Recherche avancée

Médias (2)

Mot : - Tags -/plugins

Autres articles (69)

  • Websites made ​​with MediaSPIP

    2 mai 2011, par

    This page lists some websites based on MediaSPIP.

  • Personnaliser en ajoutant son logo, sa bannière ou son image de fond

    5 septembre 2013, par

    Certains thèmes prennent en compte trois éléments de personnalisation : l’ajout d’un logo ; l’ajout d’une bannière l’ajout d’une image de fond ;

  • Creating farms of unique websites

    13 avril 2011, par

    MediaSPIP platforms can be installed as a farm, with a single "core" hosted on a dedicated server and used by multiple websites.
    This allows (among other things) : implementation costs to be shared between several different projects / individuals rapid deployment of multiple unique sites creation of groups of like-minded sites, making it possible to browse media in a more controlled and selective environment than the major "open" (...)

Sur d’autres sites (9033)

  • Setting B frames in a video with ffmpeg

    30 juin 2013, par Robert Cantarutti

    According to ffmpeg manual, setting -g is to define space between "I" frames, and setting -bf to use "B" frames. The former I got, but the latter not.

    The goal : I'm trying to have a video with a GOP 3,12 (M= 3, N=12).
    That means : 2 "B" frames separating each "P" frames, and "I" frames with 12 frames of distance. Or simply : "IBBPBBPBBPBBI"

    I think that I got only the N=12, using the commands below :

    1. ffmpeg -s cif -r 30 -b 64000 -bt 3200 -g 12 -y -i video.yuv -vcodec mpeg4 video.m4v
    2. MP4Box -hint -mtu 1460 -fps 30 -add video.m4v video.mp4
    3. ffmpeg -y -i video.mp4 video_ref.yuv
    4. ../cmd/psnr 352 288 420 video.yuv video_ref.yuv > psnr_ref.txt
    5. ../cmd/mp4trace -f -s 192.168.0.2 12346 video.mp4 > trace
    6. head -n 20 trace

    Result :

    [robert@10-2Fontes]$ head -n 20 trace
    
1   H   12002   9   0.000
    
2   P   11479   8   0.034
    
3   P   12021   9   0.066
    
4   P   11239   8   0.099
    
5   P   5407    4   0.134
    
6   P   2735    2   0.166
    
7   P   1014    1   0.199
    
8   P   850 1   0.232
    
9   P   619 1   0.265
    
10  P   979 1   0.298
    
11  P   813 1   0.331
    
12  P   806 1   0.364
    
13  H   5109    4   0.396

    *Note, the most important is the command -g 12 in ffmpeg, but I writing all the commands. The video that I'm using is the "highway", from cif page videos : http://www2.tkn.tu-berlin.de/research/evalvid/cif.html

    I don't know why the result trace is using "H" instead of "I".

    I tried to put -bf 2 in ffmpeg command, but did not worked (I think because I saw no "B" indications in the result)

    List item

    ffmpeg -s cif -r 30 -b 64000 -bt 3200 -g 12 -bf 2 -y -i video.yuv -vcodec mpeg4 video.m4v

    Result :

    [robert@10-2Fontes]$ head -n 20 trace
    
1   H   12002   9   0.001
    
2   P   11479   8   0.034
    
3   P   12021   9   0.067
    
4   P   11239   8   0.100
    
5   P   5407    4   0.132
    
6   P   2735    2   0.166
    
7   P   1014    1   0.199
    
8   P   850 1   0.232
    
9   P   619 1   0.265
    
10  P   979 1   0.298
    
11  P   813 1   0.331
    
12  P   806 1   0.363
    
13  H   5109    4   0.400

  • FFmpeg returning an error - What does it mean ?

    19 mars 2013, par user1031947

    I am using FFmpeg, libmp3lame & libx264 along with the node fluent-ffmpeg module. This is my first foray into processing uploaded videos.

    From node, I use the following code to process an uploaded video :

    var proc = new ffmpeg({ source: src, nolog: true })
    
    .usingPreset( "podcast" )
    
    .withAudioCodec( "libmp3lame" )
    
    .saveToFile( dest, function( retcode, err ){
    
         if( err ) throw err;
    
         ...
    
    });

    When I try to process a video, this fails with the following error, which I don't understand. I am hoping someone here can help point me in the right direction. Thanks !

    > ffmpeg version 0.8.5-6:0.8.5-1, Copyright (c) 2000-2012 the Libav
    
> developers   built on Jan 13 2013 12:05:48 with gcc 4.7.2
    
> *** THIS PROGRAM IS DEPRECATED *** This program is only provided for compatibility and will be removed in a future release. Please use
    
> avconv instead.
    
> 
    
> Seems stream 0 codec frame rate differs from container frame rate:
    
> 5994.00 (5994/1) -> 29.97 (2997/100) Input #0, mov,mp4,m4a,3gp,3g2,mj2, from
    
> '/home/ssp/resources/tmp/32111bf4217e87c23328ec81c56c7d02':  
    
> Metadata:
    
>     major_brand     : M4VP
    
>     minor_version   : 1
    
>     compatible_brands: M4VPM4A mp42isom
    
>     creation_time   : 2008-08-26 17:28:47   Duration: 00:00:08.01, start: 0.000000, bitrate: 944 kb/s
    
>     Stream #0.0(eng): Video: h264 (Constrained Baseline), yuv420p, 480x272, 815 kb/s, 29.97 fps, 29.97 tbr, 2997 tbn, 5994 tbc
    
>     Metadata:
    
>       creation_time   : 2008-08-26 17:28:47
    
>     Stream #0.1(eng): Audio: aac, 44100 Hz, stereo, s16, 124 kb/s
    
>     Metadata:
    
>       creation_time   : 2008-08-26 17:28:47 [buffer @ 0xb685a0] w:480 h:272 pixfmt:yuv420p [scale @ 0xb63280] w:480 h:272 fmt:yuv420p ->
    
> w:320 h:176 fmt:yuv420p flags:0x4 [libx264 @ 0xb67c20] VBV maxrate
    
> unspecified, assuming CBR [libx264 @ 0xb67c20] using cpu capabilities:
    
> MMX2 SSE2Fast SSSE3 FastShuffle SSE4.2 AVX [libx264 @ 0xb67c20]
    
> profile Main, level 1.3 Output #0, m4v, to
    
> '/home/ssp/resources/users/11/026468c8f4ea1beee0a585ebc2208137.m4v':  
    
> Metadata:
    
>     major_brand     : M4VP
    
>     minor_version   : 1
    
>     compatible_brands: M4VPM4A mp42isom
    
>     creation_time   : 2008-08-26 17:28:47
    
>     encoder         : Lavf53.21.1
    
>     Stream #0.0(eng): Video: libx264, yuv420p, 320x176, q=10-51, 512 kb/s, 90k tbn, 29.97 tbc
    
>     Metadata:
    
>       creation_time   : 2008-08-26 17:28:47
    
>     Stream #0.1(eng): Audio: libmp3lame, 44100 Hz, 1 channels, s16, 128 kb/s
    
>     Metadata:
    
>       creation_time   : 2008-08-26 17:28:47 Stream mapping:   Stream #0.0 -> #0.0   Stream #0.1 -> #0.1 Press ctrl-c to stop encoding frame=  240 fps=154 q=11.0 Lsize=     642kB time=7.97 bitrate=
    
> 659.3kbits/s     video:516kB audio:126kB global headers:0kB muxing overhead 0.000000% frame I:1     Avg QP:15.35  size:  9995 [libx264 @
    
> 0xb67c20] frame P:77    Avg QP:13.25  size:  5419 [libx264 @ 0xb67c20]
    
> frame B:162   Avg QP:18.31  size:   625 [libx264 @ 0xb67c20]
    
> consecutive B-frames:  2.5% 12.5% 30.0% 55.0% [libx264 @ 0xb67c20] mb
    
> I  I16..4:  9.1%  0.0% 90.9% [libx264 @ 0xb67c20] mb P  I16..4:  2.1% 
    
> 0.0%  2.8%  P16..4: 18.0% 29.9% 44.8%  0.0%  0.0%    skip: 2.3% [libx264 @ 0xb67c20] mb B  I16..4:  0.1%  0.0%  0.0%  B16..8: 35.2%
    
> 20.2%  1.9%  direct:14.5%  skip:28.1%  L0:26.3% L1:38.1% BI:35.6% [libx264 @ 0xb67c20] coded y,uvDC,uvAC intra: 83.7% 91.7% 84.7% inter:
    
> 27.7% 43.4% 13.9% [libx264 @ 0xb67c20] i16 v,h,dc,p: 20% 29% 42%  9% [libx264 @ 0xb67c20] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 17% 29% 20%  4% 
    
> 8%  6%  9%  3%  4% [libx264 @ 0xb67c20] i8c dc,h,v,p: 60% 19% 16%  5%
    
> [libx264 @ 0xb67c20] Weighted P-Frames: Y:2.6% UV:0.0% [libx264 @
    
> 0xb67c20] ref P L0: 75.6% 13.5%  8.0%  2.8%  0.1% [libx264 @ 0xb67c20]
    
> ref B L0: 94.5%  5.5% [libx264 @ 0xb67c20] kb/s:528.00

  • configure : Simplify cygwin/mingw/msys code

    3 novembre 2015, par Henrik Gramner
    configure : Simplify cygwin/mingw/msys code

    Avoids some code duplication.
    

    Also drop the -mno-cygwin check since that option was removed back in 2008.
    • [DH] configure

Navigation