Recherche avancée

Sur d’autres sites (5281)

• cmake build error with libswresample, works fine with clang

  19 août 2018, par Dan Gordon

  I’m building an FFmpeg project with CLion which uses cmake to compile the code. Everything has been working great until I started to use the libswresample library. For some reason, cmake isn’t seeing the dylib and won’t build the code.

  /Applications/CLion.app/Contents/bin/cmake/mac/bin/cmake --build /Users/user/CLionProjects/IC4D/cmake-build-debug --target all -- -j 4
  
  [ 50%] Linking C executable IC4D
  
  Undefined symbols for architecture x86_64:
  
    "_swr_alloc_set_opts", referenced from:
  
        _audio_decode_frame in main.c.o
  
    "_swr_convert", referenced from:
  
        _audio_decode_frame in main.c.o
  
    "_swr_free", referenced from:
  
        _audio_decode_frame in main.c.o
  
    "_swr_init", referenced from:
  
        _audio_decode_frame in main.c.o
  
    "_swr_set_compensation", referenced from:
  
        _audio_decode_frame in main.c.o
  
  ld: symbol(s) not found for architecture x86_64
  
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  
  make[2]: *** [IC4D] Error 1
  
  make[1]: *** [CMakeFiles/IC4D.dir/all] Error 2
  
  make: *** [all] Error 2

  But if I run this clang code, it compiles just fine

  clang -I/usr/local/include -L/usr/local/lib -lavcodec -lavcodec -lswscale -lavformat -lswresample -lSDL2 -lavutil -o IC4D2 ../main.c

  Here’s my CMakeList.txt file :

  cmake_minimum_required(VERSION 3.10)
  
  project(IC4D C)
  
  
  
  set(CMAKE_C_STANDARD 99)
  
  
  
  include_directories( /Users/user/CLionProjects/IC4D/include/ )
  
  link_directories( /Users/user/CLionProjects/IC4D/lib/ )
  
  
  
  find_path(AVDEVICE_INCLUDE_DIR include/libavdevice/avdevice.h)
  
  find_library(AVDEVICE_LIBRARY lib/libavdevice.58.dylib)
  
  
  
  find_path(AVFORMAT_INCLUDE_DIR include/libavformat/avformat.h)
  
  find_library(AVFORMAT_LIBRARY lib/libavformat.58.dylib)
  
  
  
  find_path(AVCODEC_INCLUDE_DIR include/libavcodec/avcodec.h)
  
  find_library(AVCODEC_LIBRARY lib/libavcodec.58.dylib)
  
  
  
  find_path(SWSCALE_INCLUDE_DIR include/libswscale/swscale.h)
  
  find_library(SWSCALE_LIBRARY lib/libswscale.5.dylib)
  
  
  
  find_path(AVUTIL_INCLUDE_DIR include/libavutil/avutil.h)
  
  find_library(AVUTIL_LIBRARY lib/libavutil.56.dylib)
  
  
  
  find_path(SWRESAMPLE_INCLUDE_DIR include/libswresample/swresample.h)
  
  find_library(SWRESAMPLE_LIBRARY lib/libswresample.3.dylib)
  
  
  
  find_package(SDL2 REQUIRED)
  
  
  
  add_executable(IC4D main.c)
  
  
  
  target_include_directories(IC4D PRIVATE ${SDL2_INCLUDE_DIRS} ${AVDEVICE_INCLUDE_DIR} ${AVFORMAT_INCLUDE_DIR} ${AVCODEC_INCLUDE_DIR} ${SWSCALE_INCLUDE_DIR} ${AVUTIL_INCLUDE_DIR} ${SWRESAMPLE_INCLUDE_DIR})
  
  target_link_libraries(IC4D PRIVATE ${SDL2_LIBRARIES} ${AVDEVICE_LIBRARY} ${AVFORMAT_LIBRARY} ${AVCODEC_LIBRARY} ${SWSCALE_LIBRARY} ${AVUTIL_LIBRARY} ${SWRESAMPLE_LIBRARY})

  What am I doing wrong with cmake ?

  Thanks

• trying to use fluent-ffpmeg on raspberry pi

  3 septembre 2018, par cdoern

  I am trying to use fluent ffmpeg to make a h264 file into an mp4 file. However, installing regular ffmpeg did not work since ti downloaded a very old version onto my pi. through some research i stumbled upon an ffmpeg installer on npm that installers a newer version and allows you to use it : https://www.npmjs.com/package/@ffmpeg-installer/ffmpeg however, when incorporating this into my project, PM2, the process manager I am using to run my files, throws a very stranger error :

  err._length = err.length;
TypeError: Cannot create property '_length' on string 'Unsupported platform/architecture: linux-arm

  below is my code for converting the file

  const ffmpegPath = require('@ffmpeg-installer/ffmpeg').path;
  
  var ffmpeg = require('fluent-ffmpeg');
  
  ffmpeg.setFfmpegPath(ffmpegPath);
  
  ffmpeg('/home/pi/Videos/video.h264').format('mp4');
  
  ffmpeg.on('error', function(err) {
  
    console.log('an error happened: ' + err.message);
  
  })
  
  // save to file
  
  ffmpeg.save('/home/pi/Videos/testmovie.mp4');

• How to setup a virtual mic and pipe audio to it from node.js

  28 octobre 2018, par Niellles

  Summary of what I am trying to achieve :

  I’m currently doing some work on a Discord bot. I’m trying to join a voice channel, which is the easy part, and then use the combined audio of the speakers in that voice channel as input for a webpage in a web browser. It doesn’t really matter which browser it is as long as it can be controlled with Selenium.

  ---

  What I’ve tried/looked into so far

  My bot so far is written up in Python using the discord.py API wrapper. Unfortunately listening to, as opposed to putting in, audio hasn’t been exactly implemented great − let alone documented − with discord.py. This made me decide to switch to node.js (i.e. discord.js) for the voice channel stuff of my bot.

  After switching to discord.js it was pretty easy to determine who’s talking and create an audio stream (PCM stream) for that user. For the next part I though I’d just pipe the audio stream to a virtual microphone and select that as the audio input on the browser. You can even use FFMPEG from within node.js ¹, to get something that looks like this :

  const Discord = require("discord.js");
  
  const client = new Discord.Client();
  
  
  
  client.on('ready', () => {
  
    voiceChannel = client.channels.get('SOME_CHANNEL_ID');
  
    voiceChannel.join()
  
      .then(conn => {
  
        console.log('Connected')
  
  
  
        const receiver = conn.createReceiver();
  
  
  
        conn.on('speaking', (user, speaking) => {
  
          if (speaking) {
  
            const audioStream = receiver.createPCMStream(user);
  
  
  
            ffmpeg(stream)
  
                .inputFormat('s32le')
  
                .audioFrequency(16000)
  
                .audioChannels(1)
  
                .audioCodec('pcm_s16le')
  
                .format('s16le')
  
                .pipe(someVirtualMic);          
  
          }
  
        });
  
      })
  
      .catch(console.log);
  
    }); 
  
  
  
  client.login('SOME_TOKEN');

  This last part, creating and streaming to a virtual microphone, has proven to be rather complicated. I’ve read a ton of SO posts and documentation on both The Advanced Linux Sound Architecture (ALSA) and the JACK Audio Connection Kit, but I simply can’t figure out how to setup a virtual microphone that will show up as a mic in my browser, or how to pipe audio to it.

  Any help or pointers to a solution would be greatly appreciated !

  ---

  Addendum

  For the past couple of days I’ve kept on looking into to this issue. I’ve now learned about ALSA loopback devices and feel that the solution must be there.

  I’ve pretty much followed a post that talks about loopback devices and aims to achieve the following :

  Simply imagine that you have a physical link between one OUT and one
  IN of the same device.

  I’ve set up the devices as described in the post and now two new audio devices show up when selecting a microphone in Firefox. I’d expect one, but I that may be because I don’t entirely understand the loopback devices (yet).

  The loop back devices are created and I think that they’re linked (if I understood the aforementioned article correctly). Assuming that’s the case the only problem I have to tackle is streaming the audio via FFMPEG from within node.js.