Recherche avancée

Sur d’autres sites (2139)

• Winamp and the March of GUI

  1er juillet 2012, par Multimedia Mike — General, ars technica, gui, user interface, winamp

  Ars Technica recently published a 15-year retrospective on the venerable Winamp multimedia player, prompting bouts of nostalgia and revelations of "Huh ? That program is still around ?" from many readers. I was among them.

  
  
  

  I remember first using Winamp in 1997. I remember finding a few of these new files called MP3s online and being able to play the first 20 seconds using the official Fraunhofer Windows player— full playback required the fully licensed version. Then I searched for another player and came up with Winamp. The first version I ever used was v1.05 in the summer of 1997. I remember checking the website often for updates and trying out every single one. I can’t imagine doing that nowadays— programs need to auto-update themselves (which Winamp probably does now ; I can’t recall the last time I used the program).

  Video Underdog
  The last time Winamp came up on my radar was early in 2003 when a new version came with support for a custom, proprietary multimedia audio/video format called Nullsoft Video (NSV). I remember the timeframe because the date is indicated in the earliest revision of my NSV spec document (back when I was maintaining such docs in a series of plaintext files). This was cobbled together from details I and others in the open source multimedia community sorted out from sample files. It was missing quite a few details, though.

  Then, Winamp founder Justin Frankel — introduced through a colleague on the xine team — emailed me his official NSV format and told me I was free to incorporate details into my document just as long as it wasn’t obvious that I had the official spec. This put me in an obnoxious position of trying to incorporate details which would have been very difficult to reverse engineer without the official doc. I think I coped with the situation by never really getting around to updating my doc in any meaningful way. Then, one day, the official spec was released to the world anyway, and it is now mirrored here at multimedia.cx.

  I don’t think the format ever really caught on in any meaningful way, so not a big deal. (Anytime I say that about a format, I always learn it saw huge adoption is some small but vocal community.)

  What’s Wrong With This Picture ?
  What I really wanted to discuss in this post was the matter of graphical user interfaces and how they have changed in the last 15 years.
  
  I still remember when I first downloaded Winamp v1.05 and tried it on my Windows machine at the time. Indignantly, the first thought I had was, "What makes this program think it’s so special that it’s allowed to violate the user interface conventions put forth by the rest of the desktop ?" All of the Windows programs followed a standard set of user interface patterns and had a consistent look and feel... and then Winamp came along and felt it could violate all those conventions.

  I guess I let the program get away with it because it was either that or only play 20-second clips from the unregistered Fraunhofer player. Though incredibly sterile by comparison, the Fraunhofer player, it should be noted, followed Windows UI guidelines to the letter.

  As the summer of 1997 progressed and more Winamp versions were released, eventually one came out (I think it was v1.6 or so) that supported skins. I was excited because there was a skin that made the program look like a proper Windows program— at least if you used the default Windows color scheme, and had all of your fonts a certain type and size.

  Skins were implemented by packaging together a set of BMP images to overlay on various UI elements. I immediately saw a number of shortcomings with this skinning approach. A big one was UI lock-in. Ironically, if you skin an app and wish to maintain backwards compatibility with the thousands of skins selflessly authored by your vibrant community (seriously, I couldn’t believe how prolific these things were), then you were effectively locked into the primary UI. Forget about adding a new button anywhere.

  Another big problem was resolution-independence. Basing your UI on static bitmaps doesn’t scale well with various resolutions. Winamp had its normal mode and it also had double-sized mode.

  Skins proliferated among many types of programs in the late 1990s. I always treasured this Suck.com (remember them ? that’s a whole other nostalgia trip) essay from April, 2000 entitled Skin Cancer. Still, Winamp was basically the standard, and the best, and I put away my righteous nerd rage and even dug through the vast troves of skins. I remember settling on Swankamp for a good part of 1998, probably due to the neo-swing revival at the time.

  
  
  

  Then again, if Winamp irked me, imagine my reaction when I was first exposed to the Sonique Music Player in 1998 :

  
  
  

  The New UI Order
  Upon reflection, I realize now that I had a really myopic view of what a computer GUI should be. I thought the GUIs were necessarily supposed to follow the WIMP (windows, icons, mouse, pointer) paradigm and couldn’t conceive of anything different. For a long time, I couldn’t envision a useful GUI on a small device (like a phone) because WIMP didn’t fit well on such a small interface (even though I saw various ill-fated attempts to make it work). This thinking seriously crippled me when I was trying to craft a GUI for a custom console media player I was developing as a hobby many years ago.

  I’m looking around at what I have open on my Windows 7 desktop right now. Google Chrome browser, Apple iTunes, Adobe Photoshop Elements, and VMware Player are 4 programs which all seem to have their own skins. Maybe Winamp doesn’t look so out of place these days.

• ffmpeg mp4 x264 encoding -> playback causes "pending" in both Chrome and IE causing 10+ seconds delay

  26 novembre 2015, par user1978645

  After encoding a video to mp4(x264 with aac) ; I have the following weird behaviour in both crome and IE :

  Im serving the content from https with spdy enables.

  It takes up to 30 seconds before the video is actually played, in the mean time i cannot reload the page it shows up as "pending". (even after i have visual on the video sometimes it takes 10-20 seconds before i can actually reload the page, or navigate to another url on the same domain)

  After looking at the "network" tab in developer tools, i see the following requests for 1 page/video :

  Path        Method Status   Type         Initiator   Size/content  Time/latency
  
  video.mp4   GET    206 OK   video/mp4    other       32.3KB/32.0kb  600ms/339MS 
  
  video.mp4   GET    206 OK   video/mp4    other       123kb/123b     21.85s/21.46s
  
  video.mp4   GET    206 OK   video/mp4    other       7.1MB/7.2MB    1.4min/2ms

  I tried to isolate the problem, When i use an mp4 video from the internet (for example the demo video of jplayer) and load it from my server, it loads rapidly, without delays.

  So it makes me think the problem lies within the encoding. I tried various things.
  FFmpeg :

  • csr 69 (low quality)

  • various options

  HTML :

  • preload="none"

  • javascript loading/playing of the movie

  • type=’mp4/video’

  • no posterimage

  But i cannot resolve the problem. Does anyone have a clue what is causing this ?

  I have a download speed of 300kb/s and the movie is 6MB.

  After the video starts, the video isn’t fully buffered, so i wonder : What is the html5 videoplayer doing all this time ?

  The problem also blocks the connections. When i press "F5" in both chrome and IE the page beeing reloaded comes up in the network tab as "pending" and it can take 10 to 20 seconds before the page actually reloads.

  ffmpeg command : (i used various commands but this is just 1 example which causes the problem)

  /root/bin/ffmpeg    -threads 1 -y  -i /home/flirtzo/public_html//userfiles/files/94e76a18a7838e62ecb23cf0c374b1b798e7b936  -threads 0 -codec:a libfdk_aac -b:a 128k  -vf "scale=-2:320" -preset veryslow -vcodec h264 -acodec aac -strict -2  /home/flirtzo/public_html/userfiles/files/b2/72/695f4eba95169a3f29564bf9571c703b05f1b5974f5156da633eb139c80a1575452e2858dfc61cc82bfca02d2b156aa64d4503695756481dc2a5d1c673a4cdea-94e76a18a7838e62ecb23cf0c374b1b798e7b936.mp4

  Output :

  ffmpeg version git-2014-04-16-c150e2c Copyright (c) 2000-2014 the FFmpeg developers
  
    built on Sep 28 2014 21:08:17 with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-4)
  
    configuration: --prefix=/root/ffmpeg_build --extra-cflags=-I/root/ffmpeg_build/include --extra-        ldflags=-L/root/ffmpeg_build/lib --bindir=/root/bin --extra-libs=-ldl --enable-gpl --enable-nonfree -    -enable-libfdk_aac --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvpx --enable-    libx264
  
    libavutil      52. 76.100 / 52. 76.100
  
    libavcodec     55. 58.103 / 55. 58.103
  
    libavformat    55. 37.100 / 55. 37.100
  
    libavdevice    55. 13.100 / 55. 13.100
  
    libavfilter     4.  4.100 /  4.  4.100
  
    libswscale      2.  6.100 /  2.  6.100
  
    libswresample   0. 18.100 /  0. 18.100
  
    libpostproc    52.  3.100 / 52.  3.100
  
  Input #0, mpeg, from         '/home/flirtzo/public_html//userfiles/files/94e76a18a7838e62ecb23cf0c374b1b798e7b936':
  
    Duration: 00:00:25.97, start: 0.340078, bitrate: 29004 kb/s
  
      Stream #0:0[0x1e0]: Video: mpeg1video, yuv420p(tv), 352x240 [SAR 200:219 DAR 880:657], 1150     kb/s, 29.97 fps, 29.97 tbr, 90k tbn, 29.97 tbc
  
      Stream #0:1[0x1c0]: Audio: mp2, 44100 Hz, stereo, s16p, 224 kb/s
  
  [libx264 @ 0x2b189c0] using SAR=1199/1314
  
  [libx264 @ 0x2b189c0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
  
  [libx264 @ 0x2b189c0] profile High, level 1.3
  
  [libx264 @ 0x2b189c0] 264 - core 142 r2 d6b4e63 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 -     http://www.videolan.org/x264.html - options: cabac=1 ref=2 deblock=1:0:0 analyse=0x3:0x113 me=hex     subme=4 psy=1 psy_rd=1.00:0.00 mixed_ref=0 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0     deadzone=21,11 fast_pskip=1 chroma_qp_offset=0 threads=12 lookahead_threads=1 sliced_threads=0 nr=0     decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0     direct=1 weightb=1 open_gop=0 weightp=1 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0     rc_lookahead=20 rc=crf mbtree=1 crf=51.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
  
  Output #0, mp4, to     '/home/flirtzo/public_html/userfiles/files/b2/72/695f4eba95169a3f29564bf9571c703b05f1b5974f5156da633e    b139c80a1575452e2858dfc61cc82bfca02d2b156aa64d4503695756481dc2a5d1c673a4cdea-    94e76a18a7838e62ecb23cf0c374b1b798e7b936.mp4':
  
    Metadata:
  
      encoder         : Lavf55.37.100
  
      Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 320x218 [SAR 1199:1314        DAR 880:657], q=-1--1, 30k tbn, 29.97 tbc
  
      Stream #0:1: Audio: aac ([64][0][0][0] / 0x0040), 44100 Hz, stereo, fltp, 128 kb/s
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (mpeg1video -> libx264)
  
    Stream #0:1 -> #0:1 (mp2 -> aac)
  
  Press [q] to stop, [?] for help
  
  frame=16127 fps=786 q=-1.0 Lsize=   10559kB time=00:08:58.12 bitrate= 160.7kbits/s dup=12 drop=0
  
  video:1586kB audio:8410kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead:     5.638589%
  
  [libx264 @ 0x2b189c0] frame I:109   Avg QP:50.58  size:   494
  
  [libx264 @ 0x2b189c0] frame P:9537  Avg QP:51.00  size:   138
  
  [libx264 @ 0x2b189c0] frame B:6481  Avg QP:51.00  size:    40
  
  [libx264 @ 0x2b189c0] consecutive B-frames: 21.8% 72.1%  5.4%  0.7%
  
  [libx264 @ 0x2b189c0] mb I  I16..4: 46.1% 53.9%  0.0%
  
  [libx264 @ 0x2b189c0] mb P  I16..4:  6.0%  6.1%  0.0%  P16..4: 12.7%  1.1%  0.1%  0.0%  0.0%        skip:74.1%
  
  [libx264 @ 0x2b189c0] mb B  I16..4:  0.1%  0.1%  0.0%  B16..8:  6.3%  0.0%  0.0%  direct: 0.7%      skip:92.9%  L0:38.6% L1:61.2% BI: 0.2%
  
  [libx264 @ 0x2b189c0] 8x8 transform intra:50.8% inter:85.6%
  
  [libx264 @ 0x2b189c0] coded y,uvDC,uvAC intra: 5.9% 39.5% 0.1% inter: 0.1% 1.0% 0.0%
  
  [libx264 @ 0x2b189c0] i16 v,h,dc,p: 56% 30%  7%  7%
  
  [libx264 @ 0x2b189c0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 12% 11% 62%  3%  3%  3%  3%  2%  2%
  
  [libx264 @ 0x2b189c0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 19%  5% 73%  2%  0%  0%  0%  0%  2%
  
  [libx264 @ 0x2b189c0] i8c dc,h,v,p: 97%  1%  2%  0%
  
  [libx264 @ 0x2b189c0] Weighted P-Frames: Y:5.5% UV:2.7%
  
  [libx264 @ 0x2b189c0] ref P L0: 64.8% 35.2%
  
  [libx264 @ 0x2b189c0] ref B L0: 75.2% 24.8%
  
  [libx264 @ 0x2b189c0] ref B L1: 99.3%  0.7%
  
  [libx264 @ 0x2b189c0] kb/s:24.13
  
  ffmpeg version git-2014-04-16-c150e2c Copyright (c) 2000-2014 the FFmpeg developers
  
    built on Sep 28 2014 21:08:17 with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-4)
  
    configuration: --prefix=/root/ffmpeg_build --extra-cflags=-I/root/ffmpeg_build/include --extra-    ldflags=-L/root/ffmpeg_build/lib --bindir=/root/bin --extra-libs=-ldl --enable-gpl --enable-nonfree -    -enable-libfdk_aac --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvpx --enable-    libx264
  
    libavutil      52. 76.100 / 52. 76.100
  
    libavcodec     55. 58.103 / 55. 58.103
  
    libavformat    55. 37.100 / 55. 37.100
  
    libavdevice    55. 13.100 / 55. 13.100
  
    libavfilter     4.  4.100 /  4.  4.100
  
    libswscale      2.  6.100 /  2.  6.100
  
    libswresample   0. 18.100 /  0. 18.100
  
    libpostproc    52.  3.100 / 52.  3.100
  
  Input #0, mpeg, from     '/home/flirtzo/public_html//userfiles/files/94e76a18a7838e62ecb23cf0c374b1b798e7b936':
  
    Duration: 00:00:25.97, start: 0.340078, bitrate: 29004 kb/s
  
      Stream #0:0[0x1e0]: Video: mpeg1video, yuv420p(tv), 352x240 [SAR 200:219 DAR 880:657], 1150         kb/s, 29.97 fps, 29.97 tbr, 90k tbn, 29.97 tbc
  
      Stream #0:1[0x1c0]: Audio: mp2, 44100 Hz, stereo, s16p, 224 kb/s
  
  [libx264 @ 0x300d9c0] using SAR=200/219
  
  [libx264 @ 0x300d9c0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
  
  [libx264 @ 0x300d9c0] profile High, level 2.2
  
  [libx264 @ 0x300d9c0] 264 - core 142 r2 d6b4e63 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 -                     http://www.videolan.org/x264.html - options: cabac=1 ref=16 deblock=1:0:0 analyse=0x3:0x133 me=umh         subme=10 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=24 chroma_me=1 trellis=2 8x8dct=1 cqm=0     deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12 lookahead_threads=1 sliced_threads=0 nr=0     decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=8 b_pyramid=2 b_adapt=2 b_bias=0     direct=3 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0     rc_lookahead=60 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
  
  Output #0, mp4, to     '/home/flirtzo/public_html/userfiles/files/b2/72/73d4a3245c0b0e174ab7ce0f872ba3f649f8b93f73a6deeab364    4a994009d73638ce61aecc7dc2e0250c4e74ff2d9a4d479ed35cef26b3f6e1a77e8bf5938518-    94e76a18a7838e62ecb23cf0c374b1b798e7b936.mp4':
  
    Metadata:
  
      encoder         : Lavf55.37.100
  
      Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 352x240 [SAR 200:219     DAR 880:657], q=-1--1, 30k tbn, 29.97 tbc
  
      Stream #0:1: Audio: aac ([64][0][0][0] / 0x0040), 44100 Hz, stereo, fltp, 128 kb/s
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (mpeg1video -> libx264)
  
    Stream #0:1 -> #0:1 (mp2 -> aac)
  
     Press [q] to stop, [?] for help
  
  frame=16127 fps= 88 q=-1.0 Lsize=   29190kB time=00:08:58.12 bitrate= 444.4kbits/s dup=12 drop=0
  
  video:20221kB audio:8410kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead:     1.954086%
  
  [libx264 @ 0x300d9c0] frame I:73    Avg QP:24.31  size:  8024
  
  [libx264 @ 0x300d9c0] frame P:4399  Avg QP:26.97  size:  2600
  
  [libx264 @ 0x300d9c0] frame B:11655 Avg QP:32.51  size:   745
  
  [libx264 @ 0x300d9c0] consecutive B-frames:  3.8%  5.0% 27.2% 18.4%  8.4% 33.9%  1.7%  0.7%  0.9%
  
  [libx264 @ 0x300d9c0] mb I  I16..4: 10.8% 68.5% 20.7%
  
  [libx264 @ 0x300d9c0] mb P  I16..4:  2.9%  7.5%  0.8%  P16..4: 45.1% 18.4% 12.4%  0.5%  0.1%        skip:12.3%
  
  [libx264 @ 0x300d9c0] mb B  I16..4:  0.6%  1.3%  0.1%  B16..8: 40.1%  8.7%  1.7%  direct: 2.1%      skip:45.5%  L0:47.2% L1:41.7% BI:11.1%
  
  [libx264 @ 0x300d9c0] 8x8 transform intra:66.7% inter:76.7%
  
  [libx264 @ 0x300d9c0] direct mvs  spatial:99.9% temporal:0.1%
  
  [libx264 @ 0x300d9c0] coded y,uvDC,uvAC intra: 60.3% 75.8% 16.4% inter: 17.3% 16.8% 0.6%
  
  [libx264 @ 0x300d9c0] i16 v,h,dc,p: 16% 27% 11% 47%
  
  [libx264 @ 0x300d9c0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 13% 13% 18%  6%  9%  9% 11%  9% 11%
  
  [libx264 @ 0x300d9c0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 13% 15%  7%  7% 14% 14% 13%  8% 10%
  
  [libx264 @ 0x300d9c0] i8c dc,h,v,p: 26% 32% 20% 22%
  
  [libx264 @ 0x300d9c0] Weighted P-Frames: Y:10.1% UV:6.9%
  
  [libx264 @ 0x300d9c0] ref P L0: 40.6% 12.1% 10.0%  5.2%  5.2%  4.7%  4.6%  3.0%  2.5%  2.1%  1.9%      1.8%  1.7%  1.7%  1.6%  1.3%
  
  [libx264 @ 0x300d9c0] ref B L0: 71.4%  5.6%  3.2%  3.0%  3.1%  2.8%  2.5%  1.8%  1.3%  1.0%  1.1%      1.2%  1.0%  0.7%  0.5%
  
  [libx264 @ 0x300d9c0] ref B L1: 96.3%  3.7%
  
  [libx264 @ 0x300d9c0] kb/s:307.82

• ffmpeg not setting GOP size for x264

  5 juillet 2012, par Chris Robinson

  Can someone please explain to me why the following settings :

  ffmpeg -i test.avi -vcodec libx264 -g 2 -keyint_min 1 -sc_threshold 100000000 -bf 1 test.mp4

  produces the following output :

  ffmpeg version N-41668-g564bb24 Copyright (c) 2000-2012 the FFmpeg developers
  
  built on Jun 17 2012 20:18:05 with gcc 4.6.3
  
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-runtime-cpudetect --enable-avisynth --enable-bzlib --enable-frei0r --enable-libass --enable-libcelt --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libfreetype --enable-libgsm --enable-libmp3lame --enable-libnut --enable-libopenjpeg --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libutvideo --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --ena  libavutil      51. 58.100 / 51. 58.100
  
    libavcodec     54. 25.100 / 54. 25.100
  
    libavformat    54.  6.101 / 54.  6.101
  
    libavdevice    54.  0.100 / 54.  0.100
  
    libavfilter     2. 81.100 /  2. 81.100
  
    libswscale      2.  1.100 /  2.  1.100
  
    libswresample   0. 15.100 /  0. 15.100
  
    libpostproc    52.  0.100 / 52.  0.100
  
  Input #0, avi, from 'test.avi':
  
    Metadata:
  
      encoder         : Lavf54.6.101
  
    Duration: 00:00:01.70, start: 0.000000, bitrate: 4258 kb/s
  
  Stream #0:0: Video: mpeg4 (Simple Profile) (DIVX / 0x58564944), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 29.97 fps, 29.97 tbr, 29.97 tbn, 30k tbc
  
  Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055), 48000 Hz, stereo, s16, 128 kb/s
  
  [buffer @ 0000000004115600] w:1280 h:720 pixfmt:yuv420p tb:1001/30000 fr:30000/1001 sar:1/1 sws_param:flags=2
  
  [ffmpeg_buffersink @ 00000000041157a0] No opaque field provided
  
  [libx264 @ 000000000411f120] using SAR=1/1
  
  [libx264 @ 000000000411f120] using cpu capabilities: MMX2 SSE2Fast SSSE3 FastShuffle SSE4.2
  
  [libx264 @ 000000000411f120] profile High, level 3.1
  
  [libx264 @ 000000000411f120] 264 - core 125 r2200 999b753 - H.264/MPEG-4 AVC codec - Copyleft 2003-2012 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=36 lookahead_threads=6 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keOutput #0, mp4, to 'test.mp4':
  
    Metadata:
  
      encoder         : Lavf54.6.101
  
      Stream #0:0: Video: h264 ([33][0][0][0] / 0x0021), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], q=-1--1, 30k tbn, 29.97 tbc
  
      Stream #0:1: Audio: aac ([64][0][0][0] / 0x0040), 48000 Hz, stereo, s16, 128 kb/s
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (mpeg4 -> libx264)
  
    Stream #0:1 -> #0:1 (mp3 -> libvo_aacenc)
  
  Press [q] to stop, [?] for help
  
  [libvo_aacenc @ 0000000001ebe240] Que input is backward in time
  
  Last message repeated 8 times
  
  frame=   35 fps=0.0 q=-1.0 Lsize=     466kB time=00:00:01.10 bitrate=3466.6kbits/s dup=1 drop=0    
  
  
  
  video:436kB audio:28kB global headers:0kB muxing overhead 0.558509%
  
  [libx264 @ 000000000411f120] frame I:1     Avg QP:24.93  size: 92398
  
  [libx264 @ 000000000411f120] frame P:28    Avg QP:26.82  size: 12010
  
  [libx264 @ 000000000411f120] frame B:6     Avg QP:30.37  size:  2764
  
  [libx264 @ 000000000411f120] consecutive B-frames: 74.3%  5.7%  8.6% 11.4%
  
  [libx264 @ 000000000411f120] mb I  I16..4: 41.5% 40.1% 18.4%
  
  [libx264 @ 000000000411f120] mb P  I16..4:  3.9%  1.4%  0.6%  P16..4: 14.3%  4.7%  3.2%  0.0%  0.0%    skip:72.0%
  
  [libx264 @ 000000000411f120] mb B  I16..4:  1.1%  0.4%  0.1%  B16..8: 14.2%  2.8%  0.6%  direct: 1.1%  skip:79.8%  L0:49.8% L1:39.5% BI:10.8%
  
  [libx264 @ 000000000411f120] 8x8 transform intra:29.9% inter:76.4%
  
  [libx264 @ 000000000411f120] coded y,uvDC,uvAC intra: 31.1% 34.4% 18.7% inter: 10.2% 6.3% 3.0%
  
  [libx264 @ 000000000411f120] i16 v,h,dc,p: 62% 34%  3%  0%
  
  [libx264 @ 000000000411f120] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 18% 23% 38%  4%  4%  3%  3%  2%  5%
  
  [libx264 @ 000000000411f120] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 40% 35% 16%  1%  2%  2%  1%  1%  1%
  
  [libx264 @ 000000000411f120] i8c dc,h,v,p: 52% 20% 24%  3%
  
  [libx264 @ 000000000411f120] Weighted P-Frames: Y:0.0% UV:0.0%
  
  [libx264 @ 000000000411f120] ref P L0: 70.5% 10.1% 12.1%  7.3%
  
  [libx264 @ 000000000411f120] ref B L0: 81.1% 16.9%  2.0%
  
  [libx264 @ 000000000411f120] ref B L1: 89.7% 10.3%
  
  [libx264 @ 000000000411f120] kb/s:3050.18

  Why am I not getting an I-Frame every second frame ? Is there something else I can set to do enforce this ? If not, can you suggest how to do this using the mpeg4 codec. It's vital that I can extract what type of frame has been encoded during the encoding process and that I can set a specific GOP structure.