out of frames, use the last good frame and loop.
-            try:
-                if len(self.currentFrame) == 0:
-                    self.frameBuffer.put((self.frameNo-1, self.lastFrame))
-                    continue
-            except AttributeError:
-                Video.threadError = ComponentError(self.component, 'video')
-                break
-
-            self.currentFrame = self.pipe.stdout.read(self.chunkSize)
-            if len(self.currentFrame) != 0:
-                self.frameBuffer.put((self.frameNo, self.currentFrame))
-                self.lastFrame = self.currentFrame
+from toolkit.ffmpeg import testAudioStream, FfmpegVideo
+from toolkit import openPipe, closePipe, checkOutput, scale
 
 
 class Component(Component):
@@ -182,22 +92,21 @@ class Component(Component):
     def preFrameRender(self, **kwargs):
         super().preFrameRender(**kwargs)
         self.updateChunksize()
-        self.video = Video(
-            ffmpeg=self.core.FFMPEG_BIN, videoPath=self.videoPath,
+        self.video = FfmpegVideo(
+            inputPath=self.videoPath, filter_=self.makeFfmpegFilter(),
             width=self.width, height=self.height, chunkSize=self.chunkSize,
             frameRate=int(self.settings.value("outputFrameRate")),
             parent=self.parent, loopVideo=self.loopVideo,
-            component=self, scale=self.scale
+            component=self
         ) if os.path.exists(self.videoPath) else None
 
     def frameRender(self, frameNo):
-        if Video.threadError is not None:
-            raise Video.threadError
-        return self.video.frame(frameNo)
+        if FfmpegVideo.threadError is not None:
+            raise FfmpegVideo.threadError
+        return self.finalizeFrame(self.video.frame(frameNo))
 
     def postFrameRender(self):
-        self.video.pipe.stdout.close()
-        self.video.pipe.send_signal(signal.SIGINT)
+        closePipe(self.video.pipe)
 
     def pickVideo(self):
         imgDir = self.settings.value("componentDir", os.path.expanduser("~"))
@@ -220,23 +129,30 @@ class Component(Component):
             '-i', self.videoPath,
             '-f', 'image2pipe',
             '-pix_fmt', 'rgba',
-            '-filter_complex', '[0:v] scale=%s:%s' % scale(
-                self.scale, width, height, str),
+        ]
+        command.extend(self.makeFfmpegFilter())
+        command.extend([
             '-vcodec', 'rawvideo', '-',
             '-ss', '90',
-            '-vframes', '1',
-        ]
+            '-frames:v', '1',
+        ])
         pipe = openPipe(
             command, stdin=subprocess.DEVNULL, stdout=subprocess.PIPE,
             stderr=subprocess.DEVNULL, bufsize=10**8
         )
         byteFrame = pipe.stdout.read(self.chunkSize)
-        pipe.stdout.close()
-        pipe.send_signal(signal.SIGINT)
+        closePipe(pipe)
 
-        frame = finalizeFrame(self, byteFrame, width, height)
+        frame = self.finalizeFrame(byteFrame)
         return frame
 
+    def makeFfmpegFilter(self):
+        return [
+            '-filter_complex',
+            '[0:v] scale=%s:%s' % scale(
+                self.scale, self.width, self.height, str),
+        ]
+
     def updateChunksize(self):
         if self.scale != 100 and not self.distort:
             width, height = scale(self.scale, self.width, self.height, int)
@@ -268,44 +184,32 @@ class Component(Component):
         print('Load a video:\n    path=/filepath/to/video.mp4')
         print('Using audio:\n    path=/filepath/to/video.mp4 audio')
 
+    def finalizeFrame(self, imageData):
+        try:
+            if self.distort:
+                image = Image.frombytes(
+                    'RGBA',
+                    (self.width, self.height),
+                    imageData)
+            else:
+                image = Image.frombytes(
+                    'RGBA',
+                    scale(self.scale, self.width, self.height, int),
+                    imageData)
+
+        except ValueError:
+            print(
+                '### BAD VIDEO SELECTED ###\n'
+                'Video will not export with these settings'
+            )
+            self.badVideo = True
+            return BlankFrame(self.width, self.height)
 
-def scale(scale, width, height, returntype=None):
-    width = (float(width) / 100.0) * float(scale)
-    height = (float(height) / 100.0) * float(scale)
-    if returntype == str:
-        return (str(math.ceil(width)), str(math.ceil(height)))
-    elif returntype == int:
-        return (math.ceil(width), math.ceil(height))
-    else:
-        return (width, height)
-
-
-def finalizeFrame(self, imageData, width, height):
-    try:
-        if self.distort:
-            image = Image.frombytes(
-                'RGBA',
-                (width, height),
-                imageData)
+        if self.scale != 100 \
+                or self.xPosition != 0 or self.yPosition != 0:
+            frame = BlankFrame(self.width, self.height)
+            frame.paste(image, box=(self.xPosition, self.yPosition))
         else:
-            image = Image.frombytes(
-                'RGBA',
-                scale(self.scale, width, height, int),
-                imageData)
-
-    except ValueError:
-        print(
-            '### BAD VIDEO SELECTED ###\n'
-            'Video will not export with these settings'
-        )
-        self.badVideo = True
-        return BlankFrame(width, height)
-
-    if self.scale != 100 \
-            or self.xPosition != 0 or self.yPosition != 0:
-        frame = BlankFrame(width, height)
-        frame.paste(image, box=(self.xPosition, self.yPosition))
-    else:
-        frame = image
-    self.badVideo = False
-    return frame
+            frame = image
+        self.badVideo = False
+        return frame
diff --git a/src/components/waveform.py b/src/components/waveform.py
new file mode 100644
index 0000000..487a3bb
--- /dev/null
+++ b/src/components/waveform.py
@@ -0,0 +1,139 @@
+from PIL import Image
+from PyQt5 import QtGui, QtCore, QtWidgets
+from PyQt5.QtGui import QColor
+import os
+import math
+import subprocess
+
+from component import Component, ComponentError
+from toolkit.frame import BlankFrame
+from toolkit import openPipe, checkOutput, rgbFromString
+from toolkit.ffmpeg import FfmpegVideo
+
+
+class Component(Component):
+    name = 'Waveform'
+    version = '1.0.0'
+
+    def widget(self, *args):
+        self.color = (255, 255, 255)
+        super().widget(*args)
+
+        self.page.lineEdit_color.setText('%s,%s,%s' % self.color)
+        btnStyle = "QPushButton { background-color : %s; outline: none; }" \
+            % QColor(*self.color1).name()
+        self.page.lineEdit_color.setStylesheet(btnStyle)
+        self.page.pushButton_color.clicked.connect(lambda: self.pickColor())
+
+        self.trackWidgets(
+            {
+                'mode': self.page.comboBox_mode,
+                'x': self.page.spinBox_x,
+                'y': self.page.spinBox_y,
+                'mirror': self.page.checkBox_mirror,
+                'scale': self.page.spinBox_scale,
+            }
+        )
+
+    def update(self):
+        self.color = rgbFromString(self.page.lineEdit_color.text())
+        btnStyle = "QPushButton { background-color : %s; outline: none; }" \
+            % QColor(*self.color).name()
+        self.page.pushButton_color.setStyleSheet(btnStyle)
+        super().update()
+
+    def previewRender(self):
+        self.updateChunksize()
+        frame = self.getPreviewFrame(self.width, self.height)
+        if not frame:
+            return BlankFrame(self.width, self.height)
+        else:
+            return frame
+
+    def preFrameRender(self, **kwargs):
+        super().preFrameRender(**kwargs)
+        self.updateChunksize()
+        self.video = FfmpegVideo(
+            inputPath=self.audioFile,
+            filter_=makeFfmpegFilter(),
+            width=self.width, height=self.height,
+            chunkSize=self.chunkSize,
+            frameRate=int(self.settings.value("outputFrameRate")),
+            parent=self.parent, component=self,
+        )
+
+    def frameRender(self, frameNo):
+        if FfmpegVideo.threadError is not None:
+            raise FfmpegVideo.threadError
+        return finalizeFrame(self.video.frame(frameNo))
+
+    def postFrameRender(self):
+        closePipe(self.video.pipe)
+
+    def getPreviewFrame(self, width, height):
+        inputFile = self.parent.window.lineEdit_audioFile.text()
+        if not inputFile or not os.path.exists(inputFile):
+            return
+
+        command = [
+            self.core.FFMPEG_BIN,
+            '-thread_queue_size', '512',
+            '-i', inputFile,
+            '-f', 'image2pipe',
+            '-pix_fmt', 'rgba',
+        ]
+        command.extend(self.makeFfmpegFilter())
+        command.extend([
+            '-vcodec', 'rawvideo', '-',
+            '-ss', '90',
+            '-frames:v', '1',
+        ])
+        pipe = openPipe(
+            command, stdin=subprocess.DEVNULL, stdout=subprocess.PIPE,
+            stderr=subprocess.DEVNULL, bufsize=10**8
+        )
+        byteFrame = pipe.stdout.read(self.chunkSize)
+        closePipe(pipe)
+
+        frame = finalizeFrame(self, byteFrame, width, height)
+        return frame
+
+    def makeFfmpegFilter(self):
+        w, h = scale(self.scale, self.width, self.height, str)
+        return [
+            '-filter_complex',
+            '[0:a] showwaves=s=%sx%s:mode=%s,format=rgba [v]' % (
+                w, h, self.mode,
+            ),
+            '-map', '[v]',
+            '-map', '0:a',
+        ]
+
+    def updateChunksize(self):
+        if self.scale != 100:
+            width, height = scale(self.scale, self.width, self.height, int)
+        else:
+            width, height = self.width, self.height
+        self.chunkSize = 4 * width * height
+
+
+def scale(scale, width, height, returntype=None):
+    width = (float(width) / 100.0) * float(scale)
+    height = (float(height) / 100.0) * float(scale)
+    if returntype == str:
+        return (str(math.ceil(width)), str(math.ceil(height)))
+    elif returntype == int:
+        return (math.ceil(width), math.ceil(height))
+    else:
+        return (width, height)
+
+
+def finalizeFrame(self, imageData, width, height):
+    # frombytes goes here
+    if self.scale != 100 \
+            or self.x != 0 or self.y != 0:
+        frame = BlankFrame(width, height)
+        frame.paste(image, box=(self.x, self.y))
+    else:
+        frame = image
+    return frame
diff --git a/src/components/waveform.ui b/src/components/waveform.ui
new file mode 100644
index 0000000..5d62150
--- /dev/null
+++ b/src/components/waveform.ui
@@ -0,0 +1,283 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>Form</class>
+ <widget class="QWidget" name="Form">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>586</width>
+    <height>197</height>
+   </rect>
+  </property>
+  <property name="sizePolicy">
+   <sizepolicy hsizetype="Preferred" vsizetype="Preferred">
+    <horstretch>0</horstretch>
+    <verstretch>0</verstretch>
+   </sizepolicy>
+  </property>
+  <property name="minimumSize">
+   <size>
+    <width>0</width>
+    <height>197</height>
+   </size>
+  </property>
+  <property name="windowTitle">
+   <string>Form</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout_2">
+   <item>
+    <layout class="QVBoxLayout" name="verticalLayout">
+     <property name="leftMargin">
+      <number>4</number>
+     </property>
+     <item>
+      <layout class="QHBoxLayout" name="horizontalLayout_8">
+       <item>
+        <widget class="QLabel" name="label_textColor">
+         <property name="sizePolicy">
+          <sizepolicy hsizetype="Fixed" vsizetype="Preferred">
+           <horstretch>0</horstretch>
+           <verstretch>0</verstretch>
+          </sizepolicy>
+         </property>
+         <property name="minimumSize">
+          <size>
+           <width>31</width>
+           <height>0</height>
+          </size>
+         </property>
+         <property name="text">
+          <string>Mode</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QComboBox" name="comboBox_mode">
+         <item>
+          <property name="text">
+           <string>Cline</string>
+          </property>
+         </item>
+         <item>
+          <property name="text">
+           <string>Line</string>
+          </property>
+         </item>
+         <item>
+          <property name="text">
+           <string>P2p</string>
+          </property>
+         </item>
+         <item>
+          <property name="text">
+           <string>Point</string>
+          </property>
+         </item>
+        </widget>
+       </item>
+       <item>
+        <spacer name="horizontalSpacer_9">
+         <property name="orientation">
+          <enum>Qt::Horizontal</enum>
+         </property>
+         <property name="sizeType">
+          <enum>QSizePolicy::Fixed</enum>
+         </property>
+         <property name="sizeHint" stdset="0">
+          <size>
+           <width>5</width>
+           <height>20</height>
+          </size>
+         </property>
+        </spacer>
+       </item>
+       <item>
+        <widget class="QLabel" name="label_xTitleAlign">
+         <property name="sizePolicy">
+          <sizepolicy hsizetype="Fixed" vsizetype="Preferred">
+           <horstretch>0</horstretch>
+           <verstretch>0</verstretch>
+          </sizepolicy>
+         </property>
+         <property name="text">
+          <string>X</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QSpinBox" name="spinBox_x">
+         <property name="sizePolicy">
+          <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
+           <horstretch>0</horstretch>
+           <verstretch>0</verstretch>
+          </sizepolicy>
+         </property>
+         <property name="maximumSize">
+          <size>
+           <width>80</width>
+           <height>16777215</height>
+          </size>
+         </property>
+         <property name="minimum">
+          <number>-10000</number>
+         </property>
+         <property name="maximum">
+          <number>10000</number>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QLabel" name="label_yTitleAlign">
+         <property name="sizePolicy">
+          <sizepolicy hsizetype="Fixed" vsizetype="Preferred">
+           <horstretch>0</horstretch>
+           <verstretch>0</verstretch>
+          </sizepolicy>
+         </property>
+         <property name="text">
+          <string>Y</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QSpinBox" name="spinBox_y">
+         <property name="sizePolicy">
+          <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
+           <horstretch>0</horstretch>
+           <verstretch>0</verstretch>
+          </sizepolicy>
+         </property>
+         <property name="maximumSize">
+          <size>
+           <width>80</width>
+           <height>16777215</height>
+          </size>
+         </property>
+         <property name="baseSize">
+          <size>
+           <width>0</width>
+           <height>0</height>
+          </size>
+         </property>
+         <property name="minimum">
+          <number>-10000</number>
+         </property>
+         <property name="maximum">
+          <number>10000</number>
+         </property>
+         <property name="value">
+          <number>0</number>
+         </property>
+        </widget>
+       </item>
+      </layout>
+     </item>
+    </layout>
+   </item>
+   <item>
+    <layout class="QHBoxLayout" name="horizontalLayout_9">
+     <item>
+      <widget class="QLabel" name="label_2">
+       <property name="text">
+        <string>Wave Color</string>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <widget class="QLineEdit" name="lineEdit_color"/>
+     </item>
+     <item>
+      <widget class="QPushButton" name="pushButton_color">
+       <property name="sizePolicy">
+        <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
+         <horstretch>0</horstretch>
+         <verstretch>0</verstretch>
+        </sizepolicy>
+       </property>
+       <property name="maximumSize">
+        <size>
+         <width>32</width>
+         <height>32</height>
+        </size>
+       </property>
+       <property name="text">
+        <string/>
+       </property>
+       <property name="default">
+        <bool>false</bool>
+       </property>
+       <property name="flat">
+        <bool>false</bool>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <spacer name="horizontalSpacer">
+       <property name="orientation">
+        <enum>Qt::Horizontal</enum>
+       </property>
+       <property name="sizeHint" stdset="0">
+        <size>
+         <width>40</width>
+         <height>20</height>
+        </size>
+       </property>
+      </spacer>
+     </item>
+     <item>
+      <widget class="QCheckBox" name="checkBox_mirror">
+       <property name="text">
+        <string>Mirror</string>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <widget class="QLabel" name="label">
+       <property name="text">
+        <string>Scale</string>
+       </property>
+       <property name="alignment">
+        <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <widget class="QSpinBox" name="spinBox_scale">
+       <property name="buttonSymbols">
+        <enum>QAbstractSpinBox::UpDownArrows</enum>
+       </property>
+       <property name="suffix">
+        <string>%</string>
+       </property>
+       <property name="minimum">
+        <number>10</number>
+       </property>
+       <property name="maximum">
+        <number>400</number>
+       </property>
+       <property name="value">
+        <number>100</number>
+       </property>
+      </widget>
+     </item>
+    </layout>
+   </item>
+   <item>
+    <spacer name="verticalSpacer">
+     <property name="orientation">
+      <enum>Qt::Vertical</enum>
+     </property>
+     <property name="sizeHint" stdset="0">
+      <size>
+       <width>20</width>
+       <height>40</height>
+      </size>
+     </property>
+    </spacer>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>
diff --git a/src/toolkit/common.py b/src/toolkit/common.py
index 251a2c1..128ed08 100644
--- a/src/toolkit/common.py
+++ b/src/toolkit/common.py
@@ -6,9 +6,22 @@ import string
 import os
 import sys
 import subprocess
+import signal
+import math
 from collections import OrderedDict
 
 
+def scale(scale, width, height, returntype=None):
+    width = (float(width) / 100.0) * float(scale)
+    height = (float(height) / 100.0) * float(scale)
+    if returntype == str:
+        return (str(math.ceil(width)), str(math.ceil(height)))
+    elif returntype == int:
+        return (math.ceil(width), math.ceil(height))
+    else:
+        return (width, height)
+
+
 def badName(name):
     '''Returns whether a name contains non-alphanumeric chars'''
     return any([letter in string.punctuation for letter in name])
@@ -34,29 +47,35 @@ def appendUppercase(lst):
         lst.append(form.upper())
     return lst
 
-
-def hideCmdWin(func):
-    ''' Stops CMD window from appearing on Windows.
-        Adapted from here: http://code.activestate.com/recipes/409002/
-    '''
-    def decorator(commandList, **kwargs):
+def pipeWrapper(func):
+    '''A decorator to insert proper kwargs into Popen objects.'''
+    def pipeWrapper(commandList, **kwargs):
         if sys.platform == 'win32':
+            # Stop CMD window from appearing on Windows
             startupinfo = subprocess.STARTUPINFO()
             startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
             kwargs['startupinfo'] = startupinfo
+
+        if 'bufsize' not in kwargs:
+            kwargs['bufsize'] = 10**8
+        if 'stdin' not in kwargs:
+            kwargs['stdin'] = subprocess.DEVNULL
         return func(commandList, **kwargs)
-    return decorator
+    return pipeWrapper
 
 
-@hideCmdWin
+@pipeWrapper
 def checkOutput(commandList, **kwargs):
     return subprocess.check_output(commandList, **kwargs)
 
 
-@hideCmdWin
+@pipeWrapper
 def openPipe(commandList, **kwargs):
     return subprocess.Popen(commandList, **kwargs)
 
+def closePipe(pipe):
+    pipe.stdout.close()
+    pipe.send_signal(signal.SIGINT)
 
 def disableWhenEncoding(func):
     def decorator(self, *args, **kwargs):
diff --git a/src/toolkit/ffmpeg.py b/src/toolkit/ffmpeg.py
index b8bc679..fea9d4e 100644
--- a/src/toolkit/ffmpeg.py
+++ b/src/toolkit/ffmpeg.py
@@ -5,11 +5,110 @@ import numpy
 import sys
 import os
 import subprocess
+import threading
+from queue import PriorityQueue
 
 import core
 from toolkit.common import checkOutput, openPipe
 
 
+class FfmpegVideo:
+    '''Opens a pipe to ffmpeg and stores a buffer of raw video frames.'''
+
+    # error from the thread used to fill the buffer
+    threadError = None
+
+    def __init__(self, **kwargs):
+        mandatoryArgs = [
+            'inputPath',
+            'filter_',
+            'width',
+            'height',
+            'frameRate',  # frames per second
+            'chunkSize',  # number of bytes in one frame
+            'parent',     # mainwindow object
+            'component',  # component object
+        ]
+        for arg in mandatoryArgs:
+            setattr(self, arg, kwargs[arg])
+
+        self.frameNo = -1
+        self.currentFrame = 'None'
+        self.map_ = None
+
+        if 'loopVideo' in kwargs and kwargs['loopVideo']:
+            self.loopValue = '-1'
+        else:
+            self.loopValue = '0'
+        if 'filter_' in kwargs:
+            if kwargs['filter_'][0] != '-filter_complex':
+                kwargs['filter_'].insert(0, '-filter_complex')
+        else:
+            kwargs['filter_'] = None
+
+        self.command = [
+            core.Core.FFMPEG_BIN,
+            '-thread_queue_size', '512',
+            '-r', str(self.frameRate),
+            '-stream_loop', self.loopValue,
+            '-i', self.inputPath,
+            '-f', 'image2pipe',
+            '-pix_fmt', 'rgba',
+        ]
+        if type(kwargs['filter_']) is list:
+            self.command.extend(
+                kwargs['filter_']
+            )
+        self.command.extend([
+            '-vcodec', 'rawvideo', '-',
+        ])
+
+        self.frameBuffer = PriorityQueue()
+        self.frameBuffer.maxsize = self.frameRate
+        self.finishedFrames = {}
+
+        self.thread = threading.Thread(
+            target=self.fillBuffer,
+            name='FFmpeg Frame-Fetcher'
+        )
+        self.thread.daemon = True
+        self.thread.start()
+
+    def frame(self, num):
+        while True:
+            if num in self.finishedFrames:
+                image = self.finishedFrames.pop(num)
+                return image
+
+            i, image = self.frameBuffer.get()
+            self.finishedFrames[i] = image
+            self.frameBuffer.task_done()
+
+    def fillBuffer(self):
+        self.pipe = openPipe(
+            self.command, stdin=subprocess.DEVNULL, stdout=subprocess.PIPE,
+            stderr=subprocess.DEVNULL, bufsize=10**8
+        )
+        while True:
+            if self.parent.canceled:
+                break
+            self.frameNo += 1
+
+            # If we run out of frames, use the last good frame and loop.
+            try:
+                if len(self.currentFrame) == 0:
+                    self.frameBuffer.put((self.frameNo-1, self.lastFrame))
+                    continue
+            except AttributeError:
+                Video.threadError = ComponentError(self.component, 'video')
+                break
+
+            self.currentFrame = self.pipe.stdout.read(self.chunkSize)
+            if len(self.currentFrame) != 0:
+                self.frameBuffer.put((self.frameNo, self.currentFrame))
+                self.lastFrame = self.currentFrame
+
+
 def findFfmpeg():
     if getattr(sys, 'frozen', False):
         # The application is frozen
diff --git a/src/video_thread.py b/src/video_thread.py
index 32e8a38..f27ec21 100644
--- a/src/video_thread.py
+++ b/src/video_thread.py
@@ -153,7 +153,7 @@ class Worker(QtCore.QObject):
         for compNo, comp in enumerate(reversed(self.components)):
             try:
                 comp.preFrameRender(
-                    worker=self,
+                    audioFile=self.inputFile,
                     completeAudioArray=self.completeAudioArray,
                     sampleSize=self.sampleSize,
                     progressBarUpdate=self.progressBarUpdate,