Newest 'ffmpeg' Questions - Stack Overflow

Les articles publiés sur le site

• FFmpeg fourcc Avi codec support list ?

  5 décembre 2013, par Sugrue

  A couple of similar questions are on stackoverflow, but I haven't been able to figure this exact problem out.

  I want to get a list of the fourccs for the avi codecs that FFMpeg can decode.

  I know how to get all the formats ffmpeg -formats and codecs ffmpeg -codecs but neither list gives me an accessible list of fourccs. Neither does the documentation I can find.

  I need this list, so that my application can access the fourcc of an avi file and determine whether to use ffmpeg or VfW (or DirectX) to try decode the file.

  Is there some ffmpeg command that can give me this list?

• how to make a video from timeline position data ?

  5 décembre 2013, par Brad

  So I have timeline position data available to me as a JSON object where a object is being moved around a screen. I want to be able to make a video using that information. How would you suggest going about doing that? (Ubuntu or OSX environment).

• What is the difference between x264 and ffmpeg ?

  5 décembre 2013, par user3067233

  So I'm trying to compile the H.264 codec so that I can use it to enhance performance in NoMachine as per https://www.nomachine.com/AR10K00695

  Instructions below deal with the following possible cases on server host:

  Case 1: You don't have x264 library already compiled

  Case 2: You have x264 library already compiled

  and on client host:

  Case 1: You have FFmpeg already installed

  Case 2: You don't have FFmpeg installed

  Case 3: You have FFmpeg libraries already compiled

  The weird thing is that it states that you compile x264 on the server and ffmpeg on the client. Shouldn't you have either have x264 compiled on both the server and the client or ffmpeg on the server and the client?

  Why use two different codecs for the server and the client?

• FFMPEG : Video decoder integration giving segmentation fault

  5 décembre 2013, par Zax

  I have integrated a decoder to FFMPEG multimedia framework. I have referred this how to post to integrate the decoder.

  How to integrate a codec to FFMPEG

  I have followed the above post and integrated my custom decoder which decodes an elementary stream into a YUV420 data.

  However, When i give an input command as shown below, i get the following messages in sequence:

  ./ffmpeg -vcodec myCustomDec -i input_416x240.bin opt.yuv
  

  For integrating a codec, we need to define 3 functions and assign them to AVCodec's structures function pointers .init, .close and .decode.

  I have given a printf statement in myCustomDec's demuxer's probe function, init function, decode function and close function.

  The output i get after executing the above command is:

  myCustomDecoder probe function Entered
  myCustomDecoder demux successful
  Codec 0x73736d77 is not in the full list.
  Init is Entered
   Last message repeated 1 times
  Decode entered
  Segmentation fault (core dumped)
  

  So, this means that i'm getting segmentation fault after after entering decode function. My decode function prototype is as shown below:

  static int myCustom_decode_frame(AVCodecContext *avctx, void *data,int *got_frame_ptr, AVPacket *avpkt)
  

  In this function what i actually do is:

  AVFrame *frame     = data;
  printf("\nDecode entered\n");
  //Here i call decode frame function
  
  //Here i call a function to fetch YUV data
  
  //now i make the pointer that is pointing to YUV buffer data to point to variable of type AVFrame *frame
  
  //set *got_frame to 1
  

  So my expectation here is that once i map my YUV buffer pointer to the AVFrame *frame variable, the FFMPEG multimedia framework will take care of dumping this yuv frame to opt.yuv which is specified in the command. My question is: Is my assumption correct that FFMPEG multimedia frame work takes care of dumping data to output file?

  Second, Why am i getting a message in the output saying Codec 0x73736d77 is not in the full list.

  And finally, How does the FFMPEG framework get to know the width and height of the input stream that i'm providing, because my parser is embeded in the decode code itself, and there is no connection with FFMPEG.

  Any suggestion regarding the same will be really helpful to me. Please do provide your suggestions. Thanks in advance.

• Using commands of .exe files in c language

  5 décembre 2013, par Light

  a few months back I wrote a batch (windows batch file .bat) code that fetches some .exe files and use their commands to do different things. e.g encoding audio, video etc... Now I want the same thing but want to do it in C language.
  

  set var = "Video"
  ffmpeg -i %var%.mkv -f wav -| neroAacEnc -ignorelength -lc -q 0.4 -if - -of %var%-Audio.aac

  This code works fine in windows batch file (given that I have specified files in the same folder.)
  
  But now I want to do this via C language. Well I know using

  system("ffmpeg -i Video.mkv -f wav -| neroAacEnc -ignorelength -lc -q 0.4 -if - -of Video-Audio.aac");

  will work for C language, but the drawback is I can't use variable while exploiting ffmpeg's and neroAacEnc's commands / parameters. So is there anyway to get around it?
  (Also, I'm gonna use other .exe files as well like x264.exe and mkvmerge.exe, so i'd appreciate it if someone could tell me how to use external .exe files parameters freely in C language.)