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Médias (91)

Autres articles (55)

  • Support de tous types de médias

    10 avril 2011

    Contrairement à beaucoup de logiciels et autres plate-formes modernes de partage de documents, MediaSPIP a l’ambition de gérer un maximum de formats de documents différents qu’ils soient de type : images (png, gif, jpg, bmp et autres...) ; audio (MP3, Ogg, Wav et autres...) ; vidéo (Avi, MP4, Ogv, mpg, mov, wmv et autres...) ; contenu textuel, code ou autres (open office, microsoft office (tableur, présentation), web (html, css), LaTeX, Google Earth) (...)

  • Support audio et vidéo HTML5

    10 avril 2011

    MediaSPIP utilise les balises HTML5 video et audio pour la lecture de documents multimedia en profitant des dernières innovations du W3C supportées par les navigateurs modernes.
    Pour les navigateurs plus anciens, le lecteur flash Flowplayer est utilisé.
    Le lecteur HTML5 utilisé a été spécifiquement créé pour MediaSPIP : il est complètement modifiable graphiquement pour correspondre à un thème choisi.
    Ces technologies permettent de distribuer vidéo et son à la fois sur des ordinateurs conventionnels (...)

  • MediaSPIP Core : La Configuration

    9 novembre 2010, par

    MediaSPIP Core fournit par défaut trois pages différentes de configuration (ces pages utilisent le plugin de configuration CFG pour fonctionner) : une page spécifique à la configuration générale du squelettes ; une page spécifique à la configuration de la page d’accueil du site ; une page spécifique à la configuration des secteurs ;
    Il fournit également une page supplémentaire qui n’apparait que lorsque certains plugins sont activés permettant de contrôler l’affichage et les fonctionnalités spécifiques (...)

Sur d’autres sites (10289)

  • Why is frame pts zero after successful avcodec_decode_video2 call ?

    15 avril 2018, par jamsme

    Why is pts value at times zero when decoding H264 video frame ?

    int ret = avcodec_decode_video2(ctx, pFrame, &got_frame, &pkt);
    
if (ret < 0)
    
{
    
LOG << "Error: avcodec_decode_video2(..) call " << __FILE__ << __LINE__<< endlog;
    
return false;
    
}
    

    
if (got_frame)
    
    LOG << "pFrame->pts = " << pFrame->pts << endlog;

  • flv reencode to mp4 for iphone/ipod via ffmpeg and x264 (quality issue)

    3 octobre 2011, par zeroasterisk

    There are a lot of questions on this topic, and I've read most of them and most of the google search results I could come up with.

    When I use FFMPEG to convert a FLV to a iphone3 compatble MP4 file, it just doesn't preserver enough of the quality. Yes, I've worked the hell out of -sameq and -b and -bt settings, text just isn't readable.

    Next I tried to split the video out and process it directly, using these instructions :
    https://sites.google.com/site/linuxencoding/x264-encoding-guide

    The problem is myplayer (via ffmpeg) was not able to determine the duration of the FLV (even though the metadata was set).

    (I assume) Because of that unknown duration, when I create the MP4 file, the resulting x264 file plays through super-fast while the audio plays at the normal rate.

    user@server:/tmp# mplayer -nosound -benchmark -sws 9 -vf dsize=640:480:0,scale=0:0,expand=640:480 -vo yuv4mpeg:file=>(x264 --demuxer y4m --crf 0 --preset slow --threads auto --output output.264 - 2>x264.log) 'input.flv'
    
MPlayer 1.0rc4-4.4.5 (C) 2000-2010 MPlayer Team
    
mplayer: could not connect to socket
    
mplayer: No such file or directory
    
Failed to open LIRC support. You will not be able to use your remote control.
    

    
Playing input.flv.
    
libavformat file format detected.
    
[flv @ 0x1202460]Estimating duration from bitrate, this may be inaccurate
    
[lavf] stream 0: video (vp6f), -vid 0
    
[lavf] stream 1: audio (nellymoser), -aid 0
    
VIDEO:  [VP6F]  1680x992  0bpp  1000.000 fps   33.4 kbps ( 4.1 kbyte/s)
    
Clip info:
    
 audiocodecid: 6
    
 audiodatarate: 86
    
 audiosamplerate: 44100
    
 audiosamplesize: 16
    
 audiosize: 6097005
    
 canSeekToEnd: true
    
 datasize: 8609138
    
 duration: 567
    
 framerate: 2
    
 hasAudio: true
    
 hasCuePoints: false
    
 hasKeyframes: true
    
 hasMetadata: true
    
 hasVideo: true
    
 height: 992
    
 lasttimestamp: 567
    
 metadatacreator: flvtool++ (Facebook, Motion project, dweatherford)
    
 stereo: false
    
 totalframes: 1043
    
 videocodecid: 4
    
 videodatarate: 33
    
 videosize: 2316256
    
 width: 1680
    
Using (default) progressive frame mode.Opening video filter: [expand w=640 h=480]
    
Expand: 640 x 480, -1 ; -1, osd: 0, aspect: 0.000000, round: 1
    
Opening video filter: [scale w=0 h=0]
    
Opening video filter: [dsize=640:480:0]
    
==========================================================================
    
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
    
Selected video codec: [ffvp6f] vfm: ffmpeg (FFmpeg VP6 Flash)
    
==========================================================================
    
Audio: no sound
    
Starting playback...
    
Movie-Aspect is undefined - no prescaling applied.
    
[swscaler @ 0x7f0c738b9620]Lanczos scaler, from yuv420p to yuv420p using MMX2
    
VO: [yuv4mpeg] 640x480 => 641x480 Planar YV12

    I have also tried specifying FPS, but no change in results

    user@server:/tmp# mplayer -nosound -fps 25-benchmark -sws 9 -vf dsize=640:480:0,scale=0:0,expand=640:480 -vo yuv4mpeg:file=>(x264 --demuxer y4m --fps 25 --crf 0 --preset slow --threads auto --output output.264 - 2>x264.log) 'input.flv'

    Can someone tell me how to either :

    1. fix my split A/V processing/timing/duration issues ?
    2. improve the
      quality of the FFMPEG conversion of FLV to iphone3 compatible
      format ?

  • flv reencode to mp4 for iphone/ipod via ffmpeg and x264 (quality issue)

    3 octobre 2011, par zeroasterisk

    There are a lot of questions on this topic, and I've read most of them and most of the google search results I could come up with.

    When I use FFMPEG to convert a FLV to a iphone3 compatble MP4 file, it just doesn't preserver enough of the quality. Yes, I've worked the hell out of -sameq and -b and -bt settings, text just isn't readable.

    Next I tried to split the video out and process it directly, using these instructions :
    https://sites.google.com/site/linuxencoding/x264-encoding-guide

    The problem is myplayer (via ffmpeg) was not able to determine the duration of the FLV (even though the metadata was set).

    (I assume) Because of that unknown duration, when I create the MP4 file, the resulting x264 file plays through super-fast while the audio plays at the normal rate.

    user@server:/tmp# mplayer -nosound -benchmark -sws 9 -vf dsize=640:480:0,scale=0:0,expand=640:480 -vo yuv4mpeg:file=>(x264 --demuxer y4m --crf 0 --preset slow --threads auto --output output.264 - 2>x264.log) 'input.flv'
    
MPlayer 1.0rc4-4.4.5 (C) 2000-2010 MPlayer Team
    
mplayer: could not connect to socket
    
mplayer: No such file or directory
    
Failed to open LIRC support. You will not be able to use your remote control.
    

    
Playing input.flv.
    
libavformat file format detected.
    
[flv @ 0x1202460]Estimating duration from bitrate, this may be inaccurate
    
[lavf] stream 0: video (vp6f), -vid 0
    
[lavf] stream 1: audio (nellymoser), -aid 0
    
VIDEO:  [VP6F]  1680x992  0bpp  1000.000 fps   33.4 kbps ( 4.1 kbyte/s)
    
Clip info:
    
 audiocodecid: 6
    
 audiodatarate: 86
    
 audiosamplerate: 44100
    
 audiosamplesize: 16
    
 audiosize: 6097005
    
 canSeekToEnd: true
    
 datasize: 8609138
    
 duration: 567
    
 framerate: 2
    
 hasAudio: true
    
 hasCuePoints: false
    
 hasKeyframes: true
    
 hasMetadata: true
    
 hasVideo: true
    
 height: 992
    
 lasttimestamp: 567
    
 metadatacreator: flvtool++ (Facebook, Motion project, dweatherford)
    
 stereo: false
    
 totalframes: 1043
    
 videocodecid: 4
    
 videodatarate: 33
    
 videosize: 2316256
    
 width: 1680
    
Using (default) progressive frame mode.Opening video filter: [expand w=640 h=480]
    
Expand: 640 x 480, -1 ; -1, osd: 0, aspect: 0.000000, round: 1
    
Opening video filter: [scale w=0 h=0]
    
Opening video filter: [dsize=640:480:0]
    
==========================================================================
    
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
    
Selected video codec: [ffvp6f] vfm: ffmpeg (FFmpeg VP6 Flash)
    
==========================================================================
    
Audio: no sound
    
Starting playback...
    
Movie-Aspect is undefined - no prescaling applied.
    
[swscaler @ 0x7f0c738b9620]Lanczos scaler, from yuv420p to yuv420p using MMX2
    
VO: [yuv4mpeg] 640x480 => 641x480 Planar YV12

    I have also tried specifying FPS, but no change in results

    user@server:/tmp# mplayer -nosound -fps 25-benchmark -sws 9 -vf dsize=640:480:0,scale=0:0,expand=640:480 -vo yuv4mpeg:file=>(x264 --demuxer y4m --fps 25 --crf 0 --preset slow --threads auto --output output.264 - 2>x264.log) 'input.flv'

    Can someone tell me how to either :

    1. fix my split A/V processing/timing/duration issues ?
    2. improve the
      quality of the FFMPEG conversion of FLV to iphone3 compatible
      format ?

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