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• Using FFMPEG to reliably convert videos to mp4 for iphone/ipod and flash players

  13 janvier 2023, par Jake Stevenson

  I need to convert videos for use in both a flash player and the iphone/ipod touch. I'm using the following batch script with ffmpeg :

  



  @echo off
ffmpeg.exe -i %1 -s qvga -acodec libfaac -ar 22050 -ab 128k -vcodec libx264 -threads 0 -f ipod %2


  



  This always outputs an mp4 file, and I can always play it on my PC. The videos also seem to play fine on my iphone 3GS. But with some input files it won't work for older iphone versions (3G and iPod touch).

  



  Here's the ffmpeg output from one such file :

  



  D:\ffmpeg>encode.bat d:\temp\recording.flv d:\temp\out.m4v
FFmpeg version SVN-r18709, Copyright (c) 2000-2009 Fabrice Bellard, et al.
  configuration: --enable-memalign-hack --prefix=/mingw --cross-prefix=i686-ming
w32- --cc=ccache-i686-mingw32-gcc --target-os=mingw32 --arch=i686 --cpu=i686 --e
nable-avisynth --enable-gpl --enable-zlib --enable-bzlib --enable-libgsm --enabl
e-libfaac --enable-libfaad --enable-pthreads --enable-libvorbis --enable-libtheo
ra --enable-libspeex --enable-libmp3lame --enable-libopenjpeg --enable-libxvid -
-enable-libschroedinger --enable-libx264
  libavutil     50. 3. 0 / 50. 3. 0
  libavcodec    52.27. 0 / 52.27. 0
  libavformat   52.32. 0 / 52.32. 0
  libavdevice   52. 2. 0 / 52. 2. 0
  libswscale     0. 7. 1 /  0. 7. 1
  built on Apr 28 2009 04:04:42, gcc: 4.2.4
[flv @ 0x187d650]skipping flv packet: type 18, size 164, flags 0
Input #0, flv, from 'd:\temp\recording.flv':
  Duration: 00:00:07.17, start: 0.001000, bitrate: N/A
    Stream #0.0: Video: flv, yuv420p, 320x240, 1k tbr, 1k tbn, 1k tbc
    Stream #0.1: Audio: nellymoser, 44100 Hz, mono, s16
[libx264 @ 0x13518b0]using cpu capabilities: MMX2 SSE2Fast SSSE3 FastShuffle SSE
4.2
[libx264 @ 0x13518b0]profile Baseline, level 4.2
Output #0, ipod, to 'd:\temp\out.m4v':
    Stream #0.0: Video: libx264, yuv420p, 320x240, q=2-31, 200 kb/s, 1k tbn, 1k
tbc
    Stream #0.1: Audio: libfaac, 22050 Hz, mono, s16, 128 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #0.1
Press [q] to stop encoding
frame=   90 fps=  0 q=-1.0 Lsize=     128kB time=6.87 bitrate= 152.4kbits/s
video:92kB audio:32kB global headers:1kB muxing overhead 2.620892%
[libx264 @ 0x13518b0]slice I:8     Avg QP:29.62  size:  7047
[libx264 @ 0x13518b0]slice P:82    Avg QP:30.83  size:   467
[libx264 @ 0x13518b0]mb I  I16..4: 17.9%  0.0% 82.1%
[libx264 @ 0x13518b0]mb P  I16..4:  0.6%  0.0%  0.0%  P16..4: 23.1%  0.0%  0.0%
 0.0%  0.0%    skip:76.3%
[libx264 @ 0x13518b0]final ratefactor: 57.50
[libx264 @ 0x13518b0]SSIM Mean Y:0.9544735
[libx264 @ 0x13518b0]kb/s:8412.6


  



  My suspicion is that it has something to do with the audio encoding. If so, does anyone know how to force it to reencode the audio to the proper format ?

  



  Any other ideas ?

  


• Serve media collection to an old iphone 3gs [on hold]

  25 février 2019, par Ale

  I’d like to serve a media collection, hosted in a home network, to an old iphone. I’m pretty much able to do this using apache web server, html, javascript, and jwplayer. But most of the media is in a format that the iphone doesn’t support and so I run into the problem of transcoding each movie I want to play but I would like it to happen on the fly to save time as well as be able to seek or fast forward to different parts of the movie. How can I go about doing this using the tools I already mention ? Php and ffmpeg are also welcome. Other tools are fine but please suggest open source if posible. I’m on a windows pc at this time. I’m sorry for not being too specific. I’m looking for a method or a different set of tools to point me in the right direction.

  Thanks in advance.

• How to deal ffplay bein too slow playing iPhone's videos ?

  21 janvier 2019, par Mikhail T.

  Trying to play a 3840x2160 video recorded by an iPhone 7 (@30fps), I get frequent pauses — in the video, music keeps playing.

  This happens both in firefox and when ffplay is invoked to play the file directly — from command-line. The CPU is a dual E6700 @3.20GHz — not super fast, but it should be able to play smoothly, shouldn’t it ? Video is Intel’s "series 4" integrated chipset — again, not a speed-daemon, but it should be adequate... Support for Intel’s VA API is included.

  I build ffmpeg-4.1 from source using FreeBSD port. As you can see, the port has a maddening amount of options — including several different ones for the 264-codec.

  Any suggestions for improving the decoding speed to the point, where it is watchable by a human ? Thank you !