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• errors of 'vaGetDisplay' and `vaGetDisplayDRM' [duplicate]

  29 novembre 2018, par Kindermann

  This question already has an answer here :

  • errors when compiling c code with ffmpeg library
    
    1 answer
    

  After updating my ubuntu OS from 14.04 to 16.04, I installed the ffmpeg library using the following configurations :

  PATH="$HOME/bin:$PATH" PKG_CONFIG_PATH="$HOME/ffmpeg_build/lib/pkgconfig" ./configure \
  
    --prefix="$HOME/ffmpeg_build" \
  
    --pkg-config-flags="--static" \
  
    --extra-cflags="-I$HOME/ffmpeg_build/include" \
  
    --extra-ldflags="-L$HOME/ffmpeg_build/lib" \
  
    --bindir="$HOME/bin" \
  
    --enable-gpl \
  
    --enable-libass \
  
    --enable-libfdk-aac \
  
    --enable-libfreetype \
  
    --enable-libmp3lame \
  
    --enable-libopus \
  
    --enable-libtheora \
  
    --enable-libvorbis \
  
    --enable-libvpx \
  
    --enable-libx264 \
  
    --enable-nonfree
  
  PATH="$HOME/bin:$PATH" make
  
  make install

  It seemed to me the installation process was ok. After that, I tried to compile my own C source code with the following Makefile :

  EDITTED(adding -lva-drm -lva-x11 at line 10)

  FFMPEG_LIBS=    libavdevice                        \
  
                  libavformat                        \
  
                  libavfilter                        \
  
                  libavcodec                         \
  
                  libswresample                      \
  
                  libswscale                         \
  
                  libavutil                          \
  
  
  
  TARGET = video_analysis
  
  LIBS = -lva -lX11 -lvdpau -lm -lva-drm -lva-x11
  
  CC = gcc
  
  CFLAGS += -O2 -g -O0
  
  CFLAGS := $(shell pkg-config --cflags $(FFMPEG_LIBS)) $(CFLAGS)
  
  LDLIBS := $(shell pkg-config --libs $(FFMPEG_LIBS)) $(LDLIBS)
  
  
  
  .PHONY: default all clean
  
  
  
  default: $(TARGET)
  
  all: default
  
  
  
  OBJECTS = $(patsubst %.c, %.o, $(wildcard *.c))
  
  HEADERS = $(wildcard *.h)
  
  
  
  %.o: %.c $(HEADERS)
  
          $(CC) $(CFLAGS) -c $< -o $@
  
  
  
  .PRECIOUS: $(TARGET) $(OBJECTS)
  
  
  
  $(TARGET): $(OBJECTS)
  
      $(CC) $(OBJECTS) $(LDLIBS) $(LIBS) -o $@
  
  
  
  clean:
  
      -rm -f *.o
  
      -rm -f $(TARGET)

  However, my compiler complained the following errors :

  /root/ffmpeg_build/lib/libavutil.a(hwcontext_vaapi.o): In function `vaapi_device_create':
  
  /home/widerstand/ffmpeg_sources/ffmpeg/libavutil/hwcontext_vaapi.c:896: undefined reference to `vaGetDisplay'
  
  /home/widerstand/ffmpeg_sources/ffmpeg/libavutil/hwcontext_vaapi.c:917: undefined reference to `vaGetDisplayDRM'
  
  collect2: error: ld returned 1 exit status
  
  Makefile:30: recipe for target 'video_analysis' failed
  
  make: *** [video_analysis] Error 1

  My question is : in which library do ’vaGetDisplay’ and `vaGetDisplayDRM’ exist ? It’s for sure that libva functions properly. I have no clue how to fix the bugs...Thank you in advance !

• Pydub installation and ffmpeg

  6 août 2021, par Lone Lunatic

  I was trying to get raw sound data out of a .mp3 file. Therefor I used the pydub module as stated here. I created a venv for this project and installed all necessary modules. But for some reason, pydub decided to give me an FileNotFoundError :

  



  (venv) Python-IT:LightsDev pythonit$ which python
/Users/pythonit/Documents/Programmieren/Python/LightsDev/venv/bin/python
(venv) Python-IT:LightsDev pythonit$ which pip3
/Users/pythonit/Documents/Programmieren/Python/LightsDev/venv/bin/pip3
(venv) Python-IT:LightsDev pythonit$ pip3 list 
------------- -------
ffmpeg        1.4
pip           18.1
pydub         0.23.0
pyee          5.0.0
python-ffmpeg 1.0.5
setuptools    39.0.1


  



  My exact code looks like that :

  



  from pydub import AudioSegment
sound = AudioSegment.from_mp3('test.mp3')
raw_data = sound._data
print(raw_data)


  



  and I get this error :

  



  FileNotFoundError: [Errno 2] No such file or directory: 'ffprobe': 'ffprobe'


  



  alongside this runtime warning :

  



  RuntimeWarning: Couldn't find ffmpeg or avconv - defaulting to ffmpeg, but may not work
warn("Couldn't find ffmpeg or avconv - defaulting to ffmpeg, but may not work", RuntimeWarning)


  



  I don't know if it is me, but some similar questions stating I should install ffmpeg or python-ffmpeg won't work. I can even import the ffmpeg module but nothing happens. I can work with ffmpeg and load files but using it with pydub won't work.

  



  EDIT : Today I changed to my windows machine and looked at the error in-depth. However I didn't manage to get it working, even with the solution provided in the comments (thank you though). I installed the ffmpeg binary as stated and i was able to get ffmpeg running in the shell, however not with pydub... I have no clue what is going on. I guess my mistake is very obvious and I am just not able to get it. Even not subprocess was able to solve this problem despite the fact, that I am able to use ffmpeg in shell. I even was able to convert the file using ffmpeg in shell...

  



   ffmpeg -i test.mp3 test.wav 
 > Output #0, wav, to 'test.wav':


  



  I think I am close to solve the problem myself anyways, but thank you anyways.

  


• RTMP live stream directly from NVENC encoder

  16 novembre 2018, par rnd

  I am trying to create a live RTMP stream containing the animation generated with NVIDIA OptiX. The stream is to be received by nginx + rtmp module and broadcasted in MPEG-DASH format. Full chain up to dash.js player is working if the video is first saved to .flv file and then I send it with ffmpeg without any reformatting using command :

  



  ffmpeg -re -i my_video.flv -c:v copy -f flv rtmp://x.x.x.x:1935/dash/test


  



  But I want to stream directly from the code. And with this I am failng... Nginx logs an error "dash : invalid avcc received (2 : No such file or directory)". Then it seems to receive the stream correctly (segments are rolling, dash manifest is there), however the stream is not possible to play in the browser.

  



  I can see only one difference in the manifest between direct stream and stream from file. Codecs attribute of the representation in the direct stream is missed : codecs="avcc1.000000" instead of "avc1.640028" which I get when streaming from file.

  



  My code opens the stream :

  



  av_register_all();
AVOutputFormat* fmt = av_guess_format("flv",
file_name, nullptr);
fmt->video_codec = AV_CODEC_ID_H264;

AVFormatContext* _oc;
avformat_alloc_output_context2(&_oc, fmt, nullptr, "rtmp://x.x.x.x:1935/dash/test");

AVStream* _vs = avformat_new_stream(_oc, nullptr);
_vs->id = 0;
_vs->time_base = AVRational { 1, 25 };
_vs->avg_frame_rate = AVRational{ 25, 1 };

AVCodecParameters *vpar = _vs->codecpar;
vpar->codec_id = fmt->video_codec;
vpar->codec_type = AVMEDIA_TYPE_VIDEO;
vpar->format = AV_PIX_FMT_YUV420P;
vpar->profile = FF_PROFILE_H264_HIGH;
vpar->level = _level;
vpar->width = _width;
vpar->height = _height;
vpar->bit_rate = _avg_bitrate;

avio_open(&_oc->pb, _oc->filename, AVIO_FLAG_WRITE);
avformat_write_header(_oc, nullptr);


  



  Width, height, bitrate, level and profile I get from NVENC encoder settings. I also do the error checking, ommited here. Then I have a loop writing each encoded packets, with IDR frames etc all prepared on the fly with NVENC. The loop body is :

  



  auto & pkt_data = _packets[i];
AVPacket pkt = { 0 };
av_init_packet(&pkt);
pkt.pts = av_rescale_q(_n_frames++, AVRational{ 1, 25 }, _vs->time_base);
pkt.duration = av_rescale_q(1, AVRational{ 1, 25 }, _vs->time_base);
pkt.dts = pkt.pts;
pkt.stream_index = _vs->index;
pkt.data = pkt_data.data();
pkt.size = (int)pkt_data.size();

if (!memcmp(pkt_data.data(), "\x00\x00\x00\x01\x67", 5))
{
    pkt.flags |= AV_PKT_FLAG_KEY;
}

av_write_frame(_oc, &pkt);


  



  Obviously ffmpeg is writing avcc code somewhere... I have no clue where to add this code so the RTMP server can recognize it. Or I am missing something else ?

  



  Any hint greatly appreciated, folks !