Newest 'x264' Questions - Stack Overflow

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• "Unknown encoder : libx264" error in Debian Squeeze

  21 août 2012, par Stas

  I built and installed FFMPEG as said here.

  But when I do this command to run the video:

  ffmpeg -i "source.mkv" -an -b 700k -r 25 -vcodec libx264 "output.mp4"
  

  I get this error:

  unknow encoder : libx264
  

  I use Debian Squeeze. How can I fix this? Please help

  Thanks!!

• x264 with multiple passes specify location of temporary file ?

  16 août 2012, par Richard Knop

  So, my situation is like this. I have three x264 commands with 3 passes I want to run in parallel:

  x264 -p 1 ...
  x264 -p 1 ...
  x264 -p 1 ...
  

  Then I want to run the second pass in parallel:

  x264 -p 2 ...
  x264 -p 2 ...
  x264 -p 2 ...
  

  And the third pass as well.

  The problem is, because I am running three x264 commands with -p option at the same time (using multiprocessing), they are all trying to use the same temporary files to save the results of the first/second pass.

  Is there a way to specify for each x264 command to use a different temporary file?

• accelerate x264 encoding

  7 août 2012, par Saraswati

  i am making use of x264 to encode raw data captured from the iphone camera .. but the encoding is very slow .Can anyone help me accelerate the encoding speed.

  I have used following settings to build x264 lib:

  //for armv6

  CC=/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc ./configure --host=arm-apple-darwin --sysroot=/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdk --prefix='dist' --extra-cflags='-arch armv6' --extra-ldflags=-L/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdk/usr/lib/system/ --extra-ldflags='-arch armv6' --enable-pic --disable-asm

  //for armv7

  CC=/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc ./configure --host=arm-apple-darwin --sysroot=/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdk --prefix='dist' --extra-cflags='-arch armv7' --extra-ldflags=-L/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdk/usr/lib/system/ --extra-ldflags='-arch armv7' --enable-pic

  I am using default preset like this:

  x264_param_default_preset(param, "slow", "zerolatency");
  

  and setting few perameters:

  param->i_bframe = 0;
  param->analyse.i_me_method = X264_ME_HEX;
  param->analyse.i_subpel_refine = 2;
  param->i_frame_reference = 1;
  param->analyse.b_mixed_references = 0;
  param->analyse.i_trellis = 0;
  param->rc.b_mb_tree = 0;
  param->analyse.i_weighted_pred = X264_WEIGHTP_NONE;
  
  
  param->rc.i_bitrate = 180;
  param->rc.i_qp_min = 20; 
  param->rc.i_qp_max = 26; 
  
  param->i_keyint_max = 15; 
  param->i_keyint_min = 15;
  
  
  param->i_width = w;
  param->i_height = h;
  
  x264_param_apply_profile(param, "baseline");
  x264_picture_alloc( &(enc->pic), X264_CSP_I420, param->i_width, param->i_height );
  

• What, if any, guarantees are there for when `nalu_process` will be called ?

  1er août 2012, par gspr

  In particular, can a call to x264_encoder_encode return before every nalu_process callback associated to it has returned? Someone in #x264 suggested it's settings-dependent; I'm talking here about the "zerolatency" preset.

  If the answer to the above question is yes, then how common is it, empirically?

• fresh ffmpeg on 10.04 Could Not Find Codec Parameters

  26 juillet 2012, par Dmitry Kharlamov

    ffmpeg version git-2012-07-24-93342de Copyright (c) 2000-2012 the FFmpeg developers
    built on Jul 24 2012 23:55:41 with gcc 4.4.3 (Ubuntu 4.4.3-4ubuntu5.1)
    configuration: --enable-libfaac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libx264 --enable-gpl --enable-nonfree --enable-postproc --enable-swscale --enable-vdpau --enable-version3 --enable-libtheora --enable-libvorbis --enable-libvpx --enable-x11grab
    libavutil      51. 65.100 / 51. 65.100
    libavcodec     54. 44.100 / 54. 44.100
    libavformat    54. 20.100 / 54. 20.100
    libavdevice    54.  2.100 / 54.  2.100
    libavfilter     3.  3.100 /  3.  3.100
    libswscale      2.  1.100 /  2.  1.100
    libswresample   0. 15.100 /  0. 15.100
    libpostproc    52.  0.100 / 52.  0.100
  [mov,mp4,m4a,3gp,3g2,mj2 @ 0x2a1b240] Could not find codec parameters for stream 0 (Video: h264 (avc1 / 0x31637661), 1280x720): unspecified pixel format
  Consider increasing the value for the 'analyzeduration' and 'probesize' options
  /path/to/video.mp4: could not find codec parameters
  
  
  ffmpeg command line:
  /usr/local/bin/ffmpeg -i /path/to/video.mp4