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• mencoder. Encoding from multiple input image files compatible with web browser (No video support and MIME type) [duplicate]

  23 juin 2020, par iblasi

  I have multiple JPG files that I want to use to make a TimeLapse video compatible with the web browser to upload it on my web page.
Create a video with mencoder from multiple images is explained in some webpages such us here, that shows how to create a video.

  


  ls -Ltr my_Pics/*.jpg >files.txt
mencoder -nosound -ovc lavc -lavcopts vcodec=mpeg4 -o video.avi -mf type=jpeg:fps=4 mf://@files.txt


  


  The video is set with no sound and to have one picture every 250ms (4 fps).
These command lines create an AVI video that I can see correctly with the VLC video tool. However, if I try to open it in a web browser it shows an error :

  


  


  No Video with Supported Format and MIME type found

  


  


  So, based on other similar comments (as here), I tryed to use ffmpeg renaming all my files as ffmpeg requires a number serial format. But it happens the same, that I can see it in VLC but not in the browser.

  


  ffmpeg -r 4 -i ./output/%04d.jpg -vcodec libx264 video.mp4


  


  Based on research made on internet I am quite sure that it is due the the encoding and/or container. I tryed multiple options of codecs nd containers existing on documentation (here) but still not able to find a way to work.

  


  If, once I create the video, I use the VLC tool to manually convert the video to ".m4v" I was able to create a video that the web browser recognizes. But I would like to do it with command lines to automate it.

  


• convert WAV to TETRA format

  14 juin 2020, par Ashish Arora

  I am trying to convert a wav file into TETRA encoded file (https://en.wikipedia.org/wiki/Terrestrial_Trunked_Radio). Tetra is used by fire-fighters, it provides a radio-like voice.

  



  I am trying to use the official tetra codec codes available at (https://www.etsi.org/deliver/etsi_en/300300_300399/30039502/01.03.01_60/) and we can easily compile it using the scripts available at https://github.com/sq5bpf/install-tetra-codec.

  



  However, I am not able to figure out how to convert a wav file into tetra codec files using these files. I tried going through the documentation of the compiled files (ccoder, cdecoder, scoder, sdecoder).

  



  I tried the following command -

  



  


  tetra/bin/scoder input.wav serial_file synth_file

  


  



  here serial_file and synth_file are the output files and have following documentation in the scoder.c file :

  



      INPUT   :   - Description : speech file to be analyzed
                - Format : binary file 16 bit-samples
                  240 samples per frame

serial_file :   - Description : serial stream output file 
            - Format : binary file 16 bit-samples
              each 16 bit-sample represents one encoded bit
              138 (= 1 + 137) bits per frame

synth_file  :   - Description : local synthesis output file 
            - Format : binary file 16 bit-samples


  



  For an input file of size 13M, I obtained serial_file and synth_file of size 8.0M and 16M. However, I thought since the wav file is getting converted into a walkie-talkie type signal the output file size will be alot smaller.

  



  I want to clarify if :

  



  

  • I used the correct code to convert an input wav file into a tetra format output file.

  


  • can you please help me understand, what is serial_file and synth_file.

  


  



  Thanks,
Ashish

  


• ffplay cannot play more than one song

  5 février 2020, par Bernie gach

  i have taken ffplay.c file from http://ffmpeg.org/doxygen/trunk/ffplay_8c-source.html and re edited it to a cpp file to embed in my win32 gui application . i have made the following changes to it.

  1. made the int main function into a local function as follows, i can pass the HWND to embedd the player

  void Ffplay::play_song(string file, HWND parent, bool* successfull)
  
  {
  
      int flags;
  
      VideoState* is;
  
      input_filename = file; 
  
      /* register all codecs, demux and protocols */
  
  #if CONFIG_AVDEVICE
  
      avdevice_register_all();
  
  #endif
  
      //avformat_network_init();
  
      //check whether the filename is valid
  
      if (input_filename.empty())
  
      {
  
          logger.log(logger.LEVEL_ERROR, "filename %s is not valid\n", file);
  
          return;
  
      }
  
      if (display_disable)
  
      {
  
          video_disable = 1;
  
      }
  
      flags = SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER;
  
      if (audio_disable)
  
          flags &= ~SDL_INIT_AUDIO;
  
      else
  
      {
  
          /* Try to work around an occasional ALSA buffer underflow issue when the
  
           * period size is NPOT due to ALSA resampling by forcing the buffer size. */
  
          if (!SDL_getenv("SDL_AUDIO_ALSA_SET_BUFFER_SIZE"))
  
              SDL_setenv("SDL_AUDIO_ALSA_SET_BUFFER_SIZE", "1", 1);
  
      }
  
      if (display_disable)
  
          flags &= ~SDL_INIT_VIDEO;
  
      SDL_SetMainReady();
  
      if (SDL_Init(flags))
  
      {
  
          logger.log(logger.LEVEL_ERROR, "Could not initialize SDL - %s\n", SDL_GetError());
  
          logger.log(logger.LEVEL_ERROR, "(Did you set the DISPLAY variable?)\n");
  
          return;
  
      }
  
      //Initialize optional fields of a packet with default values.
  
      //Note, this does not touch the data and size members, which have to be initialized separately.
  
      av_init_packet(&flush_pkt);
  
      flush_pkt.data = (uint8_t*)&flush_pkt;
  
  
  
      if (!display_disable)
  
      {
  
          int flags = SDL_WINDOW_HIDDEN;
  
          if (alwaysontop)
  
  #if SDL_VERSION_ATLEAST(2,0,5)
  
              flags |= SDL_WINDOW_ALWAYS_ON_TOP;
  
  #else
  
              logger.log(logger.LEVEL_INFO, "SDL version doesn't support SDL_WINDOW_ALWAYS_ON_TOP. Feature will be inactive.\n");
  
  #endif
  
          if (borderless)
  
              flags |= SDL_WINDOW_BORDERLESS;
  
          else
  
              flags |= SDL_WINDOW_RESIZABLE;
  
          SDL_InitSubSystem(flags);
  
          ShowWindow(parent, true);
  
          //window = SDL_CreateWindow(program_name, SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, default_width, default_height, flags);
  
          window = SDL_CreateWindowFrom(parent);
  
          SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "linear");
  
          if (window) {
  
              renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
  
              if (!renderer)
  
              {
  
                  logger.log(logger.LEVEL_ERROR, "Failed to initialize a hardware accelerated renderer: %s\n", SDL_GetError());
  
                  renderer = SDL_CreateRenderer(window, -1, 0);
  
              }
  
              if (renderer)
  
              {
  
                  if (!SDL_GetRendererInfo(renderer, &renderer_info))
  
                  {
  
                      logger.log(logger.LEVEL_INFO, "Initialized %s renderer.\n", renderer_info.name);
  
                  }
  
              }
  
          }
  
          if (!window || !renderer || !renderer_info.num_texture_formats)
  
          {
  
              logger.log(logger.LEVEL_ERROR, "Failed to create window or renderer: %s\n", SDL_GetError());
  
              return;
  
          }
  
      }
  
  
  
      is = stream_open(input_filename.c_str(), file_iformat);
  
      if (!is)
  
      {
  
          logger.log(logger.LEVEL_ERROR, "Failed to initialize VideoState!\n");
  
          return;
  
      }
  
      //the song is playing now
  
      *successfull = true;
  
      event_loop(is);
  
      //the song has quit;
  
      *successfull = false;
  
  }

  2. changed the callback functions as the static ones couldn’t be used by c++ eg,

  void Ffplay::static_sdl_audio_callback(void* opaque, Uint8* stream, int len)
  
  {
  
      static_cast(opaque)->sdl_audio_callback(opaque, stream, len);
  
  }

  closing doesn’t change from the main file to close the audio and sdl framework

  void Ffplay::do_exit(VideoState* is)
  
  {
  
      abort = true;
  
      if(is)
  
      {
  
          stream_close(is);
  
      }
  
      if (renderer)
  
          SDL_DestroyRenderer(renderer);
  
      if (window)
  
           SDL_DestroyWindow(window);
  
  #if CONFIG_AVFILTER
  
      av_freep(&vfilters_list);
  
  #endif
  
      avformat_network_deinit();
  
      SDL_Quit();
  
  
  
  }

  i call the functions as follows from main gui

  ft=std::async(launch::async, &Menu::play_song, this, songs_to_play.at(0));

  the menu::play_song function is :

  void Menu::play_song(wstring song_path)
  
  {
  
      ready_to_play_song = false;
  
      OutputDebugString(L"\nbefore song\n");
  
      using std::future;
  
      using std::async;
  
      using std::launch;
  
  
  
      string input{ song_path.begin(),song_path.end() };
  
      Ffplay ffplay;
  
      ffplay.play_song(input, h_sdl_window, &song_opened);
  
  
  
      OutputDebugString(L"\nafter song\n");
  
      ready_to_play_song = true;
  
  }

  THE PROBLEM is i can only play one song . if i call the menu::play_song function again the sound is missing and the video/art cover is occasionally missing also. it seems some resources are not been released or something like that.

  i have localised the proble to this function

  int Ffplay::packet_queue_get(PacketQueue* q, AVPacket* pkt, int block, int* serial)
  
  {
  
  
  
      MyAVPacketList* pkt1;
  
      int ret;
  
      int count=0;
  
      SDL_LockMutex(q->mutex);
  
  
  
      for (;;) 
  
      {
  
  
  
  
  
          if (q->abort_request)
  
          {
  
              ret = -1;
  
              break;
  
          }
  
  
  
          pkt1 = q->first_pkt;
  
          if (pkt1) {
  
              q->first_pkt = pkt1->next;
  
              if (!q->first_pkt)
  
                  q->last_pkt = NULL;
  
              q->nb_packets--;
  
              q->size -= pkt1->pkt.size + sizeof(*pkt1);
  
              q->duration -= pkt1->pkt.duration;
  
              *pkt = pkt1->pkt;
  
              if (serial)
  
                  *serial = pkt1->serial;
  
              av_free(pkt1);
  
              ret = 1;
  
              break;
  
          }
  
          else if (!block) {
  
              ret = 0;
  
              break;
  
          }
  
          else 
  
          {
  
              logger.log(logger.LEVEL_INFO, "packet_queue before");
  
              SDL_CondWait(q->cond, q->mutex);
  
              logger.log(logger.LEVEL_INFO, "packet_queue after");
  
  
  
          }
  
      }
  
      SDL_UnlockMutex(q->mutex);
  
      return ret;
  
  }

  the call to SDL_CondWait(q->cond, q->mutex); never returns