Recherche avancée
Autres articles (13)
-
Changer son thème graphique
22 février 2011, parLe thème graphique ne touche pas à la disposition à proprement dite des éléments dans la page. Il ne fait que modifier l’apparence des éléments.
Le placement peut être modifié effectivement, mais cette modification n’est que visuelle et non pas au niveau de la représentation sémantique de la page.
Modifier le thème graphique utilisé
Pour modifier le thème graphique utilisé, il est nécessaire que le plugin zen-garden soit activé sur le site.
Il suffit ensuite de se rendre dans l’espace de configuration du (...) -
Encoding and processing into web-friendly formats
13 avril 2011, parMediaSPIP automatically converts uploaded files to internet-compatible formats.
Video files are encoded in MP4, Ogv and WebM (supported by HTML5) and MP4 (supported by Flash).
Audio files are encoded in MP3 and Ogg (supported by HTML5) and MP3 (supported by Flash).
Where possible, text is analyzed in order to retrieve the data needed for search engine detection, and then exported as a series of image files.
All uploaded files are stored online in their original format, so you can (...) -
Other interesting software
13 avril 2011, parWe don’t claim to be the only ones doing what we do ... and especially not to assert claims to be the best either ... What we do, we just try to do it well and getting better ...
The following list represents softwares that tend to be more or less as MediaSPIP or that MediaSPIP tries more or less to do the same, whatever ...
We don’t know them, we didn’t try them, but you can take a peek.
Videopress
Website : http://videopress.com/
License : GNU/GPL v2
Source code : (...)
Sur d’autres sites (4351)
-
ffmpeg how to concat and COMPRESS at the same time ? [closed]
17 juin 2022, par Alex NoxConcat command :


ffmpeg -f concat -safe 0 -i list.txt -c copy output.mp4


Content of list.txt


file '2022-03-26-1.mp4'

file '2022-03-26-2.mp4'


The following above seems working, but I want to compress files at the same time, so I type :


ffmpeg concat -an -i list.txt -crf 23 -c:v libx264 out.mp4


But it doesn't work ? Why ?


-
How to suppress `ffmpeg` output logging when using H.265 codec in quiet mode
5 avril 2022, par user223364When I run :-


ffmpeg -v quiet -i "${INPUT}" -c:v libx265 -crf 23 "${OUTPUT}"


I'm still getting output from the command even though the
loglevelis set tosilent(see the example of the output below)

x265 [info]: HEVC encoder version 3.5+20-17839cc0d
x265 [info]: build info [Mac OS X][clang 11.0.0][64 bit] 8bit+10bit+12bit
x265 [info]: using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
x265 [info]: Main profile, Level-3 (Main tier)
x265 [info]: Thread pool created using 4 threads
x265 [info]: Slices : 1
x265 [info]: frame threads / pool features : 2 / wpp(9 rows)
x265 [warning]: Source height < 720p; disabling lookahead-slices
x265 [info]: Coding QT: max CU size, min CU size : 64 / 8
x265 [info]: Residual QT: max TU size, max depth : 32 / 1 inter / 1 intra
x265 [info]: ME / range / subpel / merge : hex / 57 / 2 / 3
x265 [info]: Keyframe min / max / scenecut / bias : 25 / 250 / 40 / 5.00
x265 [info]: Lookahead / bframes / badapt : 20 / 4 / 2
x265 [info]: b-pyramid / weightp / weightb : 1 / 1 / 0
x265 [info]: References / ref-limit cu / depth : 3 / off / on
x265 [info]: AQ: mode / str / qg-size / cu-tree : 2 / 1.0 / 32 / 1
x265 [info]: Rate Control / qCompress : CRF-23.0 / 0.60
x265 [info]: tools: rd=3 psy-rd=2.00 early-skip rskip mode=1 signhide tmvp
x265 [info]: tools: b-intra strong-intra-smoothing deblock sao


I'm using
v5offfmpeg

ffmpeg version 5.0-tessus https://evermeet.cx/ffmpeg/ Copyright (c) 2000-2022 the FFmpeg developers
 built with Apple clang version 11.0.0 (clang-1100.0.33.17)


How do I get
ffmpegto be really quiet ?

-
How to send ffmpeg AVPacket through WebRTC (using libdatachannel)
14 novembre 2022, par mikeI'm encoding a video frame with the
ffmpeglibraries, generating anAVPacketwith compressed data.

Thanks to some recent advice here on S/O, I am trying to send that frame over a network using the
WebRTClibrarylibdatachannel, specifically by adapting the example here :

https://github.com/paullouisageneau/libdatachannel/tree/master/examples/streamer

I am seeing problems inside
h264rtppacketizer.cpp(part of the library, not the example) which are almost certainly to do with how I'm providing the sample data.
(I don't think that this is anything to do with libdatachannel specifically, it will be an issue with what I'm sending)

The example code reads each encoded frame from a file, and populates a
sampleby setting the content of the file to the contents of the file :

sample = *reinterpret_cast *>(&fileContents);

sampleis just astd::vector<byte>;</byte>

I have naively copied the contents of an
AVPacket->datapointer into thesamplevector :

sample.resize(pkt->size);
memcpy(sample.data(), pkt->data, pkt->size * sizeof(std::byte)); 


but the packetizer is falling over when trying to get length values out of that data.
Specifically, in the following code, the first iteration gets a length of 1, but the second, looking up index 5, gives 1119887324. This is way too big for my data, which is only 3526 bytes (the whole frame is a single colour so likely to be small once encoded) :


while (index < message->size()) {
assert(index + 4 < message->size());
auto lengthPtr = (uint32_t *)(message->data() + index);
uint32_t length = ntohl(*lengthPtr);
auto naluStartIndex = index + 4;
auto naluEndIndex = naluStartIndex + length;
assert(naluEndIndex <= message->size()); 
 
auto begin = message->begin() + naluStartIndex;
auto end = message->begin() + naluEndIndex;
nalus->push_back(std::make_shared<nalunit>(begin, end));
index = naluEndIndex;
}
</nalunit>

Here is a dump of


uint32_t length = ntohl(*lengthPtr);


for the first few elements of the message (
*lengthPtrin parentheses) :

[2022-03-29 15:12:01.182] [info] index 0: 1 (16777216)
[2022-03-29 15:12:01.183] [info] index 1: 359 (1728118784)
[2022-03-29 15:12:01.184] [info] index 2: 91970 (1114046720)
[2022-03-29 15:12:01.186] [info] index 3: 23544512 (3225577217)
[2022-03-29 15:12:01.186] [info] index 4: 1732427807 (532693607)
[2022-03-29 15:12:01.187] [info] index 5: 1119887324 (3693068354)
[2022-03-29 15:12:01.188] [info] index 6: 3223313413 (98312128)
[2022-03-29 15:12:01.188] [info] index 7: 534512896 (384031)
[2022-03-29 15:12:01.188] [info] index 8: 3691315291 (1526728156)
[2022-03-29 15:12:01.189] [info] index 9: 83909537 (2707095557)
[2022-03-29 15:12:01.189] [info] index 10: 6004992 (10574592)
[2022-03-29 15:12:01.190] [info] index 11: 1537277952 (41307)
[2022-03-29 15:12:01.190] [info] index 12: 2701131779 (50331809)
[2022-03-29 15:12:01.192] [info] index 13: 768 (196608)


(I know I should post a complete sample, I am working on it)


- 

-
I am fairly sure I am just missing something basic. E.g. am I supposed to do something with the
AVPacketside_data, does AVPacket have or miss some header info ?

-
If I just
fwritethepkt->datafor a single frame to disk, I can read the codec information withffprobe:







Input #0, h264, from 'encodedOut.h264':
Duration: N/A, bitrate: N/A
Stream #0:0: Video: h264 (Constrained Baseline), yuv420p(progressive), 1280x720, 30 tbr, 1200k tbn


Update : This issue is solved by changing the
H264RtpPacketizerseparator setting fromH264RtpPacketizer::Separator::LengthtoH264RtpPacketizer::Separator::LongStartSequence, many thanks to author of libdatachannel paullouisageneau (see answer below)

I have issues related to settings for the
libx264encoder, but can happily encode withh264_nvencandh264_mf

-
Syndiquer tout le site
