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• Why the audio of my mp4 file is going out of async

  16 juillet 2018, par Dop

  I am having a problem converting a wmv file to mp4. I am using x264.exe this command to get the video stream

  x264 --output temporal.264 --fps 25 --preset slow --bitrate 2048 --vbv-maxrate 2048 --vbv-bufsize 9600 --min-keyint 48 --keyint 48 --scenecut 0 --no-scenecut --pass 1 --video-filter "resize:width=640,height=480" Original.wmv

  Then I use ffmpeg.exe to extract the audio stream with this line :

  ffmpeg -i .wmv -acodec libfdk_aac -b:a 32000 temporal.aac

  finally I use MP4Box to merges each stream with this line :

  MP4Box -add temporal.264 Final.mp4
MP4Box -add temporal.aac Final.mp4

  The problem is that the final.mp4 audio is out of sync. It starts good but with time it goes out of sync with time.

  I run this command :

  MP4Box -info 010004470063PE-10022017083824-2_MultiMedia--1.mp4

  and I discover that the estimated time of both streams are different :

  output of command

  * Movie Info *
       Timescale 600 - 2 tracks
       Computed Duration 01:00:03.643 - Indicated Duration 01:00:03.643
       Fragmented File: no
       File suitable for progressive download (moov before mdat)
       File Brand isom - version 1
               Compatible brands: isom avc1
       Created: GMT Wed Jun 27 16:31:44 2018
       Modified: GMT Wed Jun 27 16:31:44 2018
File has root IOD (9 bytes)
Scene PL 0xff - Graphics PL 0xff - OD PL 0xff
Visual PL: AVC/H264 Profile (0x7f)
Audio PL: AAC Profile @ Level 2 (0x29)
No streams included in root OD
Track # 1 Info - TrackID 1 - TimeScale 25000
Media Duration 00:59:57.520 - Indicated Duration 00:59:57.520
Track has 1 edit lists: track duration is 00:59:57.320
Media Info: Language "Undetermined (und)" - Type "vide:avc1" - 89938 samples
Visual Track layout: x=0 y=0 width=640 height=480
MPEG-4 Config: Visual Stream - ObjectTypeIndication 0x21
AVC/H264 Video - Visual Size 640 x 480
       AVC Info: 1 SPS - 1 PPS - Profile Main @ Level 3
       NAL Unit length bits: 32
       Chroma format YUV 4:2:0 - Luma bit depth 8 - chroma bit depth 8
       SPS#1 hash: 41EE779BEF2AA71A7131EAFD3C77C7E3BC95FD8E
       PPS#1 hash: 086E1D72A40A0E8CF35D102F34A9DF6CD44D6CEF
Self-synchronized
       RFC6381 Codec Parameters: avc1.4D401E
       Average GOP length: 250 samples
Track # 2 Info - TrackID 2 - TimeScale 44100
Media Duration 01:00:03.644 - Indicated Duration 01:00:03.644
Media Info: Language "Undetermined (und)" - Type "soun:mp4a" - 155196 samples
MPEG-4 Config: Audio Stream - ObjectTypeIndication 0x40
MPEG-4 Audio AAC LC - 2 Channel(s) - SampleRate 44100
Synchronized on stream 1
       RFC6381 Codec Parameters: mp4a.40.2
       All samples are sync

  I am not shore why this is happening, becar the original wmv is perfectly synchronize. Any help ?

• ffmpeg couldn't process files uploaded via ajax C#

  27 juin 2018, par Yan Ge

  I’ve tried to extract one part from a mp4 file using ffmpeg but it returns an empty file, could you guys please help to check on this ?really drive me mad...a big thanks on advance !

  1.I tried to set the output file to another file(not self replace) and it works.
  2.I tried to post back the filename to client by ajax, video couldn’t been load but it can play on server(the ffmpeg generated file is not corrupted)
  3.I closed the localhost and re-launch it, the mp4 file could be loaded properly.

  —question
  1.is the file uploaded to server been occupied ?(I tried to delete it, it’s workable, and I already called dispose after generated the original file)

  2.why I restart localhost, it becomes workable ??what have been done during close localhost ??

  for C# code to save file,please refer to below
  
  HttpPostedFileWrapper video---param
  
  string extension = new FileInfo(video.FileName).Extension;
  
  string videoId = DateTime.Now.Ticks.ToString();
  
  string filePath =HttpContext.Current.Server.MapPath("~/video/" + videoId + extension);
  
  var videoFile = File.Create(filePath);
  
  video.InputStream.Seek(0, SeekOrigin.Begin);
  
  video.InputStream.CopyTo(videoFile);
  
  videoFile.Close();
  
  videoFile.Dispose();

  for ffmpeg please refer to below

  E:\tools\ticon\ffmpeg-20180619-a990184-win64-static\bin>ffmpeg -ss 1.67 -t 4.10 -i E:\MyMVCProj\MyMVCProj\MyMVCProj\video\7802334805.mp4 -vcodec copy -acodec copy E:\MyMVCProj\MyMVCProj\MyMVCProj\video\7802334805.mp4 -y
  
  ffmpeg version N-91330-ga990184007 Copyright (c) 2000-2018 the FFmpeg developers
  
  built with gcc 7.3.0 (GCC)
  
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth
  
  libavutil      56. 18.102 / 56. 18.102
  
  libavcodec     58. 20.103 / 58. 20.103
  
  libavformat    58. 17.100 / 58. 17.100
  
  libavdevice    58.  4.101 / 58.  4.101
  
  libavfilter     7. 25.100 /  7. 25.100
  
  libswscale      5.  2.100 /  5.  2.100
  
  libswresample   3.  2.100 /  3.  2.100
  
  libpostproc    55.  2.100 / 55.  2.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from      
  
  'E:\MyMVCProj\MyMVCProj\MyMVCProj\video\7802334805.mp4':
  
  Metadata:
  
  major_brand     : mp42
  
  minor_version   : 1
  
  compatible_brands: mp41mp42isom
  
  creation_time   : 2018-06-21T11:26:01.000000Z
  
  Duration: 00:00:09.80, start: 0.000000, bitrate: 1284 kb/s
  
  Stream #0:0(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 62 kb/s (default)
  
  Metadata:
  
    creation_time   : 2018-06-21T11:26:01.000000Z
  
    handler_name    : Core Media Audio
  
   Stream #0:1(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, smpte170m/bt709/bt709, progressive), 960x540, 1216 kb/s, 30 fps, 30 tbr, 600 tbn, 1200 tbc (default)
  
  
  
  Metadata:
  
      rotate          : 90
  
      creation_time   : 2018-06-21T11:26:01.000000Z
  
      handler_name    : Core Media Video
  
    Side data:
  
    displaymatrix: rotation of -90.00 degrees
  
  Output #0, mp4, to 'E:\MyMVCProj\MyMVCProj\MyMVCProj\video\7802334805.mp4':
  
  Metadata:
  
  major_brand     : mp42
  
  minor_version   : 1
  
  compatible_brands: mp41mp42isom
  
  encoder         : Lavf58.17.100
  
  Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, smpte170m/bt709/bt709, progressive), 960x540, q=2-31, 1216 kb/s, 30 fps, 30 tbr, 19200 tbn, 600 tbc (default)
  
  Metadata:
  
    rotate          : 90
  
    creation_time   : 2018-06-21T11:26:01.000000Z
  
    handler_name    : Core Media Video
  
  Side data:
  
    displaymatrix: rotation of -90.00 degrees
  
  Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 62 kb/s (default)
  
  Metadata:
  
    creation_time   : 2018-06-21T11:26:01.000000Z
  
    handler_name    : Core Media Audio
  
  Stream mapping:
  
  Stream #0:1 -> #0:0 (copy)
  
  Stream #0:0 -> #0:1 (copy)
  
  Press [q] to stop, [?] for help
  
  frame=    0 fps=0.0 q=-1.0 Lsize=       0kB time=00:00:00.00 bitrate=N/A speed=   0x
  
   video:0kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown

• how to prevent FFMPEG from increasing the video size ?

  28 juin 2018, par drexdelta

  My aim is to compress the video and reduce its file size.

  ffmpeg -i input.mp4 -crf 28 output.mp4

  Now, this command, increases the size of the given input file. And on the otherside, quality of the video is same as earlier. So, it’s increasing the space for nothing.

  How can I stop this from happening .

  This is original video (size 9.5 MB) , and this is the compressed video (size 13.2 MB) .

  So, I want to know, if it is possible to detect using ffmpeg, whether the size of the final video will increase or not ?

  FYI : I am writing script. I am not planning to change the CRF factor. Because that will damage quality of other good videos.

  These are the details on my ffmpeg version :

  ffmpeg version 4.0 Copyright (c) 2000-2018 the FFmpeg developers
  
    built with Apple LLVM version 9.1.0 (clang-902.0.39.1)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/4.0 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-gpl --enable-ffplay --enable-frei0r --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopus --enable-librtmp --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxvid --enable-opencl --enable-videotoolbox --disable-lzma --enable-libopenjpeg --disable-decoder=jpeg2000 --extra-cflags=-I/usr/local/Cellar/openjpeg/2.3.0/include/openjpeg-2.3 --enable-nonfree
  
    libavutil      56. 14.100 / 56. 14.100
  
    libavcodec     58. 18.100 / 58. 18.100
  
    libavformat    58. 12.100 / 58. 12.100
  
    libavdevice    58.  3.100 / 58.  3.100
  
    libavfilter     7. 16.100 /  7. 16.100
  
    libavresample   4.  0.  0 /  4.  0.  0
  
    libswscale      5.  1.100 /  5.  1.100
  
    libswresample   3.  1.100 /  3.  1.100
  
    libpostproc    55.  1.100 / 55.  1.100

  ---

  Found something here :

  "The only downside with this mode is that you don’t know what the resulting file size or the fluctuation of the bitrate will be." . checkout here