Recherche avancée

Médias (3)

Mot : - Tags -/pdf

Autres articles (86)

  • Websites made ​​with MediaSPIP

    2 mai 2011, par

    This page lists some websites based on MediaSPIP.

  • 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" (...)

  • XMP PHP

    13 mai 2011, par

    Dixit Wikipedia, XMP signifie :
    Extensible Metadata Platform ou XMP est un format de métadonnées basé sur XML utilisé dans les applications PDF, de photographie et de graphisme. Il a été lancé par Adobe Systems en avril 2001 en étant intégré à la version 5.0 d’Adobe Acrobat.
    Étant basé sur XML, il gère un ensemble de tags dynamiques pour l’utilisation dans le cadre du Web sémantique.
    XMP permet d’enregistrer sous forme d’un document XML des informations relatives à un fichier : titre, auteur, historique (...)

Sur d’autres sites (5218)

  • Errors converting EXRs to mp4 with ffmpeg

    3 février 2021, par GaryO

    I'm using ffmpeg 4.3.1 to convert some EXRs to mp4, with tone mapping for the extended range in the source and rec709 conversion for the mp4.

    


    I'm using this command :

    


    ffmpeg -pattern_type glob  -framerate 24 -i 'frames/*.exr' -vf zscale=transfer=linear,tonemap=hable,zscale=transfer=bt709,format=yuv420p -c:v libx264 -r 24 -preset slow -crf 18 -pix_fmt yuv420p foo-tonemap-01.mp4


    


    but it gives me this error :

    


    Input #0, image2, from 'frames/*.exr':
  Duration: 00:00:00.08, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: exr, gbrapf32le, 1920x1080 [SAR 1:1 DAR 16:9], 24 tbr, 24 tbn, 24 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (exr (native) -> h264 (libx264))
code 3074: no path between colorspaces
Error while filtering: Generic error in an external library


    


    What does that error "no path between colorspaces" mean ? Do I need to tell it what colorspace the EXRs are in (scene-linear RGB) or something ?

    


    Complete log :

    


    ffmpeg started on 2020-08-05 at 22:22:33
Report written to "ffmpeg-20200805-222233.log"
Log level: 48
Command line:
ffmpeg -report -y -i frames/0240.exr -vf "zscale=transfer=linear,tonemap=clip,zscale=transfer=bt709,format=yuv420p" -c:v libx264 -r 24 -preset slow -crf 18 -pix_fmt yuv420p foo-tonemap-01.mp4
ffmpeg version 4.3.1-static https://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 8 (Debian 8.3.0-6)
  configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gmp --enable-libgme --enable-gray --enable-libaom --enable-libfribidi --enable-libass --enable-libvmaf --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librubberband --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libvorbis --enable-libopus --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libdav1d --enable-libxvid --enable-libzvbi --enable-libzimg
  libavutil      56. 51.100 / 56. 51.100
  libavcodec     58. 91.100 / 58. 91.100
  libavformat    58. 45.100 / 58. 45.100
  libavdevice    58. 10.100 / 58. 10.100
  libavfilter     7. 85.100 /  7. 85.100
  libswscale      5.  7.100 /  5.  7.100
  libswresample   3.  7.100 /  3.  7.100
  libpostproc    55.  7.100 / 55.  7.100
Splitting the commandline.
Reading option '-report' ... matched as option 'report' (generate a report) with argument '1'.
Reading option '-y' ... matched as option 'y' (overwrite output files) with argument '1'.
Reading option '-i' ... matched as input url with argument 'frames/0240.exr'.
Reading option '-vf' ... matched as option 'vf' (set video filters) with argument 'zscale=transfer=linear,tonemap=clip,zscale=transfer=bt709,format=yuv420p'.
Reading option '-c:v' ... matched as option 'c' (codec name) with argument 'libx264'.
Reading option '-r' ... matched as option 'r' (set frame rate (Hz value, fraction or abbreviation)) with argument '24'.
Reading option '-preset' ... matched as AVOption 'preset' with argument 'slow'.
Reading option '-crf' ... matched as AVOption 'crf' with argument '18'.
Reading option '-pix_fmt' ... matched as option 'pix_fmt' (set pixel format) with argument 'yuv420p'.
Reading option 'foo-tonemap-01.mp4' ... matched as output url.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option report (generate a report) with argument 1.
Applying option y (overwrite output files) with argument 1.
Successfully parsed a group of options.
Parsing a group of options: input url frames/0240.exr.
Successfully parsed a group of options.
Opening an input file: frames/0240.exr.
[NULL @ 0x6db71c0] Opening 'frames/0240.exr' for reading
[file @ 0x6db7c80] Setting default whitelist 'file,crypto,data'
[exr_pipe @ 0x6db71c0] Format exr_pipe probed with size=2048 and score=51
[exr_pipe @ 0x6db71c0] Before avformat_find_stream_info() pos: 0 bytes read:32768 seeks:0 nb_streams:1
[exr_pipe @ 0x6db71c0] parser not found for codec exr, packets or times may be invalid.
[exr_pipe @ 0x6db71c0] parser not found for codec exr, packets or times may be invalid.
[exr @ 0x6db92c0] line order: 0.
[exr_pipe @ 0x6db71c0] After avformat_find_stream_info() pos: 4970635 bytes read:4970635 seeks:0 frames:1
Input #0, exr_pipe, from 'frames/0240.exr':
  Duration: N/A, bitrate: N/A
    Stream #0:0, 1, 1/25: Video: exr, gbrapf32le, 1920x1080 [SAR 1:1 DAR 16:9], 25 tbr, 25 tbn, 25 tbc
Successfully opened the file.
Parsing a group of options: output url foo-tonemap-01.mp4.
Applying option vf (set video filters) with argument zscale=transfer=linear,tonemap=clip,zscale=transfer=bt709,format=yuv420p.
Applying option c:v (codec name) with argument libx264.
Applying option r (set frame rate (Hz value, fraction or abbreviation)) with argument 24.
Applying option pix_fmt (set pixel format) with argument yuv420p.
Successfully parsed a group of options.
Opening an output file: foo-tonemap-01.mp4.
[file @ 0x6e0a0c0] Setting default whitelist 'file,crypto,data'
Successfully opened the file.
detected 32 logical cores
Stream mapping:
  Stream #0:0 -> #0:0 (exr (native) -> h264 (libx264))
Press [q] to stop, [?] for help
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[exr @ 0x6dbe700] line order: 0.
[Parsed_zscale_0 @ 0x725c4c0] Setting 'transfer' to value 'linear'
[Parsed_tonemap_1 @ 0x725c940] Setting 'tonemap' to value 'clip'
[Parsed_zscale_2 @ 0x725d380] Setting 'transfer' to value 'bt709'
[Parsed_format_3 @ 0x725e100] Setting 'pix_fmts' to value 'yuv420p'
[graph 0 input from stream 0:0 @ 0x725eb40] Setting 'video_size' to value '1920x1080'
[graph 0 input from stream 0:0 @ 0x725eb40] Setting 'pix_fmt' to value '180'
[graph 0 input from stream 0:0 @ 0x725eb40] Setting 'time_base' to value '1/25'
[graph 0 input from stream 0:0 @ 0x725eb40] Setting 'pixel_aspect' to value '1/1'
[graph 0 input from stream 0:0 @ 0x725eb40] Setting 'frame_rate' to value '25/1'
[graph 0 input from stream 0:0 @ 0x725eb40] w:1920 h:1080 pixfmt:gbrapf32le tb:1/25 fr:25/1 sar:1/1
[format @ 0x725fc00] Setting 'pix_fmts' to value 'yuv420p'
[AVFilterGraph @ 0x6dc0000] query_formats: 7 queried, 6 merged, 0 already done, 0 delayed
[Parsed_zscale_0 @ 0x725c4c0] w:1920 h:1080 fmt:gbrapf32le sar:1/1 -> w:1920 h:1080 fmt:gbrapf32le sar:1/1
[Parsed_zscale_2 @ 0x725d380] w:1920 h:1080 fmt:gbrapf32le sar:1/1 -> w:1920 h:1080 fmt:yuv420p sar:1/1
[Parsed_zscale_0 @ 0x725c4c0] w:1920 h:1080 fmt:gbrapf32le sar:1/1 -> w:1920 h:1080 fmt:gbrapf32le sar:1/1
code 3074: no path between colorspaces
Error while filtering: Generic error in an external library
Failed to inject frame into filter network: Generic error in an external library
Error while processing the decoded data for stream #0:0
[AVIOContext @ 0x6e08a80] Statistics: 0 seeks, 0 writeouts
[AVIOContext @ 0x6dc00c0] Statistics: 4970635 bytes read, 0 seeks
Conversion failed!


    


  • lavc/cbrt_tablegen : speed up tablegen

    11 janvier 2016, par Ganesh Ajjanagadde
    lavc/cbrt_tablegen : speed up tablegen
    

    This exploits an approach based on the sieve of Eratosthenes, a popular
    method for generating prime numbers.

    Tables are identical to previous ones.

    Tested with FATE with/without —enable-hardcoded-tables.

    Sample benchmark (Haswell, GNU/Linux+gcc) :
    prev :
    7860100 decicycles in cbrt_tableinit, 1 runs, 0 skips
    7777490 decicycles in cbrt_tableinit, 2 runs, 0 skips
    [...]
    7582339 decicycles in cbrt_tableinit, 256 runs, 0 skips
    7563556 decicycles in cbrt_tableinit, 512 runs, 0 skips

    new :
    2099480 decicycles in cbrt_tableinit, 1 runs, 0 skips
    2044470 decicycles in cbrt_tableinit, 2 runs, 0 skips
    [...]
    1796544 decicycles in cbrt_tableinit, 256 runs, 0 skips
    1791631 decicycles in cbrt_tableinit, 512 runs, 0 skips

    Both small and large run count given as this is called once so small run
    count may give a better picture, small numbers are fairly consistent,
    and there is a consistent downward trend from small to large runs,
    at which point it stabilizes to a new value.

    Reviewed-by : Michael Niedermayer <michael@niedermayer.cc>
    Signed-off-by : Ganesh Ajjanagadde <gajjanagadde@gmail.com>

    • [DH] libavcodec/cbrt_tablegen.h
  • arm64 : port synth_filter_float_neon from arm

    1er décembre 2015, par Janne Grunau
    arm64 : port synth_filter_float_neon from arm
    

     25% faster dts decoding overall. The checkasm CPU cycles numbers are
    not that useful since synth_filter_float() calls FFTContext.imdct_half().

    cortex-a57 cortex-a53
    synth_filter_float_c : 1866.2 3490.9
    synth_filter_float_neon : 915.0 1531.5

    With fftc.imdct_half forced to imdct_half_neon :
    cortex-a57 cortex-a53
    synth_filter_float_c : 1718.4 3025.3
    synth_filter_float_neon : 926.2 1530.1

    • [DBH] libavcodec/aarch64/Makefile
    • [DBH] libavcodec/aarch64/asm-offsets.h
    • [DBH] libavcodec/aarch64/dcadsp_init.c
    • [DBH] libavcodec/aarch64/synth_filter_neon.S
    • [DBH] libavcodec/synth_filter.c
    • [DBH] libavcodec/synth_filter.h