cv2.VideoWriter类 将图片帧写入视频
作者：互联网
# encoding: utf-8
# module cv2.cv2
# from D:\20191031_tensorflow_yolov3\python\lib\site-packages\cv2\cv2.cp36-win_amd64.pyd
# by generator 1.147
""" Python wrapper for OpenCV. """
# imports
import cv2.cv2 as # D:\20191031_tensorflow_yolov3\python\lib\site-packages\cv2\cv2.cp36-win_amd64.pyd
import cv2.Error as Error # <module 'cv2.Error'>
import cv2.cuda as cuda # <module 'cv2.cuda'>
import cv2.detail as detail # <module 'cv2.detail'>
import cv2.dnn as dnn # <module 'cv2.dnn'>
import cv2.fisheye as fisheye # <module 'cv2.fisheye'>
import cv2.flann as flann # <module 'cv2.flann'>
import cv2.ipp as ipp # <module 'cv2.ipp'>
import cv2.ml as ml # <module 'cv2.ml'>
import cv2.ocl as ocl # <module 'cv2.ocl'>
import cv2.ogl as ogl # <module 'cv2.ogl'>
import cv2.samples as samples # <module 'cv2.samples'>
import cv2.utils as utils # <module 'cv2.utils'>
import cv2.videoio_registry as videoio_registry # <module 'cv2.videoio_registry'>
import cv2 as __cv2
from .object import object
class VideoWriter(object):
# no doc
def fourcc(self, c1, c2, c3, c4): # real signature unknown; restored from __doc__
"""
fourcc(c1, c2, c3, c4) -> retval
. @brief Concatenates 4 chars to a fourcc code
.
. @return a fourcc code
.
. This static method constructs the fourcc code of the codec to be used in the constructor
. VideoWriter::VideoWriter or VideoWriter::open.
"""
pass
def get(self, propId): # real signature unknown; restored from __doc__
"""
get(propId) -> retval
. @brief Returns the specified VideoWriter property
.
. @param propId Property identifier from cv::VideoWriterProperties (eg. cv::VIDEOWRITER_PROP_QUALITY)
. or one of @ref videoio_flags_others
.
. @return Value for the specified property. Value 0 is returned when querying a property that is
. not supported by the backend used by the VideoWriter instance.
"""
pass
def getBackendName(self): # real signature unknown; restored from __doc__
"""
getBackendName() -> retval
. @brief Returns used backend API name
.
. @note Stream should be opened.
"""
pass
def isOpened(self): # real signature unknown; restored from __doc__
"""
isOpened() -> retval
. @brief Returns true if video writer has been successfully initialized.
"""
pass
def open(self, filename, fourcc, fps, frameSize, isColor=None): # real signature unknown; restored from __doc__
"""
open(filename, fourcc, fps, frameSize[, isColor]) -> retval
. @brief Initializes or reinitializes video writer.
.
. The method opens video writer. Parameters are the same as in the constructor
. VideoWriter::VideoWriter.
. @return `true` if video writer has been successfully initialized
.
. The method first calls VideoWriter::release to close the already opened file.
open(filename, apiPreference, fourcc, fps, frameSize[, isColor]) -> retval
. @overload
open(filename, fourcc, fps, frameSize, params) -> retval
. @overload
open(filename, apiPreference, fourcc, fps, frameSize, params) -> retval
. @overload
"""
pass
def release(self): # real signature unknown; restored from __doc__
"""
release() -> None
. @brief Closes the video writer.
.
. The method is automatically called by subsequent VideoWriter::open and by the VideoWriter
. destructor.
"""
pass
def set(self, propId, value): # real signature unknown; restored from __doc__
"""
set(propId, value) -> retval
. @brief Sets a property in the VideoWriter.
.
. @param propId Property identifier from cv::VideoWriterProperties (eg. cv::VIDEOWRITER_PROP_QUALITY)
. or one of @ref videoio_flags_others
.
. @param value Value of the property.
. @return `true` if the property is supported by the backend used by the VideoWriter instance.
"""
pass
def write(self, image): # real signature unknown; restored from __doc__
"""
write(image) -> None
. @brief Writes the next video frame
.
. @param image The written frame. In general, color images are expected in BGR format.
.
. The function/method writes the specified image to video file. It must have the same size as has
. been specified when opening the video writer.
"""
pass
def __init__(self, *args, **kwargs): # real signature unknown
pass
@staticmethod # known case of __new__
def __new__(*args, **kwargs): # real signature unknown
""" Create and return a new object. See help(type) for accurate signature. """
pass
def __repr__(self, *args, **kwargs): # real signature unknown
""" Return repr(self). """
pass
MP4有许多编码格式
XviD一直是世界上最流行的视频编码器。估计在BT(BitTorrent)和eMule上至少90%的电影、电视剧是用XviD压制的。但是在中国的情况有些特殊，因为中国的影视发布者喜欢用RMVB格式。XviD的文件扩展名可以是AVI、MKV、MP4等。需要说明的是，仅从扩展名并不能看出这个视频的编码格式。
H.263是特别面向低码率的视频编码而设定的(通常只有20-30kbps或更高) H.263标准指明了对于视频编码和解码器的需求。
H.264是一种高性能的视频编解码技术。其最大的优势是具有很高的数据压缩比率，在同等图像质量的条件下，H.264能提供连续、流畅的高质量图象同H.263等标准的特率效率相比，能够平均节省大于50％的码率。
MPEG4是一种编码标准,DIVX格式的AVI是MPEG4的一种，XVID格式的AVI也是MPEG4的一种，WMV9格式的AVI，微软自己推出的MPEG4编码标准。
手机所能支持的视频格式有限，主要是H.263和Xvid编码，H.264编码目前不支持，如果是智能机的话，用播放软件可能能播放。
对于转换视频，个人推荐“格式工厂”，转换时要注意：
1、原视频要清晰,视频的清晰度取决于码率
2、转换时要适当调整视频的分辨率，码率，每秒帧数，确保手机支持。 码率太大播放时会卡
1、意思不一
X264：是ITU和MPEG联合制定的视频编码器。
H264：是MPEG-4第十部分，是由高度压缩数字视频编解码格式。
2、功能不一
X264：包含有一些心理视觉增强技术，以增强编码视频的主观质量。
H264：能提供连续、流畅的高质量图像。
3、容量不一
X264：同等清晰度下，X264的容量大于H264。
H264：影视文件中容量最小的RAW，同等清晰度下，H264的容量小于X264。
4、压缩比率不一
X264：能实现压缩比，有广泛的适用码率。
H264：具有很高的数据压缩比率。
5、特点不一
X264：自适应空间域转换、预测性的无损编码。
H264：高的编码效率、提高网络适应能力、采用混合编码结构。
示例
# 保存障碍物视频
class SaveVideo(threading.Thread):
def __init__(self):
threading.Thread.__init__(self)
def run(self):
global mice_or_not
while True:
if color_image is None:
print('SaveVideo还没好:{}'.format(time.time()))
time.sleep(1)
continue
else:
if mice_or_not:
name = datetime.datetime.now().strftime("%Y%m%d%H%M%S")
buffer_path = 'static/buffer/{}.mp4'.format(name)
video_path = 'static/obstacle_videos/{}.mp4'.format(name)
# 分辨率必须要跟摄像头输出的一致
# video_writer = cv2.VideoWriter(buffer_path, cv2.VideoWriter_fourcc('X', 'V', 'I', 'D'), 10,
# (color_image.shape[1], color_image.shape[0]))
# video_writer = cv2.VideoWriter(buffer_path, cv2.VideoWriter_fourcc('F', 'L', 'V', '1'), 10,
# (color_image.shape[1], color_image.shape[0]))
video_writer = cv2.VideoWriter(buffer_path, cv2.VideoWriter_fourcc(*'avc1'), 10,
(color_image.shape[1], color_image.shape[0]))
i = 0
# 设置视频
video_cover = color_image
data_initial = video_cover
# 将快照写入文件夹
cv2.imwrite(
'static/obstacle_snapshots/{}.jpg'.format(name),
data_initial)
# 判断obstacle_snapshots文件夹文件是否超出，超出就删除最久的文件
remove_old_file('static/obstacle_snapshots/', 12)
# 判断color_image是不是同一帧图片，是同一帧就跳过，不是就写入缓存buffer（不能产生大数组会卡住？？）
while True:
if not (color_image == data_initial).all():
i += 1
print('i = ', i)
# 30秒视频，每秒30帧
# Dontla20210409：30秒视频，每秒10帧
# if 1 <= i <= 900:
if 1 <= i <= 300:
# 也不知道写入成功的标志是什么？怎么解除占用？应该是release()函数
video_writer.write(color_image)
data_initial = color_image
else:
# 释放占用（否则显示文件被其他应用使用中）
video_writer.release()
# 将视频封面图写入文件夹（尽量在生成视频前并贴在一起）
cv2.imwrite('static/obstacle_videos_front_cover/{}.jpg'.format(name), video_cover)
# 转移视频……
print('开始转移视频……')
shutil.move(buffer_path, video_path)
# 视频转移完成
print('视频转移成功')
# 清空buffer文件夹
del_list = os.listdir('static/buffer/')
for _ in del_list:
file_path = os.path.join('static/buffer/', _)
if os.path.exists(file_path): # 需要判断一下防止出错
os.remove(file_path)
# 判断obstacle_videos文件夹文件是否超出，超出就删除最久的文件以及在obstacle_videos_front_cover中它的封面图
remove_old_file('static/obstacle_videos/', 12)
remove_old_file('static/obstacle_videos_front_cover/', 12)
# 重置mice_or_not
mice_or_not = False
break
标签：__,cv2,image,写入,video,import,VideoWriter 来源： https://blog.csdn.net/Dontla/article/details/116169590