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• Using VLC for MPEG2 video encoding with I-frames only

  4 mars 2014, par user3319428

  Is there a VLC option to be able to do MPEG2 video encoding with I-frames only (not P and B) ? I would like to be able to transcode from one file format (such as AVI) to another with MPEG2 transcoding done so that only I-frames are encoded. Later this file will be streamed to an MPEG2 decoder, and I would like to have this feature to simplify the decoder (due to hardware/software restrictions).

  It looks like the ffmpeg module in VLC may be able to do this, but I am not sure of the options for it. I tried to use the keyint=0 option (where the key frames are considered to be I-frames), but it did not seem to work, as the same output file size resulted with or without this option.

  What I really want is for the output file to be in transport stream format too.

  I am using VLC ver. 2.1.3 under Windows 7.

  Thanks in advance for any help you can offer.

• how to use ffmpeg -cookies to download aes encrypted hls stream

  3 mars 2014, par Shuman

  i need this cookies, so i can download stream from a m3u8 file,(it has this line

  #EXT-X-KEY:METHOD=AES-128,URI="https://xxx/myStream.php?wowzasessionid=861683502"

  so i can get the key right ? ( i have the login credential cookies to that site )

  according to this discussion, it was there, and i checked the code on github, it has the option.

  but when i compile it with the default options, there is no cookies option. how do i turn it on ?

  > ./ffmpeg -buildconf
  
  ffmpeg version N-61050-g2dcaa1b Copyright (c) 2000-2014 the FFmpeg developers
  
    built on Mar  3 2014 14:31:05 with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-3)
  
    configuration:
  
    libavutil      52. 66.100 / 52. 66.100
  
    libavcodec     55. 52.102 / 55. 52.102
  
    libavformat    55. 33.100 / 55. 33.100
  
    libavdevice    55. 10.100 / 55. 10.100
  
    libavfilter     4.  2.100 /  4.  2.100
  
    libswscale      2.  5.101 /  2.  5.101
  
    libswresample   0. 18.100 /  0. 18.100
  
  
  
    configuration:
  
  
  
  
  
  > ffmpeg -cookies
  
  /sww/gfx/lib64/python2.6/pytz/__init__.py:32: UserWarning: Module argparse was already imported from /sww/tools/lib64/python2.6/argparse.py, but /usr/lib/python2.6/site-packages is being added to sys.path
  
    from pkg_resources import resource_stream
  
  ffmpeg version 1.2 Copyright (c) 2000-2013 the FFmpeg developers
  
    built on Mar 22 2013 09:58:42 with gcc 4.1.2 (GCC) 20080704 (Red Hat 4.1.2-44)
  
    configuration: --prefix=/dept/srd/vendor/ffmpeg/bundle.rhel5/ffmpeg1.2.0 --enable-static --enable-pthreads --enable-gpl --disable-ffserver --disable-ffplay --disable-ffprobe --extra-cflags=-I/dept/srd/vendor/ffmpeg/extern/rhel5/include --extra-ldflags=-L/dept/srd/vendor/ffmpeg/extern/rhel5/lib --enable-x11grab --enable-libx264 --enable-nonfree --enable-fontconfig --enable-libfreetype --enable-swscale --enable-libmp3lame --enable-libfaac
  
    libavutil      52. 18.100 / 52. 18.100
  
    libavcodec     54. 92.100 / 54. 92.100
  
    libavformat    54. 63.104 / 54. 63.104
  
    libavdevice    54.  3.103 / 54.  3.103
  
    libavfilter     3. 42.103 /  3. 42.103
  
    libswscale      2.  2.100 /  2.  2.100
  
    libswresample   0. 17.102 /  0. 17.102
  
    libpostproc    52.  2.100 / 52.  2.100
  
  Unrecognized option 'cookies'.
  
  Error splitting the argument list: Option not found

• Preventing the python and ffmpeg heroku buildpacks from overwriting LD_LIBRARY_PATH

  3 mars 2014, par Simon

  I'm deployng a Django app to heroku, which requires ffmpeg. To accomplish this I am using heroku-buildpack-multi to install both heroku-buildpack-ffmpeg and heroku-buildpack-python, and all of that works fine. The problem is my that app also depends on django-pylibmc-sasl, python-memcached, pylibmc et al. which, as per usual, heroku senses and automatically installs libmemcached for me.

  Here's where something goes a little wrong. If I remove the custom buildpack everything runs fine (except for ffmpeg obviously). As soon as I add it in, however, while I can run ffmpeg, python fails on import pylibmc (or rather on import _pylibmc inside the module itself). After a amount of head-scratching I decided to have a look at the environment variables, here's what I got :

  With only the Python buildpack enabled :

  LD_LIBRARY_PATH=/app/.heroku/vendor/lib

  With both the Python and the ffmpeg buildpacks enabled :

  LD_LIBRARY_PATH=:vendor/ffmpeg/lib

  It looks like one or both of the buildpacks simply overwrites the other, or avoids setting the variable should it be already set. The ffmpeg buildpack seems to set LD_LIBRARY_PATH in a way that looks kosher to me, while the Python buildpack does a few things that I don't really understand the reason for.

  Solution

  Anyway, after manually overriding the library path using heroku config:set LD_LIBRARY_PATH=/app/.heroku/vendor/lib:vendor/ffmpeg/lib I am able to use both libmemcached and ffmpeg, but it doesn't feel too robust. What if something changes in one of the buildpacks path settings, or I add another buildpack - then I would have to manually edit the library path variable.

  Better solution ?

  So, while this is not really an urgent question at all, I simply would like to know :

  • Is there a better way of solving this issue ?
  • Might I have made some configuration error leading up to the path conflict ?
  • Should this be considered a bug in either of the buildpacks ?