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• Why is audio bitrate value of ffprobe output higher ?

  9 mars 2023, par 19xlr95

  When I check audio bitrate of my video via OS file details, media players or ffprobe -i my_video.mp4, I get the bitrate is 128 kbps. And I want to get more detailed meta information of the video by ffprobe -loglevel 0 -print_format json -show_format -show_streams my_video.mp4. However audio bitrate value of the output is 128615 bps.

  


  I thought it should be 128000 not 128615. Or 128 x 1024 = 131072. I wonder why it is not one of the values that I assumed. Also how can I safely say that this 128615 bps is 128 kbps ?

  


  Below is the detailed meta information for my video.

  


  {
    "streams": [
        {
            "index": 0,
            "codec_name": "aac",
            "codec_long_name": "AAC (Advanced Audio Coding)",
            "profile": "LC",
            "codec_type": "audio",
            "codec_tag_string": "mp4a",
            "codec_tag": "0x6134706d",
            "sample_fmt": "fltp",
            "sample_rate": "48000",
            "channels": 2,
            "channel_layout": "stereo",
            "bits_per_sample": 0,
            "initial_padding": 0,
            "id": "0x1",
            "r_frame_rate": "0/0",
            "avg_frame_rate": "0/0",
            "time_base": "1/48000",
            "start_pts": 0,
            "start_time": "0.000000",
            "duration_ts": 965760,
            "duration": "20.120000",
            "bit_rate": "128615",
            "nb_frames": "946",
            "extradata_size": 2,
            "disposition": {
                "default": 1,
                "dub": 0,
                "original": 0,
                "comment": 0,
                "lyrics": 0,
                "karaoke": 0,
                "forced": 0,
                "hearing_impaired": 0,
                "visual_impaired": 0,
                "clean_effects": 0,
                "attached_pic": 0,
                "timed_thumbnails": 0,
                "captions": 0,
                "descriptions": 0,
                "metadata": 0,
                "dependent": 0,
                "still_image": 0
            },
            "tags": {
                "creation_time": "2023-02-20T09:00:58.000000Z",
                "language": "deu",
                "handler_name": "Core Media Audio",
                "vendor_id": "[0][0][0][0]"
            }
        },
        {
            "index": 1,
            "codec_name": "h264",
            "codec_long_name": "H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10",
            "profile": "High",
            "codec_type": "video",
            "codec_tag_string": "avc1",
            "codec_tag": "0x31637661",
            "width": 1080,
            "height": 1920,
            "coded_width": 1080,
            "coded_height": 1920,
            "closed_captions": 0,
            "film_grain": 0,
            "has_b_frames": 0,
            "sample_aspect_ratio": "1:1",
            "display_aspect_ratio": "9:16",
            "pix_fmt": "yuv420p",
            "level": 42,
            "color_range": "tv",
            "color_space": "bt709",
            "color_transfer": "bt709",
            "color_primaries": "bt709",
            "chroma_location": "left",
            "field_order": "progressive",
            "refs": 1,
            "is_avc": "true",
            "nal_length_size": "4",
            "id": "0x2",
            "r_frame_rate": "50/1",
            "avg_frame_rate": "50/1",
            "time_base": "1/50000",
            "start_pts": 0,
            "start_time": "0.000000",
            "duration_ts": 1006000,
            "duration": "20.120000",
            "bit_rate": "20958903",
            "bits_per_raw_sample": "8",
            "nb_frames": "1006",
            "extradata_size": 35,
            "disposition": {
                "default": 1,
                "dub": 0,
                "original": 0,
                "comment": 0,
                "lyrics": 0,
                "karaoke": 0,
                "forced": 0,
                "hearing_impaired": 0,
                "visual_impaired": 0,
                "clean_effects": 0,
                "attached_pic": 0,
                "timed_thumbnails": 0,
                "captions": 0,
                "descriptions": 0,
                "metadata": 0,
                "dependent": 0,
                "still_image": 0
            },
            "tags": {
                "creation_time": "2023-02-20T09:00:58.000000Z",
                "language": "und",
                "handler_name": "Core Media Video",
                "vendor_id": "[0][0][0][0]"
            }
        }
    ],
    "format": {
        "filename": "my_video.mp4",
        "nb_streams": 2,
        "nb_programs": 0,
        "format_name": "mov,mp4,m4a,3gp,3g2,mj2",
        "format_long_name": "QuickTime / MOV",
        "start_time": "0.000000",
        "duration": "20.120000",
        "size": "53309460",
        "bit_rate": "21196604",
        "probe_score": 100,
        "tags": {
            "major_brand": "mp42",
            "minor_version": "1",
            "compatible_brands": "isommp41mp42",
            "creation_time": "2023-02-20T09:00:58.000000Z"
        }
    }
}


  


  I checked 1 kbps is 1000 bps and assumed 128 kbps of the audio bitrate should be 128000 bps. But it is 128615 bps when I run ffprobe.

  


• FileNotFoundError when extracting audio from recently saved video using FFMPEG"

  3 août 2023, par Peter Long

  Scenario : I'm using this tool to record tiktok live. I write another script to call the main.pytool because I want to add some additional options, for example, to extract the audio of the live video that is recorded
  

  


  FFMPEG is used to extract the audio. First the video is saved (with FFMPEG) and after I want to extract the audio of that video (again with FFMPEG). The path where the video is recorded and saved is C:\Users\Administrator\Desktop\tiktok

  


  The problem is that I see the file and it is saved, but this error is generated as output : FileNotFoundError: [WinError 2] The system cannot find the file specified

  


  I can't figure out why it doesn't detect the last saved video file in general

  


  I try with this

  


  import os
import subprocess
import time
from moviepy.editor import VideoFileClip

def main():
    # Command to run main.py and record the video
    cmd = 'python main.py -user ryzebenny -output "C:\\Users\\Administrator\\Desktop\\tiktok" -ffmpeg -duration 30 --auto-convert'
    subprocess.run(cmd, shell=True)

    # Wait for the video file to appear in the folder
    wait_for_video("C:\\Users\\Administrator\\Desktop\\tiktok")

    # Extract audio from recorded video
    video_filename = find_latest_file("C:\\Users\\Administrator\\Desktop\\tiktok", ".mp4")
    if video_filename:
        video_path = os.path.join("C:\\Users\\Administrator\\Desktop\\tiktok", video_filename)
        audio_filename = video_filename.replace(".mp4", ".mp3")
        audio_path = os.path.join("C:\\Users\\Administrator\\Desktop\\tiktok", audio_filename)

        video_clip = VideoFileClip(video_path)
        audio_clip = video_clip.audio
        audio_clip.write_audiofile(audio_path)
        audio_clip.close()
        video_clip.close()
        print(f"Audio extraction completed: {audio_filename}")
    else:
        print("No video files found.")

def wait_for_video(directory):
    max_wait_time = 60  # Maximum time to wait in seconds
    start_time = time.time()
    while time.time() - start_time < max_wait_time:
        if find_latest_file(directory, ".mp4"):
            break
        time.sleep(1)

def find_latest_file(directory, extension):
    list_of_files = [f for f in os.listdir(directory) if f.endswith(extension) and os.path.isfile(os.path.join(directory, f))]
    if list_of_files:
        return max(list_of_files, key=os.path.getctime)
    return None

if __name__ == "__main__":
    main()


  


  but i get this error

  


  [*] 2023-08-03 15:57:09 - INFO - START RECORDING FOR 30 SECONDS&#xA;[*] 2023-08-03 15:57:09 - INFO - [PRESS &#x27;q&#x27; TO STOP RECORDING]&#xA;[*] 2023-08-03 15:57:31 - INFO - FINISH: C:\Users\Administrator\Desktop\tiktok\TK_ryzebenny_2023.08.03_15-57-09_flv.mp4&#xA;&#xA;Traceback (most recent call last):&#xA;  File "C:\Users\Administrator\Desktop\tiktok\TikTok-Live-Recorder\run_main.py", line 45, in <module>&#xA;    main()&#xA;  File "C:\Users\Administrator\Desktop\tiktok\TikTok-Live-Recorder\run_main.py", line 12, in main&#xA;    wait_for_video("C:\\Users\\Administrator\\Desktop\\tiktok")&#xA;  File "C:\Users\Administrator\Desktop\tiktok\TikTok-Live-Recorder\run_main.py", line 34, in wait_for_video&#xA;    if find_latest_file(directory, ".mp4"):&#xA;       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^&#xA;  File "C:\Users\Administrator\Desktop\tiktok\TikTok-Live-Recorder\run_main.py", line 41, in find_latest_file&#xA;    return max(list_of_files, key=os.path.getctime)&#xA;           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^&#xA;  File "<frozen genericpath="genericpath">", line 65, in getctime&#xA;FileNotFoundError: [WinError 2] The system cannot find the file specified: &#x27;TK_ryzebenny_2023.08.03_15-57-09.mp4&#x27;&#xA;</frozen></module>

  


  Instead, I expect that once I save the video (in .mp4) the audio of that video will be extracted afterwards

  


• Parse dynamic mpd file with Media Source Extensions

  17 février 2023, par FrankC

  I just started learning about adaptive streaming, and currently I'm working on a project that needs showing a live video. In order to control some of the elements in mpd file, I determined to use MSE instead of dash.js. I refer to the code at the following URL :https://learn.microsoft.com/en-us/previous-versions/windows/internet-explorer/ie-developer/samples/dn551368(v=vs.85)
But I found out that there is no "Initialization" tag or "range" attribute in my mpd file. I don't find any relative attribute as well. By the way I'm use nginx-rtmp + ffmpeg to generate dash file.
So here is my dash file looks like

  


  &lt;?xml version="1.0"?>&#xA; &#xA;  <period start="PT0S">&#xA;    &#xA;      &#xA;        &#xA;          <segmenttimeline>&#xA;             <s t="0" d="10000"></s>&#xA;             <s t="10000" d="10000"></s>&#xA;             <s t="20000" d="5000"></s>&#xA;             <s t="25000" d="10000"></s>&#xA;          </segmenttimeline>&#xA;        &#xA;      &#xA;    &#xA;  </period>&#xA;&#xA;

  


  My question is :
1.Did I have any missing parameters in using ffmpeg or nginx-rtmp resulting in losting tag in mpd file ?
2.Or there is other way to setup "Initialization"/"range" attribute and let my program work ?
3.I also curious about why my mpd file doesn't have a baseURL element ?

  


  ※My mpd file works fine with dash.js, I can see the video properly

  


  THANKS A LOT