Question

In the code I have a list of tuples (start frame,end frame) and I want to take the whole list and create a new video file from it, the problem it takes only the last couple on the list

    import cv2

    vidPath = "wingate_18-11-18_3mp_25m_pm_4m(3).mp4"

    shotsPath = "new.avi"

    segRange = [(0,40),(50,100),(200,400)]  # a list of starting/ending frame indices pairs

    cap = cv2.VideoCapture(vidPath)

    fps = int(cap.get(cv2.CAP_PROP_FPS))

  size =
  (int(cap.get(cv2.CAP_PROP_FRAME_WIDTH)),int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT)))

   fourcc = int(cv2.VideoWriter_fourcc('X','V','I','D')) # XVID codecs


     for idx, (begFidx, endFidx) in enumerate(segRange):

         writer = cv2.VideoWriter(shotsPath, fourcc, fps, size)

         cap.set(cv2.CAP_PROP_POS_FRAMES, begFidx)

          ret = True  # has frame returned

          while (cap.isOpened() and ret and writer.isOpened()):

              ret, frame = cap.read()

              frame_number = cap.get(cv2.CAP_PROP_POS_FRAMES) - 1

              if frame_number < endFidx:

                  writer.write(frame)

              else:

                  break


 writer.release()

The new video was created from 200 to 400 , not including any frames before. thanks very much for the help

Answer 1

这是因为您的writer用文件名shotsPath=new.avi中的最后一个200-400覆盖了1-40和50-100。在每个段中向新文件声明一个新的writer。

[编辑]

import cv2

vidPath = "1.MOV"
shotsPath = "new.avi"
segRange = [(0,40),(50,100),(200,400)]  # a list of starting/ending frame indices pairs
cap = cv2.VideoCapture(vidPath)
fps = int(cap.get(cv2.CAP_PROP_FPS))
size = (int(cap.get(cv2.CAP_PROP_FRAME_WIDTH)),int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT)))
fourcc = int(cv2.VideoWriter_fourcc('X','V','I','D')) # XVID codecs
#declare writer before the for loop
writer = cv2.VideoWriter(shotsPath, fourcc, fps, size)

for idx, (begFidx, endFidx) in enumerate(segRange):
    cap.set(cv2.CAP_PROP_POS_FRAMES, begFidx)
    ret = True  # has frame returned
    while (cap.isOpened() and ret and writer.isOpened()):
        ret, frame = cap.read()
        frame_number = cap.get(cv2.CAP_PROP_POS_FRAMES) - 1
        print(frame_number)
        if frame_number < endFidx:
            writer.write(frame)
        else:
            break
writer.release()

#Check how many frame that new.avi has
cap2 = cv2.VideoCapture("new.avi")
print(cap2.get(cv2.CAP_PROP_FRAME_COUNT))

>> 290 frames

结果正确。

I am trying to cut the video into sections by the frames , but the code is not working

1 个答案: