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• Trying to compile x264 and ffmpeg for iPhone - "missing required architecture arm in file"

  11 février 2013, par jtrim

  I'm trying to compile x264 for use in an iPhone application. I see there are instructions on how to compile ffmpeg for use on the platform here : http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2009-October/076618.html , but I can't seem to find anything this complete for compiling x264 on the iPhone. I've found this source tree : http://gitorious.org/x264-arm that seems to have support for the ARM platform.

  Here is my config line :

  ./configure —cross-prefix=/usr/bin/ —host=arm-apple-darwin10 —extra-cflags="-B /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS3.2.sdk/usr/lib/ -I /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS3.2.sdk/usr/lib/"
  

  ...and inside configure I'm using the gas-preprocessor script (first link above) as my assembler :

  gas-preprocessor.pl gcc
  

  When I start compiling, it chunks away for a little while, then it spits out these warnings and a huge list of undefined symbols :

  ld : warning : option -s is obsolete and being ignored
  ld : warning : -force_cpusubtype_ALL will become unsupported for ARM architectures
  ld : warning : in /usr/lib/crt1.o, missing required architecture arm in file
  ld : warning : in /usr/X11R6/lib/libX11.dylib, missing required architecture arm in file
  ld : warning : in /usr/lib/libm.dylib, missing required architecture arm in file
  ld : warning : in /usr/lib/libpthread.dylib, missing required architecture arm in file
  ld : warning : in /usr/lib/libgcc_s.1.dylib, missing required architecture arm in file
  ld : warning : in /usr/lib/libSystem.dylib, missing required architecture arm in file
  Undefined symbols :
  

  My guess would be that the problem has to do with the "missing required architecture arm in file" warning...any ideas ?

• iPhone - A problem with decoding H264 using ffmpeg

  25 mars 2012, par HAPPY_TIGER

  I am working with ffmpeg to decode H264 stream from server.

  I referenced DecoderWrapper from http://github.com/dropcam/dropcam_for_iphone.

  I compiled it successfully, but I don't know how use it.

  Here are the function that has problem.

  - (id)initWithCodec:(enum VideoCodecType)codecType 
  
           colorSpace:(enum VideoColorSpace)colorSpace 
  
                width:(int)width 
  
               height:(int)height 
  
          privateData:(NSData*)privateData {
  
      if(self = [super init]) {
  
  
  
          codec = avcodec_find_decoder(CODEC_ID_H264);
  
          codecCtx = avcodec_alloc_context();
  
  
  
          // Note: for H.264 RTSP streams, the width and height are usually not specified (width and height are 0).  
  
          // These fields will become filled in once the first frame is decoded and the SPS is processed.
  
          codecCtx->width = width;
  
          codecCtx->height = height;
  
  
  
          codecCtx->extradata = av_malloc([privateData length]);
  
          codecCtx->extradata_size = [privateData length];
  
          [privateData getBytes:codecCtx->extradata length:codecCtx->extradata_size];
  
          codecCtx->pix_fmt = PIX_FMT_YUV420P;
  
  #ifdef SHOW_DEBUG_MV
  
          codecCtx->debug_mv = 0xFF;
  
  #endif
  
  
  
          srcFrame = avcodec_alloc_frame();
  
          dstFrame = avcodec_alloc_frame();
  
  
  
          int res = avcodec_open(codecCtx, codec);
  
          if (res < 0)
  
          {
  
              NSLog(@"Failed to initialize decoder");
  
          }
  
      }
  
  
  
      return self;    
  
  }

  What is the privateData parameter of this function ? I don't know how to set the parameter...

  Now avcodec_decode_video2 returns -1 ;

  The framedata is coming successfully.

  How solve this problem.

  Thanks a lot.

• Close and reopen stream

  7 janvier 2020, par Expressingx

  I’m streaming video from a camera into a file. Using mp4 but if there is unexpected power off the video gets corrupted. So I’m going to store the video in a backup file where ffmpeg will write frames to temporary file and in some interval the content of that file will be copied to the backup file. So far so good, but in order backup file to be not corrupted I have to write the trailer first (I guess) to the temp file and eventually close the stream and then copy the content. After that reopen the stream to the temp file. But I’m getting Attempted to read or write protected memory if I try to call av_write_trailer() after its already called once.

  Is there even a way to achieve that or if I expect power off I should use other format like flv ?