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• ffmpeg url protocol - annoying issue with url_seek

  7 juin 2014, par Gieas

  I’m trying to add my own URL protocol to my improved dranger’s video player using ffmpeg.

  The URLPRotocol is : http://www.ffmpeg.org/doxygen/2.1/structURLProtocol.html

  It seems that (For some weird reason) ffmpeg calls my ’url_seek’ before the movie even starts.

  The function prototype is the same as lseek’s :

  int64_t my_url_seek(URLContext *h, int64_t pos, int whence)

  FFmpeg first calls the function with the values : POS = 0 , WHENCE = 65536

  According to ffmpeg’s docs the value 65536 (AVSEEK_SIZE) means that ffmpeg wants the video size - so, my server responses to it with the video size.
  But after that, it tries to seek with weird values :
  POS = 8827210, WHENCE = 0, POS = 9912, WHENCE = 0 and so on.. (Same values all the time)
  Anyways, according to ffmpeg’s doc whence should return the current position of the file (measured from the beginning of the file in bytes) and that is what I’m giving him (Except special case when it wants the video size as I mentioned before) - but it still doesn’t work.

  I don’t get it. What is it trying to do ? It can’t really be my fault because I did just use dranger’s video player and registered my own protocol. anyone has any idea what’s going on here ?

• Cannot Compile C Program That Uses a Library (FFmpeg) with GCC Because of the Library's Include Statements

  12 septembre 2019, par NetherGranite

  I am unable to compile a C project that uses a library called "FFmpeg" with a compiler called "GCC", and I believe it might be either because I don’t quite understand how #include works or because I am using the wrong compilation process.

  In a folder called Test, I have a file Test/test.c with the following contents :

  #include 
  
  #include 
  
  #include "FFmpeg/libavcodec/avcodec.h"

  The folder FFmpeg is located at Test/FFmpeg. When I try to compile this with GCC, I receive the following error :

  fatal error: libavutil/samplefmt.h: No such file or directory

  The file Test/FFmpeg/libavcodec/avcodec.h has the following code in it :

  #include "libavutil/samplefmt.h"
  
  #include "libavutil/attributes.h"
  
  #include "libavutil/avutil.h"
  
  ... //many more #include statements

  Is the issue here that I need to add "FFmpeg/" to all of these include statements ?

  If so, is there a way to automatically do this ? This library is enormous and probably has hundreds of these statements.

  If not, what should I be doing instead ? Should I attempt to compile the library by itself ? If so, how do I then include this compiled version of the library in my program ?

  ---

  Notes :

  • The command I am using to compile is gcc -c test.c.
  • I have GCC installed via MinGW.
  • I ultimately need to be able to compile this program to both a .dll and an .so.

  ---

  I apologize if any of the terminology I use here is incorrect or if my explanations are poor. I know almost nothing about compilation. Please let me know if I need to fill in more information.

• avformat/audiointerleave : Check before dereferencing

  26 janvier 2020, par Andreas Rheinhardt

  avformat/audiointerleave : Check before dereferencing
  In order to use ff_audio_rechunk_interleave() (a special interleavement
  
  function for situations where the ordinary "interleave by dts" is not
  
  appropriate), the AVStreams must have private data and this private data
  
  must begin with an AudioInterleaveContext which contains a fifo that may
  
  need to be freed and when ff_audio_interleave_close() was called, it just
  
  assumed that everything has been properly set up, i.e. that every streams
  
  priv_data exists. This implies that this function can not be called from
  
  the deinit function of a muxer, because such functions might be called
  
  if the private data has not been successfully allocated. In order to
  
  change this, add a check for whether the private data exists before
  
  trying to free the fifo in it.
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
  
  Reviewed-by : Paul B Mahol <onemda@gmail.com>
  
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavformat/audiointerleave.c