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• ffmpeg download mp3 in chunks slower than whole file

  6 août 2021, par loretoparisi

  I'm programmatically downloading in Python mp3 file's as wav chunks, seeking at position with ss and t with ffmpeg resulting in a sequence of ffmpeg commands

  


  ffmpeg -i https://file-examples-com.github.io/uploads/2017/11/file_example_MP3_5MG.mp3 -acodec pcm_s16le -ac 1 -ar 44100 -ss 0:08:55.780000 -t 0:01:00.000000 -sn -vn -y -f wav pipe:1
ffmpeg -i https://file-examples-com.github.io/uploads/2017/11/file_example_MP3_5MG.mp3 -acodec pcm_s16le -ac 1 -ar 44100 -ss -ss 0:09:55.780000 -t 0:01:00.000000 -sn -vn -y -f wav pipe:1
ffmpeg -i https://file-examples-com.github.io/uploads/2017/11/file_example_MP3_5MG.mp3 -acodec pcm_s16le -ac 1 -ar 44100 -ss -ss -ss 0:10:55.780000 -t 0:01:00.000000 -sn -vn -y -f wav pipe:1
...


  


  executed via concurrent.futures.ThreadPoolExecutor in this way :

  


  with concurrent.futures.ThreadPoolExecutor(max_workers=NTHREADS) as executor:
        for i,cmd in enumerate(process_list):
            futures.append(executor.submit(downloader.chunk_download,(cmd,i)))

        for future in concurrent.futures.as_completed(futures):
            try:
                completed.append(future.result())
            except Exception as e:print(e)
    completed.sort() 
    for k,c in enumerate(completed):
        if not k:
            waveform = c[1]
        else:
            waveform = np.append(waveform,c[1])


  


  where chunk_download is concat the chunks into the whole waveform

  


  def chunk_download(self,args):
        cmd=args[0]
        i=args[1]
        print('Downloading chunk n° %i' % i)

        print( ' '.join(cmd))
        process = subprocess.run(cmd,
                            stdout=subprocess.PIPE,
                            stderr=subprocess.PIPE,
                            bufsize=10**8)
        #buffer, stderr = process.communicate()
        buffer = process.stdout
        stderr = process.stderr
        print('chunk n° %i DOWNLOADED' % i)
        # convert to signal
        chunk_waveform = np.frombuffer(buffer=buffer, dtype=np.uint16, offset=8*44)
        chunk_waveform = chunk_waveform.astype(self.dtype)  
        print(len(chunk_waveform)/44100) 

        return i,chunk_waveform


  


  this works ok, but if I download the whole mp3, executing the command in cmd like :

  


  ffmpeg -i https://file-examples-com.github.io/uploads/2017/11/file_example_MP3_5MG.mp3 -acodec pcm_s16le -ac 1 -ar 44100 -sn -vn -y -f wav pipe:1


  


  It will take less time than the concurrent chunks download for the same file length, while I would expect the opposite. Could be this related to ffmpeg threading option (param --thread ?). If not, why the concurrent chunks download operation is slower ?

  


• Download a part of youtube video using a powershell script

  26 octobre 2024, par Nguyễn Đức Minh

  I'm writing this Powershell script :

  


  $URL = "https://www.youtube.com/watch?v=KbuwueqEJL0"
$from = 00:06:15
$to = 00:09:17

$cmdOutput = (youtube-dl --get-url $URL) 

ffmpeg -ss $from -to $to -i  -ss $from -to $to -i  output.mkv


  


  This script's purpose is to download a part of a Youtube video. I've set the variable $URL to specify the Youtube URL, while $from and $to is the start and end time of the part I want to download.

  


  $cmdOutput is used to output the stream URL. The output would have two lines : the first one is the URL for the video stream, while the second one is the audio stream URL.

  


  Currently, I don't know how to use the output as a variable and specify the line number of $cmdOutput to put it into the correct stream. I guess and would be replaced by something like $cmdOutput[line 1], and $cmdOutput[line 2], though I know that those are incorrect.

  


  I've consulted this answer, and it is handy for me to write this script. I've also read Boris Lipschitz's answer on how to do the same thing with Python, but his answer does not work.

  


  In that script, the -ss flag inputs the seeking point, and the -t <duration></duration> flag tells FFmpeg to stop encoding after the specified duration. For example, if the start time is 00:02:00 and the duration is 00:03:00, FFmpeg would download from 00:02:00 to 00:05:00, which is not the expected outcome. For some reason, his Python script skips the first 5 seconds of output, even if I replace the -t flag with -to . I've tried to edit his script, but it does not work unless you explicitly specify the time for both video and audio stream, as well as their respective stream URL.

  


• Can not download a streamable m3u8 link with IDM and ffmpeg

  15 juillet 2021, par long

  This is the link : https://v13.phephim.xyz/vod/v2/packaged:mp4/6005b3591918ee01c9ef67e4/playlist.m3u8

  


  It's ok to play the link with play-hls-m3u8 chrome extension or by the site https://www.hlsplayer.net/ but I got errors when trying to download it by ffmpeg :

  


  ffmpeg -i https://v13.phephim.xyz/vod/v2/packaged:mp4/6005b3591918ee01c9ef67e4/playlist.m3u8 -c copy OUTPUT.MP4


  


  Full log :

  


     ffmpeg version 4.2.4-1ubuntu0.1 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
  configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
[hls @ 0x561c95a74c40] Skip ('#EXT-X-VERSION:3')
[hls @ 0x561c95a74c40] Opening 'https://v13.phephim.xyz/vod/v2/packaged:mp4/6005b3591918ee01c9ef67e4/0.ts?e=ad32a6dc7559f830a29b88ca30b975d90daef6578a563b09e97c798063c39de9fc124d470f75ad0220b9f440b7bd6767' for reading
[hls @ 0x561c95a74c40] Opening 'https://v13.phephim.xyz/vod/v2/packaged:mp4/6005b3591918ee01c9ef67e4/1.ts?e=e9b0a737f46906cdb4d67aed95e65ae4ab8eb401100eebce4e711ffdaf43c68fc2d8a49add4295587b38fe90c9d4cf86' for reading
[hls @ 0x561c95a74c40] Could not find codec parameters for stream 0 (Video: png, none(pc)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, hls, from 'https://v13.phephim.xyz/vod/v2/packaged:mp4/6005b3591918ee01c9ef67e4/playlist.m3u8':
  Duration: 01:02:06.42, bitrate: 0 kb/s
  Program 0 
    Metadata:
      variant_bitrate : 0
    Stream #0:0: Video: png, none(pc), 25 tbr, 25 tbn, 25 tbc
    Metadata:
      variant_bitrate : 0
Output #0, mp4, to 'OUTPUT.MP4':
Output file #0 does not contain any stream


  


  I have tried to add some other command options but still got the same errors.

  


  Doing devtools inspect, I found
the .ts segment link redirected to another link that has the response header :

  


  content-disposition: inline;filename="unnamed.png"
content-type: image/png


  


  Is it normal ?

  


  Image : response header

  


  Pls help me to download the video. Thanks !

  


  p/s : sorry for my bad english :)