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Autres articles (27)
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Qu’est ce qu’un éditorial
21 juin 2013, parEcrivez votre de point de vue dans un article. Celui-ci sera rangé dans une rubrique prévue à cet effet.
Un éditorial est un article de type texte uniquement. Il a pour objectif de ranger les points de vue dans une rubrique dédiée. Un seul éditorial est placé à la une en page d’accueil. Pour consulter les précédents, consultez la rubrique dédiée.
Vous pouvez personnaliser le formulaire de création d’un éditorial.
Formulaire de création d’un éditorial Dans le cas d’un document de type éditorial, les (...) -
Déploiements possibles
31 janvier 2010, parDeux types de déploiements sont envisageable dépendant de deux aspects : La méthode d’installation envisagée (en standalone ou en ferme) ; Le nombre d’encodages journaliers et la fréquentation envisagés ;
L’encodage de vidéos est un processus lourd consommant énormément de ressources système (CPU et RAM), il est nécessaire de prendre tout cela en considération. Ce système n’est donc possible que sur un ou plusieurs serveurs dédiés.
Version mono serveur
La version mono serveur consiste à n’utiliser qu’une (...) -
MediaSPIP v0.2
21 juin 2013, parMediaSPIP 0.2 is the first MediaSPIP stable release.
Its official release date is June 21, 2013 and is announced here.
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 (...)
Sur d’autres sites (4203)
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Terminate ffmpeg.exe loop
5 mars 2019, par jinahoGetting a thumbnail from a RTSP source results in infinit output from ffmpeg without exiting which makes the batch script not resume.
It is basically only one line that calls the ffmpeg process like this (example) :
ffmpeg -i rtsp://192.168.1.89:554/11 -f image2 -r 1 thumb%03d.jpgThe input is user generated and for some ffmpeg is not returning a thumbnail but a warning message :
Could not find codec parameters for stream 0 (Video: h264, 1 reference frame, none(left), 1280x720, 1/180000): unspecified pixel formatAfter that instead of quiting and let the batch script resume, ffmpeg outputs :
Press [q] to stop, [?] for help
frame= 0 fps=0.0 q=0.0 size=N/A time=-577014:32:22.77 bitrate=N/A speed=N/A
frame= 0 fps=0.0 q=0.0 size=N/A time=-577014:32:22.77 bitrate=N/A speed=N/A
frame= 0 fps=0.0 q=0.0 size=N/A time=-577014:32:22.77 bitrate=N/A speed=N/A
frame= 0 fps=0.0 q=0.0 size=N/A time=-577014:32:22.77 bitrate=N/A speed=N/A
frame= 0 fps=0.0 q=0.0 size=N/A time=-577014:32:22.77 bitrate=N/A speed=N/A
frame= 0 fps=0.0 q=0.0 size=N/A time=-577014:32:22.77 bitrate=N/A speed=N/A
frame= 0 fps=0.0 q=0.0 size=N/A time=-577014:32:22.77 bitrate=N/A speed=N/A
frame= 0 fps=0.0 q=0.0 size=N/A time=-577014:32:22.77 bitrate=N/A speed=N/A
frame= 0 fps=0.0 q=0.0 size=N/A time=-577014:32:22.77 bitrate=N/A speed=N/A
frame= 0 fps=0.0 q=0.0 size=N/A time=-577014:32:22.77 bitrate=N/A speed=N/A
frame= 0 fps=0.0 q=0.0 size=N/A time=-577014:32:22.77 bitrate=N/A speed=N/A
frame= 0 fps=0.0 q=0.0 size=N/A time=-577014:32:22.77 bitrate=N/A speed=N/A
frame= 0 fps=0.0 q=0.0 size=N/A time=-577014:32:22.77 bitrate=N/A speed=N/A
frame= 0 fps=0.0 q=0.0 size=N/A time=-577014:32:22.77 bitrate=N/A speed=N/AThis goes on forever meaning that the batch script does not resume. Manual invertention is required which is not intended.
I am looking for a way to tell the script that ffmpeg has a hanging condition and make the script quit ffmpeg so it can resume. -
Understanding PTS and DTS in video frames
8 août 2015, par theateistI had fps issues when transcoding from avi to mp4(x264). Eventually the problem was in PTS and DTS values, so lines 12-15 where added before av_interleaved_write_frame function :
1. AVFormatContext* outContainer = NULL;
2. avformat_alloc_output_context2(&outContainer, NULL, "mp4", "c:\\test.mp4";
3. AVCodec *encoder = avcodec_find_encoder(AV_CODEC_ID_H264);
4. AVStream *outStream = avformat_new_stream(outContainer, encoder);
5. // outStream->codec initiation
6. // ...
7. avformat_write_header(outContainer, NULL);
8. // reading and decoding packet
9. // ...
10. avcodec_encode_video2(outStream->codec, &encodedPacket, decodedFrame, &got_frame)
11.
12. if (encodedPacket.pts != AV_NOPTS_VALUE)
13. encodedPacket.pts = av_rescale_q(encodedPacket.pts, outStream->codec->time_base, outStream->time_base);
14. if (encodedPacket.dts != AV_NOPTS_VALUE)
15. encodedPacket.dts = av_rescale_q(encodedPacket.dts, outStream->codec->time_base, outStream->time_base);
16.
17. av_interleaved_write_frame(outContainer, &encodedPacket)After reading many posts I still do not understand :
outStream->codec->time_base= 1/25 andoutStream->time_base= 1/12800. The 1st one was set by me but I cannot figure out why and who set 12800 ? I noticed that before line (7)outStream->time_base= 1/90000 and right after it it changes to 1/12800, why ?
When I transcode from avi to avi, meaning changing the line (2) toavformat_alloc_output_context2(&outContainer, NULL, "avi", "c:\\test.avi";, so before and after line (7)outStream->time_baseremains always 1/25 and not like in mp4 case, why ?- What is the difference between time_base of
outStream->codecandoutStream? - To calc the pts
av_rescale_qdoes : takes 2 time_base, multiplies their fractions in cross and then compute the pts. Why it does this in this way ? As I debugged, theencodedPacket.ptshas value incremental by 1, so why changing it if it does has value ? - At the beginning the dts value is -2 and after each rescaling it still has negative number, but despite this the video played correctly ! Shouldn’t it be positive ?
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Understanding PTS and DTS in video frames
28 juin 2017, par theateistI had fps issues when transcoding from avi to mp4(x264). Eventually the problem was in PTS and DTS values, so lines 12-15 where added before av_interleaved_write_frame function :
1. AVFormatContext* outContainer = NULL;
2. avformat_alloc_output_context2(&outContainer, NULL, "mp4", "c:\\test.mp4";
3. AVCodec *encoder = avcodec_find_encoder(AV_CODEC_ID_H264);
4. AVStream *outStream = avformat_new_stream(outContainer, encoder);
5. // outStream->codec initiation
6. // ...
7. avformat_write_header(outContainer, NULL);
8. // reading and decoding packet
9. // ...
10. avcodec_encode_video2(outStream->codec, &encodedPacket, decodedFrame, &got_frame)
11.
12. if (encodedPacket.pts != AV_NOPTS_VALUE)
13. encodedPacket.pts = av_rescale_q(encodedPacket.pts, outStream->codec->time_base, outStream->time_base);
14. if (encodedPacket.dts != AV_NOPTS_VALUE)
15. encodedPacket.dts = av_rescale_q(encodedPacket.dts, outStream->codec->time_base, outStream->time_base);
16.
17. av_interleaved_write_frame(outContainer, &encodedPacket)After reading many posts I still do not understand :
outStream->codec->time_base= 1/25 andoutStream->time_base= 1/12800. The 1st one was set by me but I cannot figure out why and who set 12800 ? I noticed that before line (7)outStream->time_base= 1/90000 and right after it it changes to 1/12800, why ?
When I transcode from avi to avi, meaning changing the line (2) toavformat_alloc_output_context2(&outContainer, NULL, "avi", "c:\\test.avi";, so before and after line (7)outStream->time_baseremains always 1/25 and not like in mp4 case, why ?- What is the difference between time_base of
outStream->codecandoutStream? - To calc the pts
av_rescale_qdoes : takes 2 time_base, multiplies their fractions in cross and then compute the pts. Why it does this in this way ? As I debugged, theencodedPacket.ptshas value incremental by 1, so why changing it if it does has value ? - At the beginning the dts value is -2 and after each rescaling it still has negative number, but despite this the video played correctly ! Shouldn’t it be positive ?
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