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• Reducing the bit rate is dropping the audio stream [closed]

  19 février 2013, par user977505

  I'm a newbie to the ffmpeg, x264 commands and conversion. So please bear w/ me.

  I've a H.264 content w/ very high bit rate and I'm using ffmepg, x264 commands to reduce the bit rate. The bit rate is getting reduced but the problem is the output doesn't have the audio stream anymore.

  Here are the commands, I'm using :

  ffmpeg.exe  -i King_Maker_Leader.mp4 -pix_fmt yuv420p -vf scale=1024:576 -r 24 \
    -f yuv4mpegpipe - | x264.exe  —bitrate 1664 —demuxer y4m \
    —preset slow —ref 3 —threads 6 —thread-input —no-scenecut \
    —no-interlaced —stats King_Maker_Leader.stats —vbv-bufsize 3328000 \
    —vbv-maxrate 1996 —pass 1 —output NUL —profile main —level 3.1 —sar 1:1 \
    —tune film —keyint 96 -
  ffmpeg.exe  -i King_Maker_Leader.mp4 -pix_fmt yuv420p -vf scale=1024:576 \
  
    -r 24 -f yuv4mpegpipe - | x264.exe  —bitrate 1664 —demuxer y4m \
  
    —preset slow —ref 3 —threads 6 —thread-input —no-scenecut \
  
    —no-interlaced —stats King_Maker_Leader.stats —vbv-bufsize 3328000 \
  
    —vbv-maxrate 1996 —pass 2 —output King_Maker_Leader_generated.mp4 \
  
    —profile main —level 3.1 —sar 1:1 —tune film —keyint 96 -
  

  I cannot figure out what is wrong with the above commands.

  I'm attaching the partial logs from pass 2 command that show the input has two streams (video and audio) and the output has only video stream.

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '..\yathrakkarude_sathruka.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf54.6.101
  
    Duration: 00:01:00.37, start: 0.000000, bitrate: 8587 kb/s
  
      Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 720x576 [
  
  SAR 16:11 DAR 20:11], 8073 kb/s, 25 fps, 25 tbr, 25k tbn, 50 tbc
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, s16, 508
  
   kb/s
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Output #0, yuv4mpegpipe, to 'pipe:':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf54.25.104
  
      Stream #0:0(eng): Video: rawvideo (I420 / 0x30323449), yuv420p, 1024x576 [SA
  
  R 45:44 DAR 20:11], q=2-31, 200 kb/s, 90k tbn, 24 tbc
  
      Metadata:
  
        handler_name    : VideoHandler
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (h264 -> rawvideo)
  
  Press [q] to stop, [?] for help
  
  [yuv4mpegpipe @ 016d5800] Encoder did not produce proper pts, making some up.
  
  y4m [info]: 1024x576p 45:44 @ 24/1 fps (cfr)
  
  x264 [info]: using SAR=1/1
  
  x264 [warning]: VBV buffer (2000000) > level limit (14000)
  
  x264 [info]: using cpu capabilities: MMX2 SSE2Fast FastShuffle SSEMisalign LZCNT

• create mono and stereo stream in the same file with ffmpeg ?

  24 juillet 2017, par user2216280

  I have a film with 2 mono audio stream of avi file.

  I would like to create a third file, with one stereo stream from the 2 mono stream, and one mono stream, addition of the 2 monos audio source...
  here’s the code to make mono stream :

  ffmpeg -i input.avi-ac 1 mono.avi

  here’s the code to make an stereo stream from 2 mono stream :

  ffmpeg -i input.avi-filter_complex "[0:1][0:2] amerge=inputs=2" -c:a pcm_s16le output.avi

  How could I merge those 2codes to make one audio file with one stero track, and one mono track ?
  tiouss ! thanks in advance

• FFmpeg : Interpolation for Fade-In

  6 juillet 2017, par Sir Bad News

  I’m currently using the following to fade-in a short film.

  ffmpeg -i input.mp4 -filter:v fade=in:0:360 -c:v libx264 -preset:v slower -crf:v 24 -pix_fmt yuv420p output.mp4

  ---

  Everything works as expected ; however, the interpolation of the fade is not what I’m after (seems to be linear). I’d like to play around with exponential, cubic, sinusoidal, etc.

  Is there any way to achieve this with FFmpeg ? The visual material I’m working with is pure white and pure black, and the fade-in as it stands is too harsh ; I can see the material appear almost as soon as the fade starts as a result of the (apparently) linear progression. I’d like it to be more organic.

  Any help greatly appreciated.