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• 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.

  


• 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 ?

  


• When downloading HLS video with FFMPEG it does not download the audio

  3 août 2021, par Thiago Franklin

  I have a problem, when I try to download an HLS video with FFMPEG, it downloads the video track, but it doesn't find the AUDIO. When running the HLS .m3u8 file in a player, it plays normally, audio and video, but when trying to download, it shows an error message saying that the audio cannot be found.

  


  I'm running the following command :

  


  ffmpeg.exe -i "https://teste-etv.espiritismo.tv/437602.m3u8" -codec:a libmp3lame -b:a 96k teste-hls.mp3

  


  Displays the following error when trying to download the audio :

  


  [hls @ 0000021b5d9ad940] Skip ('#EXT-X-VERSION:3')
[hls @ 0000021b5d9ad940] Skip ('#EXT-X-INDEPENDENT-SEGMENTS')
[hls @ 0000021b5d9ad940] Opening 'https://appsetv.b-cdn.net/hls/437602/437602-1080p.m3u8' for reading
[hls @ 0000021b5d9ad940] Skip ('#EXT-X-VERSION:3')
[https @ 0000021b5e10ee00] Opening 'https://appsetv.b-cdn.net/hls/437602/437602-720p.m3u8' for reading
[hls @ 0000021b5d9ad940] Skip ('#EXT-X-VERSION:3')
[https @ 0000021b5e10ee00] Opening 'https://appsetv.b-cdn.net/hls/437602/437602-540p.m3u8' for reading
[hls @ 0000021b5d9ad940] Skip ('#EXT-X-VERSION:3')
[https @ 0000021b5e10ee00] Opening 'https://appsetv.b-cdn.net/hls/437602/437602-360p.m3u8' for reading
[hls @ 0000021b5d9ad940] Skip ('#EXT-X-VERSION:3')
[hls @ 0000021b5d9ad940] Opening 'https://appsetv.b-cdn.net/hls/437602/437602-1080p_00001.ts' for reading
[hls @ 0000021b5d9ad940] Opening 'https://appsetv.b-cdn.net/hls/437602/437602-1080p_00002.ts' for reading
[hls @ 0000021b5d9ad940] Opening 'https://appsetv.b-cdn.net/hls/437602/437602-720p_00001.ts' for reading
[hls @ 0000021b5d9ad940] Opening 'https://appsetv.b-cdn.net/hls/437602/437602-720p_00002.ts' for reading
[hls @ 0000021b5d9ad940] Opening 'https://appsetv.b-cdn.net/hls/437602/437602-540p_00001.ts' for reading
[hls @ 0000021b5d9ad940] Opening 'https://appsetv.b-cdn.net/hls/437602/437602-540p_00002.ts' for reading
[hls @ 0000021b5d9ad940] Opening 'https://appsetv.b-cdn.net/hls/437602/437602-360p_00001.ts' for reading
[hls @ 0000021b5d9ad940] Opening 'https://appsetv.b-cdn.net/hls/437602/437602-360p_00002.ts' for reading
[hls @ 0000021b5d9ad940] Could not find codec parameters for stream 1 (Audio: aac ([15][0][0][0] / 0x000F), 0 channels, fltp): unspecified sample rate
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[hls @ 0000021b5d9ad940] Could not find codec parameters for stream 3 (Audio: aac ([15][0][0][0] / 0x000F), 0 channels, fltp): unspecified sample rate
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[hls @ 0000021b5d9ad940] Could not find codec parameters for stream 5 (Audio: aac ([15][0][0][0] / 0x000F), 0 channels, fltp): unspecified sample rate
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[hls @ 0000021b5d9ad940] Could not find codec parameters for stream 7 (Audio: aac ([15][0][0][0] / 0x000F), 0 channels, fltp): unspecified sample rate
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, hls, from 'https://appsetv.b-cdn.net/hls/437602/437602.m3u8':
  Duration: 00:01:41.00, start: 2.083333, bitrate: 0 kb/s
  Program 0
    Metadata:
      variant_bitrate : 2509173
    Stream #0:0: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 24 fps, 24 tbr, 90k tbn, 48 tbc
    Metadata:
      variant_bitrate : 2509173
    Stream #0:1: Audio: aac ([15][0][0][0] / 0x000F), 0 channels, fltp
    Metadata:
      variant_bitrate : 2509173
  Program 1
    Metadata:
      variant_bitrate : 1205957
    Stream #0:2: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 24 fps, 24 tbr, 90k tbn, 48 tbc
    Metadata:
      variant_bitrate : 1205957
    Stream #0:3: Audio: aac ([15][0][0][0] / 0x000F), 0 channels, fltp
    Metadata:
      variant_bitrate : 1205957
  Program 2
    Metadata:
      variant_bitrate : 1165600
    Stream #0:4: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p, 960x540 [SAR 1:1 DAR 16:9], 24 fps, 24 tbr, 90k tbn, 48 tbc
    Metadata:
      variant_bitrate : 1165600
    Stream #0:5: Audio: aac ([15][0][0][0] / 0x000F), 0 channels, fltp
    Metadata:
      variant_bitrate : 1165600
  Program 3
    Metadata:
      variant_bitrate : 656245
    Stream #0:6: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p, 640x360 [SAR 1:1 DAR 16:9], 24 fps, 24 tbr, 90k tbn, 48 tbc
    Metadata:
      variant_bitrate : 656245
    Stream #0:7: Audio: aac ([15][0][0][0] / 0x000F), 0 channels, fltp
    Metadata:
      variant_bitrate : 656245
Output #0, mp3, to 'teste-hls.mp3':
Output file #0 does not contain any stream