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La conservation du net art au musée. Les stratégies à l’œuvre
26 mai 2011
Mis à jour : Juillet 2013
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MediaSPIP 0.1 Beta version
25 avril 2011, parMediaSPIP 0.1 beta is the first version of MediaSPIP proclaimed as "usable".
The zip file provided here only contains the sources of MediaSPIP in its standalone version.
To get a working installation, you must manually install all-software dependencies on the server.
If you want to use this archive for an installation in "farm mode", you will also need to proceed to other manual (...) -
Multilang : améliorer l’interface pour les blocs multilingues
18 février 2011, parMultilang est un plugin supplémentaire qui n’est pas activé par défaut lors de l’initialisation de MediaSPIP.
Après son activation, une préconfiguration est mise en place automatiquement par MediaSPIP init permettant à la nouvelle fonctionnalité d’être automatiquement opérationnelle. Il n’est donc pas obligatoire de passer par une étape de configuration pour cela. -
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 (...)
Sur d’autres sites (6444)
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How to set up a cron job for ffmpeg in centOS 6
9 mars 2018, par user27240I can convert from mp4 file to jpg file manually one by one with the below command on centOS 6 environment.
Now, could anyone help me out how to set up a cron for any mp4 file in the directory to be converted automatically
to jpg file with the same file name as mp4 file such as03052022_5a9d28723d2da.jpg
for the below environment ?OS:centos-6 (x86_64)
ffmpeg version 2.2.2
Plesk 17.0.17
[root@server-xxxxxxxx-x ~]# ffmpeg -i \
/var/www/vhosts/xxxxx.com/httpdocs/save/03052022_5a9d28723d2da.mp4 \
/var/www/vhosts/xxxxx.com/httpdocs/save/03052022_5a9d28723d2da.jpgWith ’s/.conf$/.jpg/p’ :
[root@server-xxxxxx-x ~]# for i in `find /var/www/vhosts/xxxxxx.com/httpdocs/save/ -type f -name "*.mp4"`; do ffmpeg -i $i `echo $i | sed -En 's/.conf$/.jpg/p'`; done
ffmpeg version 2.2.2 Copyright (c) 2000-2014 the FFmpeg developers
built on Feb 21 2018 03:03:24 with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-18)
configuration :
libavutil 52. 66.100 / 52. 66.100
libavcodec 55. 52.102 / 55. 52.102
libavformat 55. 33.100 / 55. 33.100
libavdevice 55. 10.100 / 55. 10.100
libavfilter 4. 2.100 / 4. 2.100
libswscale 2. 5.102 / 2. 5.102
libswresample 0. 18.100 / 0. 18.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from ’/var/www/vhosts/xxxxxx.com/httpdocs/save/03081956_5aa116c836015.mp4’ :
Metadata :
major_brand : mp42
minor_version : 0
compatible_brands : isommp42
creation_time : 2018-02-14 04:42:34
Duration : 00:00:00.83, start : 0.000000, bitrate : 23270 kb/s
Stream #0:0(eng) : Video : h264 (Baseline) (avc1 / 0x31637661), yuvj420p(pc, smpte170m), 1920x1080, 25370 kb/s, SAR 65536:65536 DAR 16:9, 29.73 fps, 30 tbr, 90k tbn, 180k tbc (default)
Metadata :
rotate : 90
creation_time : 2018-02-14 04:42:34
handler_name : VideoHandle
Stream #0:1(eng) : Audio : aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 96 kb/s (default)
Metadata :
creation_time : 2018-02-14 04:42:34
handler_name : SoundHandle
At least one output file must be specified
Conversion failed !With "s/.conf$/.jpg/p" :
[root@server-xxxxxxx-x ~]# for i in `find /var/www/vhosts/xxxxxx.com/httpdocs/save/ -type f -name "*.mp4"`; do ffmpeg -i $i `echo $i | sed -En "s/.conf$/.jpg/p"`; done
ffmpeg version 2.2.2 Copyright (c) 2000-2014 the FFmpeg developers
built on Feb 21 2018 03:03:24 with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-18)
configuration :
libavutil 52. 66.100 / 52. 66.100
libavcodec 55. 52.102 / 55. 52.102
libavformat 55. 33.100 / 55. 33.100
libavdevice 55. 10.100 / 55. 10.100
libavfilter 4. 2.100 / 4. 2.100
libswscale 2. 5.102 / 2. 5.102
libswresample 0. 18.100 / 0. 18.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from ’/var/www/vhosts/xxxxxx.com/httpdocs/save/03081956_5aa116c836015.mp4’ :
Metadata :
major_brand : mp42
minor_version : 0
compatible_brands : isommp42
creation_time : 2018-02-14 04:42:34
Duration : 00:00:00.83, start : 0.000000, bitrate : 23270 kb/s
Stream #0:0(eng) : Video : h264 (Baseline) (avc1 / 0x31637661), yuvj420p(pc, smpte170m), 1920x1080, 25370 kb/s, SAR 65536:65536 DAR 16:9, 29.73 fps, 30 tbr, 90k tbn, 180k tbc (default)
Metadata :
rotate : 90
creation_time : 2018-02-14 04:42:34
handler_name : VideoHandle
Stream #0:1(eng) : Audio : aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 96 kb/s (default)
Metadata :
creation_time : 2018-02-14 04:42:34
handler_name : SoundHandle
At least one output file must be specified
Conversion failed !With "s/.mp4$/.jpg/p"
[root@server-xxxxx-x ~]# for i in `find /var/www/vhosts/xxxxxx.com/httpdocs/save/ -type f -name "*.mp4"`; do ffmpeg -i $i `echo $i | sed -En "s/.mp4$/.jpg/p"`; done
[image2 @ 0x2c488e0] Could not get frame filename number 2 from pattern ’/var/www/vhosts/xxxxxx.com/httpdocs/save/03100013_5aa2a49bb67bc.jpg’ (either set updatefirst or use a pattern like %03d within the filename pattern)
av_interleaved_write_frame() : Invalid argument
frame= 2 fps=0.0 q=3.2 Lsize=N/A time=00:00:00.06 bitrate=N/A
video:289kB audio:0kB subtitle:0 data:0 global headers:0kB muxing overhead -100.007446%
Conversion failed ! -
Different PTS values in ffmpeg and MP4 CTS values obtained using ctts and stts
26 septembre 2023, par userDtrmI have been studying PTS values in .mp4 media files. PTS for video stream can be extracted from ffmpeg CLI using




 ffmpeg -hide_banner -i -vf "showinfo" -f null -




For a sample .mp4 I have downloaded from the internet shows the following output.




 Press [q] to stop, [?] for help
 [Parsed_showinfo_0 @ 0x3741c00] config in time_base : 1/30, frame_rate : 30/1
 [Parsed_showinfo_0 @ 0x3741c00] config out time_base : 0/0, frame_rate : 0/0
 [Parsed_showinfo_0 @ 0x3741c00] n : 0 pts : 0 pts_time:0 pos : 58852 fmt:yuv420p sar:1/1 s:1920x1080 i:P iskey:1 type:I checksum:49058BA3 plane_checksum :[E852D7DE 07E2B7D4 EA12FBD3] mean :[75 123 124] stdev :[52.7 4.8 11.7]
 [Parsed_showinfo_0 @ 0x3741c00] side data - User Data Unregistered :
 [Parsed_showinfo_0 @ 0x3741c00] UUID=dc45e9bd-e6d9-48b7-962c-d820d923eeef
 [Parsed_showinfo_0 @ 0x3741c00] User Data=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
 [Parsed_showinfo_0 @ 0x3741c00] 
 [Parsed_showinfo_0 @ 0x3741c00] color_range:tv color_space:bt709 color_primaries:bt709 color_trc:bt709
 Output #0, null, to 'pipe :' :
 Metadata :
 major_brand : mp42
 minor_version : 0
 compatible_brands : mp42mp41isomavc1
 encoder : Lavf59.27.100
 Stream #0:0(und) : Video : wrapped_avframe, yuv420p(tv, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 30 fps, 30 tbn (default)
 Metadata :
 creation_time : 2018-01-23T22:02:00.000000Z
 handler_name : L-SMASH Video Handler
 vendor_id : [0][0][0][0]
 encoder : Lavc59.37.100 wrapped_avframe
 Stream #0:1(und) : Audio : pcm_s16le, 48000 Hz, mono, s16, 768 kb/s (default)
 Metadata :
 creation_time : 2018-01-23T22:02:00.000000Z
 handler_name : L-SMASH Audio Handler
 vendor_id : [0][0][0][0]
 encoder : Lavc59.37.100 pcm_s16le
 [Parsed_showinfo_0 @ 0x3741c00] n : 1 pts : 1 pts_time:0.0333333 pos : 149037 fmt:yuv420p sar:1/1 s:1920x1080 i:P iskey:0 type:B checksum:2005D769 plane_checksum :[92BD4F7B 3501F48D 0CAA9352] mean :[75 124 124] stdev :[52.5 4.7 11.7]
 [Parsed_showinfo_0 @ 0x3741c00] color_range:tv color_space:bt709 color_primaries:bt709 color_trc:bt709
 [Parsed_showinfo_0 @ 0x3741c00] n : 2 pts : 2 pts_time:0.0666667 pos : 139805 fmt:yuv420p sar:1/1 s:1920x1080 i:P iskey:0 type:B checksum:09AFB702 plane_checksum :[3E62184D 9D0A0753 8BF09762] mean :[75 124 124] stdev :[52.4 4.6 11.5]
 [Parsed_showinfo_0 @ 0x3741c00] color_range:tv color_space:bt709 color_primaries:bt709 color_trc:bt709
 [Parsed_showinfo_0 @ 0x3741c00] n : 3 pts : 3 pts_time:0.1 pos : 157017 fmt:yuv420p sar:1/1 s:1920x1080 i:P iskey:0 type:B checksum:99F05FA9 plane_checksum :[FFA84276 7A3D6D59 0290AFCB] mean :[75 124 124] stdev :[52.2 4.5 11.3]
 [Parsed_showinfo_0 @ 0x3741c00] color_range:tv color_space:bt709 color_primaries:bt709 color_trc:bt709
 [Parsed_showinfo_0 @ 0x3741c00] n : 4 pts : 4 pts_time:0.133333 pos : 117259 fmt:yuv420p sar:1/1 s:1920x1080 i:P iskey:0 type:P checksum:00935CD8 plane_checksum :[F81E097E 5F17005D B01452FD] mean :[74 124 124] stdev :[52.2 4.5 11.3]
 [Parsed_showinfo_0 @ 0x3741c00] color_range:tv color_space:bt709 color_primaries:bt709 color_trc:bt709
 [Parsed_showinfo_0 @ 0x3741c00] n : 5 pts : 5 pts_time:0.166667 pos : 197428 fmt:yuv420p sar:1/1 s:1920x1080 i:P iskey:0 type:B checksum:30E77B4C plane_checksum :[393DAA75 DFA88599 E2164B2F] mean :[74 124 125] stdev :[52.3 4.4 11.0]
 [Parsed_showinfo_0 @ 0x3741c00] color_range:tv color_space:bt709 color_primaries:bt709 color_trc:bt709
 [Parsed_showinfo_0 @ 0x3741c00] n : 6 pts : 6 pts_time:0.2 pos : 187073 fmt:yuv420p sar:1/1 s:1920x1080 i:P iskey:0 type:B checksum:BD5C25BC plane_checksum :[CC66DD70 F4ACA5DB 955DA253] mean :[75 124 125] stdev :[52.2 4.4 10.8]




As seen above, the output shows a starting PTS of 0 for 1st frame. However, I was looking at ctts, and stts entries in the MP4 headers with the help of ParseTimingInfoInMp4.py. This shows a different PTS (e.g., 0.0667s) for the 1st frame as seen below.




 ftyp size 32
 mvhd size 108
 iods size 42
 tkhd size 92
 edts size 36
 mdhd size 32
 Trak type : b'vide'
 Video Trak Number 0 found
 video track timescale is 30
 mdhd size 32
 hdlr size 54
 vmhd size 20
 dinf size 36
 stsd size 195
 stts size 2944 ctts size 2944
 0 dts = 0.0000 s, pts = 0.0667 s, diff in ms 66.67
 1 dts = 0.0333 s, pts = 0.2000 s, diff in ms 166.67
 2 dts = 0.0667 s, pts = 0.1333 s, diff in ms 66.67
 3 dts = 0.1000 s, pts = 0.1000 s, diff in ms 0.00
 4 dts = 0.1333 s, pts = 0.1667 s, diff in ms 33.33
 5 dts = 0.1667 s, pts = 0.3333 s, diff in ms 166.67
 6 dts = 0.2000 s, pts = 0.2667 s, diff in ms 66.67
 7 dts = 0.2333 s, pts = 0.2333 s, diff in ms 0.00
 8 dts = 0.2667 s, pts = 0.3000 s, diff in ms 33.33
 9 dts = 0.3000 s, pts = 0.4333 s, diff in ms 133.33
 10 dts = 0.3333 s, pts = 0.3667 s, diff in ms 33.33




MP4Analyser shows the following entries for stss, ctts, and edts-> for video track.







The sample file I have been using can be found in Sample mp4.


Can someone please help me to understand


- 

- why the PTS values shown in ffmpeg are different from PTS derived from stss and ctts ?
- What is the correct process in deriving PTS from stts, ctts and edts entries in MP4 header ?






-
Different PTS values in ffmpeg and MP4 CTS values obtained using ctts and stss
25 septembre 2023, par userDtrmI have been studying PTS values in .mp4 media files. PTS for video stream can be extracted from ffmpeg CLI using




 ffmpeg -hide_banner -i -vf "showinfo" -f null -




For a sample .mp4 I have downloaded from the internet shows the following output.




 Press [q] to stop, [?] for help
 [Parsed_showinfo_0 @ 0x3741c00] config in time_base : 1/30, frame_rate : 30/1
 [Parsed_showinfo_0 @ 0x3741c00] config out time_base : 0/0, frame_rate : 0/0
 [Parsed_showinfo_0 @ 0x3741c00] n : 0 pts : 0 pts_time:0 pos : 58852 fmt:yuv420p sar:1/1 s:1920x1080 i:P iskey:1 type:I checksum:49058BA3 plane_checksum :[E852D7DE 07E2B7D4 EA12FBD3] mean :[75 123 124] stdev :[52.7 4.8 11.7]
 [Parsed_showinfo_0 @ 0x3741c00] side data - User Data Unregistered :
 [Parsed_showinfo_0 @ 0x3741c00] UUID=dc45e9bd-e6d9-48b7-962c-d820d923eeef
 [Parsed_showinfo_0 @ 0x3741c00] User Data=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
 [Parsed_showinfo_0 @ 0x3741c00] 
 [Parsed_showinfo_0 @ 0x3741c00] color_range:tv color_space:bt709 color_primaries:bt709 color_trc:bt709
 Output #0, null, to 'pipe :' :
 Metadata :
 major_brand : mp42
 minor_version : 0
 compatible_brands : mp42mp41isomavc1
 encoder : Lavf59.27.100
 Stream #0:0(und) : Video : wrapped_avframe, yuv420p(tv, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 30 fps, 30 tbn (default)
 Metadata :
 creation_time : 2018-01-23T22:02:00.000000Z
 handler_name : L-SMASH Video Handler
 vendor_id : [0][0][0][0]
 encoder : Lavc59.37.100 wrapped_avframe
 Stream #0:1(und) : Audio : pcm_s16le, 48000 Hz, mono, s16, 768 kb/s (default)
 Metadata :
 creation_time : 2018-01-23T22:02:00.000000Z
 handler_name : L-SMASH Audio Handler
 vendor_id : [0][0][0][0]
 encoder : Lavc59.37.100 pcm_s16le
 [Parsed_showinfo_0 @ 0x3741c00] n : 1 pts : 1 pts_time:0.0333333 pos : 149037 fmt:yuv420p sar:1/1 s:1920x1080 i:P iskey:0 type:B checksum:2005D769 plane_checksum :[92BD4F7B 3501F48D 0CAA9352] mean :[75 124 124] stdev :[52.5 4.7 11.7]
 [Parsed_showinfo_0 @ 0x3741c00] color_range:tv color_space:bt709 color_primaries:bt709 color_trc:bt709
 [Parsed_showinfo_0 @ 0x3741c00] n : 2 pts : 2 pts_time:0.0666667 pos : 139805 fmt:yuv420p sar:1/1 s:1920x1080 i:P iskey:0 type:B checksum:09AFB702 plane_checksum :[3E62184D 9D0A0753 8BF09762] mean :[75 124 124] stdev :[52.4 4.6 11.5]
 [Parsed_showinfo_0 @ 0x3741c00] color_range:tv color_space:bt709 color_primaries:bt709 color_trc:bt709
 [Parsed_showinfo_0 @ 0x3741c00] n : 3 pts : 3 pts_time:0.1 pos : 157017 fmt:yuv420p sar:1/1 s:1920x1080 i:P iskey:0 type:B checksum:99F05FA9 plane_checksum :[FFA84276 7A3D6D59 0290AFCB] mean :[75 124 124] stdev :[52.2 4.5 11.3]
 [Parsed_showinfo_0 @ 0x3741c00] color_range:tv color_space:bt709 color_primaries:bt709 color_trc:bt709
 [Parsed_showinfo_0 @ 0x3741c00] n : 4 pts : 4 pts_time:0.133333 pos : 117259 fmt:yuv420p sar:1/1 s:1920x1080 i:P iskey:0 type:P checksum:00935CD8 plane_checksum :[F81E097E 5F17005D B01452FD] mean :[74 124 124] stdev :[52.2 4.5 11.3]
 [Parsed_showinfo_0 @ 0x3741c00] color_range:tv color_space:bt709 color_primaries:bt709 color_trc:bt709
 [Parsed_showinfo_0 @ 0x3741c00] n : 5 pts : 5 pts_time:0.166667 pos : 197428 fmt:yuv420p sar:1/1 s:1920x1080 i:P iskey:0 type:B checksum:30E77B4C plane_checksum :[393DAA75 DFA88599 E2164B2F] mean :[74 124 125] stdev :[52.3 4.4 11.0]
 [Parsed_showinfo_0 @ 0x3741c00] color_range:tv color_space:bt709 color_primaries:bt709 color_trc:bt709
 [Parsed_showinfo_0 @ 0x3741c00] n : 6 pts : 6 pts_time:0.2 pos : 187073 fmt:yuv420p sar:1/1 s:1920x1080 i:P iskey:0 type:B checksum:BD5C25BC plane_checksum :[CC66DD70 F4ACA5DB 955DA253] mean :[75 124 125] stdev :[52.2 4.4 10.8]




As seen above, the output shows a starting PTS of 0 for 1st frame. However, I was looking at ctts, and stss entries in the MP4 headers with the help of ParseTimingInfoInMp4.py. This shows a different PTS (e.g., 0.0667s) for the 1st frame as seen below.




 ftyp size 32
 mvhd size 108
 iods size 42
 tkhd size 92
 edts size 36
 mdhd size 32
 Trak type : b'vide'
 Video Trak Number 0 found
 video track timescale is 30
 mdhd size 32
 hdlr size 54
 vmhd size 20
 dinf size 36
 stsd size 195
 stts size 2944 ctts size 2944
 0 dts = 0.0000 s, pts = 0.0667 s, diff in ms 66.67
 1 dts = 0.0333 s, pts = 0.2000 s, diff in ms 166.67
 2 dts = 0.0667 s, pts = 0.1333 s, diff in ms 66.67
 3 dts = 0.1000 s, pts = 0.1000 s, diff in ms 0.00
 4 dts = 0.1333 s, pts = 0.1667 s, diff in ms 33.33
 5 dts = 0.1667 s, pts = 0.3333 s, diff in ms 166.67
 6 dts = 0.2000 s, pts = 0.2667 s, diff in ms 66.67
 7 dts = 0.2333 s, pts = 0.2333 s, diff in ms 0.00
 8 dts = 0.2667 s, pts = 0.3000 s, diff in ms 33.33
 9 dts = 0.3000 s, pts = 0.4333 s, diff in ms 133.33
 10 dts = 0.3333 s, pts = 0.3667 s, diff in ms 33.33




MP4Analyser shows the following entries for stss, ctts, and edts-> for video track.







The sample file I have been using can be found in Sample mp4.


Can someone please help me to understand


- 

- why the PTS values shown in ffmpeg are different from PTS derived from stss and ctts ?
- What is the correct process in deriving PTS from stss, ctts and edts entries in MP4 header ?