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• Maintain aspect ratio when converting video ? - ffmpeg

  27 décembre 2011, par RadiantHex

  I'm trying to convert movies from .avi to an iphone readable format wherever I look, people suggest the following options for ffmpeg

  ffmpeg -s 320x240 -aspect 320:240 [...]

  This does not bode well for videos with a different aspect ratio!

  ---

  How can I keep the aspect ratio from changing? Is there a way to set the size dynamically?

  e.g. have the height to be 240 and the width variable?

• onLowMemory caused in Android

  27 décembre 2011, par Satheesh

  Am developing a live wallpaper application in android. I face problem of onLowMemory. My application runs quite normally for 5 or odd minutes in the device after that causing the low memory error and its quit and restart again. How to resolve this error.

• Undefined reference to _aacplusEncOpen

  26 décembre 2011, par Tarun

  Following is the copy of my config.log file->

  http://pastebin.com/embed_js.php?i=UyTBTTZv

  Following is copy of configure file->

  http://pastebin.com/embed_js.php?i=2c15zppN

  One more thing..As of now I am trying to cross-compile ffmpeg on ubuntu,But If I just compile it for linux..The same command doesnt gives any error and executes smoothly and then I am able to get ffmpeg with aacplus support for my linux machine, But why the problem is coming when I am cross compiling it.

  Another thing as aacplus is not on by default, If in configuration I dont put any (off by default) library support like if I remove aacplus from it, Then also it goes smoothly.

  Help please ASAP

• ‘undefined reference to xxxxx’ , 'check the directory for the files' it does not work

  26 décembre 2011, par sirupa

  Merry Christmas, everybody,

  I’m coding ffmpeg with gcc.

  But, on the build process, I met the errors of ‘undefined reference to xxxxx’ for all functions that I coded in my program, and I recognized that it was due to the libxxx.a file.

  And the every adviser on internet suggested that check the directory for the files.

  So, I searched the files in which include the function names in my computer, and I found the .a files are correctly set in the directory which I coded.

  And there are the other files which are named ‘libxxx.dll.a’, so I tried to build with the files ‘libxxx.dll.a’, but I got the same result.

  On this point, I have got some questions.

  1) If the gcc could not find the libxxx.a files, it would say that ‘cannot find the –lxxx’. But it just said ‘undefined reference to xxxx’. It means that those libxxx.a files are in the correct directories.

  2) And if the files do not define the functions, it is strange. Because those files include the function names and are the same files/directories I had searched in my computer, and I think it should have the definitions of the functions. But I am not sure that the files define the functions or not, because I cannot read the file myself.

  If I am wrong, what was my mistake?

  3) Can libxxxlib.a files be replaced with the libxxx.a? And if it can, what is the difference between libxxxlib.a and libxxx.a? And the same for the libz and libzlib?a

  Here is my line commend, the directory which include the libxxx.a files.

  g++ -o C:\ffmpeg\ffmpegTest C:\ffmpeg\ffmpegTest.cc -IC:\ffmpeg -LC:\ffmpeg\3rdparty\lib -lavutil -lavformat -lavcodec -lz -lavutil -lm -D__STDC_CONSTANT_MACROS

  C:\ffmpeg\3rdparty\lib

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0xec>: undefined reference to 'av_register_all()'

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x11c>: undefined reference to 'av_open_input_file(AVFormatContext*, char const, AVInputFormat*, int, AVFormatParameters*)'

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x13b>: undefined reference to 'av_find_stream_info(AVFormatContext*)'

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x174>: undefined reference to 'dump_format(AVFormatContext, int, char const*, int)'

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x224>: undefined reference to 'avcodec_find_decoder(CodecID)'

  and all the errors are

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x281>: undefined reference to 'avcodec_open(AVCodecContext*, AVCodec)'

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x297>: undefined reference to 'avcodec_alloc_frame()'

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x2a3>: undefined reference to 'avcodec_alloc_frame()'

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x2e6>: undefined reference to 'avpicture_get_size(PixelFormat,int,int)'

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x2fc>: undefined reference to 'av_malloc(unsigned int)'

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x341>: undefined reference to 'avpicture_fill(AVPicture*, unsigned char*, PixelFormat, int, int)'

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x38c>: undefined reference to 'avcodec_decode_video2(AVCodecContext, AVFrame*, int, AVPacket*)'

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x409>: undefined reference to 'sws_getContext(int, int, PixelFormat, int, int, PixelFormat, int, SwsFilter*, swsFilter*, double const*)'

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x463>: undefined reference to 'sws_scale(SwsContext*, unsigned char const* const*, int const*, int, int, unsigned char* const*, int const*)'

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x4bb>: undefined reference to 'av_free_packet(AVPacket*)'

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x4cf>: undefined reference to 'av_read_frame(AVFormatContext, AVPacket*)'

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x36c>: undefined reference to 'av_free(void*)'

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x36c>: undefined reference to ' avcodec_close(AVCodecContext*)'

  C:\Users\AppData\Local\Temp\ccVHLzjK.o:ffmpegTest.cc:<.text+0x36c>: undefined reference to 'av_close_input_file(AVFormatContext)'

• Should I buy ffmpeg ? [closed]

  25 décembre 2011, par Matt

  I work for a online-video company, and looking for some tools to convert wmv/mkv/avi and so on to mp4. I know ffmpeg can do this. Should I buy it in thes condition?

  thanks.