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• avcodec/mpegvideo_enc : Don't find encoder by ID

  28 janvier 2022, par Andreas Rheinhardt

  avcodec/mpegvideo_enc : Don't find encoder by ID
  mpegvideo-based encoders supporting bframes implement this
  
  by opening encoders of their own to test how long the chains
  
  of bframes are supposed to be. The needed AVCodec was obtained
  
  via avcodec_find_encoder(). This is complicated, as the current
  
  encoder can be directly obtained. And it also is not guaranteed
  
  that one actually gets the current encoder or not another encoder
  
  for the same codec ID (the latter does not seem to be the case now).
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] libavcodec/mpegvideo_enc.c

• FFMPEG command for video and audio

  19 mai 2012, par StackOverflowNewbie

  I'm not building the next YouTube or iTunes, but I do need to give my users the ability to upload their videos and audios — then present it on the web at the highest possible quality with the lowest possible file size.

  Questions :

  1. FOR INPUT : What video and audio formats should I support ? I'm guessing I should try to support the most common formats, but I'm not entirely sure what they are. Also, I'm not sure if I should support the most common formats. Maybe there is a reason not to support a certain format.

  2. FOR OUTPUT : What video and audio output formats should I generate ? I'd like to use HTML5's and tags, but know I should consider supporting non-HTML5 browsers. Should I do OGG, MP4 and FLV for videos ? What about audios ?

  3. Given an unknown video and audio file uploaded by the user, what command should I use to generate the desired output formats. I'd like one command to convert to particular outputs — and hopefully not have to do anything different to the commands depending on the input (it'll be a pain for me to know what the MIME type is of the file, etc. and can't really do an "if input is a WMV, then run this command" logic).

  Suggestion FFMPEG experts ?

• asyncio.create_subprocess_shell error : Future exception was never retrieved - BrokenPipeError

  10 juin 2021, par Abdelmalek

  Whenever I use asyncio.create_subprocess_shell() with sp.communicate() I get this error at the end of my program.

  


  If I run multiple suprocesses using asyncio, the error would be print at the end for each one of them.

  


  Aulthough it doesn't affect my program, I want to find the source and fix the issue. Thanks for the help !

  


  Traceback :

  


  Future exception was never retrieved&#xA;future: <future finished="finished" exception="BrokenPipeError(32," pipe="pipe" has="has" been="been">&#xA;Traceback (most recent call last):&#xA;  File "C:\Users\user\AppData\Local\Programs\Python\Python39\lib\asyncio\subprocess.py", line 153, in _feed_stdin&#xA;    await self.stdin.drain()&#xA;  File "C:\Users\user\AppData\Local\Programs\Python\Python39\lib\asyncio\streams.py", line 387, in drain&#xA;    await self._protocol._drain_helper()&#xA;  File "C:\Users\user\AppData\Local\Programs\Python\Python39\lib\asyncio\streams.py", line 197, in _drain_helper&#xA;    await waiter&#xA;  File "C:\Users\user\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 379, in _loop_writing&#xA;    f.result()&#xA;  File "C:\Users\user\AppData\Local\Programs\Python\Python39\lib\asyncio\windows_events.py", line 812, in _poll&#xA;    value = callback(transferred, key, ov)&#xA;  File "C:\Users\user\AppData\Local\Programs\Python\Python39\lib\asyncio\windows_events.py", line 538, in finish_send&#xA;    return ov.getresult()&#xA;BrokenPipeError: [WinError 109] The pipe has been ended&#xA;</future>

  


  Code :

  


  async def get(cs, url):
    async with cs.get(url) as r:
        b = b''
        while True:
            chunk = await r.content.read(4000000)
            b += chunk
            if not chunk:
                break
        
        if int(r.headers['content-length']) < 8000000:
            result = BytesIO(b)
            return [result, 'full']
        else:
            command = f"ffmpeg -y -i - -c:v copy -fs 8000000 -f matroska -"
            sp = await asyncio.create_subprocess_shell(command, stdin=asyncio.subprocess.PIPE,
                stdout=asyncio.subprocess.PIPE, stderr=asyncio.subprocess.PIPE)
            stdout, stderr = await sp.communicate(b)
            sp.wait()

            print(stderr.decode())
            print(len(stdout))
            output = str(stderr)
            index_d = output.find('Duration: ')
            index_t = output.rfind('time=')
            duration = await get_sec(output[index_d + 10:].split(",")[0])
            time_ = await get_sec(output[index_t + 5:].split(" ")[0])
            percentage = f"{round((time_ / duration) * 100)}%"

            result = BytesIO(stdout)
            return [result, 'preview', percentage]

async def main(urls):
    async with aiohttp.ClientSession() as cs:
            
        tasks = []
        for url in urls:
            task = asyncio.create_task(get(cs, url))
            tasks.append(task)
        
        results = []
        for task in tasks:
            result = await task
            results.append(result)
        
        return results

loop = asyncio.get_event_loop()
results = loop.run_until_complete(main(urls))