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• audio sample format s16p, ffmpeg or audio codec bug ?

  5 février 2016, par Arton

  I have a video file and I had dumped the video info to a txt file with ffmpeg nearly 3 year ago.

  ...
  
  Stream #0:1[0x1c0]: Audio: mp2, 48000 Hz, stereo, s16, 256 kb/s
  
  Stream #0:2[0x1c1]: Audio: mp2, 48000 Hz, stereo, s16, 256 kb/s

  But I found the format changed when I used the update ffprobe (ffprobe version N-78046-g46f67f4 Copyright (c) 2007-2016 the FFmpeg developers).

  ...
  
  Stream #0:1[0x1c0]: Audio: mp2, 48000 Hz, stereo, s16p, 256 kb/s
  
  Stream #0:2[0x1c1]: Audio: mp2, 48000 Hz, stereo, s16p, 256 kb/s

  With the same video, its sample format changes to s16p.

  I implemented a simple video player which uses ffmpeg. It can play video 3 years ago, but failed to output the correct pcm stream after changing to update ffmpeg. I spent lots time and finally found that the audio should have been s16 instead of s16p. The decoded audio stream works after I added the line before calling avcodec_decode_audio4,

  audio_codec_ctx->sample_fmt = AV_SAMPLE_FMT_S16

  but it is just a hack. Does anyone encounter this issue ? How to make ffmpeg work correctly ? Any hint is appreciated. Thanks !

• Analytics for the Internet of Things : collecting all your things’ data with Piwik to stay in control ?

  25 novembre 2015, par Matthieu Aubry — About

  At Piwik and Piwik PRO, our mission is to create the leading free and open source analytics platform, and supporting global organisations and communities to keep full control over their data.

  Our broad mission started 8 years ago and we focused at first helping people to liberate their website analytics data, then liberate their mobile app analytics data. But it is clear that there is much more than Web + Mobile : data is everywhere and a lot more data is being generated by software, people and their activities, robots, sensors…

  I’d like to share an interesting article which highlights one of the growing trends of technology : the rise of the Internet Of Things : 6 Ways Analytics And The Internet Of Things Will Transform Business.

  Here is an extract :

  The tech industry is no stranger to change, but the data derived from the IoT is taking disruption to a new level.

  At IBM’s Insight conference last month, Bob Picciano, senior vice president of IBM Analytics, talked about the rise of the “cognitive business”, or an enterprise that engages with analytics to improve its customer relations, business processes, and decision-making capabilities.

  There are dueling predictions over how ubiquitous the Internet of Things will be, but most indicate that the marketplace will host between 50 and 75 billion connected objects by 2020, signaling novel challenges for hardware manufacturing and development. Software engineers, likewise, may need to completely revamp programs to better exploit the influx of data, while innovators need to wrestle with the changes wrought by analytics.

  IBM’s Insight event unfolded in light of this wave of disruption. The lineup of corporate presenters converged on the same message : Analytics is for everyone, and your viability in the marketplace depends on it.

  […]

  IBM’s Insight 2015 conference sounded off on the most important trends in data usage and management. It also served a wake-up call for developers, engineers, and tech leaders. As the Internet of Things alters the landscape of analytics, hardware design needs to change, software development requires novel approaches, and tech management must become more agile in order to realize data’s greatest benefits.

  So far there are 1 million websites using Piwik… but what if there could be 10 or 50 million things (sensors, devices) being measured by Piwik ?

  Together we will be creating the best open source and generic analytics platform, that is engineered to last, and designed to help humanity keep control and gain Freedom.

  We aim for Piwik to be the ideal platform to measure the Internet Of Things.

  We’re still at the beginning of this journey and it will take the best of all of us to get there.

  See you on the way !

  PS : if you’d like to get involved with Piwik, we would be glad to welcome you !

• Reading geolocation data from a video file using FFMpeg/Xuggler

  23 décembre 2015, par agent154

  Using the MediaInfo application, I am able to see that a file taken with an iPhone 5 contains geolocation metadata, tagged both with ©xyz and com.apple.quicktime.location.ISO6709. I am not able to find any way to get this data using xuggler, however.

  Format                                   : MPEG-4
  
  Format profile                           : QuickTime
  
  Codec ID                                 : qt   0000.00 (qt  )
  
  File size                                : 7.50 MiB
  
  Duration                                 : 3s 537ms
  
  Overall bit rate                         : 17.8 Mbps
  
  Recorded date                            : 2015-12-17T14:32:23-0330
  
  Encoded date                             : UTC 2015-12-17 18:02:23
  
  Tagged date                              : UTC 2015-12-17 18:02:27
  
  Writing application                      : 8.4.1
  
  Writing library                          : Apple QuickTime
  
  Model                                    : iPhone 5
  
  ©xyz                                     : +47.5184-052.8046+133.390/
  
  Make                                     : Apple
  
  com.apple.quicktime.make                 : Apple
  
  com.apple.quicktime.creationdate         : 2015-12-17T14:32:23-0330
  
  com.apple.quicktime.location.ISO6709     : +47.5184-052.8046+133.390/
  
  com.apple.quicktime.software             : 8.4.1
  
  com.apple.quicktime.model                : iPhone 5

  As an aside, there seems to be a lot of metadata on this file that I can’t immediately find while debugging via xuggler.

  The question at Reading Geolocation from Quicktime Movies with Java (Xuggler) ? is asking the exact same question, but has no answers or comments at all, and is over 4 years old.

  Is anybody aware of a way to be able to get this data using xuggler as it is, or how I can modify the source and re-compile to make it work ? I am required to get this data for a work project. Thanks.