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• Recapping WebM’s First Week

  25 mai 2010, par noreply@blogger.com (John Luther) — webm, vp8, vorbis

  The WebM project launched last Wednesday with broad industry backing (watch video of the announcement). The list of supporters keeps growing with new additions such as the popular VLC media player, Miro Video Converter, HeyWatch cloud encoding platform, and videantis programmable processor platform. We’re also happy to see that future versions of IE will support playback of VP8 when the user has installed the codec.

  Our announcement sparked discussions in the community around the design and quality of our developer release. We’ve done extensive testing of VP8 and know that the codec can match or exceed the quality of other leading codecs. Starting this week, the engineers behind WebM will post frequently to this blog with details on how to make optimal use of its VP8 video codec and Vorbis audio codec. We are confident that the open development model will bring additional improvements that will further optimize WebM. In fact, the power of open development is already visible, with developers submitting patches and the folks at Flumotion enabling live streaming support in their product just three days after the project was launched.

  Keep an eye on this blog for regular updates on the adoption and development of WebM. To participate in the conversation or to ask questions of the WebM team, please join our discussion group.

  John Luther
  Product Manager, Google

  

• Terminal prompt disappears after asyncio script with ffmpeg writing things is run

  8 avril 2022, par David I

  I've followed a simple example https://docs.python.org/3/library/asyncio-task.html#running-tasks-concurrently in trying to learn the basics of asyncio.

  


  It works as expected with most commands however when employed with three ffmpeg commands that take an input and write an output, see the example below, the terminal window prompt becomes invisible after the script has (seemingly successfully run). It responds to typed commands and shows the result but the input isn't shown until I start a new terminal session. It's the same with Code's bash terminal as with Kitty.

  


  It doesn't seem to be a "write to file system concurrantly" problem as the echo lines don't produce the problem. The ffprobe commands don't produce it either but "command1" and 2 and 3 always do. It's the same with other ffmpeg commands that write to the file system via a conversion or a split of an audio input file.

  


  The processes exit with 0 and ffmpeg issues most output to stderr so the output looks like

  


  


  ['ffmpeg -y -i "01 Dia Artio.m4a" "oof1.wav"' exited with 0]
[stderr]
ffmpeg version N-104926-gc8b5f2848d Copyright (c) 2000-2021 the FFmpeg developers
built with gcc 11 (GCC)...

  


  


  import asyncio

async def run(cmd):
    proc = await asyncio.create_subprocess_shell(
        cmd,
        stdout=asyncio.subprocess.PIPE,
        stderr=asyncio.subprocess.PIPE)

    stdout, stderr = await proc.communicate()
    print(f'[{cmd!r} exited with {proc.returncode}]')
    print(f'[stderr]\n{stderr.decode()}')

async def main():
    # Schedule three calls *concurrently*:
    command1 = "ffmpeg -y -i '01 Dia Artio.m4a' 'oof1.wav'"
    command2 = "ffmpeg -y -i '03 Cleansing.m4a' 'oof3.wav'"
    command3 = "ffmpeg -y -i 'The Cranberries - 10 - Dreaming My Dreams.flac' 'oof2.wav'"

    cat1 = "echo 'cat' > cat.txt"
    cat2 = "echo 'kitteh' > kat.txt"
    cat3 = "echo 'eirlyss' > eirlyss.txt"

    ffprobe1 = "ffprobe oof1.wav"
    ffprobe2 = "ffprobe oof2.wav"
    ffprobe3 = "ffprobe oof1.wav"
    await asyncio.gather(
        run(command1),
        run(command2),
        run(command3)
    )
    
 
asyncio.run(main())


  


  This problem has only happened with this combination of asyncio and ffmpeg and it appears consistent and I would very much like to know what might be the cause of it.

  


  I'm on Fedora 35 with Python 3.10.4 and a self built (via ffmpegs instructs) ffmpeg from a few months back).

  


• Recapping WebM’s First Week

  25 mai 2010, par noreply@blogger.com (John Luther) — webm, vp8, vorbis

  The WebM project launched last Wednesday with broad industry backing (watch video of the announcement). The list of supporters keeps growing with new additions such as the popular VLC media player, Miro Video Converter, HeyWatch cloud encoding platform, and videantis programmable processor platform. We’re also happy to see that future versions of IE will support playback of VP8 when the user has installed the codec.

  Our announcement sparked discussions in the community around the design and quality of our developer release. We’ve done extensive testing of VP8 and know that the codec can match or exceed the quality of other leading codecs. Starting this week, the engineers behind WebM will post frequently to this blog with details on how to make optimal use of its VP8 video codec and Vorbis audio codec. We are confident that the open development model will bring additional improvements that will further optimize WebM. In fact, the power of open development is already visible, with developers submitting patches and the folks at Flumotion enabling live streaming support in their product just three days after the project was launched.

  Keep an eye on this blog for regular updates on the adoption and development of WebM. To participate in the conversation or to ask questions of the WebM team, please join our discussion group.

  John Luther
  Product Manager, Google