Recherche avancée
Autres articles (53)
-
Participer à sa traduction
10 avril 2011Vous pouvez nous aider à améliorer les locutions utilisées dans le logiciel ou à traduire celui-ci dans n’importe qu’elle nouvelle langue permettant sa diffusion à de nouvelles communautés linguistiques.
Pour ce faire, on utilise l’interface de traduction de SPIP où l’ensemble des modules de langue de MediaSPIP sont à disposition. ll vous suffit de vous inscrire sur la liste de discussion des traducteurs pour demander plus d’informations.
Actuellement MediaSPIP n’est disponible qu’en français et (...) -
Les autorisations surchargées par les plugins
27 avril 2010, parMediaspip core
autoriser_auteur_modifier() afin que les visiteurs soient capables de modifier leurs informations sur la page d’auteurs -
Publier sur MédiaSpip
13 juin 2013Puis-je poster des contenus à partir d’une tablette Ipad ?
Oui, si votre Médiaspip installé est à la version 0.2 ou supérieure. Contacter au besoin l’administrateur de votre MédiaSpip pour le savoir
Sur d’autres sites (8733)
-
qt-faststart : Avoid unintentionally sign extending BE_32
28 février 2014, par Martin Storsjöqt-faststart : Avoid unintentionally sign extending BE_32
Without this cast, the BE_32() expression is sign extended when
assigned to an uint64_t, since the uint8_t|uint8_t expression
is promoted to an int.Also avoid undefined behaviour when left shifting an uint8_t
by 24 by casting it to an uint32_t explicitly before shifting.Based on a patch by Michael Niedermayer.
Signed-off-by : Martin Storsjö <martin@martin.st>
-
Getting small file size from ffmpeg [duplicate]
20 février 2020, par sukachI am not an ffmpeg expert. I am trying to get some movies converted to a smaller DIVX file for a cheap portable DVD player for a family trip. The movies are for my kids so I’m not too concerned about quality.
The DVD player is a 10.1", 1024x600 screen. It says it supports DIVX/MPEG2 files. It took me a lot of experimentation to get the right ffmpeg settings to even get it to work, but I found another answer that provided a very complex set of parameters that ultimately worked.
I have converted about 20 movies with this setting and every one results in a file size of 1.1GB. I have tried different file sizes and crf settings and it is the same every time.
Here is an example. First, the original file :
General
Complete name : Charlotte's Web.m4v
Format : MPEG-4
Format profile : Base Media / Version 2
Codec ID : mp42 (isom/iso2/avc1/mp41)
File size : 4.17 GiB
Duration : 1 h 36 min
Overall bit rate mode : Variable
Overall bit rate : 6 161 kb/s
Movie name : Charlotte's Web
Performer : Julia Roberts, Steve Buscemi, John Cleese, Oprah Winfrey, Cedric the Entertainer, Reba McEntire, Kathy Bates, Robert Redford, Thomas Haden Church, André Benjamin, Dominic Scott Kay, Sam Shepard, Abraham Benrubi, Dakota Fanning, Kevin Anderson, Essie Davis, Siobhan Fallon, Louis Corbett, Robyn Arthur, Julian O'Donnell, Gary Basaraba, Nate Mooney, Nicholas Bell, Beau Bridges, Teague Rook, Julia Zemiro, Denise Kirby, Robert Plazek, Joseph Lotesto, Michael Roland, Don Bridges, Ian Watkin, Joel McCrary, Brian Stepanek, Fred Tatasciore, Bradley White, Maia Kirkpatrick, Jennessa Rose, Briana Hodge, Dale Azzopardi, Geoff Burgess, Ella Scott Lynch, Greg Marian, Stefano Mazzeo, Elizabeth Saunders
Director : Gary Winick
Actor : Julia Roberts / Steve Buscemi / John Cleese / Oprah Winfrey / Cedric the Entertainer / Reba McEntire / Kathy Bates / Robert Redford / Thomas Haden Church / André Benjamin / Dominic Scott Kay / Sam Shepard / Abraham Benrubi / Dakota Fanning / Kevin Anderson / Essie Davis / Siobhan Fallon / Louis Corbett / Robyn Arthur / Julian O'Donnell / Gary Basaraba / Nate Mooney / Nicholas Bell / Beau Bridges / Teague Rook / Julia Zemiro / Denise Kirby / Robert Plazek / Joseph Lotesto / Michael Roland / Don Bridges / Ian Watkin / Joel McCrary / Brian Stepanek / Fred Tatasciore / Bradley White / Maia Kirkpatrick / Jennessa Rose / Briana Hodge / Dale Azzopardi / Geoff Burgess / Ella Scott Lynch / Greg Marian / Stefano Mazzeo / Elizabeth Saunders
Screenplay by : Karey Kirkpatrick / Susannah Grant / Earl Hamner / Jr. / E.B. White
Producer : Julia Pistor / Jordan Kerner / Paul Neesan / Edgar M. Bronfman / Bernard Williams / Tony Winley
Genre : Comedy
ContentType : Short Film
Description : Wilbur the pig is scared of the end of the season, because he knows that come that time, he will end up on the dinner table. He hatches a plan with Charlotte, a spider that lives in his pen, to ensure that this will never happen.
Recorded date : UTC 2006-12-15 11:00:00
Encoded date : UTC 2017-01-23 02:37:54
Tagged date : UTC 2017-01-24 01:19:52
Writing application : HandBrake 1.0.1 2016122900
Cover : Yes
LongDescription : Wilbur the pig is scared of the end of the season, because he knows that come that time, he will end up on the dinner table. He hatches a plan with Charlotte, a spider that lives in his pen, to ensure that this will never happen.
ContentRating : mpaa|G|100|
Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4
Format settings : CABAC / 4 Ref Frames
Format settings, CABAC : Yes
Format settings, ReFrames : 4 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 1 h 36 min
Bit rate : 5 691 kb/s
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Variable
Frame rate : 23.976 (24000/1001) FPS
Minimum frame rate : 23.974 FPS
Maximum frame rate : 23.981 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.114
Stream size : 3.86 GiB (92%)
Writing library : x264 core 148 r2708 86b7198
Encoding settings : cabac=1 / ref=3 / deblock=1:-1:-1 / analyse=0x3:0x113 / me=hex / subme=7 / psy=1 / psy_rd=1.00:0.15 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-3 / 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=240 / keyint_min=24 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=crf / mbtree=1 / crf=22.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / vbv_maxrate=25000 / vbv_bufsize=31250 / crf_max=0.0 / nal_hrd=none / filler=0 / ip_ratio=1.40 / aq=1:1.00
Encoded date : UTC 2017-01-23 02:37:54
Tagged date : UTC 2017-01-23 02:37:54
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Menus : 4Here is the first encode settings :
ffmpeg -i "$1" -sn -c:a libmp3lame -ar 48000 -ab 128k -ac 2 -c:v mpeg4 -crf 24 -vtag DIVX -vf scale=1024x600:force_original_aspect_ratio=decrease -mbd rd -flags +mv4+aic -trellis 2 -cmp 2 -subcmp 2 -g 30 -vb 1500k "$2"And the resulting mediainfo :
General
Complete name : Charlotte's Web (2006) - DIVX.avi
Format : AVI
Format/Info : Audio Video Interleave
Format profile : OpenDML
File size : 1.11 GiB
Duration : 1 h 36 min
Overall bit rate : 1 644 kb/s
Movie name : Charlotte's Web
Director : Julia Roberts, Steve Buscemi, John Cleese, Oprah Winfrey, Cedric the Entertainer, Reba McEntire, Kathy Bates, Robert Redford, Thomas Haden Church, André Benjamin, Dominic Scott Kay, Sam Shepard, Abraham Benrubi, Dakota Fanning, Kevin Anderson, Essie Davis, Siobhan Fallon, Louis Corbett, Robyn Arthur, Julian O'Donnell, Gary Basaraba, Nate Mooney, Nicholas Bell, Beau Bridges, Teague Rook, Julia Zemiro, Denise Kirby, Robert Plazek, Joseph Lotesto, Michael Roland, Don Bridges, Ian Watkin, Joel McCrary, Brian Stepanek, Fred Tatasciore, Bradley White, Maia Kirkpatrick, Jennessa Rose, Briana Hodge, Dale Azzopardi, Geoff Burgess, Ella Scott Lynch, Greg Marian, Stefano Mazzeo, Elizabeth Saunders
Genre : Comedy
Recorded date : UTC 2006-12-15 11:00:00
Writing application : Lavf57.56.100
Video
ID : 0
Format : MPEG-4 Visual
Format profile : Simple@L1
Format settings, BVOP : No
Format settings, QPel : No
Format settings, GMC : No warppoints
Format settings, Matrix : Default (H.263)
Codec ID : DIVX
Codec ID/Info : Project Mayo
Codec ID/Hint : DivX 4
Duration : 1 h 36 min
Bit rate : 1 500 kb/s
Width : 1 024 pixels
Height : 576 pixels
Display aspect ratio : 16:9
Frame rate : 23.976 (24000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.106
Stream size : 1.02 GiB (91%)
Writing library : Lavc57.64.100Here was my attempt at a smaller file size (lower crf and smaller scale setting) :
ffmpeg -i "Charlotte's Web.m4v" -sn -c:a libmp3lame -ar 48000 -ab 128k -ac 2 -c:v mpeg4 -crf 30 -vtag DIVX -vf scale=800:480 -mbd rd -flags +mv4+aic -trellis 2 -cmp 2 -subcmp 2 -g 30 -vb 1500k "Charlotte's Web (2006) - DIVX 2.avi"And the resulting mediainfo :
General
Complete name : Charlotte's Web (2006) - DIVX 2.avi
Format : AVI
Format/Info : Audio Video Interleave
Format profile : OpenDML
File size : 1.11 GiB
Duration : 1 h 36 min
Overall bit rate : 1 643 kb/s
Movie name : Charlotte's Web
Director : Julia Roberts, Steve Buscemi, John Cleese, Oprah Winfrey, Cedric the Entertainer, Reba McEntire, Kathy Bates, Robert Redford, Thomas Haden Church, André Benjamin, Dominic Scott Kay, Sam Shepard, Abraham Benrubi, Dakota Fanning, Kevin Anderson, Essie Davis, Siobhan Fallon, Louis Corbett, Robyn Arthur, Julian O'Donnell, Gary Basaraba, Nate Mooney, Nicholas Bell, Beau Bridges, Teague Rook, Julia Zemiro, Denise Kirby, Robert Plazek, Joseph Lotesto, Michael Roland, Don Bridges, Ian Watkin, Joel McCrary, Brian Stepanek, Fred Tatasciore, Bradley White, Maia Kirkpatrick, Jennessa Rose, Briana Hodge, Dale Azzopardi, Geoff Burgess, Ella Scott Lynch, Greg Marian, Stefano Mazzeo, Elizabeth Saunders
Genre : Comedy
Recorded date : UTC 2006-12-15 11:00:00
Writing application : Lavf57.56.100
Video
ID : 0
Format : MPEG-4 Visual
Format profile : Simple@L1
Format settings, BVOP : No
Format settings, QPel : No
Format settings, GMC : No warppoints
Format settings, Matrix : Default (H.263)
Codec ID : DIVX
Codec ID/Info : Project Mayo
Codec ID/Hint : DivX 4
Duration : 1 h 36 min
Bit rate : 1 499 kb/s
Width : 800 pixels
Height : 480 pixels
Display aspect ratio : 16:9
Frame rate : 23.976 (24000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.163
Stream size : 1.02 GiB (91%)
Writing library : Lavc57.64.100Same file size but lower resolution.
Any ideas on what the best settings to achieve my goal ?
-
avcodec/smacker : Use unsigned for prediction values
26 juin 2020, par Andreas Rheinhardtavcodec/smacker : Use unsigned for prediction values
Up until now, the Smacker decoder has pretended that the prediction
values are signed in code like 'pred[0] += (unsigned)sign_extend(val, 16)'
(the cast has been added to this code later to fix undefined behaviour).
This has been even done in case the PCM format is u8.Yet in case of 8/16 bit samples, only the lower 8/16 bit of the predicition
values are ever used, so one can just as well just use unsigned and
remove the sign extensions. This is what this commit does.For GCC 9 the time for one call to smka_decode_frame() for the sample from
ticket #2425 decreased from 1709043 to 1693619 decicycles ; for Clang 9
it went up from 1355273 to 1369089 decicycles.Reviewed-by : Paul B Mahol <onemda@gmail.com>
Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Syndiquer tout le site
