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Publier une image simplement
13 avril 2011, par ,
Mis à jour : Février 2012
Langue : français
Type : Video
Autres articles (54)
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Websites made with MediaSPIP
2 mai 2011, parThis page lists some websites based on MediaSPIP.
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Creating farms of unique websites
13 avril 2011, parMediaSPIP 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" (...) -
Submit enhancements and plugins
13 avril 2011If you have developed a new extension to add one or more useful features to MediaSPIP, let us know and its integration into the core MedisSPIP functionality will be considered.
You can use the development discussion list to request for help with creating a plugin. As MediaSPIP is based on SPIP - or you can use the SPIP discussion list SPIP-Zone.
Sur d’autres sites (6692)
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On ALAC’s Open Sourcing
1er novembre 2011, par Multimedia Mike — Codec TechnologyApple open sourced their lossless audio codec last week. Pretty awesome ! I have a theory that, given enough time, absolutely every codec will be open source in one way or another.
I know I shouldn’t bother reading internet conversation around any news related to multimedia technology. And if I do read it, I shouldn’t waste any effort getting annoyed about them. But here are some general corrections :
- ALAC is not in the same league as — nor is it a suitable replacement for — MP3/AAC/Vorbis or any other commonly used perceptual audio codec. It’s not a matter of better or worse ; they’re just different families of codecs designed for different purposes.
- Apple open sourced ALAC, not AAC– easy mistake, though there’s nothing to ‘open source’ about AAC (though people can, and will, argue about its absolute ‘open-ness’).
- There’s not much technical room to argue between ALAC and FLAC, the leading open source lossless audio compressor. Both perform similarly in terms of codec speeds (screamingly fast) and compression efficiency (results vary slightly depending on source material).
- Perhaps the most frustrating facet is the blithe ignorance about ALAC’s current open source status. While this event simply added an official “open source” status to the codec, ALAC has effectively been open source for a very long time. According to my notes, the ALAC decoding algorithm was reverse engineered in 2005 and added into FFmpeg in March of the same year. Then in 2008, Google — through their Summer of Code program — sponsored an open source ALAC encoder.
From the multimedia-savvy who are versed in these concepts, the conversation revolves around which would win in a fight, ALAC or FLAC ? And who between Apple and FFmpeg/Libav has a faster ALAC decoder ? The faster and more efficient ALAC encoder ? I contend that these issues don’t really matter. If you have any experience working with lossless audio encoders, you know that they tend to be ridiculously fast to both encode and decode and that many different lossless codecs compress at roughly the same ratios.
As for which encoder is the fastest : use whatever encoder is handiest and most familiar, either iTunes or FFmpeg/Libav.
As for whether to use FLAC or ALAC — if you’ve already been using one or the other for years, keep on using it. Support isn’t going to vanish. If you’re deciding which to use for a new project, again, perhaps choose based on software you’re already familiar with. Also, consider hardware support– ALAC enjoys iPod support, FLAC is probably better supported in a variety of non-iPod devices, though that may change going forward due to this open sourcing event.
For my part, I’m just ecstatic that the question of moral superiority based on open source status has been removed from the equation.
Code-wise, I’m interested in studying the official ALAC code to see if it has any corner-case modes that the existing open source decoders don’t yet account for. The source makes mention of multichannel (i.e., greater than stereo) configurations, but I don’t know if that’s in FFmpeg/Libav.
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checkasm : add vvc_sao
14 décembre 2024, par Shaun Loocheckasm : add vvc_sao
This is a part of Google Summer of Code 2023
AVX2 :
- vvc_sao.sao_band [OK]
- vvc_sao.sao_edge [OK]
checkasm : all 54 tests passed
vvc_sao_band_8_8_c : 157.4 ( 1.00x)
vvc_sao_band_8_8_avx2 : 30.7 ( 5.12x)
vvc_sao_band_8_10_c : 119.4 ( 1.00x)
vvc_sao_band_8_10_avx2 : 29.2 ( 4.09x)
vvc_sao_band_8_12_c : 144.6 ( 1.00x)
vvc_sao_band_8_12_avx2 : 30.0 ( 4.82x)
vvc_sao_band_16_8_c : 446.5 ( 1.00x)
vvc_sao_band_16_8_avx2 : 103.3 ( 4.32x)
vvc_sao_band_16_10_c : 399.2 ( 1.00x)
vvc_sao_band_16_10_avx2 : 64.3 ( 6.21x)
vvc_sao_band_16_12_c : 472.9 ( 1.00x)
vvc_sao_band_16_12_avx2 : 56.5 ( 8.37x)
vvc_sao_band_32_8_c : 2430.9 ( 1.00x)
vvc_sao_band_32_8_avx2 : 203.3 (11.96x)
vvc_sao_band_32_10_c : 1405.7 ( 1.00x)
vvc_sao_band_32_10_avx2 : 208.5 ( 6.74x)
vvc_sao_band_32_12_c : 2054.3 ( 1.00x)
vvc_sao_band_32_12_avx2 : 213.0 ( 9.64x)
vvc_sao_band_48_8_c : 3835.4 ( 1.00x)
vvc_sao_band_48_8_avx2 : 604.2 ( 6.35x)
vvc_sao_band_48_10_c : 3624.6 ( 1.00x)
vvc_sao_band_48_10_avx2 : 468.8 ( 7.73x)
vvc_sao_band_48_12_c : 3752.4 ( 1.00x)
vvc_sao_band_48_12_avx2 : 477.5 ( 7.86x)
vvc_sao_band_64_8_c : 6061.1 ( 1.00x)
vvc_sao_band_64_8_avx2 : 803.9 ( 7.54x)
vvc_sao_band_64_10_c : 6142.5 ( 1.00x)
vvc_sao_band_64_10_avx2 : 827.3 ( 7.43x)
vvc_sao_band_64_12_c : 6106.6 ( 1.00x)
vvc_sao_band_64_12_avx2 : 839.9 ( 7.27x)
vvc_sao_band_80_8_c : 9478.0 ( 1.00x)
vvc_sao_band_80_8_avx2 : 1516.7 ( 6.25x)
vvc_sao_band_80_10_c : 10300.5 ( 1.00x)
vvc_sao_band_80_10_avx2 : 1298.7 ( 7.93x)
vvc_sao_band_80_12_c : 8941.1 ( 1.00x)
vvc_sao_band_80_12_avx2 : 1315.3 ( 6.80x)
vvc_sao_band_96_8_c : 13351.5 ( 1.00x)
vvc_sao_band_96_8_avx2 : 1815.4 ( 7.35x)
vvc_sao_band_96_10_c : 13197.5 ( 1.00x)
vvc_sao_band_96_10_avx2 : 1872.4 ( 7.05x)
vvc_sao_band_96_12_c : 11969.0 ( 1.00x)
vvc_sao_band_96_12_avx2 : 1895.8 ( 6.31x)
vvc_sao_band_112_8_c : 19936.9 ( 1.00x)
vvc_sao_band_112_8_avx2 : 2802.3 ( 7.11x)
vvc_sao_band_112_10_c : 19534.9 ( 1.00x)
vvc_sao_band_112_10_avx2 : 2635.0 ( 7.41x)
vvc_sao_band_112_12_c : 16520.6 ( 1.00x)
vvc_sao_band_112_12_avx2 : 2591.8 ( 6.37x)
vvc_sao_band_128_8_c : 25967.5 ( 1.00x)
vvc_sao_band_128_8_avx2 : 3155.3 ( 8.23x)
vvc_sao_band_128_10_c : 24002.6 ( 1.00x)
vvc_sao_band_128_10_avx2 : 3374.6 ( 7.11x)
vvc_sao_band_128_12_c : 20829.4 ( 1.00x)
vvc_sao_band_128_12_avx2 : 3377.0 ( 6.17x)
vvc_sao_edge_8_8_c : 174.6 ( 1.00x)
vvc_sao_edge_8_8_avx2 : 37.0 ( 4.72x)
vvc_sao_edge_8_10_c : 174.4 ( 1.00x)
vvc_sao_edge_8_10_avx2 : 58.5 ( 2.98x)
vvc_sao_edge_8_12_c : 171.1 ( 1.00x)
vvc_sao_edge_8_12_avx2 : 58.5 ( 2.93x)
vvc_sao_edge_16_8_c : 677.7 ( 1.00x)
vvc_sao_edge_16_8_avx2 : 72.2 ( 9.39x)
vvc_sao_edge_16_10_c : 724.8 ( 1.00x)
vvc_sao_edge_16_10_avx2 : 106.4 ( 6.81x)
vvc_sao_edge_16_12_c : 647.0 ( 1.00x)
vvc_sao_edge_16_12_avx2 : 106.6 ( 6.07x)
vvc_sao_edge_32_8_c : 3001.8 ( 1.00x)
vvc_sao_edge_32_8_avx2 : 157.6 (19.04x)
vvc_sao_edge_32_10_c : 3071.1 ( 1.00x)
vvc_sao_edge_32_10_avx2 : 404.2 ( 7.60x)
vvc_sao_edge_32_12_c : 2698.6 ( 1.00x)
vvc_sao_edge_32_12_avx2 : 398.8 ( 6.77x)
vvc_sao_edge_48_8_c : 6557.7 ( 1.00x)
vvc_sao_edge_48_8_avx2 : 380.1 (17.25x)
vvc_sao_edge_48_10_c : 6319.9 ( 1.00x)
vvc_sao_edge_48_10_avx2 : 896.3 ( 7.05x)
vvc_sao_edge_48_12_c : 6306.4 ( 1.00x)
vvc_sao_edge_48_12_avx2 : 885.5 ( 7.12x)
vvc_sao_edge_64_8_c : 11510.7 ( 1.00x)
vvc_sao_edge_64_8_avx2 : 504.1 (22.84x)
vvc_sao_edge_64_10_c : 10917.4 ( 1.00x)
vvc_sao_edge_64_10_avx2 : 1608.3 ( 6.79x)
vvc_sao_edge_64_12_c : 11499.8 ( 1.00x)
vvc_sao_edge_64_12_avx2 : 1586.4 ( 7.25x)
vvc_sao_edge_80_8_c : 18193.2 ( 1.00x)
vvc_sao_edge_80_8_avx2 : 930.2 (19.56x)
vvc_sao_edge_80_10_c : 17984.3 ( 1.00x)
vvc_sao_edge_80_10_avx2 : 2420.9 ( 7.43x)
vvc_sao_edge_80_12_c : 18289.4 ( 1.00x)
vvc_sao_edge_80_12_avx2 : 2412.1 ( 7.58x)
vvc_sao_edge_96_8_c : 26361.8 ( 1.00x)
vvc_sao_edge_96_8_avx2 : 1118.4 (23.57x)
vvc_sao_edge_96_10_c : 26162.2 ( 1.00x)
vvc_sao_edge_96_10_avx2 : 3666.9 ( 7.13x)
vvc_sao_edge_96_12_c : 25926.6 ( 1.00x)
vvc_sao_edge_96_12_avx2 : 3433.9 ( 7.55x)
vvc_sao_edge_112_8_c : 36562.9 ( 1.00x)
vvc_sao_edge_112_8_avx2 : 1741.0 (21.00x)
vvc_sao_edge_112_10_c : 38126.4 ( 1.00x)
vvc_sao_edge_112_10_avx2 : 5153.3 ( 7.40x)
vvc_sao_edge_112_12_c : 36345.7 ( 1.00x)
vvc_sao_edge_112_12_avx2 : 4684.9 ( 7.76x)
vvc_sao_edge_128_8_c : 46379.8 ( 1.00x)
vvc_sao_edge_128_8_avx2 : 2012.4 (23.05x)
vvc_sao_edge_128_10_c : 47029.5 ( 1.00x)
vvc_sao_edge_128_10_avx2 : 6162.2 ( 7.63x)
vvc_sao_edge_128_12_c : 49647.3 ( 1.00x)
vvc_sao_edge_128_12_avx2 : 6127.1 ( 8.10x)Co-authored-by : Nuo Mi <nuomi2021@gmail.com>
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Adding AY Files To The Game Music Website
1er décembre 2013, par Multimedia Mike — GeneralFor the first time since I launched the site in the summer of last year, I finally added support for new systems for my Game Music Appreciation site : A set of chiptune music files which bear the file extension AY. These files come from games that were on the ZX Spectrum and Amstrad CPC computer systems.
Right now, there are over 650 ZX Spectrum games in the site while there are all of 20 Amstrad CPC games. The latter system seems a bit short-changed, but I read that a lot of Amstrad games were straight ports from the Spectrum anyway since the systems possessed assorted similarities. This might help explain the discrepancy.
Technically
The AY corpus has always been low hanging fruit due to the fact that the site already supports the format courtesy of the game-music-emu backend. The thing that blocked me was that I didn’t know much about these systems. I knew that there were 2 systems (and possibly more) that shared the same chiptune format. Apparently, these machines were big in Europe (I was only vaguely aware of them before I started this project).Both the Spectrum and the Amstrad used Zilog Z-80 CPUs for computing and created music using a General Instruments synthesizer chip designated AY-3-8912, hence the chiptune file extension AY. This has 3 channels similar to the C64 SID chip. Additionally, there’s a fourth channel that game music emu calls “beeper” (and which Wikipedia describes as “one channel with 10 octaves”). Per my listening, it seems similar to the old PC speaker/honker. The metadata for a lot of the songs will specify either (AY) or (Beeper).
Wrangling Metadata
Large collections of AY files are easy to find ; as is typical for pure chiptunes, the files are incredibly small.As usual, the hardest part of the whole process was munging metadata. There seems to be 2 slightly different conventions for AY metadata, likely from 2 different people doing the bulk of the work and releasing the fruits of their labor into the wild. After I recognized the subtle differences between the 2 formats, it was straightforward to craft a tool to perform most of the work, leaving only a minimum of cleanup effort required afterwards.
(As an aside, I think this process is called extract – transform – load, or ETL. Sounds fancy and complicated, yet it’s technically one of the first computer programming tasks I was ever paid to perform.)
Collateral Damage
While pushing this feature, I managed to break the site’s search engine. The search solution I developed was always sketchy (involving compiling a C program as a static binary CGI script and trusting it to run on the server). I will probably need to find a better approach, preferably sooner than later.
Syndiquer tout le site
