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• fluent-ffmpeg unable to achieve consistent audio bitrate

  20 septembre 2020, par Martin

  I am working on an electron app that runs ffmpeg commands to combine an audio file + image file into a video file. I'm using an fluent-ffmpeg command I wrote, which works, but the outputted video fiels always have a lower audio bit rate, even though I specify 320kbps in my command.

  


  I've been running multiple tests with mp3/flac/wav files that I logged below ; using my fluent-ffmpeg command as follows :

  


  ffmpeg()
            .input(imgPath)
            .loop()
            .addInputOption('-framerate 2')
            .input(audioPath)
            .videoCodec('libx264')
            .audioCodec('aac')
            //.audioCodec('copy')
            .audioBitrate('320k')
            .videoBitrate('8000k', true)
            .size('1920x1080')
            .outputOptions([
                '-preset medium',
                '-tune stillimage',
                '-crf 18',
                '-b:a 320k',
                '-pix_fmt yuv420p',
                '-shortest'
            ])

            .on('progress', function (progress) {
                document.getElementById(updateInfoLocation).innerText = `Generating Video: ${Math.round(progress.percent)}%`
                console.info(`vid() Processing : ${progress.percent} % done`);
            })
            .on('codecData', function (data) {
                console.log('vid() codecData=', data);
            })
            .on('end', function () {
                document.getElementById(updateInfoLocation).innerText = `Video generated.`
                console.log('vid()  file has been converted succesfully; resolve() promise');
                resolve();
            })
            .on('error', function (err) {
                document.getElementById(updateInfoLocation).innerText = `Error generating video.`
                console.log('vid() an error happened: ' + err.message, ', reject()');
                reject(err);
            })
            .output(vidOutput).run()


  


  1) 320bkps mp3 file

  


  

  • imgPath = C :\Users\marti\Documents\projects\mp3 audio\img.jpg

  


  • audioPath = C :\Users\marti\Documents\projects\mp3 audio\08. Strange - Gigi D'Agostino.mp3

  


  • vidOutput = C :\Users\marti\Documents\projects\mp3 audio\08. Strange - Gigi D'Agostino.mp4

  


  


  My audio file has a bit rate of 320kbps :


  


  If I use my above ffmpeg function with .audioCodec('aac'), the output video file has an audio bitrate of 300kbps. If I use .audioCodec('copy') instead, my output video file has an audio bitrate of 317kbps.

  


  2) 1411kbps wav file

  


  

  • audioPath = C :\Users\marti\Documents\projects\wav audio\01 Nem Kaldi.wav

  


  • imgPath = C :\Users\marti\Documents\projects\wav audio\cover.jpg

  


  • vidOutput = C :\Users\marti\Documents\projects\wav audio\01 Nem Kaldi.mp4

  


  


  My wav file has an audio bit rate of 1411kbps ; 
When I run my ffmpeg command using .audioCodec('aac'), my output video file is again only 303kbps


  


  3) 937kbps flac file

  


  

  • audioPath = C :\Users\marti\Documents\projects\flac audio\02 - ryokika.flac

  


  • imgPath = C :\Users\marti\Documents\projects\flac audio\R-1042328-1388635895-5022.jpeg.jpg

  


  • vidOutput = C :\Users\marti\Documents\projects\flac audio\02 - ryokika.mp4

  


  


  When I run my ffmpeg command with.audioCodec('aac'), the outputted video file is only 304kbps

  


  is there any command or additional flag I need to add to ensure my output video files have a high quality audio bitrate ?

  


• flv reencode to mp4 for iphone/ipod via ffmpeg and x264 (quality issue)

  3 octobre 2011, par zeroasterisk

  There are a lot of questions on this topic, and I've read most of them and most of the google search results I could come up with.

  When I use FFMPEG to convert a FLV to a iphone3 compatble MP4 file, it just doesn't preserver enough of the quality. Yes, I've worked the hell out of -sameq and -b and -bt settings, text just isn't readable.

  Next I tried to split the video out and process it directly, using these instructions :
  https://sites.google.com/site/linuxencoding/x264-encoding-guide

  The problem is myplayer (via ffmpeg) was not able to determine the duration of the FLV (even though the metadata was set).

  (I assume) Because of that unknown duration, when I create the MP4 file, the resulting x264 file plays through super-fast while the audio plays at the normal rate.

  user@server:/tmp# mplayer -nosound -benchmark -sws 9 -vf dsize=640:480:0,scale=0:0,expand=640:480 -vo yuv4mpeg:file=>(x264 --demuxer y4m --crf 0 --preset slow --threads auto --output output.264 - 2>x264.log) 'input.flv'
  
  MPlayer 1.0rc4-4.4.5 (C) 2000-2010 MPlayer Team
  
  mplayer: could not connect to socket
  
  mplayer: No such file or directory
  
  Failed to open LIRC support. You will not be able to use your remote control.
  
  
  
  Playing input.flv.
  
  libavformat file format detected.
  
  [flv @ 0x1202460]Estimating duration from bitrate, this may be inaccurate
  
  [lavf] stream 0: video (vp6f), -vid 0
  
  [lavf] stream 1: audio (nellymoser), -aid 0
  
  VIDEO:  [VP6F]  1680x992  0bpp  1000.000 fps   33.4 kbps ( 4.1 kbyte/s)
  
  Clip info:
  
   audiocodecid: 6
  
   audiodatarate: 86
  
   audiosamplerate: 44100
  
   audiosamplesize: 16
  
   audiosize: 6097005
  
   canSeekToEnd: true
  
   datasize: 8609138
  
   duration: 567
  
   framerate: 2
  
   hasAudio: true
  
   hasCuePoints: false
  
   hasKeyframes: true
  
   hasMetadata: true
  
   hasVideo: true
  
   height: 992
  
   lasttimestamp: 567
  
   metadatacreator: flvtool++ (Facebook, Motion project, dweatherford)
  
   stereo: false
  
   totalframes: 1043
  
   videocodecid: 4
  
   videodatarate: 33
  
   videosize: 2316256
  
   width: 1680
  
  Using (default) progressive frame mode.Opening video filter: [expand w=640 h=480]
  
  Expand: 640 x 480, -1 ; -1, osd: 0, aspect: 0.000000, round: 1
  
  Opening video filter: [scale w=0 h=0]
  
  Opening video filter: [dsize=640:480:0]
  
  ==========================================================================
  
  Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
  
  Selected video codec: [ffvp6f] vfm: ffmpeg (FFmpeg VP6 Flash)
  
  ==========================================================================
  
  Audio: no sound
  
  Starting playback...
  
  Movie-Aspect is undefined - no prescaling applied.
  
  [swscaler @ 0x7f0c738b9620]Lanczos scaler, from yuv420p to yuv420p using MMX2
  
  VO: [yuv4mpeg] 640x480 => 641x480 Planar YV12

  I have also tried specifying FPS, but no change in results

  user@server:/tmp# mplayer -nosound -fps 25-benchmark -sws 9 -vf dsize=640:480:0,scale=0:0,expand=640:480 -vo yuv4mpeg:file=>(x264 --demuxer y4m --fps 25 --crf 0 --preset slow --threads auto --output output.264 - 2>x264.log) 'input.flv'

  Can someone tell me how to either :

  1. fix my split A/V processing/timing/duration issues ?
  2. improve the
     quality of the FFMPEG conversion of FLV to iphone3 compatible
     format ?

• flv reencode to mp4 for iphone/ipod via ffmpeg and x264 (quality issue)

  3 octobre 2011, par zeroasterisk

  There are a lot of questions on this topic, and I've read most of them and most of the google search results I could come up with.

  When I use FFMPEG to convert a FLV to a iphone3 compatble MP4 file, it just doesn't preserver enough of the quality. Yes, I've worked the hell out of -sameq and -b and -bt settings, text just isn't readable.

  Next I tried to split the video out and process it directly, using these instructions :
  https://sites.google.com/site/linuxencoding/x264-encoding-guide

  The problem is myplayer (via ffmpeg) was not able to determine the duration of the FLV (even though the metadata was set).

  (I assume) Because of that unknown duration, when I create the MP4 file, the resulting x264 file plays through super-fast while the audio plays at the normal rate.

  user@server:/tmp# mplayer -nosound -benchmark -sws 9 -vf dsize=640:480:0,scale=0:0,expand=640:480 -vo yuv4mpeg:file=>(x264 --demuxer y4m --crf 0 --preset slow --threads auto --output output.264 - 2>x264.log) 'input.flv'
  
  MPlayer 1.0rc4-4.4.5 (C) 2000-2010 MPlayer Team
  
  mplayer: could not connect to socket
  
  mplayer: No such file or directory
  
  Failed to open LIRC support. You will not be able to use your remote control.
  
  
  
  Playing input.flv.
  
  libavformat file format detected.
  
  [flv @ 0x1202460]Estimating duration from bitrate, this may be inaccurate
  
  [lavf] stream 0: video (vp6f), -vid 0
  
  [lavf] stream 1: audio (nellymoser), -aid 0
  
  VIDEO:  [VP6F]  1680x992  0bpp  1000.000 fps   33.4 kbps ( 4.1 kbyte/s)
  
  Clip info:
  
   audiocodecid: 6
  
   audiodatarate: 86
  
   audiosamplerate: 44100
  
   audiosamplesize: 16
  
   audiosize: 6097005
  
   canSeekToEnd: true
  
   datasize: 8609138
  
   duration: 567
  
   framerate: 2
  
   hasAudio: true
  
   hasCuePoints: false
  
   hasKeyframes: true
  
   hasMetadata: true
  
   hasVideo: true
  
   height: 992
  
   lasttimestamp: 567
  
   metadatacreator: flvtool++ (Facebook, Motion project, dweatherford)
  
   stereo: false
  
   totalframes: 1043
  
   videocodecid: 4
  
   videodatarate: 33
  
   videosize: 2316256
  
   width: 1680
  
  Using (default) progressive frame mode.Opening video filter: [expand w=640 h=480]
  
  Expand: 640 x 480, -1 ; -1, osd: 0, aspect: 0.000000, round: 1
  
  Opening video filter: [scale w=0 h=0]
  
  Opening video filter: [dsize=640:480:0]
  
  ==========================================================================
  
  Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
  
  Selected video codec: [ffvp6f] vfm: ffmpeg (FFmpeg VP6 Flash)
  
  ==========================================================================
  
  Audio: no sound
  
  Starting playback...
  
  Movie-Aspect is undefined - no prescaling applied.
  
  [swscaler @ 0x7f0c738b9620]Lanczos scaler, from yuv420p to yuv420p using MMX2
  
  VO: [yuv4mpeg] 640x480 => 641x480 Planar YV12

  I have also tried specifying FPS, but no change in results

  user@server:/tmp# mplayer -nosound -fps 25-benchmark -sws 9 -vf dsize=640:480:0,scale=0:0,expand=640:480 -vo yuv4mpeg:file=>(x264 --demuxer y4m --fps 25 --crf 0 --preset slow --threads auto --output output.264 - 2>x264.log) 'input.flv'

  Can someone tell me how to either :

  1. fix my split A/V processing/timing/duration issues ?
  2. improve the
     quality of the FFMPEG conversion of FLV to iphone3 compatible
     format ?