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MediaSPIP Simple : futur thème graphique par défaut ?
26 septembre 2013, par
Mis à jour : Octobre 2013
Langue : français
Type : Video
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avec chosen
13 septembre 2013, par
Mis à jour : Septembre 2013
Langue : français
Type : Image
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sans chosen
13 septembre 2013, par
Mis à jour : Septembre 2013
Langue : français
Type : Image
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config chosen
13 septembre 2013, par
Mis à jour : Septembre 2013
Langue : français
Type : Image
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SPIP - plugins - embed code - Exemple
2 septembre 2013, par
Mis à jour : Septembre 2013
Langue : français
Type : Image
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GetID3 - Bloc informations de fichiers
9 avril 2013, par
Mis à jour : Mai 2013
Langue : français
Type : Image
Autres articles (83)
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Mise à jour de la version 0.1 vers 0.2
24 juin 2013, parExplications des différents changements notables lors du passage de la version 0.1 de MediaSPIP à la version 0.3. Quelles sont les nouveautés
Au niveau des dépendances logicielles Utilisation des dernières versions de FFMpeg (>= v1.2.1) ; Installation des dépendances pour Smush ; Installation de MediaInfo et FFprobe pour la récupération des métadonnées ; On n’utilise plus ffmpeg2theora ; On n’installe plus flvtool2 au profit de flvtool++ ; On n’installe plus ffmpeg-php qui n’est plus maintenu au (...) -
Personnaliser en ajoutant son logo, sa bannière ou son image de fond
5 septembre 2013, parCertains thèmes prennent en compte trois éléments de personnalisation : l’ajout d’un logo ; l’ajout d’une bannière l’ajout d’une image de fond ;
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Ecrire une actualité
21 juin 2013, parPrésentez les changements dans votre MédiaSPIP ou les actualités de vos projets sur votre MédiaSPIP grâce à la rubrique actualités.
Dans le thème par défaut spipeo de MédiaSPIP, les actualités sont affichées en bas de la page principale sous les éditoriaux.
Vous pouvez personnaliser le formulaire de création d’une actualité.
Formulaire de création d’une actualité Dans le cas d’un document de type actualité, les champs proposés par défaut sont : Date de publication ( personnaliser la date de publication ) (...)
Sur d’autres sites (9523)
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Illegal instruction : 4 in ffmpeg
27 mai 2017, par rs41I tried brew installed ffmpeg, i am also tried to compile ffmpeg but in all cases i have the error
Illegal instruction : 4
I run something like this :
./ffmpeg -i /Users/ruslan/Torrents/Weird\ smiling\ dog.3gp -codec:v libx264 -b:v 360k -maxrate 360k -bufsize 720k -movflags +faststart -vprofile high -preset slow -vf 'scale=trunc(iw/2)*2:360' -threads 0 -codec:a libfdk_aac -b:a 96k -ac 2 -f mp4 -threads 0 -y /dev/null >> /Users/ruslan/erosite/log/ffmpeg_convertation.log 2>&1
Illegal instruction: 4Or only ffmpeg with options when used homebrews installed version
Additional info :
OS X Yosemite 10.10.2
MacBook Pro (15-inch, Mid 2009)
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Running Windows XP In 2016
2 janvier 2016, par Multimedia MikeI have an interest in getting a 32-bit Windows XP machine up and running. I have a really good yet slightly dated and discarded computer that seemed like a good candidate for dedicating to this task. So the question is : Can Windows XP still be installed from scratch on a computer, activated, and used in 2016 ? I wasn’t quite sure since I have heard stories about how Microsoft has formally ended support for Windows XP as of the first half of 2014 and I wasn’t entirely sure what that meant.
Spoiler : It’s still possible to install and activate Windows XP as of the writing of this post. It’s also possible to download and install all the updates published up until support ended.
The Candidate Computer
This computer was assembled either in late 2008 or early 2009. It was a beast at the time.
Click for a larger image
It was built around the newly-released NVIDIA GTX 280 video card. The case is a Thermaltake DH-101, which is a home theater PC thing. The motherboard is an Asus P5N32-SLI Premium with a Core 2 Duo X6800 2.93 GHz CPU on board. 2 GB of RAM and a 1.5 TB hard drive are also present.
The original owner handed it off to me because their family didn’t have much use for it anymore (too many other machines in the house). Plus it was really, obnoxiously loud. The noisy culprit was the stock blue fan that came packaged with the Intel processor (seen in the photo) whining at around 65 dB. I replaced the fan and brought the noise level way down.
As for connectivity, the motherboard has dual gigabit NICs (of 2 different chipsets for some reason) and onboard wireless 802.11g. I couldn’t make the latter work and this project was taking place a significant distance from my wired network. Instead, I connected a USB 802.11ac dongle and antenna which is advertised to work in both Windows XP and Linux. It works great under Windows XP. Meanwhile, making the adapter work under Linux provided a retro-computing adventure in which I had to modify C code to make the driver work.
So, score 1 for Windows XP over Linux here.
The Simple Joy of Retro-computing
One thing you have to watch out for when you get into retro-computing is fighting the urge to rant about the good old days of computing. Most long-time computer users have a good understanding of the frustration that computers keep getting faster by orders of magnitude and yet using them somehow feels slower and slower over successive software generations.
This really hits home when you get old software running, especially on high-end hardware (relative to what was standard contemporary hardware). After I got this new Windows XP machine running, as usual, I was left wondering why software was so much faster a few generations ago.
Of course, as mentioned, it helps when you get to run old software on hardware that would have been unthinkably high end at the software’s release. Apparently, the minimum WinXP specs as set by MS are a 233 MHz Pentium CPU and 64 MB of RAM, with 1.5 GB of hard drive space. This machine has more than 10x the clock speed (and 2 CPUs), 32x the RAM, and 1000x the HD space. Further, I’m pretty sure 100 Mbit ethernet was the standard consumer gear in 2001 while 802.11b wireless was gaining traction. The 802.11ac adapter makes networking quite pleasant.
Purpose
Retro-computing really seems to be ramping up in popularity lately. For some reason, I feel compelled to declare at this juncture that I was into it before it was cool.Why am I doing this ? I have a huge collection of old DOS/Windows computer games. I also have this nerdy obsession with documenting old video games in the MobyGames database. I used to do a lot of this a few years ago, tracking the effort on my gaming blog. In the intervening years, I have still collected a lot of old, unused, unloved video games, usually either free or very cheap while documenting my collection efforts on that same blog.
So I want to work my way through some of this backlog, particularly the games that are not yet represented in the MobyGames database, and even more pressing, ones that the internet (viewed through Google at least) does not seem to know about. To that end, I thought this was a good excuse to get Windows XP on this old machine. A 32-bit Windows XP machine is capable of running any software advertised as supporting Windows XP, Windows ME, Windows 98, Windows 95, and even 16-bit Windows 3.x (I have games for all these systems). That covers a significant chunk of PC history. It can probably be made to run DOS games as well, but those are (usually) better run under DosBox. In order to get the right display feel, I even invested in a (used) monitor sporting a 4:3 aspect ratio. If I know these old games, most will be engineered and optimized for that ratio rather than the widescreen resolutions seen nowadays.
I would also like to get back to that Xbox optical disc experimentation I was working on a few years ago. Another nice feature of this motherboard is that it still provides a 40-pin IDE/PATA adapter which makes the machine useful for continuing that old investigation (and explains why I have that long IDE cable to no where pictured hanging off the board).
The Messy Details
I did the entire installation process twice. The first time was a bumbling journey of discovery and copious note-taking. I still have Windows XP installation media that includes service pack 2 (SP2), along with 2 separate licenses that haven’t been activated for a long time. My plan was to install it fresh, then install the relevant drivers. Then I would investigate the Windows update and activation issues and everything should be fine.So what’s the deal with Windows Update for XP, and with activations ? Second item first : it IS possible to still activate Windows XP. The servers are still alive and respond quickly. However, as always, you don’t activate until you’re sure everything is working at some baseline. It took awhile to get there.
As for whether Windows Update still works for XP, that’s a tougher question. Short answer is yes ; longer answer is that it can be difficult to kick off the update process. At least on SP2, the “Windows Update” program launches IE6 and navigates to a special microsoft.com URL which initiates the update process (starting with an ActiveX control). This URL no longer exists.
From what I can piece together from my notes, this seems to be the route I eventually took :
- Install Windows XP fresh
- Install drivers for the hardware ; fortunately, Asus still has all the latest drivers necessary for the motherboard and its components but it’s necessary to download these from another network-connected PC since the networking probably won’t be running “out of the box”
- Download the .NET 3.5 runtime, which is the last one supported by Windows XP, and install it
- Download the latest NVIDIA drivers ; this needs to be done after the previous step because the installer requires the .NET runtime ; run the driver installer and don’t try to understand why it insists on re-downloading .NET 3.5 runtime before installation
- While you’re downloading stuff on other computers to be transported to this new machine, be sure to download either Chrome or Firefox per your preference ; if you try to download via IE6, you may find that their download pages aren’t compatible with IE6
- Somewhere along the line (I’m guessing as a side effect of the .NET 3.5 installation), the proper, non-IE6-based Windows Update program magically springs to life ; once this happens, there will be 144 updates (in my case anyway) ; installing these will probably require multiple reboots, but SP3 and all known pre-deprecation security fixes will be installed
- Expect that, even after installing all of these, a few more updates will appear ; eventually, you’ll be at the end of the update road
- Once you’re satisfied everything is working satisfactorily, take the plunge and activate your installation
Residual Quirks
Steam runs great on Windows XP, as do numerous games I have purchased through the service. So that opens up a whole bunch more games that I could play on this machine. Steam’s installer highlights a curious legacy problem of Windows XP– it seems there are many languages that it does not support “out of the box” :
It looks like the Chinese options and a few others that are standard now weren’t standard 15 years ago.
Also, a little while after booting up, I’ll get a crashing error concerning a process called geoforms.scr. This appears to be NVIDIA-related. However, I don’t notice anything obviously operationally wrong with the system.
Regarding DirectX support, DirectX 9 is the highest version officially supported by Windows XP. There are allegedly methods to get DirectX 10 running as well, but I don’t care that much. I did care, briefly, when I realized that a bunch of the demos for the NVIDIA GTX 280 required DX10 which left me wondering why it was possible to install them on Windows XP.
Eventually, by installing enough of these old games, I fully expect to have numerous versions of .NET, DirectX, QT, and Video for Windows installed side by side.
Out of curiosity, I tried playing a YouTube HD/1080p video. I wanted to see if the video was accelerated through my card. The video played at full speed but I noticed some tearing. Then I inspected the CPU usage and noticed that the CPU was quite loaded. So either the GTX 280 doesn’t have video acceleration, or Windows XP doesn’t provide the right APIs, or Chrome is not able to access the APIs in Windows XP, or perhaps some combination of the foregoing.
Games are working well, though. I tried one of my favorite casual games and got sucked into that for, like, an entire night because that’s what casual games do. But then, I booted up a copy of WarCraft III that I procured sometime ago. I don’t have any experience with the WarCraft universe (RTS or MMO) but I developed a keen interest in StarCraft II over the past few years and wanted to try WarCraft III. Unfortunately, I couldn’t get WarCraft III to work correctly on several different Windows 7 installations (movies didn’t play, which left me slightly confused as to what I was supposed to do).
Still works beautifully on the new old Windows XP machine.
The post Running Windows XP In 2016 first appeared on Breaking Eggs And Making Omelettes.
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Why does the frame count change when scaling with FFmpeg ?
22 octobre 2016, par ajmicekI use this to scale 1920x1080 H.264 videos :
ffmpeg -i IMG_1438.MOV -threads 2 -vf scale=-2:600 IMG_1438_scaledTo600.MOVAnd it works great ! But here is my question : most of the time, the frame rate stays exactly the same between the original file and the scaled file. For example :
$ mediainfo -F IMG_1426.MOV | grep Frame\ rate
Frame rate : 29.970
Frame rate : 29.970 FPS
Frame rate mode : VFR
Frame rate mode : Variable
Frame rate : 29.970
Frame rate : 29.970 (29970/1000) FPS
$ mediainfo -F IMG_1426_scaledTo600.MOV | grep Frame\ rate
Frame rate : 29.970
Frame rate : 29.970 FPS
Frame rate mode : CFR
Frame rate mode : Constant
Frame rate : 29.970
Frame rate : 29.970 (30000/1001) FPSBut sometimes, the frame rate increases dramatically :
$ mediainfo -F IMG_1438.MOV | grep Frame\ rate
Frame rate : 25.044
Frame rate : 25.044 FPS
Frame rate mode : VFR
Frame rate mode : Variable
Frame rate : 25.044
Frame rate : 25.044 FPS
$ mediainfo -F IMG_1438_scaledTo600.MOV | grep Frame\ rate
Frame rate : 120.000
Frame rate : 120.000 FPS
Frame rate mode : CFR
Frame rate mode : Constant
Frame rate : 120.000
Frame rate : 120.000 FPSWhat should I know about FFmpeg or libx264 or libswscale that will help me understand why this happens ? (Hoping to hear from LordNeckbeard, in particular).
mediainfo IMG_1438.MOV --Fulloutputs :General
Count : 327
Count of stream of this kind : 1
Kind of stream : General
Kind of stream : General
Stream identifier : 0
Count of video streams : 1
Count of audio streams : 1
OtherCount : 2
Video_Format_List : AVC
Video_Format_WithHint_List : AVC
Codecs Video : AVC
Audio_Format_List : AAC
Audio_Format_WithHint_List : AAC
Audio codecs : AAC LC
Complete name : IMG_1438.MOV
File name : IMG_1438
File extension : MOV
Format : MPEG-4
Format : MPEG-4
Format/Extensions usually used : mp4 m4v m4a m4b m4p 3gpp 3gp 3gpp2 3g2 k3g jpm jpx mqv ismv isma f4v
Commercial name : MPEG-4
Format profile : QuickTime
Internet media type : video/mp4
Codec ID : qt
Codec ID : qt 0000.00 (qt )
Codec ID/Url : http://www.apple.com/quicktime/download/standalone.html
CodecID_Version : 0000.00
CodecID_Compatible : qt
Codec : MPEG-4
Codec : MPEG-4
Codec/Extensions usually used : mp4 m4v m4a m4b m4p 3gpp 3gp 3gpp2 3g2 k3g jpm jpx mqv ismv isma f4v
File size : 113990140
File size : 109 MiB
File size : 109 MiB
File size : 109 MiB
File size : 109 MiB
File size : 108.7 MiB
Duration : 52268
Duration : 52 s 268 ms
Duration : 52 s 268 ms
Duration : 52 s 268 ms
Duration : 00:00:52.268
Duration : 00:00:52:09
Duration : 00:00:52.268 (00:00:52:09)
Overall bit rate : 17447026
Overall bit rate : 17.4 Mb/s
Frame rate : 25.044
Frame rate : 25.044 FPS
Frame count : 1309
Stream size : 56670
Stream size : 55.3 KiB (0%)
Stream size : 55 KiB
Stream size : 55 KiB
Stream size : 55.3 KiB
Stream size : 55.34 KiB
Stream size : 55.3 KiB (0%)
Proportion of this stream : 0.00050
HeaderSize : 28
DataSize : 113966271
FooterSize : 23841
IsStreamable : No
Encoded date : UTC 2016-10-08 22:51:19
Tagged date : UTC 2016-10-08 22:52:12
File last modification date : UTC 2016-10-08 22:51:19
File last modification date (local) : 2016-10-08 17:51:19
Writing library : Apple QuickTime
Writing library : Apple QuickTime
Encoded_Library_Name : Apple QuickTime
com.apple.quicktime.make : Apple
com.apple.quicktime.model : iPhone 5
com.apple.quicktime.software : 10.0.2
com.apple.quicktime.creationdate : 2016-10-08T17:51:19-0500
Video
Count : 334
Count of stream of this kind : 1
Kind of stream : Video
Kind of stream : Video
Stream identifier : 0
StreamOrder : 0
ID : 1
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format/Url : http://developers.videolan.org/x264.html
Commercial name : AVC
Format profile : High@L4.1
Format settings : CABAC / 1 Ref Frames
Format settings, CABAC : Yes
Format settings, CABAC : Yes
Format settings, ReFrames : 1
Format settings, ReFrames : 1 frame
Internet media type : video/H264
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Codec ID/Url : http://www.apple.com/quicktime/download/standalone.html
Codec : AVC
Codec : AVC
Codec/Family : AVC
Codec/Info : Advanced Video Codec
Codec/Url : http://developers.videolan.org/x264.html
Codec/CC : avc1
Codec profile : High@L4.1
Codec settings : CABAC / 1 Ref Frames
Codec settings, CABAC : Yes
Codec_Settings_RefFrames : 1
Duration : 52268
Duration : 52 s 268 ms
Duration : 52 s 268 ms
Duration : 52 s 268 ms
Duration : 00:00:52.268
Duration : 00:00:52:09
Duration : 00:00:52.268 (00:00:52:09)
Bit rate : 17375530
Bit rate : 17.4 Mb/s
Width : 1920
Width : 1 920 pixels
Height : 1080
Height : 1 080 pixels
Stored_Height : 1088
Sampled_Width : 1920
Sampled_Height : 1080
Pixel aspect ratio : 1.000
Display aspect ratio : 1.778
Display aspect ratio : 16:9
Rotation : 90.000
Rotation : 90°
Frame rate mode : VFR
Frame rate mode : Variable
Frame rate : 25.044
Frame rate : 25.044 FPS
Minimum frame rate : 23.077
Minimum frame rate : 23.077 FPS
Maximum frame rate : 30.000
Maximum frame rate : 30.000 FPS
Frame count : 1309
Resolution : 8
Resolution : 8 bits
Colorimetry : 4:2:0
Color space : YUV
Chroma subsampling : 4:2:0
Chroma subsampling : 4:2:0
Bit depth : 8
Bit depth : 8 bits
Scan type : Progressive
Scan type : Progressive
Interlacement : PPF
Interlacement : Progressive
Bits/(Pixel*Frame) : 0.335
Stream size : 113523046
Stream size : 108 MiB (100%)
Stream size : 108 MiB
Stream size : 108 MiB
Stream size : 108 MiB
Stream size : 108.3 MiB
Stream size : 108 MiB (100%)
Proportion of this stream : 0.99590
Title : Core Media Video
Encoded date : UTC 2016-10-08 22:51:19
Tagged date : UTC 2016-10-08 22:52:12
Color range : Limited
colour_description_present : Yes
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Audio
Count : 272
Count of stream of this kind : 1
Kind of stream : Audio
Kind of stream : Audio
Stream identifier : 0
StreamOrder : 1
ID : 2
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Commercial name : AAC
Format profile : LC
Codec ID : 40
Codec : AAC LC
Codec : AAC LC
Codec/Family : AAC
Codec/CC : 40
Duration : 52268
Duration : 52 s 268 ms
Duration : 52 s 268 ms
Duration : 52 s 268 ms
Duration : 00:00:52.268
Duration : 00:00:52:15
Duration : 00:00:52.268 (00:00:52:15)
Source duration : 52338
Source duration : 52 s 338 ms
Source duration : 52 s 338 ms
Source duration : 52 s 338 ms
Source duration : 00:00:52.338
Bit rate mode : CBR
Bit rate mode : Constant
Bit rate : 64000
Bit rate : 64.0 kb/s
Channel(s) : 1
Channel(s) : 1 channel
Channel positions : Front: C
Channel positions : 1/0/0
ChannelLayout : C
Samples per frame : 1024
Sampling rate : 44100
Sampling rate : 44.1 kHz
Samples count : 2305019
Frame rate : 43.066
Frame rate : 43.066 FPS (1024 spf)
Frame count : 2251
Source frame count : 2254
Compression mode : Lossy
Compression mode : Lossy
Stream size : 410424
Stream size : 401 KiB (0%)
Stream size : 401 KiB
Stream size : 401 KiB
Stream size : 401 KiB
Stream size : 400.8 KiB
Stream size : 401 KiB (0%)
Proportion of this stream : 0.00360
Source stream size : 410894
Source stream size : 401 KiB (0%)
Source stream size : 401 KiB
Source stream size : 401 KiB
Source stream size : 401 KiB
Source stream size : 401.3 KiB
Source stream size : 401 KiB (0%)
Source_StreamSize_Proportion : 0.00360
Title : Core Media Audio
Encoded date : UTC 2016-10-08 22:51:19
Tagged date : UTC 2016-10-08 22:52:12
Other #1
Count : 112
Count of stream of this kind : 2
Kind of stream : Other
Kind of stream : Other
Stream identifier : 0
Stream identifier : 1
Type : meta
Duration : 52268
Duration : 52 s 268 ms
Duration : 52 s 268 ms
Duration : 52 s 268 ms
Duration : 00:00:52.268
Duration : 00:00:52.268
Frame count : 6
Bit rate mode : VBR
Other #2
Count : 112
Count of stream of this kind : 2
Kind of stream : Other
Kind of stream : Other
Stream identifier : 1
Stream identifier : 2
Type : meta
Duration : 52268
Duration : 52 s 268 ms
Duration : 52 s 268 ms
Duration : 52 s 268 ms
Duration : 00:00:52.268
Duration : 00:00:52.268
Frame count : 1
Bit rate mode : CBRand
ffprobe IMG_1438.MOVoutputs :ffprobe version 3.1.3 Copyright (c) 2007-2016 the FFmpeg developers
built with Apple LLVM version 7.3.0 (clang-703.0.31)
configuration: --prefix=/usr/local/Cellar/ffmpeg/3.1.3 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-opencl --enable-libx264 --enable-libmp3lame --enable-libxvid --disable-lzma --enable-vda
libavutil 55. 28.100 / 55. 28.100
libavcodec 57. 48.101 / 57. 48.101
libavformat 57. 41.100 / 57. 41.100
libavdevice 57. 0.101 / 57. 0.101
libavfilter 6. 47.100 / 6. 47.100
libavresample 3. 0. 0 / 3. 0. 0
libswscale 4. 1.100 / 4. 1.100
libswresample 2. 1.100 / 2. 1.100
libpostproc 54. 0.100 / 54. 0.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'IMG_1438.MOV':
Metadata:
major_brand : qt
minor_version : 0
compatible_brands: qt
creation_time : 2016-10-08 22:51:19
com.apple.quicktime.make: Apple
com.apple.quicktime.model: iPhone 5
com.apple.quicktime.software: 10.0.2
com.apple.quicktime.creationdate: 2016-10-08T17:51:19-0500
Duration: 00:00:52.27, start: 0.000000, bitrate: 17446 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080, 17375 kb/s, 25.04 fps, 120 tbr, 600 tbn, 1200 tbc (default)
Metadata:
rotate : 90
creation_time : 2016-10-08 22:51:19
handler_name : Core Media Data Handler
encoder : H.264
Side data:
displaymatrix: rotation of -90.00 degrees
Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 62 kb/s (default)
Metadata:
creation_time : 2016-10-08 22:51:19
handler_name : Core Media Data Handler
Stream #0:2(und): Data: none (mebx / 0x7862656D), 0 kb/s (default)
Metadata:
creation_time : 2016-10-08 22:51:19
handler_name : Core Media Data Handler
Stream #0:3(und): Data: none (mebx / 0x7862656D), 0 kb/s (default)
Metadata:
creation_time : 2016-10-08 22:51:19
handler_name : Core Media Data Handler
Unsupported codec with id 0 for input stream 2
Unsupported codec with id 0 for input stream 3UPDATE
To clarify : my video above, the one with the high framerate (120 FPS) output after scaling, plays perfectly before and after scaling with FFmpeg (no sync issues, and 120 FPS is only about 14% larger in file size), I am simply trying to understand why this increase in framerate happens (just a little beyond Mulvya’s note that the framerate stored in the container is wrong).From a programming perspective, the initial issue I ran into was that I was using
frame=from FFmpeg’s sterr console output to determine progress, which reports erroneous results when the frame count increases dramatically on output ("I’m 372% done encoding ?!") ; I have since read another stackoverflow answer and changed my code to usetime=, which appears to be a more robust way for me to display FFmpeg progress. (Also, there is FFmpeg’s-progressoption, of course).Improving on the original command
My new command to scale, preserve a useful framerate, and optimize threads :
ffmpeg -i IMG_1438.MOV -vf scale=-2:600 -r 30 -vsync 0 IMG_1438_scaledTo600.MOVWhere
30is the "Maximum frame rate" frommediainfo.Thanks to help in the comments, I now know I do not fully understand FFmpeg’s use of three different time bases for timestamps :
tbn,tbc, andtbr.
They were explained by Robert Swain in 2009 and his explanation was also used to answer a Stackoverflow question about tbn, tbc, tbr.It sounds to me, as I’m pulling together comments from Mulvya below and Michael Rampe at another forum, that
tbris guessed ; it is frequently but not always the best value to use when changing from a variable to a constant frame rate video.Which leaves these 2 questions...
(1)
tbris incorrect when "field rate and frame rate" differ ? Does this happen a lot ?
(2) Is-r 30where30is the maximum frame rate reported bymediainfothe best way to do it for most codec/container combinations ? (Or should I only use this method when I am scaling a H.264/MPEG-4 AVC video ?)
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