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• ffmpeg, live MPEG-TS demux & decode

  8 mai 2017, par NadavRub

  Environment

  • Ubuntu-14
  • C++
  • ffmpeg

  Use-case

  • Live SPTS is received via UDP by a 3rd party module
  • TS Packets are received iteratively
  • The TS Video (ES) should be decoded in minimal latency

  Considered Implementation

  • Upon TS packet reception, immediately push it to the TS demux
  • Once enough packets are received the video format is resolvable, create the video codec
  • Push each video packet into the video decoder
  • Once enough video packets were processed the video codec result a valid output frame

  Problem at-hand

  Can this be done w/ ffmpeg ?!?!, … using “avformat_open_input” mandate a file to read from… I need a way where I can iteratively push packets to the TS demuxer ( w/ minimal latency )…

  Does ffmpeg support the above mentioned use-case ? How ?

• ffmpeg app using node occasionally crashes as file doesn't appear to be read correctly

  31 mai 2022, par Zabs

  I have an simple Node application that allows me to pass an AWS S3 URL link to a file (in this case video files). It uses the FFMPEG library to read the video file and return data like codecs, duration, bitrate etc..

  


  The script is called from PHP script which in turn send the data to the Node endpoint and passes the Amazon S3 URL to node. Sometimes for no obvious reasons the video file fails to return the expected values regarding container, codec, duration etc... and just returns '0'. But when I try the exact same file/request again it returns this data correctly e.g container:mp4

  


  I'm not sure but I think the script somehow needs the createWriteStream to be closed but I cannot be sure, the problem is the issue I have found doesn't happen all the time but sporadically so its hard to get to the issue when its difficult to replicate it.

  


  Any ideas ?

  


  router.post('/', async function(req, res) {
  const fileURL = new URL(req.body.file);
  var path = fileURL.pathname;
  path = 'tmp/'+path.substring(1);    // removes the initial / from the path

  let file = fs.createWriteStream(path);  // create the file locally
  const request = https.get(fileURL, function(response) {
    response.pipe(file);
  });
  
  // after file has saved
  file.on('finish', function () {
    var process = new ffmpeg(path);
    process.then(function (video) {
      let metadata = formatMetadata(video.metadata);

      res.send ({
        status: '200',
        data: metadata,
        errors: errors,
        response: 'success'
      });

    }, function (err) {
      console.warn('Error: ' + err);

      res.send ({
        status: '400',
        data: 'Something went wrong processing this video',
        response: 'fail',
      });
    });
  });

  file.on('error', function (err) {
    console.warn(err);
  });

});

function formatMetadata(metadata) {
  const data = {
    'video' : metadata.video,
    'audio' : metadata.audio,
    'duration' : metadata.duration
  };
  return data;
}


  


  // Expected output

  


  {"data":{"video":{"container":"mov","bitrate":400,"stream":0,"codec":"h264","resolution":{"w":1280,"h":720},"resolutionSquare":{"w":1280,"h":720},"aspect":{"x":16,"y":9,"string":"16:9","value":1.7777777777777777},"rotate":0,"fps":25,"pixelString":"1:1","pixel":1},"audio":{"codec":"aac","bitrate":"127","sample_rate":44100,"stream":0,"channels":{"raw":"stereo","value":2}},"duration":{"raw":"00:00:25.68","seconds":25}}


  


  // Actual output

  


  {"data":{"video":{"container":"","bitrate":0,"stream":0,"codec":"","resolution":{"w":0,"h":0},"resolutionSquare":{"w":0,"h":null},"aspect":{},"rotate":0,"fps":0,"pixelString":"","pixel":0},"audio":{"codec":"","bitrate":"","sample_rate":0,"stream":0,"channels":{"raw":"","value":""}},"duration":{"raw":"","seconds":0}}


  


  Note - this happens sporadically

  


• lavc/aarch64 : motion estimation functions in neon

  26 juin 2022, par Swinney, Jonathan

  lavc/aarch64 : motion estimation functions in neon
   - ff_pix_abs16_neon
  
   - ff_pix_abs16_xy2_neon
  In direct micro benchmarks of these ff functions verses their C implementations,
  
  these functions performed as follows on AWS Graviton 3.
  ff_pix_abs16_neon :
  
  pix_abs_0_0_c : 141.1
  
  pix_abs_0_0_neon : 19.6
  ff_pix_abs16_xy2_neon :
  
  pix_abs_0_3_c : 269.1
  
  pix_abs_0_3_neon : 39.3
  Tested with :
  
  ./tests/checkasm/checkasm —test=motion —bench —disable-linux-perf
  Signed-off-by : Jonathan Swinney <jswinney@amazon.com>
  
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DH] libavcodec/aarch64/Makefile
  • [DH] libavcodec/aarch64/me_cmp_init_aarch64.c
  • [DH] libavcodec/aarch64/me_cmp_neon.S
  • [DH] libavcodec/me_cmp.c
  • [DH] libavcodec/me_cmp.h
  • [DH] tests/checkasm/Makefile
  • [DH] tests/checkasm/checkasm.c
  • [DH] tests/checkasm/checkasm.h
  • [DH] tests/checkasm/motion.c
  • [DH] tests/fate/checkasm.mak