Newest 'libx264' Questions - Stack Overflow

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• libx264 : which parameters can be changed on fly ?

  12 janvier, par Dan Tumaykin

  I know that it is possible to change some encoder parameters on fly, using x264_encoder_reconfig(). From this commit I can deduce that we can change ratecontrol parameters - but I was unable to find a clear list of parameters that may be changed.

  Question: which parameters of x264 encoder can be changed on fly?

• encode x264(libx264) raw yuv frame data

  12 janvier, par Mohamed El-Sayed

  I am trying to encode an MP4 video using raw YUV frames data, but I am not sure how can I fill the plane data (preferably without using other libraries like ffmpeg)

  The frame data is already encoded in I420, and does not need conversion.

  Here is what I am trying to do:

  const char *frameData = /* Raw frame data */;
  
  x264_t *encoder = x264_encoder_open(&param);
  x264_picture_t imgInput, imgOutput;
  x264_picture_alloc(&imgInput, X264_CSP_I420, width, height);
  
  // how can I fill the struct data of imgInput
  
  x264_nal_t *nals;
  int i_nals;
  int frameSize = x264_encoder_encode(encoder, &nals, &i_nals, &imgInput, &imgOutput);
  

  The equivalent command line that I have found is :

   x264 --output video.mp4 --fps 15 --input-res 1280x800 imgdata_01.raw 
  

  But I could not figure out how the app does it.

  Thanks.

• Create a deep copy of internal x264 encoder's state

  9 janvier, par Ragdoll Car

  I am using x264 library: https://github.com/mirror/x264

  We can create a new encoder handler this way:

  x264_param_t param{};  // fill with proper values
  x264_t* handler = x264_encoder_open(&param);
  

  But how can we create a deep copy of handler so we can have two the same encoders with exactly the same internal state?

• is it possible to compile x264 for webassembly using emscripten ?

  4 novembre 2024, par sunder kandasamy

  I am trying to build x264 code for webassembly. i use emconfigure to configure. like below

  emconfigure ./configure --prefix="$(pwd)/em" --enable-shared --enable-static  --disable-cli  --disable-gpl
  

  But this was throwing "No working C compiler found." error. i have gcc compiler 9.3.0 version and have tried reinstalling build-essentials and gcc but still same issue.

  config.log also doesn't help.

  If i provide --host cross compiler flag then it is generating libx264.so file, but i am not sure whether this is right as the wasm code should work in every browser in (windows/mac/linux)

  please tell me first whether compiling x264 using emscripten is possible? If yes, please tell me what is the correct steps to do it

• How to set correct parameters for x264 lib

  29 octobre 2024, par galuk

  I depacketize the H264 video fragments from an IP.RTP stream and save them to video.ivf file. After depacketizing i have only [SPS] ,[PPS] and [non-IDR slice]. I try to create IDR slice by using x264 lib. x264 lib creates IDR frame which consists of 0x000001[SPS nal type 7] 0x000001[PPS nal type 8] 0x0001[SE slice nal type 6] and 0x0001[I slice nal type 5]. How to set correct parameters for x264 lib if i have real SPS and PPS frames to get the same SPS and PPS frames

  i parse SPS and PPS but i don't know which parameters of x264_param_t param i should set. can someone give me some examples.