Recherche avancée

Sur d’autres sites (5380)

• How to make audio sound better ? (C + FFMpeg audio generation example)

  21 février 2017, par Rella

  So I found this great C FFMpeg official example which I simplified :

  #include 
  
  #include 
  
  #include 
  
  
  
  #ifdef HAVE_AV_CONFIG_H
  
  #undef HAVE_AV_CONFIG_H
  
  #endif
  
  
  
  #include "libavcodec/avcodec.h"
  
  #include "libavutil/mathematics.h"
  
  
  
  #define INBUF_SIZE 4096
  
  #define AUDIO_INBUF_SIZE 20480
  
  #define AUDIO_REFILL_THRESH 4096
  
  
  
  /*
  
   * Audio encoding example
  
   */
  
  static void audio_encode_example(const char *filename)
  
  {
  
      AVCodec *codec;
  
      AVCodecContext *c= NULL;
  
      int frame_size, i, j, out_size, outbuf_size;
  
      FILE *f;
  
      short *samples;
  
      float t, tincr;
  
      uint8_t *outbuf;
  
  
  
      printf("Audio encoding\n");
  
  
  
      /* find the MP2 encoder */
  
      codec = avcodec_find_encoder(CODEC_ID_MP2);
  
      if (!codec) {
  
          fprintf(stderr, "codec not found\n");
  
          exit(1);
  
      }
  
  
  
      c= avcodec_alloc_context();
  
  
  
      /* put sample parameters */
  
      c->bit_rate = 64000;
  
      c->sample_rate = 44100;
  
      c->channels = 2;
  
  
  
      /* open it */
  
      if (avcodec_open(c, codec) < 0) {
  
          fprintf(stderr, "could not open codec\n");
  
          exit(1);
  
      }
  
  
  
      /* the codec gives us the frame size, in samples */
  
      frame_size = c->frame_size;
  
      samples = malloc(frame_size * 2 * c->channels);
  
      outbuf_size = 10000;
  
      outbuf = malloc(outbuf_size);
  
  
  
      f = fopen(filename, "wb");
  
      if (!f) {
  
          fprintf(stderr, "could not open %s\n", filename);
  
          exit(1);
  
      }
  
  
  
      /* encode a single tone sound */
  
      t = 0;
  
      tincr = 2 * M_PI * 440.0 / c->sample_rate;
  
      for(i=0;i<200;i++) {
  
          for(j=0;j* encode the samples */
  
          out_size = avcodec_encode_audio(c, outbuf, outbuf_size, samples);
  
          fwrite(outbuf, 1, out_size, f);
  
      }
  
      fclose(f);
  
      free(outbuf);
  
      free(samples);
  
  
  
      avcodec_close(c);
  
      av_free(c);
  
  }
  
  
  
  int main(int argc, char **argv)
  
  {
  
  
  
      /* must be called before using avcodec lib */
  
      avcodec_init();
  
  
  
      /* register all the codecs */
  
      avcodec_register_all();
  
  
  
      audio_encode_example("test.mp2");
  
  
  
      return 0;
  
  }

  How should it sound like ? May be I don’t get something but it sounds awful =( how to make audio generation sound better/ more interesting/ melodical in a wary shourt way (no special functions just how to change this code to make it sound better) ?

• How to fix call lib ffmpeg by c#

  20 février 2017, par Thang Tran

  string _a= -i "D:_InputFolder\Jamaican man talking the truth about #zika virus.mp4" -filter_complex "[0:a]atempo=0.9,volume=1.6,asetrate=r=44100*33.6/30,atempo=30/33.6,highpass=f=400,lowpass=f=4100,earwax,biquad,compensationdelay,equalizer=f=222:width_type=o:width=2:g=5,equalizer=f=444:width_type=h:width=220:g=5 ; setpts=PTS/0.9" -vcodec libx264 -pix_fmt yuv420p -r 30 -g 60 -b:v 1400k -profile:v main -level 3.1 -acodec libmp3lame -b:a 128k -ar 44100 -metadata title="" -metadata artist="" -metadata album_artist="" -metadata album="" -metadata date="" -metadata track="" -metadata genre="" -metadata publisher="" -metadata encoded_by="" -metadata copyright="" -metadata composer="" -metadata performer="" -metadata TIT1="" -metadata TIT3="" -metadata disc="" -metadata TKEY="" -metadata TBPM="" -metadata language="eng" -metadata encoder="" -threads 0 -preset superfast "D:_OutputFolder\videoOutput.mp4"

  -----------this is the code goi goi sua sound in c # error

  string _b= -i "D:_InputFolder\Jamaican man talking the truth about #zika virus.mp4" -acodec pcm_u8 -ar 22050 "D:_OutputFolder\videoOutput.wav"
  — with code editing video style is back.

  file class run ffmpeg
  call c# :
  string _result = ffmpeg.RunCommand(_b) ;//wordless

  string _result2 = ffmpeg.RunCommand(_a) ;//error

  file class call ffmpeg :

  -file project demo error :
  https://drive.google.com/open?id=0B9dxSeLrFswjVmNGd1IzcUpncE0

  thank you and sorry if my english is the poor

• How to make mp4 from MediaStream in Chrome browser

  18 février 2017, par otiai10

  MediaRecorder.isTypeSupported('video/mp4') is false in Chrome. So I found MediaStreamRecorder https://github.com/streamproc/MediaStreamRecorder then I did

  var recorder = new MediaStreamRecorder(stream, {
  
    mimeType: 'video/mp4',
  
  });
  
  // also
  
  recorder.mimeType = 'video/mp4';

  But the output is webm as I checked with ffmpeg -i

  Input #0, matroska,webm, from '/Users/otiai10/Downloads/example.mp4':
  
    Metadata:
  
      encoder         : Chrome
  
    Duration: N/A, start: 0.000000, bitrate: N/A
  
      Stream #0:0(eng): Video: vp8, yuv420p, 640x480, SAR 1:1 DAR 4:3, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)

  The video is playable in Chrome but NOT on QuickTime Player, in evidence.

  Here are more details and (not !) working example of this problem.

  It was said muaz-khan/Ffmpeg.js can convert webm to mp4, but the file size matters.

  Is there any workaround to record and save as mp4 ?