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Organiser par catégorie
17 mai 2013, parDans MédiaSPIP, une rubrique a 2 noms : catégorie et rubrique.
Les différents documents stockés dans MédiaSPIP peuvent être rangés dans différentes catégories. On peut créer une catégorie en cliquant sur "publier une catégorie" dans le menu publier en haut à droite ( après authentification ). Une catégorie peut être rangée dans une autre catégorie aussi ce qui fait qu’on peut construire une arborescence de catégories.
Lors de la publication prochaine d’un document, la nouvelle catégorie créée sera proposée (...) -
Récupération d’informations sur le site maître à l’installation d’une instance
26 novembre 2010, parUtilité
Sur le site principal, une instance de mutualisation est définie par plusieurs choses : Les données dans la table spip_mutus ; Son logo ; Son auteur principal (id_admin dans la table spip_mutus correspondant à un id_auteur de la table spip_auteurs)qui sera le seul à pouvoir créer définitivement l’instance de mutualisation ;
Il peut donc être tout à fait judicieux de vouloir récupérer certaines de ces informations afin de compléter l’installation d’une instance pour, par exemple : récupérer le (...) -
Le plugin : Podcasts.
14 juillet 2010, parLe problème du podcasting est à nouveau un problème révélateur de la normalisation des transports de données sur Internet.
Deux formats intéressants existent : Celui développé par Apple, très axé sur l’utilisation d’iTunes dont la SPEC est ici ; Le format "Media RSS Module" qui est plus "libre" notamment soutenu par Yahoo et le logiciel Miro ;
Types de fichiers supportés dans les flux
Le format d’Apple n’autorise que les formats suivants dans ses flux : .mp3 audio/mpeg .m4a audio/x-m4a .mp4 (...)
Sur d’autres sites (4846)
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Problem with ffplay from webcam stream using complex filters
29 mai 2022, par efelbarI'm trying to stream video from a webcam (at
/dev/video2
) through ffplay to scale and recolor it, add some text, and then reduce the number of colors with palettes. I don't get any errors, but running the ffplay command :

ffplay -i /dev/video2 -vf "hflip,\
 colorbalance=\
 rs=0.4:\
 bs=-0.4\
 ,\
 scale=\
 trunc(iw/8):\
 trunc(ih/8)\
 ,\
 drawtext=\
 text=\
 'efelbar':\
 fontcolor=white:\
 fontsize=10:\
 box=1:\
 boxcolor=black:\
 boxborderw=5:\
 x=(w-text_w)/2:\
 y=(h-text_h)/2\
 ,\
 split[s0][s1];\
 [s0]palettegen=\
 max_colors=16\
 [p];\
 [s1][p]paletteuse"



seems to stall, and fails to produce video output.


Running the simpler command
ffplay -i /dev/video2 -vf "split[s0][s1];[s0]palettegen=max_colors=16[p];[s1][p]paletteuse"
, which takes a stream from a webcam and (should) reduce the number of colors, results in it just sitting there without showing the actual output stream. This might just be a performance issue because I'm on older hardware, but it doesn't give output relfective of that.

The output of that command is as follows :


ffplay version n5.0 Copyright (c) 2003-2022 the FFmpeg developers
 built with gcc 11.2.0 (GCC)
 configuration: --prefix=/usr --disable-debug --disable-static --disable-stripping --enable-amf --enable-avisynth --enable-cuda-llvm --enable-lto --enable-fontconfig --enable-gmp --enable-gnutls --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libdav1d --enable-libdrm --enable-libfreetype --enable-libfribidi --enable-libgsm --enable-libiec61883 --enable-libjack --enable-libmfx --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librav1e --enable-librsvg --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-libzimg --enable-nvdec --enable-nvenc --enable-shared --enable-version3
 libavutil 57. 17.100 / 57. 17.100
 libavcodec 59. 18.100 / 59. 18.100
 libavformat 59. 16.100 / 59. 16.100
 libavdevice 59. 4.100 / 59. 4.100
 libavfilter 8. 24.100 / 8. 24.100
 libswscale 6. 4.100 / 6. 4.100
 libswresample 4. 3.100 / 4. 3.100
 libpostproc 56. 3.100 / 56. 3.100
Input #0, video4linux2,v4l2, from '/dev/video2':B sq= 0B f=0/0 
 Duration: N/A, start: 254970.739108, bitrate: 147456 kb/s
 Stream #0:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 640x480, 147456 kb/s, 30 fps, 30 tbr, 1000k tbn



I'm running this on a thinkpad t420s, so I definitely wouldn't be surprised if my laptop just can't process video that quickly. If that is the case, suggestions for optimizations would be great !


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capture my webcam and encode to mp4 with ffmpeg, but the x264 works bad
17 septembre 2015, par zhangxm1991here is my version :
ffmpeg version : 2.3.3
libx264 version:142.xI wat to capture my video and use ffmpeg and x264 to a mp4 file. the solution is 320x240.
But i found that the video file is so big. Then i found that the P frame and B frame is very big, even nearly equal to the I frame.I do not know why.here is my code :
c->codec_id = codec_id;
c->bit_rate = 400000;
c->width = 320;
c->height = 240;
c->time_base.den = 10;
c->time_base.num = 1;
c->pix_fmt = AV_PIX_FMT_YUV420P;Here is my program output :
[libx264 @ 0xb6200fc0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
[libx264 @ 0xb6200fc0] profile High, level 1.3
[libx264 @ 0xb6200fc0] 264 - core 142 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - 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=6 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=2 keyint=250 keyint_min=10 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=abr mbtree=1 bitrate=400 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to '/home/2014_09_12/0002b6429579/5/2014_09_12_18_39_12_600.mp4':
Stream #0:0: Video: h264 (libx264), yuv420p, 320x240, q=-1--1, 400 kb/s, 10 tbc
Stream #0:1: Audio: aac, 8000 Hz, mono, fltp, 32 kb/s
[mp4 @ 0xb62005e0] Using AVStream.codec.time_base as a timebase hint to the muxer is deprecated. Set AVStream.time_base instead.
[mp4 @ 0xb62005e0] Using AVStream.codec.time_base as a timebase hint to the muxer is deprecated. Set AVStream.time_base instead.
[mp4 @ 0xb62005e0] Encoder did not produce proper pts, making some up.
[libx264 @ 0xb6200fc0] frame I:3 Avg QP: 2.79 size: 72996
[libx264 @ 0xb6200fc0] frame P:383 Avg QP: 0.14 size: 54075
[libx264 @ 0xb6200fc0] frame B:216 Avg QP: 1.95 size: 64784
[libx264 @ 0xb6200fc0] consecutive B-frames: 30.1% 63.2% 6.0% 0.7%
[libx264 @ 0xb6200fc0] mb I I16..4: 16.1% 12.7% 71.2%
[libx264 @ 0xb6200fc0] mb P I16..4: 3.5% 5.1% 15.9% P16..4: 20.3% 22.8% 14.0% 0.0% 0.0% skip:18.3%
[libx264 @ 0xb6200fc0] mb B I16..4: 0.4% 2.5% 8.2% B16..8: 32.6% 19.8% 13.5%
direct:22.2% skip: 0.8% L0:25.5% L1:12.8% BI:61.6%
[libx264 @ 0xb6200fc0] final ratefactor: -32.89
[libx264 @ 0xb6200fc0] 8x8 transform intra:21.0% inter:29.6%
[libx264 @ 0xb6200fc0] coded y,uvDC,uvAC intra: 100.0% 100.0% 100.0% inter: 83.3% 80.9% 80.9%
[libx264 @ 0xb6200fc0] i16 v,h,dc,p: 5% 7% 42% 46%
[libx264 @ 0xb6200fc0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 14% 12% 23% 8% 6% 6% 8% 9% 14%
[libx264 @ 0xb6200fc0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 12% 11% 19% 10% 8% 8% 10% 10% 12%
[libx264 @ 0xb6200fc0] i8c dc,h,v,p: 78% 3% 4% 15%
[libx264 @ 0xb6200fc0] Weighted P-Frames: Y:0.5% UV:0.3%
[libx264 @ 0xb6200fc0] ref P L0: 43.4% 14.6% 19.0% 22.9% 0.1%
[libx264 @ 0xb6200fc0] ref B L0: 63.3% 35.7% 1.1%
[libx264 @ 0xb6200fc0] ref B L1: 97.0% 3.0%
[libx264 @ 0xb6200fc0] kb/s:4.53
[aac @ 0xb6201ba0] 2 frames left in the queue on closing -
capture my webcam and encode to mp4 with ffmpeg, but the x264 works bad
17 septembre 2015, par zhangxm1991here is my version :
ffmpeg version : 2.3.3
libx264 version:142.xI wat to capture my video and use ffmpeg and x264 to a mp4 file. the solution is 320x240.
But i found that the video file is so big. Then i found that the P frame and B frame is very big, even nearly equal to the I frame.I do not know why.here is my code :
c->codec_id = codec_id;
c->bit_rate = 400000;
c->width = 320;
c->height = 240;
c->time_base.den = 10;
c->time_base.num = 1;
c->pix_fmt = AV_PIX_FMT_YUV420P;Here is my program output :
[libx264 @ 0xb6200fc0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
[libx264 @ 0xb6200fc0] profile High, level 1.3
[libx264 @ 0xb6200fc0] 264 - core 142 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - 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=6 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=2 keyint=250 keyint_min=10 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=abr mbtree=1 bitrate=400 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to '/home/2014_09_12/0002b6429579/5/2014_09_12_18_39_12_600.mp4':
Stream #0:0: Video: h264 (libx264), yuv420p, 320x240, q=-1--1, 400 kb/s, 10 tbc
Stream #0:1: Audio: aac, 8000 Hz, mono, fltp, 32 kb/s
[mp4 @ 0xb62005e0] Using AVStream.codec.time_base as a timebase hint to the muxer is deprecated. Set AVStream.time_base instead.
[mp4 @ 0xb62005e0] Using AVStream.codec.time_base as a timebase hint to the muxer is deprecated. Set AVStream.time_base instead.
[mp4 @ 0xb62005e0] Encoder did not produce proper pts, making some up.
[libx264 @ 0xb6200fc0] frame I:3 Avg QP: 2.79 size: 72996
[libx264 @ 0xb6200fc0] frame P:383 Avg QP: 0.14 size: 54075
[libx264 @ 0xb6200fc0] frame B:216 Avg QP: 1.95 size: 64784
[libx264 @ 0xb6200fc0] consecutive B-frames: 30.1% 63.2% 6.0% 0.7%
[libx264 @ 0xb6200fc0] mb I I16..4: 16.1% 12.7% 71.2%
[libx264 @ 0xb6200fc0] mb P I16..4: 3.5% 5.1% 15.9% P16..4: 20.3% 22.8% 14.0% 0.0% 0.0% skip:18.3%
[libx264 @ 0xb6200fc0] mb B I16..4: 0.4% 2.5% 8.2% B16..8: 32.6% 19.8% 13.5%
direct:22.2% skip: 0.8% L0:25.5% L1:12.8% BI:61.6%
[libx264 @ 0xb6200fc0] final ratefactor: -32.89
[libx264 @ 0xb6200fc0] 8x8 transform intra:21.0% inter:29.6%
[libx264 @ 0xb6200fc0] coded y,uvDC,uvAC intra: 100.0% 100.0% 100.0% inter: 83.3% 80.9% 80.9%
[libx264 @ 0xb6200fc0] i16 v,h,dc,p: 5% 7% 42% 46%
[libx264 @ 0xb6200fc0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 14% 12% 23% 8% 6% 6% 8% 9% 14%
[libx264 @ 0xb6200fc0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 12% 11% 19% 10% 8% 8% 10% 10% 12%
[libx264 @ 0xb6200fc0] i8c dc,h,v,p: 78% 3% 4% 15%
[libx264 @ 0xb6200fc0] Weighted P-Frames: Y:0.5% UV:0.3%
[libx264 @ 0xb6200fc0] ref P L0: 43.4% 14.6% 19.0% 22.9% 0.1%
[libx264 @ 0xb6200fc0] ref B L0: 63.3% 35.7% 1.1%
[libx264 @ 0xb6200fc0] ref B L1: 97.0% 3.0%
[libx264 @ 0xb6200fc0] kb/s:4.53
[aac @ 0xb6201ba0] 2 frames left in the queue on closing