Python 使用QThread将动态创建的QImage帧转换为ffmpeg标准
我正在尝试使用ffmpeg创建视频文件,使用在单独线程上动态创建的帧 虽然我可以创建这些帧并将它们存储在磁盘/内存中,但我希望避免这种情况,因为帧的数量/大小可能很高,并且可以使用不同的格式或选项创建许多“作业”。但是,同样重要的是,我想更好地理解这背后的逻辑,因为我承认我对线程/处理实际上是如何工作的还不是很了解 现在我正在尝试在QThread对象中创建QProcess,然后在进程启动后立即运行映像创建线程,但它似乎不起作用:没有创建任何文件,我甚至没有从标准错误中获得任何输出(但我知道我应该这样做,因为如果我不使用线程,我可以获得它) 不幸的是,由于我对QProcess如何处理线程和管道(以及所有可能的ffmpeg选项)知之甚少,我真的不明白如何实现这一点 除了获得创建的输出文件外,预期的结果是能够启动编码(同时可能对更多编码进行排队),同时保持UI响应并获得当前处理状态的通知Python 使用QThread将动态创建的QImage帧转换为ffmpeg标准,python,ffmpeg,pyqt5,pipe,qprocess,Python,Ffmpeg,Pyqt5,Pipe,Qprocess,我正在尝试使用ffmpeg创建视频文件,使用在单独线程上动态创建的帧 虽然我可以创建这些帧并将它们存储在磁盘/内存中,但我希望避免这种情况,因为帧的数量/大小可能很高,并且可以使用不同的格式或选项创建许多“作业”。但是,同样重要的是,我想更好地理解这背后的逻辑,因为我承认我对线程/处理实际上是如何工作的还不是很了解 现在我正在尝试在QThread对象中创建QProcess,然后在进程启动后立即运行映像创建线程,但它似乎不起作用:没有创建任何文件,我甚至没有从标准错误中获得任何输出(但我知道我应该
import re
from PyQt5 import QtCore, QtGui, QtWidgets
logRegExp = r'(?:(n:\s+)(?P<frame>\d+)\s).*(?:(pts_time:\s*)(?P<time>\d+.\d*))'
class Encoder(QtCore.QThread):
completed = QtCore.pyqtSignal()
frameDone = QtCore.pyqtSignal(object)
def __init__(self, width=1280, height=720, frameCount=100):
super().__init__()
self.width = width
self.height = height
self.frameCount = frameCount
def start(self):
self.currentLog = ''
self.currentData = bytes()
self.process = QtCore.QProcess()
self.process.setReadChannel(self.process.StandardError)
self.process.finished.connect(self.completed)
self.process.readyReadStandardError.connect(self.stderr)
self.process.started.connect(super().start)
self.process.start('ffmpeg', [
'-y',
'-f', 'png_pipe',
'-i', '-',
'-c:v', 'libx264',
'-b:v', '800k',
'-an',
'-vf', 'showinfo',
'/tmp/test.h264',
])
def stderr(self):
self.currentLog += str(self.process.readAllStandardError(), 'utf-8')
*lines, self.currentLog = self.currentLog.split('\n')
for line in lines:
print('STDERR: {}'.format(line))
match = re.search(logRegExp, line)
if match:
data = match.groupdict()
self.frameDone.emit(int(data['frame']))
def run(self):
font = QtGui.QFont()
font.setPointSize(80)
rect = QtCore.QRect(0, 0, self.width, self.height)
for frame in range(1, self.frameCount + 1):
img = QtGui.QImage(QtCore.QSize(self.width, self.height), QtGui.QImage.Format_ARGB32)
img.fill(QtCore.Qt.white)
qp = QtGui.QPainter(img)
qp.setFont(font)
qp.setPen(QtCore.Qt.black)
qp.drawText(rect, QtCore.Qt.AlignCenter, 'Frame {}'.format(frame))
qp.end()
img.save(self.process, 'PNG')
print('frame creation complete')
class Test(QtWidgets.QWidget):
def __init__(self):
super().__init__()
layout = QtWidgets.QVBoxLayout(self)
self.startButton = QtWidgets.QPushButton('Start')
layout.addWidget(self.startButton)
self.frameLabel = QtWidgets.QLabel()
layout.addWidget(self.frameLabel)
self.process = Encoder()
self.process.completed.connect(lambda: self.startButton.setEnabled(True))
self.process.frameDone.connect(self.frameLabel.setNum)
self.startButton.clicked.connect(self.create)
def create(self):
self.startButton.setEnabled(False)
self.process.start()
import sys
app = QtWidgets.QApplication(sys.argv)
test = Test()
test.show()
sys.exit(app.exec_())
好处:我在Linux上,我不知道它在Windows上是否有不同的工作方式(我想它在MacOS上也会有类似的工作方式),但无论如何,我想知道是否有不同之处,以及如何处理它们。事实证明,我部分是对的,部分是错的
showinfo
filter输出),以便线程在该点实际被视为完成。在多个作业的情况下,可以使用一些优化来排队进一步创建映像,但考虑到这可能不会大大提高性能,我更喜欢当前的方法
这是修改后的代码,我用不同的格式进行了测试,它似乎可以按预期工作
import re
from PyQt5 import QtCore, QtGui, QtWidgets
logRegExp = r'(?:(n:\s+)(?P<frame>\d+)\s).*(?:(pts_time:\s*)(?P<time>\d+.\d*))'
class Encoder(QtCore.QThread):
completed = QtCore.pyqtSignal()
frameDone = QtCore.pyqtSignal(object)
imageReady = QtCore.pyqtSignal(object)
def __init__(self):
super().__init__()
self.imageReady.connect(self.writeImage)
self.queue = []
self.process = QtCore.QProcess()
self.process.setReadChannel(self.process.StandardError)
self.process.finished.connect(self.processQueue)
self.process.readyReadStandardError.connect(self.stderr)
self.process.started.connect(self.start)
def addJob(self, width=1280, height=720, frameCount=500, format='h264', *opts):
self.queue.append((width, height, frameCount, format, opts))
if not self.process.state():
self.processQueue()
def writeImage(self, image):
self.process.write(image)
self.imageCount += 1
if self.imageCount == self.frameCount:
self.process.closeWriteChannel()
def processQueue(self):
if not self.queue:
return
self.currentLog = ''
self.lastFrameWritten = -1
self.imageCount = 0
self.width, self.height, self.frameCount, format, opts = self.queue.pop(0)
args = [
'-y',
'-f', 'png_pipe',
'-i', '-',
]
if opts:
args += [str(o) for o in opts]
args += [
'-an',
'-vf', 'showinfo',
'/tmp/test.{}'.format(format),
]
self.process.start('ffmpeg', args)
def stderr(self):
self.currentLog += str(self.process.readAllStandardError(), 'utf-8')
*lines, self.currentLog = self.currentLog.split('\n')
for line in lines:
match = re.search(logRegExp, line)
if match:
data = match.groupdict()
self.lastFrameWritten = int(data['frame'])
self.frameDone.emit(self.lastFrameWritten + 1)
else:
print(line)
def run(self):
font = QtGui.QFont()
font.setPointSize(80)
rect = QtCore.QRect(0, 0, self.width, self.height)
for frame in range(1, self.frameCount + 1):
img = QtGui.QImage(QtCore.QSize(self.width, self.height),
QtGui.QImage.Format_ARGB32)
img.fill(QtCore.Qt.white)
qp = QtGui.QPainter(img)
qp.setFont(font)
qp.setPen(QtCore.Qt.black)
qp.drawText(rect, QtCore.Qt.AlignCenter, 'Frame {}'.format(frame))
qp.end()
ba = QtCore.QByteArray()
buffer = QtCore.QBuffer(ba)
img.save(buffer, 'PNG')
self.imageReady.emit(ba)
while self.lastFrameWritten < self.frameCount - 1:
self.sleep(.5)
self.completed.emit()
class Test(QtWidgets.QWidget):
def __init__(self):
super().__init__()
layout = QtWidgets.QVBoxLayout(self)
self.startButton = QtWidgets.QPushButton('Start')
layout.addWidget(self.startButton)
self.frameLabel = QtWidgets.QLabel()
layout.addWidget(self.frameLabel)
self.encoder = Encoder()
self.encoder.completed.connect(lambda: self.startButton.setEnabled(True))
self.encoder.frameDone.connect(self.frameLabel.setNum)
self.startButton.clicked.connect(self.create)
def create(self):
self.startButton.setEnabled(False)
self.encoder.addJob()
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
test = Test()
test.show()
sys.exit(app.exec_())
重新导入
从PyQt5导入QtCore、QtGui、QtWidgets
logRegExp=r'(?:(n:\s+(-P\d+)\s)。*(?:(pts\u-time:\s*)(-P\d+。-d*))
类编码器(QtCore.QThread):
已完成=QtCore.pyqtSignal()
frameDone=QtCore.pyqtSignal(对象)
imageReady=QtCore.pyqtSignal(对象)
定义初始化(自):
super()。\uuuu init\uuuuu()
self.imageReady.connect(self.writeImage)
self.queue=[]
self.process=QtCore.QProcess()
self.process.setReadChannel(self.process.StandardError)
self.process.finished.connect(self.processQueue)
self.process.readyReadStandardError.connect(self.stderr)
self.process.start.connect(self.start)
def addJob(self,宽度=1280,高度=720,帧数=500,格式=h264',*选项):
self.queue.append((宽度、高度、帧数、格式、选项))
如果不是self.process.state():
self.processQueue()
def writeImage(自我、图像):
self.process.write(图像)
self.imageCount+=1
如果self.imageCount==self.frameCount:
self.process.closeWriteChannel()
def processQueue(自):
如果不是自队列:
返回
self.currentLog=“”
self.lastFrameWrited=-1
self.imageCount=0
self.width、self.height、self.frameCount、format、opts=self.queue.pop(0)
args=[
“-y”,
“-f”、“png_管道”,
“-i”、“-”,
]
如果选择:
args+=[str(o)表示选项中的o]
args+=[
“-安”,
“-vf”、“showinfo”,
“/tmp/test.{}”.format(format),
]
self.process.start('ffmpeg',args)
def标准差(自身):
self.currentLog+=str(self.process.readAllStandardError(),'utf-8')
*行,self.currentLog=self.currentLog.split('\n')
对于行中的行:
匹配=重新搜索(logRegExp,第行)
如果匹配:
data=match.groupdict()
self.lastFrameWrite=int(数据['frame'])
self.frameDone.emit(self.lastFrameWrited+1)
其他:
打印(行)
def运行(自):
font=QtGui.QFont()
font.setPointSize(80)
rect=QtCore.QRect(0,0,self.width,self.height)
对于范围内的帧(1,self.frameCount+1):
img=QtGui.QImage(QtCore.QSize(self.width,self.height),
QtGui.QImage.Format_ARGB32)
img.填充(QtCore.Qt.白色)
qp=QtGui.QPainter(img)
qp.setFont(字体)
qp.setPen(QtCore.Qt.black)
drawText(rect,QtCore.Qt.AlignCenter,'Frame{}'。格式(Frame))
qp.end()
ba=QtCore.QByteArray()
buffer=QtCore.QBuffer(ba)
img.save(缓冲区'PNG')
self.imageReady.emit(ba)
self.lastFrameWriteimport re
from PyQt5 import QtCore, QtGui, QtWidgets
logRegExp = r'(?:(n:\s+)(?P<frame>\d+)\s).*(?:(pts_time:\s*)(?P<time>\d+.\d*))'
class Encoder(QtCore.QThread):
completed = QtCore.pyqtSignal()
frameDone = QtCore.pyqtSignal(object)
imageReady = QtCore.pyqtSignal(object)
def __init__(self):
super().__init__()
self.imageReady.connect(self.writeImage)
self.queue = []
self.process = QtCore.QProcess()
self.process.setReadChannel(self.process.StandardError)
self.process.finished.connect(self.processQueue)
self.process.readyReadStandardError.connect(self.stderr)
self.process.started.connect(self.start)
def addJob(self, width=1280, height=720, frameCount=500, format='h264', *opts):
self.queue.append((width, height, frameCount, format, opts))
if not self.process.state():
self.processQueue()
def writeImage(self, image):
self.process.write(image)
self.imageCount += 1
if self.imageCount == self.frameCount:
self.process.closeWriteChannel()
def processQueue(self):
if not self.queue:
return
self.currentLog = ''
self.lastFrameWritten = -1
self.imageCount = 0
self.width, self.height, self.frameCount, format, opts = self.queue.pop(0)
args = [
'-y',
'-f', 'png_pipe',
'-i', '-',
]
if opts:
args += [str(o) for o in opts]
args += [
'-an',
'-vf', 'showinfo',
'/tmp/test.{}'.format(format),
]
self.process.start('ffmpeg', args)
def stderr(self):
self.currentLog += str(self.process.readAllStandardError(), 'utf-8')
*lines, self.currentLog = self.currentLog.split('\n')
for line in lines:
match = re.search(logRegExp, line)
if match:
data = match.groupdict()
self.lastFrameWritten = int(data['frame'])
self.frameDone.emit(self.lastFrameWritten + 1)
else:
print(line)
def run(self):
font = QtGui.QFont()
font.setPointSize(80)
rect = QtCore.QRect(0, 0, self.width, self.height)
for frame in range(1, self.frameCount + 1):
img = QtGui.QImage(QtCore.QSize(self.width, self.height),
QtGui.QImage.Format_ARGB32)
img.fill(QtCore.Qt.white)
qp = QtGui.QPainter(img)
qp.setFont(font)
qp.setPen(QtCore.Qt.black)
qp.drawText(rect, QtCore.Qt.AlignCenter, 'Frame {}'.format(frame))
qp.end()
ba = QtCore.QByteArray()
buffer = QtCore.QBuffer(ba)
img.save(buffer, 'PNG')
self.imageReady.emit(ba)
while self.lastFrameWritten < self.frameCount - 1:
self.sleep(.5)
self.completed.emit()
class Test(QtWidgets.QWidget):
def __init__(self):
super().__init__()
layout = QtWidgets.QVBoxLayout(self)
self.startButton = QtWidgets.QPushButton('Start')
layout.addWidget(self.startButton)
self.frameLabel = QtWidgets.QLabel()
layout.addWidget(self.frameLabel)
self.encoder = Encoder()
self.encoder.completed.connect(lambda: self.startButton.setEnabled(True))
self.encoder.frameDone.connect(self.frameLabel.setNum)
self.startButton.clicked.connect(self.create)
def create(self):
self.startButton.setEnabled(False)
self.encoder.addJob()
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
test = Test()
test.show()
sys.exit(app.exec_())