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• COMPILATION ISSUES : FFMPEG CODE ON VS2012

  7 novembre 2013, par user2964667

  I have downloaded FFMPEG source code(c code) by the following link

  http://ffmpeg.zeranoe.com/builds/

  After that,I have completed the configuration part then i was generated and linked the library files *[avcodec-54.lib,avdevice-54.lib,avfilter-3.lib,avformat-54.lib,avutil-52.lib,swresample-0.lib,swscale-2.lib ]*on Microsoft Visual Studio C++ by creating a new project by including all .c and header files.

  Referred Links:
  http://www.ffmpeg.org/platform.html#Microsoft-Visual-C_002b_002b-or-Intel-C_002b_002b-Compiler-for-Windows

  When I was compiling on Visual studio 2010... I am getting more than 300 errors under all the files libavcodec,libavdevice,libavfilter,libavformat,libavresample,libavutil,libpostproc,libswresample,libswscale like

  ASM ERRORS:

  error C2400: inline assembler syntax error in 'opcode'; found 'data type'
  error C2065: '__asm__' : undeclared identifier
  error C2143: syntax error : missing ';' before 'volatile'
  

  SYNTAX ERRORS:

  error C2143: syntax error : missing '}' before '.'
  error C2143: syntax error : missing ';' before '.'
  error C2059: syntax error : '.'
  error C2143: syntax error : missing ';' before '}'
  error C2059: syntax error : '}'
  error C2143: syntax error : missing ';' before '{'
  error C2447: '{' : missing function header (old-style formal list?)
  error C2059: syntax error : ','
  error C2143: syntax error : missing ';' before '{'
  error C2447: '{' : missing function header (old-style formal list?)
  

  Please anyone let me know how to compile a ffmpeg c code on vs2010 successfully.

• Android ffmpeg0.8 is not compiling with android ndk5 with cygwin compiler

  7 novembre 2013, par itsrajesh4uguys

  I am using the following tutorial for ffmpeg compilation .

  http://www.roman10.net/how-to-build-ffmpeg-for-android/

  I am followed all the instructions which they have provided. have changed the path in build_android.sh ,
  i am using android ndk5 and cygwing latest compiler. But i am facing following issue. .so file is not gets created .

  Krajesh@Rajesh /cygdrive/D/RAJESH-ANDROID/Rajesh-workspace/FFMPEG_2
  $ /cygdrive/d/Android_NDK/android-ndk-r5/ndk-build
  Prebuilt       : libffmpeg.so <= jni/ffmpeg-0.8/android/armv7-a/
  Install        : libffmpeg.so => libs/armeabi-v7a/libffmpeg.so
  install: cannot open `/cygdrive/D/RAJESH-ANDROID/Rajesh-workspace/FFMPEG_2/obj/local/armeabi-v7a/libffmpeg.so' for reading: Permission denied
  /cygdrive/d/Android_NDK/android-ndk-r5/build/core/build-binary.mk:305: recipe for target `/cygdrive/D/RAJESH-ANDROID/Rajesh-workspace/FFMPEG_2/libs/armeabi-v7a/libffmpeg.so' failed
  make: *** [/cygdrive/D/RAJESH-ANDROID/Rajesh-workspace/FFMPEG_2/libs/armeabi-v7a/libffmpeg.so] Error 1
  

  Can any one please explain why i am getting that permission denied issue and how to overcome that . i am using windows 7 pc.

  Thanks. Rajesh K

• Receiving "End of file" while streaming RTSP on iOS

  7 novembre 2013, par Tushar Koul

  I'm using ffmpeg library to stream RTSP from an IP camera in the local network. The streaming is working fine with the code.

  The only problem is that the stream seems to stop after some time. On further debugging I found out that I'm receiving an "End of file" and thats why the loop is breaking.

  while(!playerShouldStop)// && (av_read_frame(pFormatCtx, &pkt1)>=0))
      {
              int ret = av_read_frame(pFormatCtx, &pkt1);
              NSLog(@"av read frame returned = %s",av_err2str(ret));
              if(ret >= 0)
              {
                  // process video
              }
              else 
                 break;
      }
  

  Logs says

  av read frame returned = End of file

  I downloaded Wireshark to check what RTSP packets I'm getting but no help there.

  

  First of all is it normal to receive EOF in a live stream (which is not supposed to end).

  Secondly, calling av_read_frame() again and again is not helping either, but when I restart the entire method ( right from avformat_open_input ) then it works. Just that the streaming isn't smooth and comes to a pause every now and then.

• FFMPEG sensible defaults

  7 novembre 2013, par ddlshack

  I'm using ffmpeg to watermark videos with a PNG file using vfilters like so:

  ffmpeg -i 26.wmv -vcodec libx264 -acodec copy -vf "movie=logo.png [watermark]; [in][watermark] overlay=10:10 [out]" 26_w.mkv
  

  However, the input files are all of different quality/bitrates, and I want the output files to be of similar quality/bitrate to the input files. How would I achieve this? Also, I know almost nothing about ffmpeg, so are there any options which would be sensible to set to give a good quality:filesize ratio?

• Parsing NAL units using FFMPEG

  6 novembre 2013, par 2ndlife

  I am new to MPEG-4 and taking baby steps to learn it. I am using FFMPEG as reference.

  1. I understand that all mpeg-4 are encoded into NAL units and wrt to FFMPEG av_read_frame() function returns one NAL unit, Am I right? Is frame a NAL unit? (though it can be a combination of multiple NALs)

  2. I also saw that h264_parser.c implements a function called h264_parse which is calling parse_nal_units() inside, If i need to get NAL units how can I use this parse_nal_units from my main function?

  3. What is av_parse_Parse2() function do? does it return decoded NAL units?

  4. OR FFMPEG has -vbsf h264_mp4toannexb switch to dump raw NAL units, Can somebody help me understand how I can use the same from my main function?

  Please help me out here... -ash5