Concatenate a video, image and audio using ffmpeg - python

I am trying to concatenate a group of images with associated audio with a video clip at the start and front of the video. Whenever I concatenate the image with the associated audio it dosen't playback correctly in VLC media player and only displays the image for a frame before cutting to black and continually playing audio. I came across this github issue: https://github.com/kkroening/ffmpeg-python/issues/274 where the accepted solution was the one I implemented but one of the comments mentioned this issue of incorrect playback and error on youtube.
'''
Generates a clip from an image and a wav file, helper function for export_video
'''
def generate_clip(img):
transition_cond = os.path.exists("static/transitions/" + img + ".mp4")
chart_path = os.path.exists("charts/" + img + ".png")
if transition_cond:
clip = ffmpeg.input("static/transitions/" + img + ".mp4")
elif chart_path:
clip = ffmpeg.input("charts/" + img + ".png")
else:
clip = ffmpeg.input("static/transitions/Transition.jpg")
audio_clip = ffmpeg.input("audio/" + img + ".wav")
clip = ffmpeg.concat(clip, audio_clip, v=1, a=1)
clip = ffmpeg.filter(clip, "setdar","16/9")
return clip
'''
Combines the charts from charts/ and the audio from audio/ to generate one final video that will be uploaded to Youtube
'''
def export_video(CHARTS):
clips = []
intro = generate_clip("Intro")
clips.append(intro)
for key in CHARTS.keys():
value = CHARTS.get(key)
value.insert(0, key)
subclip = []
for img in value:
subclip.append(generate_clip(img))
concat_clip = ffmpeg.concat(*subclip)
clips.append(concat_clip)
outro = generate_clip("Outro")
clips.append(outro)
concat_clip = ffmpeg.concat(*clips)
concat_clip.output("export/export.mp4").run(overwrite_output=True)

It is unfortunate concat filter does not offer the shortest option like overlay. Anyway, the issue here is that image2 demuxer uses 25 fps by default, so a video stream with one image only lasts for 1/25 seconds long. There are a several ways to address this, but you first need to get the duration of the paired audio files. To incorporate the duration information to the ffmpeg command, you can:
Use tpad filter for each video (in series with setdar) to make the video duration to match the audio. Padded amount should be 1/25 seconds less than the audio duration.
Specify -loop 1 input option so the image will loop (indefinitely) and then specify an additional -t {duration} input option to limit the number of loops. Caution that the video duration may not be exact.
Specify -r {1/duration} so the image will last as long as the audio and use fps filter on each input to the output frame rate.
I'm not familiar with ffmpeg-python so I cannot provide its solution, but if you're interested, I'd be happy to post an equivalent code with my ffmpegio package.
[edit]
ffmpegio Solution
Here is how I'd code the 3rd solution with ffmpegio:
import ffmpegio
def generate_clip(img):
"""
Generates a clip from an image and a wav file,
helper function for export_video
"""
transition_cond = path.exists("static/transitions/" + img + ".mp4")
chart_path = path.exists("charts/" + img + ".png")
if transition_cond:
video_file = "static/transitions/" + img + ".mp4"
elif chart_path:
video_file = "charts/" + img + ".png"
else:
video_file = "static/transitions/Transition.jpg"
audio_file = "audio/" + img + ".wav"
video_opts = {}
if not transition_cond:
# audio_streams_basic() returns audio duration in seconds as Fraction
# set the "framerate" of the video to be the reciprocal
info = ffmpegio.probe.audio_streams_basic(audio_file)
video_opts["r"] = 1 / info[0]["duration"]
return [(video_file, video_opts), (audio_file, None)]
def export_video(CHARTS):
"""
Combines the charts from charts/ and the audio from audio/
to generate one final video that will be uploaded to Youtube
"""
# get all input files (video/audio pairs)
clips = [
generate_clip("Intro"),
*(generate_clip(img) for key, value in CHARTS.items() for img in value),
generate_clip("Outro"),
]
# number of clips
nclips = len(clips)
# filter chains to set DAR and fps of all video streams
vfilters = (f"[{2*n}:v]setdar=16/9,fps=30[v{n}]" for n in range(nclips))
# concatenation filter input: [v0][1:a][v1][3:a][v2][5:a]...
concatfilter = "".join((f"[v{n}][{2*n+1}:a]" for n in range(nclips))) + f"concat=n={nclips}:v=1:a=1[vout][aout]"
# form the full filtergraph
fg = ";".join((*vfilters, concatfilter))
# set output file and options
output = ("export/export.mp4", {"map": ["[vout]", "[aout]"]})
# run ffmpeg
ffmpegio.ffmpegprocess.run(
{
"inputs": [input for pair in clips for input in pair],
"outputs": [output],
"global_options": {"filter_complex": fg},
},
overwrite=True,
)
Since this code does not use the read/write features, ffmpegio-core package suffices:
pip install ffmpegio-core
Make sure that FFmpeg binary can be found by ffmpegio. See the installation doc.
Here are the direct links to the documentations of the functions used:
ffmpegprocess.run
ffmpeg_args dict argument
probe.audio_streams_basic (Ignore the documentation error both duration and start_time are both of Fraction type.
The code has not been fully validated. If you encounter a problem, it might be the easiest to post it on the GitHub Discussions to proceed.

Related

Python New n frame video is heavier than the input video

I managed to write a code to decimate my video and take only 1 frame out of 10, in order to make my neural network more efficient in the future for character recognition.
The new video exit_video is well decimated because it's way faster than the previous one.
1: When I print the fps of the new video, I have 30 again despite the decimation
2: Why is my new video heavier ? 50.000 ko and it was 42.000 ko for the firts one
Thanks for your help
import cv2
#import os
import sys
video = cv2.VideoCapture("./video/inputvideo.mp4")
frameWidth = int(video.get(cv2.CAP_PROP_FRAME_WIDTH))
frameHeight = int(video.get(cv2.CAP_PROP_FRAME_HEIGHT))
frameFourcc = int(video.get(cv2.CAP_PROP_FOURCC))
success,image = video.read()
if not success:
print('impossible de prendre une frame')
sys.exit()
fps = video.get(cv2.CAP_PROP_FPS)
print("fps de base " + str(fps))
print(frameFourcc)
count = 0
exit_file = 'decimated_v1.mp4'
exit_video = cv2.VideoWriter(exit_file, frameFourcc, fps, (frameWidth, frameHeight))
while True:
if ((count % 10 ) ==0):
exit_video.write(image)
success,image = video.read()
if not success:
break
count +=1
exit_video.release()
exit_video_info = cv2.VideoCapture("decimated_v1.mp4")
fps_sortie = exit_video_info.get(cv2.CAP_PROP_FPS)
print("fps de sortie " + str(fps_sortie))
Decimating a video file that's not all Intra frames will require re-encoding. Unless your input file is e.g. ProRes or MJPEG, that's likely going to be the case.
Since you're not setting encoding parameters, OpenCV likely end up using some defaults that end up with a higher bitrate than your input file.
You'll probably have a better time using the FFmpeg tool than OpenCV, and its select filter.
ffmpeg -i ./video/inputvideo.mp4 -vf select='not(mod(n\,10))' ./decimated_v1.mp4
would be the basic syntax to use every tenth frame from the input; you can then add your desired encoding parameters such as -crf to adjust the H.264 rate factor – or, of course, you can change to a different codec altogether.

How to Locate Timestamps of a Subset of a Video

I have never done any video-based programming before, and although this SuperUser post provides a way to do it on the command line, I prefer a programmatic approach, preferably with Python.
I have a bunch of sub-videos. Suppose one of them is called 1234_trimmed.mp4 which is a short segment cut from the original, much-longer video 1234.mp4. How can I figure out the start and end timestamps of 1234_trimmed.mp4 inside 1234.mp4?
FYI, the videos are all originally on YouTube anyway ("1234" corresponds to the YouTube video ID) if there's any shortcut that way.
I figured it out myself with cv2. My strategy was to get the first and last frames of the subvideo and iterate over each frame of the original video, where I compare the current frame's dhash (minimum hamming distance instead of checking for equality in case of resizing and other transformations) against the first and last frames. I'm sure there may be some optimization opportunities but I need this yesterday.
import cv2
original_video_fpath = '5 POPULAR iNSTAGRAM BEAUTY TRENDS (DiY Feather Eyebrows, Colored Mascara, Drippy Lips, Etc)-vsNVU7y6dUE.mp4'
subvideo_fpath = 'vsNVU7y6dUE_trimmed-out.mp4'
def dhash(image, hashSize=8):
# resize the input image, adding a single column (width) so we
# can compute the horizontal gradient
resized = cv2.resize(image, (hashSize + 1, hashSize))
# compute the (relative) horizontal gradient between adjacent
# column pixels
diff = resized[:, 1:] > resized[:, :-1]
# convert the difference image to a hash
return sum([2 ** i for (i, v) in enumerate(diff.flatten()) if v])
def hamming(a, b):
return bin(a^b).count('1')
def get_video_frame_by_index(video_cap, frame_index):
# get total number of frames
totalFrames = video_cap.get(cv2.CAP_PROP_FRAME_COUNT)
if frame_index < 0:
frame_index = int(totalFrames) + frame_index
# check for valid frame number
if frame_index >= 0 & frame_index <= totalFrames:
# set frame position
video_cap.set(cv2.CAP_PROP_POS_FRAMES, frame_index)
_, frame = video_cap.read()
return frame
def main():
cap_original_video = cv2.VideoCapture(original_video_fpath)
cap_subvideo = cv2.VideoCapture(subvideo_fpath)
first_frame_subvideo = get_video_frame_by_index(cap_subvideo, 0)
last_frame_subvideo = get_video_frame_by_index(cap_subvideo, -1)
first_frame_subvideo_gray = cv2.cvtColor(first_frame_subvideo, cv2.COLOR_BGR2GRAY)
last_frame_subvideo_gray = cv2.cvtColor(last_frame_subvideo, cv2.COLOR_BGR2GRAY)
hash_first_frame_subvideo = dhash(first_frame_subvideo)
hash_last_frame_subvideo = dhash(last_frame_subvideo)
min_hamming_dist_with_first_frame = float('inf')
closest_frame_index_first = None
closest_frame_timestamp_first = None
min_hamming_dist_with_last_frame = float('inf')
closest_frame_index_last = None
closest_frame_timestamp_last = None
frame_index = 0
while(cap_original_video.isOpened()):
frame_exists, curr_frame = cap_original_video.read()
if frame_exists:
timestamp = cap_original_video.get(cv2.CAP_PROP_POS_MSEC) // 1000
hash_curr_frame = dhash(curr_frame)
hamming_dist_with_first_frame = hamming(hash_curr_frame, hash_first_frame_subvideo)
hamming_dist_with_last_frame = hamming(hash_curr_frame, hash_last_frame_subvideo)
if hamming_dist_with_first_frame < min_hamming_dist_with_first_frame:
min_hamming_dist_with_first_frame = hamming_dist_with_first_frame
closest_frame_index_first = frame_index
closest_frame_timestamp_first = timestamp
if hamming_dist_with_last_frame < min_hamming_dist_with_last_frame:
min_hamming_dist_with_last_frame = hamming_dist_with_last_frame
closest_frame_index_last = frame_index
closest_frame_timestamp_last = timestamp
frame_index += 1
else:
print('processed {} frames'.format(frame_index+1))
break
cap_original_video.release()
print('timestamp_start={}, timestamp_end={}'.format(closest_frame_timestamp_first, closest_frame_timestamp_last))
if __name__ == '__main__':
main()
MP4 utilizes relative timestamps. When the file was trimmed the old timestamps were lost, and the new file now begins at time stamp zero.
So the only way to identify where this file may overlap with another file is to use computer vision or perceptual hashing. Both options are too complex to describe in a single stackoverflow answer.
If they were simply -codec copy'd, the timestamps should be as they were in the original file. If they weren't, ffmpeg is not the tool for the job. In that case, you should look into other utilities that can find an exactly matching video and audio frame in both files and get the timestamps from there.

How to read the mask of an image using opencv in python

I am working on this challenge called Carvana Segmentation in kaggle. The dataset consists of 5088 images, for each image there is a mask. For eg, the below is a single image (.jpg file) and its corresponding mask (.gif file).
I was able to read .jpg files using cv2, but not the .gif files. The syntax i used to read .gif file is
>>> image = cv2.imread('filename.gif',cv2.IMREAD_GRAYSCALE)
When I try to print the image, returns None
>>> print(image) -> None
Can someone suggest any other method, please
imageio allows to read gifs like this:
import imageio
img = imageio.imread('filename.gif')
Following this repo:
https://github.com/asharma327/Read_Gif_OpenCV_Python/blob/master/gif_to_pic.py
you can do the following to read the image
import cv2
import os
def convert_gif_to_frames(gif):
# Initialize the frame number and create empty frame list
frame_num = 0
frame_list = []
# Loop until there are frames left
while True:
try:
# Try to read a frame. Okay is a BOOL if there are frames or not
okay, frame = gif.read()
# Append to empty frame list
frame_list.append(frame)
# Break if there are no other frames to read
if not okay:
break
# Increment value of the frame number by 1
frame_num += 1
except KeyboardInterrupt: # press ^C to quit
break
return frame_list
def output_frames_as_pics(frame_list):
# Reduce the list of frames by half to make the list more managable
frame_list_reduce = frame_list[0::2]
# Get the path of the current working directory
path = os.getcwd()
# Set then name of your folder
'''Replace this name with what you want your folder name to be'''
folder_name = 'Picturebook_Pics_Kiss'
# If the folder does not exist, then make it
if not os.path.exists(path + '/' + folder_name):
os.makedirs(path + '/' + folder_name)
for frames_idx in range(len(frame_list_reduce)):
cv2.imwrite(os.path.join(path + '/' + folder_name, str(frames_idx+1) + '.png'), frame_list_reduce[frames_idx])
return
gif = cv2.VideoCapture('/home/ahmedramzy/Documents/gif/giphy.gif')
# here you can get the frames and work on it
xx = convert_gif_to_frames(gif_kiss)
# here if you want to write it on hard disk using imwrite
output_frames_as_pics(xx)
You can't use imread(), there's no codec for that builtin (still a license problem)[https://answers.opencv.org/question/185929/how-to-read-gif-in-python/]
Since you are interested in python, you may use PIL library as mentioned here.
from PIL import Image
im = Image.open("animation.gif")
# To iterate through the entire gif
try:
while 1:
im.seek(im.tell()+1)
# do something to im
except EOFError:
pass # end of sequence

how to convert videos into frames with openCV python? [duplicate]

So I've followed this tutorial but it doesn't seem to do anything. Simply nothing. It waits a few seconds and closes the program. What is wrong with this code?
import cv2
vidcap = cv2.VideoCapture('Compton.mp4')
success,image = vidcap.read()
count = 0
success = True
while success:
success,image = vidcap.read()
cv2.imwrite("frame%d.jpg" % count, image) # save frame as JPEG file
if cv2.waitKey(10) == 27: # exit if Escape is hit
break
count += 1
Also, in the comments it says that this limits the frames to 1000? Why?
EDIT:
I tried doing success = True first but that didn't help. It only created one image that was 0 bytes.
From here download this video so we have the same video file for the test. Make sure to have that mp4 file in the same directory of your python code. Then also make sure to run the python interpreter from the same directory.
Then modify the code, ditch waitKey that's wasting time also without a window it cannot capture the keyboard events. Also we print the success value to make sure it's reading the frames successfully.
import cv2
vidcap = cv2.VideoCapture('big_buck_bunny_720p_5mb.mp4')
success,image = vidcap.read()
count = 0
while success:
cv2.imwrite("frame%d.jpg" % count, image) # save frame as JPEG file
success,image = vidcap.read()
print('Read a new frame: ', success)
count += 1
How does that go?
To extend on this question (& answer by #user2700065) for a slightly different cases, if anyone does not want to extract every frame but wants to extract frame every one second. So a 1-minute video will give 60 frames(images).
import sys
import argparse
import cv2
print(cv2.__version__)
def extractImages(pathIn, pathOut):
count = 0
vidcap = cv2.VideoCapture(pathIn)
success,image = vidcap.read()
success = True
while success:
vidcap.set(cv2.CAP_PROP_POS_MSEC,(count*1000)) # added this line
success,image = vidcap.read()
print ('Read a new frame: ', success)
cv2.imwrite( pathOut + "\\frame%d.jpg" % count, image) # save frame as JPEG file
count = count + 1
if __name__=="__main__":
a = argparse.ArgumentParser()
a.add_argument("--pathIn", help="path to video")
a.add_argument("--pathOut", help="path to images")
args = a.parse_args()
print(args)
extractImages(args.pathIn, args.pathOut)
This is Function which will convert most of the video formats to number of frames there are in the video. It works on Python3 with OpenCV 3+
import cv2
import time
import os
def video_to_frames(input_loc, output_loc):
"""Function to extract frames from input video file
and save them as separate frames in an output directory.
Args:
input_loc: Input video file.
output_loc: Output directory to save the frames.
Returns:
None
"""
try:
os.mkdir(output_loc)
except OSError:
pass
# Log the time
time_start = time.time()
# Start capturing the feed
cap = cv2.VideoCapture(input_loc)
# Find the number of frames
video_length = int(cap.get(cv2.CAP_PROP_FRAME_COUNT)) - 1
print ("Number of frames: ", video_length)
count = 0
print ("Converting video..\n")
# Start converting the video
while cap.isOpened():
# Extract the frame
ret, frame = cap.read()
if not ret:
continue
# Write the results back to output location.
cv2.imwrite(output_loc + "/%#05d.jpg" % (count+1), frame)
count = count + 1
# If there are no more frames left
if (count > (video_length-1)):
# Log the time again
time_end = time.time()
# Release the feed
cap.release()
# Print stats
print ("Done extracting frames.\n%d frames extracted" % count)
print ("It took %d seconds forconversion." % (time_end-time_start))
break
if __name__=="__main__":
input_loc = '/path/to/video/00009.MTS'
output_loc = '/path/to/output/frames/'
video_to_frames(input_loc, output_loc)
It supports .mts and normal files like .mp4 and .avi. Tried and Tested on .mts files. Works like a Charm.
This is a tweak from previous answer for python 3.x from #GShocked, I would post it to the comment, but dont have enough reputation
import sys
import argparse
import cv2
print(cv2.__version__)
def extractImages(pathIn, pathOut):
vidcap = cv2.VideoCapture(pathIn)
success,image = vidcap.read()
count = 0
success = True
while success:
success,image = vidcap.read()
print ('Read a new frame: ', success)
cv2.imwrite( pathOut + "\\frame%d.jpg" % count, image) # save frame as JPEG file
count += 1
if __name__=="__main__":
print("aba")
a = argparse.ArgumentParser()
a.add_argument("--pathIn", help="path to video")
a.add_argument("--pathOut", help="path to images")
args = a.parse_args()
print(args)
extractImages(args.pathIn, args.pathOut)
The previous answers have lost the first frame. And it will be nice to store the images in a folder.
# create a folder to store extracted images
import os
folder = 'test'
os.mkdir(folder)
# use opencv to do the job
import cv2
print(cv2.__version__) # my version is 3.1.0
vidcap = cv2.VideoCapture('test_video.mp4')
count = 0
while True:
success,image = vidcap.read()
if not success:
break
cv2.imwrite(os.path.join(folder,"frame{:d}.jpg".format(count)), image) # save frame as JPEG file
count += 1
print("{} images are extacted in {}.".format(count,folder))
By the way, you can check the frame rate by VLC. Go to windows -> media information -> codec details
After a lot of research on how to convert frames to video I have created this function hope this helps. We require opencv for this:
import cv2
import numpy as np
import os
def frames_to_video(inputpath,outputpath,fps):
image_array = []
files = [f for f in os.listdir(inputpath) if isfile(join(inputpath, f))]
files.sort(key = lambda x: int(x[5:-4]))
for i in range(len(files)):
img = cv2.imread(inputpath + files[i])
size = (img.shape[1],img.shape[0])
img = cv2.resize(img,size)
image_array.append(img)
fourcc = cv2.VideoWriter_fourcc('D', 'I', 'V', 'X')
out = cv2.VideoWriter(outputpath,fourcc, fps, size)
for i in range(len(image_array)):
out.write(image_array[i])
out.release()
inputpath = 'folder path'
outpath = 'video file path/video.mp4'
fps = 29
frames_to_video(inputpath,outpath,fps)
change the value of fps(frames per second),input folder path and output folder path according to your own local locations
This code extract frames from the video and save the frames in .jpg formate
import cv2
import numpy as np
import os
# set video file path of input video with name and extension
vid = cv2.VideoCapture('VideoPath')
if not os.path.exists('images'):
os.makedirs('images')
#for frame identity
index = 0
while(True):
# Extract images
ret, frame = vid.read()
# end of frames
if not ret:
break
# Saves images
name = './images/frame' + str(index) + '.jpg'
print ('Creating...' + name)
cv2.imwrite(name, frame)
# next frame
index += 1
In 2022 you also have the option to use ImageIO to do this, which IMHO is much more hasslefree and readable.
import imageio.v3 as iio
for idx, frame in enumerate(iio.imiter("imageio:cockatoo.mp4")):
iio.imwrite(f"extracted_images/frame{idx:03d}.jpg", frame)
Sidenote 1: "imageio:cockatoo.mp4" is a standard image provided by ImageIO for testing and demonstration purposes. You can simply replace it with "path/to/your/video.mp4".
Sidenote 2: You will have to install one of ImageIO's optional dependencies to read video data, which can be done via pip install imageio-ffmpeg or pip install av.
You can time this against OpenCV and you will find that, there isn't that much to gain from OpenCV on this front either:
Read-Only Timings
=================
OpenCV: 0.453
imageio_ffmpeg: 0.765
imageio_pyav: 0.272
Read + Write Timings
====================
OpenCV: 3.237
imageio_ffmpeg: 1.597
imageio_pyav: 1.506
By default, OpenCV and ImageIO+av are about equally fast when reading. Both direct bind into the FFmpeg libraries under the hood so this is rather unsurprising. However, ImageIO allows you to tweak FFmpeg's default threadding model (thread_type="FRAME") which is much faster when bulk reading.
More importantly, ImageIO is much faster at writing JPEG compared to OpenCV. This is because pillow is faster than OpenCV here which ImageIO capitalizes on. Writing images dominates runtime for this scenario, so you end up with an overall 2x improvement when using ImageIO instead of OpenCV.
Here is the code for reference:
import imageio.v3 as iio
import cv2
import timeit
from pathlib import Path
# create a common local file for benchmarking
video_file = "shared_video.mp4"
if not Path(video_file).exists():
frames = iio.imread("imageio:cockatoo.mp4")
meta = iio.immeta("imageio:cockatoo.mp4", exclude_applied=False)
iio.imwrite(video_file, frames, fps=meta["fps"])
repeats = 10
def read_cv2():
vidcap = cv2.VideoCapture(video_file)
success, image = vidcap.read()
idx = 0
while success:
cv2.imwrite(f"extracted_images/frame{idx:03d}.jpg", image)
success, image = vidcap.read()
idx += 1
def read_imageio_ffmpeg():
for idx, frame in enumerate(iio.imiter(video_file, plugin="FFMPEG")):
iio.imwrite(f"extracted_images/frame{idx:03d}.jpg", frame)
def read_imageio_pyav():
for idx, frame in enumerate(
iio.imiter(video_file, plugin="pyav", format="rgb24", thread_type="FRAME")
):
iio.imwrite(f"extracted_images/frame{idx:03d}.jpg", frame)
time_cv2 = (
timeit.timeit("read_cv2()", setup="from __main__ import read_cv2", number=repeats)
/ repeats
)
time_imageio_ffmpeg = (
timeit.timeit(
"read_imageio_ffmpeg()",
setup="from __main__ import read_imageio_ffmpeg",
number=repeats,
)
/ repeats
)
time_imageio_pyav = (
timeit.timeit(
"read_imageio_pyav()",
setup="from __main__ import read_imageio_pyav",
number=repeats,
)
/ repeats
)
print(
f"""
Timings
=======
OpenCV: {time_cv2:<3.3f}
imageio_ffmpeg: {time_imageio_ffmpeg:<3.3f}
imageio_pyav: {time_imageio_pyav:<3.3f}
"""
)
Following script will extract frames every half a second of all videos in folder. (Works on python 3.7)
import cv2
import os
listing = os.listdir(r'D:/Images/AllVideos')
count=1
for vid in listing:
vid = r"D:/Images/AllVideos/"+vid
vidcap = cv2.VideoCapture(vid)
def getFrame(sec):
vidcap.set(cv2.CAP_PROP_POS_MSEC,sec*1000)
hasFrames,image = vidcap.read()
if hasFrames:
cv2.imwrite("D:/Images/Frames/image"+str(count)+".jpg", image) # Save frame as JPG file
return hasFrames
sec = 0
frameRate = 0.5 # Change this number to 1 for each 1 second
success = getFrame(sec)
while success:
count = count + 1
sec = sec + frameRate
sec = round(sec, 2)
success = getFrame(sec)
This function extracts images from video with 1 fps, IN ADDITION it identifies the last frame and stops reading also:
import cv2
import numpy as np
def extract_image_one_fps(video_source_path):
vidcap = cv2.VideoCapture(video_source_path)
count = 0
success = True
while success:
vidcap.set(cv2.CAP_PROP_POS_MSEC,(count*1000))
success,image = vidcap.read()
## Stop when last frame is identified
image_last = cv2.imread("frame{}.png".format(count-1))
if np.array_equal(image,image_last):
break
cv2.imwrite("frame%d.png" % count, image) # save frame as PNG file
print '{}.sec reading a new frame: {} '.format(count,success)
count += 1
I am using Python via Anaconda's Spyder software. Using the original code listed in the question of this thread by #Gshocked, the code does not work (the python won't read the mp4 file). So I downloaded OpenCV 3.2 and copied "opencv_ffmpeg320.dll" and "opencv_ffmpeg320_64.dll" from the "bin" folder. I pasted both of these dll files to Anaconda's "Dlls" folder.
Anaconda also has a "pckgs" folder...I copied and pasted the entire "OpenCV 3.2" folder that I downloaded to the Anaconda "pckgs" folder.
Finally, Anaconda has a "Library" folder which has a "bin" subfolder. I pasted the "opencv_ffmpeg320.dll" and "opencv_ffmpeg320_64.dll" files to that folder.
After closing and restarting Spyder, the code worked. I'm not sure which of the three methods worked, and I'm too lazy to go back and figure it out. But it works so, cheers!
i might be late here but you can use this pip package to quickly generate images from videos. You can also get images using specific fps.
pip install videoToImages
then type the following command in terminal
videoToimages --videoFolder [pathToVideosFolder]
Example: videoToimages --videoFolder "c:/videos"
for specific output fps , set --fps 10 to any required value. --fps 1 means one image per one second of the video.
Full commands:
videoToimages --videoFolder "c:/videos"
videoToimages --videoFolder "c:/videos" --fps 10 --img_size (512, 512)
This code is simple and guarantees reliable execution.
# path of video file
video_path = "path/to/video.mp4"
# Open video file
video = cv2.VideoCapture(video_path)
# number of frames in video
frame_count = int(video.get(cv2.CAP_PROP_FRAME_COUNT))
# Convert frame to image and save to file
for i in range(frame_count):
ret, frame = video.read()
if ret:
image_path = f"path/to/image_{i}.jpg"
cv2.imwrite(image_path, frame)
# Close video file
video.release()
There are several reasons to extract slides/frames from a video presentation, especially in the case of education or conference related videos. It allows you to access the study notes without watching the whole video.
I have faced this issue several times, so I decided to create a solution for it myself using python. I have made the code open-source, you can easily set up this tool and run it in few simple steps.
Refer to this for youtube video tutorial.
Steps on how to use this tool.
Clone this project video2pdfslides
Set up your environment by running "pip install -r requirements.txt"
Copy your video path
Run "python video2pdfslides.py <video_path>"
Boom! the pdf slides will be available in in output folder
Make notes and enjoy!

Generate 2d images of molecules from PubChem FTP data

Rather than crawl PubChem's website, I'd prefer to be nice and generate the images locally from the PubChem ftp site:
ftp://ftp.ncbi.nih.gov/pubchem/specifications/
The only problem is that I'm limited to OSX and Linux and I can't seem to find a way of programmatically generating the 2d images that they have on their site. See this example:
https://pubchem.ncbi.nlm.nih.gov/compound/6#section=Top
Under the heading "2D Structure" we have this image here:
https://pubchem.ncbi.nlm.nih.gov/image/imgsrv.fcgi?cid=6&t=l
That is what I'm trying to generate.
If you want something working out of the box I would suggest using molconvert from ChemAxon's Marvin (https://www.chemaxon.com/products/marvin/), which is free for academics. It can be used easily from the command line and it supports plenty of input and output formats. So for your example it would be:
molconvert "png" -s "C1=CC(=C(C=C1[N+](=O)[O-])[N+](=O)[O-])Cl" -o cdnb.png
Resulting in the following image:
It also allows you to set parameters such as width, height, quality, background color and so on.
However, if you are a programmer I would definitely recommend RDKit. Follows a code which generates images for a pair of compounds given as smiles.
from rdkit import Chem
from rdkit.Chem import Draw
ms_smis = [["C1=CC(=C(C=C1[N+](=O)[O-])[N+](=O)[O-])Cl", "cdnb"],
["C1=CC(=CC(=C1)N)C(=O)N", "3aminobenzamide"]]
ms = [[Chem.MolFromSmiles(x[0]), x[1]] for x in ms_smis]
for m in ms: Draw.MolToFile(m[0], m[1] + ".svg", size=(800, 800))
This gives you following images:
So I also emailed the PubChem guys and they got back to me very quickly with this response:
The only bulk access we have to images is through the download
service: https://pubchem.ncbi.nlm.nih.gov/pc_fetch/pc_fetch.cgi
You can request up to 50,000 images at a time.
Which is better than I was expecting, but still not amazing since it requires downloading things that I in theory could generate locally. So I'm leaving this question open until some kind soul writes an open source library to do the same.
Edit:
I figure I might as well save people some time if they are doing the same thing as I am. I've created a Ruby Gem backed on Mechanize to automate the downloading of images. Please be kind to their servers and only download what you need.
https://github.com/zachaysan/pubchem
gem install pubchem
An open source option is the Indigo Toolkit, which also has pre-compiled packages for Linux, Windows, and MacOS and language bindings for Python, Java, .NET, and C libraries. I chose the 1.4.0 beta.
I had a similar interest to yours in converting SMILES to 2D structures and adapted my Python to address your question and to capture timing information. It uses the PubChem FTP (Compound/Extras) download of CID-SMILES.gz. The following script is an implementation of a local SMILES-to-2D-structure converter that reads a range of rows from the PubChem CID-SMILES file of isomeric SMILES (which contains over 102 million compound records) and converts the SMILES to PNG images of the 2D structures. In three tests with 1000 SMILES-to-structure conversions, it took 35, 50, and 60 seconds to convert 1000 SMILES at file row offsets of 0, 100,000, and 10,000,000 on my Windows 10 laptop (Intel i7-7500U CPU, 2.70GHz) with a solid state drive and running Python 3.7.4. The 3000 files totaled 100 MB in size.
from indigo import *
from indigo.renderer import *
import subprocess
import datetime
def timerstart():
# start timer and print time, return start time
start = datetime.datetime.now()
print("Start time =", start)
return start
def timerstop(start):
# end timer and print time and elapsed time, return elapsed time
endtime = datetime.datetime.now()
elapsed = endtime - start
print("End time =", endtime)
print("Elapsed time =", elapsed)
return elapsed
numrecs = 1000
recoffset = 0 # 10000000 # record offset
starttime = timerstart()
indigo = Indigo()
renderer = IndigoRenderer(indigo)
# set render options
indigo.setOption("render-atom-color-property", "color")
indigo.setOption("render-coloring", True)
indigo.setOption("render-comment-position", "bottom")
indigo.setOption("render-comment-offset", "20")
indigo.setOption("render-background-color", 1.0, 1.0, 1.0)
indigo.setOption("render-output-format", "png")
# set data path (including data file) and output file path
datapath = r'../Download/CID-SMILES'
pngpath = r'./2D/'
# read subset of rows from data file
mycmd = "head -" + str(recoffset+numrecs) + " " + datapath + " | tail -" + str(numrecs)
print(mycmd)
(out, err) = subprocess.Popen(mycmd, stdout=subprocess.PIPE, shell=True).communicate()
lines = str(out.decode("utf-8")).split("\n")
count = 0
for line in lines:
try:
cols = line.split("\t") # split on tab
key = cols[0] # cid in cols[0]
smiles = cols[1] # smiles in cols[1]
mol = indigo.loadMolecule(smiles)
s = "CID=" + key
indigo.setOption("render-comment", s)
#indigo.setOption("render-image-size", 200, 250)
#indigo.setOption("render-image-size", 400, 500)
renderer.renderToFile(mol, pngpath + key + ".png")
count += 1
except:
print("Error processing line after", str(count), ":", line)
pass
elapsedtime = timerstop(starttime)
print("Converted", str(count), "SMILES to PNG")

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