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Autres articles (55)
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Personnaliser les catégories
21 juin 2013, parFormulaire de création d’une catégorie
Pour ceux qui connaissent bien SPIP, une catégorie peut être assimilée à une rubrique.
Dans le cas d’un document de type catégorie, les champs proposés par défaut sont : Texte
On peut modifier ce formulaire dans la partie :
Administration > Configuration des masques de formulaire.
Dans le cas d’un document de type média, les champs non affichés par défaut sont : Descriptif rapide
Par ailleurs, c’est dans cette partie configuration qu’on peut indiquer le (...) -
Participer à sa documentation
10 avril 2011La documentation est un des travaux les plus importants et les plus contraignants lors de la réalisation d’un outil technique.
Tout apport extérieur à ce sujet est primordial : la critique de l’existant ; la participation à la rédaction d’articles orientés : utilisateur (administrateur de MediaSPIP ou simplement producteur de contenu) ; développeur ; la création de screencasts d’explication ; la traduction de la documentation dans une nouvelle langue ;
Pour ce faire, vous pouvez vous inscrire sur (...) -
Encodage et transformation en formats lisibles sur Internet
10 avril 2011MediaSPIP transforme et ré-encode les documents mis en ligne afin de les rendre lisibles sur Internet et automatiquement utilisables sans intervention du créateur de contenu.
Les vidéos sont automatiquement encodées dans les formats supportés par HTML5 : MP4, Ogv et WebM. La version "MP4" est également utilisée pour le lecteur flash de secours nécessaire aux anciens navigateurs.
Les documents audios sont également ré-encodés dans les deux formats utilisables par HTML5 :MP3 et Ogg. La version "MP3" (...)
Sur d’autres sites (9272)
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ffmpeg : unable to use hardware encoder h264_rkmpp with software decoded ATSC OTA transmission
20 août 2020, par Brad BruggemannWhen attempting to hardware encode to h264 using the Rockchip MPP encoder h264_rkmpp from an ATSC source, FFMPEG errors out with :


"Impossible to convert between the formats supported by the filter 'Parsed_null_0' and the filter 'auto_scaler_0'"


The sample file used in this example can be downloaded here : https://transfer.sh/BRMej/out.ts


The full command used and resulting output is as follows :


$ ffmpeg -loglevel 48 -c:v mpeg2video -f mpegts -i out.ts -f mp4 -c:v h264_rkmpp -c:a libfdk_aac -preset ultrafast -mbd rd -copyinkf -flags +ilme+ildct -fflags +genpts out.mp4 -y

ffmpeg version N-98732-g9f702fc8f4 Copyright (c) 2000-2020 the FFmpeg developers
 built with gcc 9.3.0 (GCC)
 configuration: --prefix=/usr/local --extra-libs='-lpthread -lm' --enable-hardcoded-tables --enable-gpl --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264 --enable-rkmpp --enable-version3 --enable-libdrm --enable-libx265 --enable-nonfree
 libavutil 56. 58.100 / 56. 58.100
 libavcodec 58.100.100 / 58.100.100
 libavformat 58. 51.100 / 58. 51.100
 libavdevice 58. 11.101 / 58. 11.101
 libavfilter 7. 87.100 / 7. 87.100
 libswscale 5. 8.100 / 5. 8.100
 libswresample 3. 8.100 / 3. 8.100
 libpostproc 55. 8.100 / 55. 8.100

Splitting the commandline.
Reading option '-loglevel' ... matched as option 'loglevel' (set logging level) with argument '48'.
Reading option '-c:v' ... matched as option 'c' (codec name) with argument 'mpeg2video'.
Reading option '-f' ... matched as option 'f' (force format) with argument 'mpegts'.
Reading option '-i' ... matched as input url with argument 'out.ts'.
Reading option '-f' ... matched as option 'f' (force format) with argument 'mp4'.
Reading option '-c:v' ... matched as option 'c' (codec name) with argument 'h264_rkmpp'.
Reading option '-c:a' ... matched as option 'c' (codec name) with argument 'libfdk_aac'.
Reading option '-preset' ... matched as AVOption 'preset' with argument 'ultrafast'.
Reading option '-mbd' ... matched as AVOption 'mbd' with argument 'rd'.
Reading option '-copyinkf' ... matched as option 'copyinkf' (copy initial non-keyframes) with argument '1'.
Reading option '-flags' ... matched as AVOption 'flags' with argument '+ilme+ildct'.
Reading option '-fflags' ... matched as AVOption 'fflags' with argument '+genpts'.
Reading option 'out.mp4' ... matched as output url.
Reading option '-y' ... matched as option 'y' (overwrite output files) with argument '1'.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option loglevel (set logging level) with argument 48.
Applying option y (overwrite output files) with argument 1.
Successfully parsed a group of options.
Parsing a group of options: input url out.ts.
Applying option c:v (codec name) with argument mpeg2video.
Applying option f (force format) with argument mpegts.
Successfully parsed a group of options.
Opening an input file: out.ts.
[mpegts @ 0xaaaaec9acf20] Opening 'out.ts' for reading
[file @ 0xaaaaec9ad830] Setting default whitelist 'file,crypto,data'
[mpegts @ 0xaaaaec9acf20] Before avformat_find_stream_info() pos: 0 bytes read:5013504 seeks:1 nb_streams:0
[mpegts @ 0xaaaaec9acf20] stream=0 stream_type=0 pid=31 prog_reg_desc=
[mpegts @ 0xaaaaec9acf20] probing stream 0 pp:2500
[mpegts @ 0xaaaaec9acf20] Probe with size=204749, packets=1 detected mpegvideo with score=25
[mpegts @ 0xaaaaec9acf20] probed stream 0
[mpegts @ 0xaaaaec9acf20] stream=1 stream_type=0 pid=34 prog_reg_desc=
[mpeg2video @ 0xaaaaec9cb7d0] Format yuv420p chosen by get_format().
[mpegts @ 0xaaaaec9acf20] probing stream 1 pp:2500
[mpegts @ 0xaaaaec9acf20] Probe with size=7680, packets=1 detected ac3 with score=25
[mpegts @ 0xaaaaec9acf20] probed stream 1
[mpegts @ 0xaaaaec9acf20] max_analyze_duration 5000000 reached at 5005000 microseconds st:0
[mpegts @ 0xaaaaec9acf20] PES packet size mismatch
[mpegts @ 0xaaaaec9acf20] Packet corrupt (stream = 1, dts = 2632691898).
[mpegts @ 0xaaaaec9acf20] After avformat_find_stream_info() pos: 0 bytes read:9195664 seeks:3 frames:306
Input #0, mpegts, from 'out.ts':
 Duration: 00:00:18.42, start: 29234.532200, bitrate: 5406 kb/s
 Stream #0:0[0x31], 152, 1/90000: Video: mpeg2video (Main), 1 reference frame, yuv420p(yuv420p) (tv, bt709, top first, left), 1920x1080 [SAR 1:1 DAR 16:9], 0/1, Closed Captions, 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc
 Side data:
 cpb: bitrate max/min/avg: 15000000/0/0 buffer size: 7995392 vbv_delay: N/A
 Stream #0:1[0x34], 154, 1/90000: Audio: ac3, 48000 Hz, 5.1(side), fltp, 384 kb/s
Successfully opened the file.
Parsing a group of options: output url out.mp4.
Applying option f (force format) with argument mp4.
Applying option c:v (codec name) with argument h264_rkmpp.
Applying option c:a (codec name) with argument libfdk_aac.
Applying option copyinkf (copy initial non-keyframes) with argument 1.
Successfully parsed a group of options.
Opening an output file: out.mp4.
Codec AVOption preset (Set the encoding preset (cf. x264 --fullhelp)) specified for output file #0 (out.mp4) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some encoder which was not actually used for any stream.
[file @ 0xaaaaec9cef20] Setting default whitelist 'file,crypto,data'
Successfully opened the file.
detected 4 logical cores
Stream mapping:
 Stream #0:0 -> #0:0 (mpeg2video (native) -> h264 (h264_rkmpp))
 Stream #0:1 -> #0:1 (ac3 (native) -> aac (libfdk_aac))
Press [q] to stop, [?] for help
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[mpeg2video @ 0xaaaaec9cf7b0] Format yuv420p chosen by get_format().
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[mpeg2video @ 0xaaaaec9cf7b0] Skipping B slice due to open GOP
 Last message repeated 67 times
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[mpeg2video @ 0xaaaaec9cf7b0] Skipping B slice due to open GOP
 Last message repeated 67 times
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[graph 0 input from stream 0:0 @ 0xaaaaecd8c290] Setting 'video_size' to value '1920x1080'
[graph 0 input from stream 0:0 @ 0xaaaaecd8c290] Setting 'pix_fmt' to value '0'
[graph 0 input from stream 0:0 @ 0xaaaaecd8c290] Setting 'time_base' to value '1/90000'
[graph 0 input from stream 0:0 @ 0xaaaaecd8c290] Setting 'pixel_aspect' to value '1/1'
[graph 0 input from stream 0:0 @ 0xaaaaecd8c290] Setting 'frame_rate' to value '30000/1001'
[graph 0 input from stream 0:0 @ 0xaaaaecd8c290] w:1920 h:1080 pixfmt:yuv420p tb:1/90000 fr:30000/1001 sar:1/1
[format @ 0xaaaaecadf950] Setting 'pix_fmts' to value 'drm_prime'
[auto_scaler_0 @ 0xaaaaecd80070] Setting 'flags' to value 'bicubic'
[auto_scaler_0 @ 0xaaaaecd80070] w:iw h:ih flags:'bicubic' interl:0
[format @ 0xaaaaecadf950] auto-inserting filter 'auto_scaler_0' between the filter 'Parsed_null_0' and the filter 'format'
Impossible to convert between the formats supported by the filter 'Parsed_null_0' and the filter 'auto_scaler_0'
Error reinitializing filters!
Failed to inject frame into filter network: Function not implemented
Error while processing the decoded data for stream #0:0
[AVIOContext @ 0xaaaaec9cf190] Statistics: 0 seeks, 0 writeouts
[AVIOContext @ 0xaaaaec9b5900] Statistics: 9556112 bytes read, 3 seeks
Conversion failed!


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doc : Fix spelling of ’Transmission’
26 mai 2015, par Sebastian Ramacher -
Simulating MPEG1/2 transmission over a noisy channel [on hold]
17 novembre 2015, par StepTNTThe question may sound out of scope here but this is my last resource.
I need to write a software that does :
- Get an uncompressed video from disk
- Compress it into MPEG-1 or MPEG-2 being able to change quantization matrix, GOP size and/or macroblock size for DCT/motion search
- Apply a repetition code to add redundancy
- Simulate transmission over a noisy channel with given error rate
- Reconstruct the original stream from the repetition code
- Decode the video and compare it with the original one by gathering stats like frame-by-frame difference, file size and stuff like that
This should by done by a nice GUI to show the input and output videos, alongside their frame difference.
Given what I need to do, I can write some requirements :
- An encoder which allows me to change some of the parameters (needed for point 2)
- A language that allows me to work at bit level (needed for points 3 and 5)
- A language that allows me to build a nice GUI using a designer (GUI is not the core of the project so I can’t afford wasting time by writing one)
So far my searches have led to mixed results that are not giving me enough resources to start.
My first find was this MATLAB project which implements MPEG and has some parameters that can be tweaked (like quantization matrix and GOP pattern for example).
The problem here is that I don’t know MATLAB at all, so I have no idea on how to link everything and build a GUI.So the next step was to move to JAVA, and I found a LOT of FFMPEG wrappers, but none seems to allow me to set the parameters that I need. My last try was with Xuggler but the Wiki is down and the documentation does not talk about what I need. Plus, JAVA doesn’t work at bit level so I’d have issues applying the repetition code.
Failing with JAVA led me to C# and DirectShowNet, but the documentation is quite lacking and I don’t know how to start because I didn’t find anything related to setting the parameters that I need using Filters.
The question now is : is there any language/framework/platform that allows me to do what I need without having to deal with pure C/C++ ?
I’d expect a lot of stuff on this matter since we’re talking about well known codecs, still I’m having a hard time finding what I need.
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