Recherche avancée

Sur d’autres sites (9290)

• FFmpeg Cropping Fps Drop

  7 mai 2022, par James

  FFmpeg Commands works but having a problem in fps drop also using libx264 for encoding any idea to get this good

  


  "-y" "-noautorotate" "-ss" "301" "-t" "11" "-i" "/mnt/shared/Pictures/[BTCLOD.COM] COSTA RICA IN 4K 60fps HDR (ULTRA HD)-1080p60.mp4" \
"-strict" "experimental" "-vf" "crop=w=606:h=1080:x=657:y=0" \
"-vcodec" "libx264" "-crf" "18" "-r" "15" "-b:v" "2500k" \
"-acodec" "copy" "-ab" "128k" "-sample_fmt" "s16" \
"-ss" "0" "-t" "11" "/storage/emulated/0/VEditor/VideoCroper/[BTCLOD.COM] COSTA RICA IN 4K 60fps HDR (ULTRA HD)-1080p60-0-6.mp4"


  


• Python cv2 script that scans a giant image to a video. Why do I need pad two extra lines

  27 avril 2022, par Mahrarena

  I wrote a script that scans a giant image to make a video. Normally I just post my scripts straight to my Code Review account, but this script is ugly, needs to be refactored, implements only horizontal scrolling and most importantly I just fixed a bug but I don't completely understand why it works.

  


  Example :

  


  Original image (Google Drive)

  


  Video Output (Google Drive)

  


  As you can see from the video, everything is working properly except the fact that I don't know how it works.

  


  Full working code

  


  ---

  


  import cv2
import numpy as np
import random
import rpack
from fractions import Fraction
from math import prod

def resize_guide(image_size, target_area):
    aspect_ratio = Fraction(*image_size).limit_denominator()
    horizontal = aspect_ratio.numerator
    vertical = aspect_ratio.denominator
    unit_length = (target_area/(horizontal*vertical))**.5
    return (int(horizontal*unit_length), int(vertical*unit_length))

fourcc = cv2.VideoWriter_fourcc(*'mp4v')
FRAME = np.zeros((1080, 1920, 3), dtype=np.uint8)

def new_frame():
    return np.ndarray.copy(FRAME)

def center(image):
    frame = new_frame()
    h, w = image.shape[:2]
    yoff = round((1080-h)/2)
    xoff = round((1920-w)/2)
    frame[yoff:yoff+h, xoff:xoff+w] = image
    return frame

def image_scanning(file, fps=60, pan_increment=64, horizontal_increment=8):
    image = cv2.imread(file)
    height, width = image.shape[:2]
    assert width*height >= 1920*1080
    video_writer = cv2.VideoWriter(file+'.mp4', fourcc, fps, (1920, 1080))
    fit_height = True
    if height < 1080:
        width = width*1080/height
        image = cv2.resize(image, (width, 1080), interpolation = cv2.INTER_AREA)
    aspect_ratio = width / height
    zooming_needed = False
    if 4/9 <= aspect_ratio <= 16/9:
        new_width = round(width*1080/height)
        fit = cv2.resize(image, (new_width, 1080), interpolation = cv2.INTER_AREA)
        zooming_needed = True
    
    elif 16/9 < aspect_ratio <= 32/9:
        new_height = round(height*1920/width)
        fit = cv2.resize(image, (1920, new_height), interpolation = cv2.INTER_AREA)
        fit_height = False
        zooming_needed = True
    
    centered = center(fit)
    for i in range(fps):
        video_writer.write(centered)
    if fit_height:
        xoff = round((1920 - new_width)/2)
        while xoff:
            if xoff - pan_increment >= 0:
                xoff -= pan_increment
            else:
                xoff = 0
            frame = new_frame()
            frame[0:1080, xoff:xoff+new_width] = fit
            video_writer.write(frame)
    else:
        yoff = round((1080 - new_height)/2)
        while yoff:
            if yoff - pan_increment >= 0:
                yoff -= pan_increment
            else:
                yoff = 0
            frame = new_frame()
            frame[yoff:yoff+new_height, 0:1920] = fit
            video_writer.write(frame)
    
    if zooming_needed:
        if fit_height:
            width_1, height_1 = new_width, 1080
        else:
            width_1, height_1 = 1920, new_height
        new_area = width_1 * height_1
        original_area = width * height
        area_diff = original_area - new_area
        unit_diff = area_diff / fps
        for i in range(1, fps+1):
            zoomed = cv2.resize(image, resize_guide((width_1, height_1), new_area+unit_diff*i), interpolation=cv2.INTER_AREA)
            zheight, zwidth = zoomed.shape[:2]
            zheight = min(zheight, 1080)
            zwidth = min(zwidth, 1920)
            frame = new_frame()
            frame[0:zheight, 0:zwidth] = zoomed[0:zheight, 0:zwidth]
            video_writer.write(frame)
    
    if (width - 1920) % horizontal_increment:
        new_width = ((width - 1920) // horizontal_increment + 1) * horizontal_increment + 1920
        frame = np.zeros([height, new_width, 3], dtype=np.uint8)
        frame[0:height, 0:width] = image
        width = new_width
        image = frame
    
    if height % 1080:
        new_height = (height // 1080 + 2) * 1080
        frame = np.zeros([new_height, width, 3], dtype=np.uint8)
        frame[0:height, 0:width] = image
        height = new_height - 1080
        image = frame
    
    y, x = 0, 0
    for y in range(0, height, 1080):
        for x in range(0, width-1920, horizontal_increment):
            frame = image[y:y+1080, x:x+1920]
            video_writer.write(frame)
        x = width - 1920
        frame = image[y:y+1080, x:x+1920]
        for i in range(round(fps/3)):
            video_writer.write(frame)
    cv2.destroyAllWindows()
    video_writer.release()
    del video_writer


  


  I don't know why I need to pad two extra lines instead of one, meaning if I change this :

  


      if height % 1080:
        new_height = (height // 1080 + 2) * 1080
        frame = np.zeros([new_height, width, 3], dtype=np.uint8)
        frame[0:height, 0:width] = image
        height = new_height - 1080
        image = frame


  


  To this :

  


      if height % 1080:
        new_height = (height // 1080 + 1) * 1080
        frame = np.zeros([new_height, width, 3], dtype=np.uint8)
        frame[0:height, 0:width] = image
        height = new_height
        image = frame


  


  The program raises exceptions :

  


  OpenCV: FFMPEG: tag 0x34363268/&#x27;h264&#x27; is not supported with codec id 27 and format &#x27;mp4 / MP4 (MPEG-4 Part 14)&#x27;&#xA;OpenCV: FFMPEG: fallback to use tag 0x31637661/&#x27;avc1&#x27;&#xA;---------------------------------------------------------------------------&#xA;error                                     Traceback (most recent call last)&#xA; in <module>&#xA;----> 1 image_scanning("D:/collages/91f53ebcea2a.png")&#xA;&#xA; in image_scanning(file, fps, pan_increment, horizontal_increment, fast_decrement)&#xA;    122                     x &#x2B;= horizontal_increment&#xA;    123                     frame = image[y:y&#x2B;1080, x:x&#x2B;1920]&#xA;--> 124                     video_writer.write(frame)&#xA;    125     cv2.destroyAllWindows()&#xA;    126     video_writer.release()&#xA;&#xA;error: Unknown C&#x2B;&#x2B; exception from OpenCV code&#xA;</module>

  


  I guess it was caused by indexing error because the last line would not have enough pixels so padding the height of the image to a multiple of 1080 should work.

  


  But that's not the case, I need to pad two lines, why is that ? I really don't understand why it is working.

  


  ---

  


  No, I really wrote all of it, I understand all the principles, the ideas are all mine, but there is one small problem in implementation. I don't know why I need extra pixels in the bottom to make it work, because if I don't pad the height to a multiple of 1080, I can't get the bottom line, the lowest potion of height % 1080 would be lost.

  


  If I tried to get the lowest part, the program will raise exceptions even if I pad the height to a multiple of 1080, I think it is related to indexing but I don't fully understand it, turns out I need to pad the height and add extra pixels, even 1 pixel would work.

  


  I don't know why it raises exceptions and how add extra pixels got rid of the exception, but I understand everything else perfectly clear, after all I wrote it.

  


  There's a bug in my program, I don't know what caused it, and I want you to help me debugging, and that's the entire point of the question !

  


• Python cv2 script that scans a giant image to a video. Raises error : Unknown C++ exception from OpenCV code

  26 avril 2022, par Mahrarena

  I wrote a script that scans a giant image to make a video. Normally I just post my scripts straight to my Code Review account, but this script is ugly, needs to be refactored, implements only horizontal scrolling and contains a bug that I can't get rid of.

  


  It is working but not perfect, I can't get the last line at the bottom of the image, with height of image_height % 1080. If I ignore it, the code is working fine, if I try to fix it, it throws exceptions.

  


  Example :

  


  Original image (Google Drive)

  


  Video Output (Google Drive)

  


  As you can see from the video, everything is working properly except the fact that I can't get the bottom line.

  


  Full working code

  


  ---

  


  import cv2
import numpy as np
import random
import rpack
from fractions import Fraction
from math import prod

def resize_guide(image_size, target_area):
    aspect_ratio = Fraction(*image_size).limit_denominator()
    horizontal = aspect_ratio.numerator
    vertical = aspect_ratio.denominator
    unit_length = (target_area/(horizontal*vertical))**.5
    return (int(horizontal*unit_length), int(vertical*unit_length))

fourcc = cv2.VideoWriter_fourcc(*'h264')
FRAME = np.zeros((1080, 1920, 3), dtype=np.uint8)

def new_frame():
    return np.ndarray.copy(FRAME)

def center(image):
    frame = new_frame()
    h, w = image.shape[:2]
    yoff = round((1080-h)/2)
    xoff = round((1920-w)/2)
    frame[yoff:yoff+h, xoff:xoff+w] = image
    return frame

def image_scanning(file, fps=60, pan_increment=64, horizontal_increment=8, fast_decrement=256):
    image = cv2.imread(file)
    height, width = image.shape[:2]
    assert width*height >= 1920*1080
    video_writer = cv2.VideoWriter(file+'.mp4', fourcc, fps, (1920, 1080))
    fit_height = True
    if height < 1080:
        width = width*1080/height
        image = cv2.resize(image, (width, 1080), interpolation = cv2.INTER_AREA)
    aspect_ratio = width / height
    zooming_needed = False
    if 4/9 <= aspect_ratio <= 16/9:
        new_width = round(width*1080/height)
        fit = cv2.resize(image, (new_width, 1080), interpolation = cv2.INTER_AREA)
        zooming_needed = True
    
    elif 16/9 < aspect_ratio <= 32/9:
        new_height = round(height*1920/width)
        fit = cv2.resize(image, (1920, new_height), interpolation = cv2.INTER_AREA)
        fit_height = False
        zooming_needed = True
    
    centered = center(fit)
    for i in range(fps):
        video_writer.write(centered)
    if fit_height:
        xoff = round((1920 - new_width)/2)
        while xoff:
            if xoff - pan_increment >= 0:
                xoff -= pan_increment
            else:
                xoff = 0
            frame = new_frame()
            frame[0:1080, xoff:xoff+new_width] = fit
            video_writer.write(frame)
    else:
        yoff = round((1080 - new_height)/2)
        while yoff:
            if yoff - pan_increment >= 0:
                yoff -= pan_increment
            else:
                yoff = 0
            frame = new_frame()
            frame[yoff:yoff+new_height, 0:1920] = fit
            video_writer.write(frame)
    
    if zooming_needed:
        if fit_height:
            width_1, height_1 = new_width, 1080
        else:
            width_1, height_1 = 1920, new_height
        new_area = width_1 * height_1
        original_area = width * height
        area_diff = original_area - new_area
        unit_diff = area_diff / fps
        for i in range(1, fps+1):
            zoomed = cv2.resize(image, resize_guide((width_1, height_1), new_area+unit_diff*i), interpolation=cv2.INTER_AREA)
            zheight, zwidth = zoomed.shape[:2]
            zheight = min(zheight, 1080)
            zwidth = min(zwidth, 1920)
            frame = new_frame()
            frame[0:zheight, 0:zwidth] = zoomed[0:zheight, 0:zwidth]
            video_writer.write(frame)
    y, x = 0, 0
    completed = False
    while y != height - 1080:
        x = 0
        while x != width - 1920:
            if x + horizontal_increment + 1920 <= width:
                x += horizontal_increment
                frame = image[y:y+1080, x:x+1920]
                video_writer.write(frame)
            else:
                x = width - 1920
                frame = image[y:y+1080, x:x+1920]
                for i in range(round(fps/3)):
                    video_writer.write(frame)
                if y == height - 1080:
                    completed = True
        while x != 0:
            if x - fast_decrement - 1920 >= 0:
                x -= fast_decrement
            else:
                x = 0
            frame = image[y:y+1080, x:x+1920]
            video_writer.write(frame)
        if y + 2160 <= height:
            y += 1080
        else:
            y = height - 1080
    cv2.destroyAllWindows()
    video_writer.release()
    del video_writer


  


  The above the the code needed to produce the example video. It is working but the bottom line is missing.

  


  Now if I change the last few lines to this :

  


          if y + 2160 <= height:
            y += 1080
        else:
            y = height - 1080
            x = 0
            while x != width - 1920:
                if x + horizontal_increment + 1920 <= width:
                    x += horizontal_increment
                    frame = image[y:y+1080, x:x+1920]
                    video_writer.write(frame)
    cv2.destroyAllWindows()
    video_writer.release()
    del video_writer


  


  I expect it to include the bottom line, but it just throws exceptions instead :

  


  OpenCV: FFMPEG: tag 0x34363268/&#x27;h264&#x27; is not supported with codec id 27 and format &#x27;mp4 / MP4 (MPEG-4 Part 14)&#x27;&#xA;OpenCV: FFMPEG: fallback to use tag 0x31637661/&#x27;avc1&#x27;&#xA;---------------------------------------------------------------------------&#xA;error                                     Traceback (most recent call last)&#xA; in <module>&#xA;----> 1 image_scanning("D:/collages/91f53ebcea2a.png")&#xA;&#xA; in image_scanning(file, fps, pan_increment, horizontal_increment, fast_decrement)&#xA;    122                     x &#x2B;= horizontal_increment&#xA;    123                     frame = image[y:y&#x2B;1080, x:x&#x2B;1920]&#xA;--> 124                     video_writer.write(frame)&#xA;    125     cv2.destroyAllWindows()&#xA;    126     video_writer.release()&#xA;&#xA;error: Unknown C&#x2B;&#x2B; exception from OpenCV code&#xA;</module>

  


  (If you can't get the example code working I can't help you, but I am using Python 3.9.10 x64 on Windows 10, and I have this file : "C :\Windows\System32\openh264-1.8.0-win64.dll", the '.avi' format generates video files with Gibibytes (binary unit, not SI Gigabyte) of size)

  


  How to get rid of the exception ?

  


  ---

  


  Okay I yield, I admit the tone of the original post was very aggressive and provoking, but I was very frustrated and I really don't know why my posts keep getting downvoted. Now I deleted all offending portions so will you people please really have a look at my code and tell me what I did wrong. I can solve it by myself, I always do, but I am so stupid I can spend hours missing the obvious. So please will you help me ?