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• New Piwik Mobile 2.2.0 is released

  21 décembre 2014, par Thomas Steur — Piwik Mobile Releases

  We are proud to announce that Piwik Mobile 2.2.0 is now available ! This new version brings many improvements to our Android app. Here’s the list of changes :

  • Android : The keyboard is no longer displayed when opening the app [#5320]
  • Android : Back button did not work in a few screens and could cause the app to unexpectedly close under circumstances [#5316]
  • Android : The graph is now displayed fullscreen on tablets when maximizing it [#5315]
  • Android : New material design icons [#5310]
  • Android : Better exit workflow – we now open the left sidebar before closing the app if the left sidebar was opened at least once. Another back button press closes the app [#4305]
  • iOS : The left sidebar was positioned too far down on iPhone 4s with iOS 8 [#5306]
  • Region is now shown in visitor screen if possible [#5300]
  • Other performance, UI and usability improvements
  • List of all 18 closed issues

  Download

  Update now or install either the iOS version or the Android version.
  In case you are an Android user who is not using the Google Play Store you can download Piwik Mobile 2.2.0 for Android 4+.

  Feel free to send us feature wishes, bug reports, wireframes, mockups or even layouts. We can improve Piwik Mobile much better with your feedback. and suggestions

• ffmpeg concatenating videos of different fps while keeping the total length not changed

  23 novembre 2017, par A_Matar

  I wanna pad an mp4 video stream with another video clip of a static image that I created using :

  def generate_white_vid (duration):
  
      output_filename = os.path.join(p_path,'white_vid_'+" 0:.2f}".format(duration)+'.mp4')
  
      ffmpeg_create_vid_from_static_img = 'ffmpeg -loop 1 -i /path/WhiteBackground.jpg -c:v libx264 -t %f -pix_fmt yuv420p -vf scale=1920:1080 %s' % (duration, output_filename)
  
      p = subprocess.Popen(ffmpeg_create_vid_from_static_img, shell=True)
  
      p.communicate()
  
      return output_filename

  I use the following to concatenate :

  def concat_vids(clip_paths):
  
      filenames_txt = open('clips_to_join.txt','w')
  
      for clip in clip_paths:
  
          filenames_txt.write ('file \''+ clip+'\'\n')
  
      filenames_txt.close()
  
      output_filename = clip_paths[0].split('.', 2)[0]
  
      output_file_path = os.path.join(root_path, output_filename+'-padded.mp4')
  
      # join the clips
  
      ffmpeg_command = ["ffmpeg", "-f", "concat", "-safe", "0", "-i", "clips_to_join.txt", "-codec", "copy", output_file_path] # output_filename = ch0X-start_time-end_time
  
      p = subprocess.Popen(ffmpeg_command)
  
      p.communicate() # wait till the subprocess finishes. You can send commands to process as well.
  
      return output_file_path

  When I check the length of the resulting video after concatenation, I find that it is not equal to the sum of the two segments that I concatenated, and sometimes it is even less by some seconds !!

  Here is how I get the video length in seconds :

  def ffmpeg_len(vid_path):
  
      '''
  
      Returns length in seconds using ffmpeg
  
      '''
  
      ffmpeg_get_mediafile_length = ['sh', '-c', 'ffmpeg -i "$1" 2>&1 | grep Duration', '_', vid_path]
  
      p = subprocess.Popen(ffmpeg_get_mediafile_length, stdout=subprocess.PIPE, stderr=subprocess.PIPE)    
  
      output, err = p.communicate()
  
      length_regexp = 'Duration: (\d{2}):(\d{2}):(\d{2})(\.\d+),'
  
      re_length = re.compile(length_regexp)
  
      matches = re_length.search(output)
  
      if matches:
  
          video_length = int(matches.group(1)) * 3600 + \
  
                          int(matches.group(2)) * 60 + \
  
                          int(matches.group(3)) + float(matches.group(4))
  
          return video_length
  
      else:
  
          print("Can't determine video length.")
  
          print err
  
          raise SystemExit

  My guess is that maybe the concatenation unifies the fps rate for the all the clips to be joined, if this is the case, how to prevent this from happening ? How can I get a video of the desired length exactly.

  Maybe it worth mentioning that the video to padded is very short 0.42 second, the original video is 210.58 and the resultant video is 210.56 !

  I have verified that ffmpeg does generate the desired padding region and it is of the desired length 0.42 I got a 0.43 segment when I forced 30 fps but it is okay.

• I'm trying to hide information in a H264 video. When I stitch the video up, split it into frames again and try to read it, the information is lost

  18 mai 2024, par Wer Wer

  I'm trying to create a video steganography python script. The algorithm for hiding will be...

  


  

  1. convert any video codec into h264 lossless

  


  2. save the audio of the video and split the h264 video into frames

  


  3. hide my txt secret into frame0 using LSB replacement method

  


  4. stitch the video back up and put in the audio

  


  


  ...and when I want to recover the text, I'll

  


  

  1. save the audio of the video and split the encoded h264 video into frames

  


  2. retrieve my hidden text from frame0 and print the text

  


  


  So, this is what I can do :

  


  

  1. split the video

  


  2. hide the text in frame0

  


  3. retrieve the text from frame0

  


  4. stitch the video

  


  


  But after stitching the video, when I tried to retrieve the text by splitting that encrypted video, it appears that the text has been lost. This is because i got the error

  


  UnicodeEncodeError: &#x27;charmap&#x27; codec can&#x27;t encode character &#x27;\x82&#x27; in position 21: character maps to <undefined>&#xA;</undefined>

  


  I'm not sure if my LSB replacement algorithm was lost, which results in my not being able to retrieve my frame 0 information, or if the H264 conversion command I used was a converted my video into H264 lossy version instead of lossless (which I don't believe so because I specified -qp 0)
This was the command I used to convert my video

  


  ffmpeg -i video.mp4 -t 12 -c:v libx264 -preset veryslow -qp 0 output.mp4


  


  These are my codes

  


  import json
import os
import magic
import ffmpeg
import cv2
import numpy as np

import subprocess

# Path to the file you want to check
here = os.path.dirname(os.path.abspath(__file__))
file_path = os.path.join(here, "output.mp4")
raw_video = cv2.VideoCapture(file_path)
audio_output_path = os.path.join(here, "audio.aac")
final_video_file = os.path.join(here, "output.mp4")

# create a folder to save the frames.
frames_directory = os.path.join(here, "data1")
try:
    if not os.path.exists(frames_directory):
        os.makedirs(frames_directory)
except OSError:
    print("Error: Creating directory of data")

file_path_txt = os.path.join(here, "hiddentext.txt")
# Read the content of the file in binary mode
with open(file_path_txt, "r") as f:
    file_content = f.read()
# txt_binary_representation = "".join(format(byte, "08b") for byte in file_content)
# print(file_content)

"""
use this cmd to convert any video to h264 lossless. original vid in 10 bit depth format
ffmpeg -i video.mp4 -c:v libx264 -preset veryslow -qp 0 output.mp4

use this cmd to convert any video to h264 lossless. original vid in 8 bit depth format
ffmpeg -i video.mp4 -c:v libx264 -preset veryslow -crf 0 output.mp4

i used this command to only get first 12 sec of video because the h264 vid is too large 
ffmpeg -i video.mp4 -t 12 -c:v libx264 -preset veryslow -qp 0 output.mp4

check for multiple values to ensure its h264 lossless:
1. CRF = 0
2. qp = 0
3. High 4:4:4 Predictive
"""


# region --codec checking. ensure video is h264 lossless--
def check_h264_lossless(file_path):
    try:
        # Use ffprobe to get detailed codec information, including tags
        result = subprocess.run(
            [
                "ffprobe",
                "-v",
                "error",
                "-show_entries",
                "stream=codec_name,codec_long_name,profile,level,bit_rate,avg_frame_rate,nb_frames,tags",
                "-of",
                "json",
                file_path,
            ],
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE,
            text=True,
        )
        # Check if the file is lossless
        metadata = check_h264_lossless(file_path)
        print(json.dumps(metadata, indent=4))

        # Check if the CRF value is available in the tags
        for stream in metadata.get("streams", []):
            if stream.get("codec_name") == "h264":
                tags = stream.get("tags", {})
                crf_value = tags.get("crf")
                encoder = tags.get("encoder")
                print(f"CRF value: {crf_value}")
                print(f"Encoder: {encoder}")
        return json.loads(result.stdout)
    except Exception as e:
        return f"An error occurred: {e}"


# endregion


# region --splitting video into frames--
def extract_audio(input_video_path, audio_output_path):
    if os.path.exists(audio_output_path):
        print(f"Audio file {audio_output_path} already exists. Skipping extraction.")
        return
    command = [
        "ffmpeg",
        "-i",
        input_video_path,
        "-q:a",
        "0",
        "-map",
        "a",
        audio_output_path,
    ]
    try:
        subprocess.run(command, check=True)
        print(f"Audio successfully extracted to {audio_output_path}")
    except subprocess.CalledProcessError as e:
        print(f"An error occurred: {e}")


def split_into_frames():
    extract_audio(file_path, audio_output_path)
    currentframe = 0
    print("Splitting...")
    while True:
        ret, frame = raw_video.read()
        if ret:
            name = os.path.join(here, "data1", f"frame{currentframe}.png")
            # print("Creating..." + name)
            cv2.imwrite(name, frame)
            currentframe += 1
        else:
            print("Complete")
            break


# endregion


# region --merge all back into h264 lossless--
# output_video_file = "output1111.mp4"


def stitch_frames_to_video(frames_dir, output_video_path, framerate=60):
    command = [
        "ffmpeg",
        "-y",
        "-framerate",
        str(framerate),
        "-i",
        os.path.join(frames_dir, "frame%d.png"),
        "-c:v",
        "libx264",
        "-preset",
        "veryslow",
        "-qp",
        "0",
        output_video_path,
    ]

    try:
        subprocess.run(command, check=True)
        print(f"Video successfully created at {output_video_path}")
    except subprocess.CalledProcessError as e:
        print(f"An error occurred: {e}")


def add_audio_to_video(video_path, audio_path, final_output_path):
    command = [
        "ffmpeg",
        "-i",
        video_path,
        "-i",
        audio_path,
        "-c:v",
        "copy",
        "-c:a",
        "aac",
        "-strict",
        "experimental",
        final_output_path,
    ]
    try:
        subprocess.run(command, check=True)
        print(f"Final video with audio created at {final_output_path}")
    except subprocess.CalledProcessError as e:
        print(f"An error occurred: {e}")


# endregion


def to_bin(data):
    if isinstance(data, str):
        return "".join([format(ord(i), "08b") for i in data])
    elif isinstance(data, bytes) or isinstance(data, np.ndarray):
        return [format(i, "08b") for i in data]
    elif isinstance(data, int) or isinstance(data, np.uint8):
        return format(data, "08b")
    else:
        raise TypeError("Type not supported")


def encode(image_name, secret_data):
    image = cv2.imread(image_name)
    n_bytes = image.shape[0] * image.shape[1] * 3 // 8
    print("[*] Maximum bytes to encode:", n_bytes)
    secret_data += "====="
    if len(secret_data) > n_bytes:
        raise ValueError("[!] Insufficient bytes, need bigger image or less data")
    print("[*] Encoding Data")

    data_index = 0
    binary_secret_data = to_bin(secret_data)
    data_len = len(binary_secret_data)
    for row in image:
        for pixel in row:
            r, g, b = to_bin(pixel)
            if data_index < data_len:
                pixel[0] = int(r[:-1] + binary_secret_data[data_index], 2)
                data_index += 1
            if data_index < data_len:
                pixel[1] = int(g[:-1] + binary_secret_data[data_index], 2)
                data_index += 1
            if data_index < data_len:
                pixel[2] = int(b[:-1] + binary_secret_data[data_index], 2)
                data_index += 1
            if data_index >= data_len:
                break
    return image


def decode(image_name):
    print("[+] Decoding")
    image = cv2.imread(image_name)
    binary_data = ""
    for row in image:
        for pixel in row:
            r, g, b = to_bin(pixel)
            binary_data += r[-1]
            binary_data += g[-1]
            binary_data += b[-1]
    all_bytes = [binary_data[i : i + 8] for i in range(0, len(binary_data), 8)]
    decoded_data = ""
    for byte in all_bytes:
        decoded_data += chr(int(byte, 2))
        if decoded_data[-5:] == "=====":
            break
    return decoded_data[:-5]


frame0_path = os.path.join(here, "data1", "frame0.png")
encoded_image_path = os.path.join(here, "data1", "frame0.png")


def encoding_function():
    split_into_frames()

    encoded_image = encode(frame0_path, file_content)
    cv2.imwrite(encoded_image_path, encoded_image)

    stitch_frames_to_video(frames_directory, file_path)
    add_audio_to_video(file_path, audio_output_path, final_video_file)


def decoding_function():
    split_into_frames()
    decoded_message = decode(encoded_image_path)
    print(f"[+] Decoded message: {decoded_message}")


# encoding_function()
decoding_function()



  


  So I tried to put my decoding function into my encoding function like this

  


  def encoding_function():
    split_into_frames()

    encoded_image = encode(frame0_path, file_content)
    cv2.imwrite(encoded_image_path, encoded_image)

#immediately get frame0 and decode without stitching to check if the data is there
    decoded_message = decode(encoded_image_path)
    print(f"[+] Decoded message: {decoded_message}")

    stitch_frames_to_video(frames_directory, file_path)
    add_audio_to_video(file_path, audio_output_path, final_video_file)



  


  This returns my secret text from frame0. But splitting it after stitching does not return my hidden text. The hidden text was lost

  


  def decoding_function():
    split_into_frames()
#this function is after the encoding_function(). the secret text is lost, resulting in charmap codec #can't encode error
    decoded_message = decode(encoded_image_path)
    print(f"[+] Decoded message: {decoded_message}")


  


  EDIT :
So i ran the encoding function first, copied frame0.png out and placed it some where. Then I ran the decoding function, and got another frame0.png.

  


  I ran both frame0.png into this python function

  


  frame0_data1_path = os.path.join(here, "data1", "frame0.png")
frame0_data2_path = os.path.join(here, "data2", "frame0.png")
frame0_data1 = cv2.imread(frame0_data1_path)
frame0_data2 = cv2.imread(frame0_data2_path)

if frame0_data1 is None:
    print(f"Error: Could not load image from {frame0_data1_path}")
elif frame0_data2 is None:
    print(f"Error: Could not load image from {frame0_data2_path}")
else:

    if np.array_equal(frame0_data1, frame0_data2):
        print("The frames are identical.")
    else:
        print("The frames are different.")


  


  ...and apparently both are different. This means my frame0 binary got changed when I stitch back into the video after encoding. Is there a way to make it not change ? Or will h264 or any video codec change a little bit when you stitch the frames back up ?