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Revolution of Open-source and film making towards open film making
6 octobre 2011, par
Mis à jour : Juillet 2013
Langue : English
Type : Texte
Autres articles (76)
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Le profil des utilisateurs
12 avril 2011, parChaque utilisateur dispose d’une page de profil lui permettant de modifier ses informations personnelle. Dans le menu de haut de page par défaut, un élément de menu est automatiquement créé à l’initialisation de MediaSPIP, visible uniquement si le visiteur est identifié sur le site.
L’utilisateur a accès à la modification de profil depuis sa page auteur, un lien dans la navigation "Modifier votre profil" est (...) -
Configurer la prise en compte des langues
15 novembre 2010, parAccéder à la configuration et ajouter des langues prises en compte
Afin de configurer la prise en compte de nouvelles langues, il est nécessaire de se rendre dans la partie "Administrer" du site.
De là, dans le menu de navigation, vous pouvez accéder à une partie "Gestion des langues" permettant d’activer la prise en compte de nouvelles langues.
Chaque nouvelle langue ajoutée reste désactivable tant qu’aucun objet n’est créé dans cette langue. Dans ce cas, elle devient grisée dans la configuration et (...) -
XMP PHP
13 mai 2011, parDixit Wikipedia, XMP signifie :
Extensible Metadata Platform ou XMP est un format de métadonnées basé sur XML utilisé dans les applications PDF, de photographie et de graphisme. Il a été lancé par Adobe Systems en avril 2001 en étant intégré à la version 5.0 d’Adobe Acrobat.
Étant basé sur XML, il gère un ensemble de tags dynamiques pour l’utilisation dans le cadre du Web sémantique.
XMP permet d’enregistrer sous forme d’un document XML des informations relatives à un fichier : titre, auteur, historique (...)
Sur d’autres sites (7634)
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pexpect.run() terminates before ending ffmpeg without finishing the conversion
24 novembre 2012, par DaviseinI'm working on a python script that does a custom conversion of videos via ffmpeg.
My problem is that the execution of ffmpeg stops suddenly after a bit of conversion (usually 3-4 mb out of 100mb) with a None exit code.
I'm using the pexpect library. Currently I do not check the progress but I will in a close future. It seems that I am right using pexpect regarding these questions FFMPEG and Pythons subprocess and Getting realtime output from ffmpeg to be used in progress bar (PyQt4, stdout). This is the command that I'm running (I have checked that it's exactly this one)
nice ffmpeg -i '/full/path' -s 640x360 -strict experimental -vcodec libx264
-f mp4 - coder 0 -bf 0 -refs 1 -flags2 -wpred-dct8x8 -level 30 -crf 26
-bufsize 4000k -maxrate 350k -preset medium -acodec libvo_aacenc
-ar 48000.0 -ab 128K -threads 2 -y '/full/path/out'I am using nice but I have tried also without it and the result ends up being the same.
I'm running pexpect this way :
output, exit = pexpect.run(self.command(), withexitstatus=True,\
logfile=logfile)
print output
print exitOf course I have tried the same command on the command line and it works fine.
Any clue on what might be happening ?
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Could not open codec FFMPEg
3 juin 2016, par Van GanI’m working on a Project in C++ with FFMPEG. I’m stuck on the Problem , that he codec is found but cannot be opened. Here’s my code :
codec = avcodec_find_encoder(AV_CODEC_ID_H264);
c = avcodec_alloc_context3(codec);
if (!codec) {
fprintf(stderr, "Codec not found\n");
exit(1);
}
/* open the codec */
if (avcodec_open2(c, codec,NULL) < 0)
{
fprintf(stderr, "Codec could not be opened\n");
exit(1);
}I have aleady registered all the codec in the main function. Any help would be very appeciated !
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H.264 muxing to MP4 from CCTV (HW) encoder using ffmpeg library in C / C++, how to fetch AVCodecContext::extradata
26 mai 2016, par DomI am trying to mux a video to mp4 file from packets received via SDK API of CCTV camera. The stream from CCTV seems to consist of packets of h264 I and P-frames only (no B-frames).
The problem is, that the file is not playable in Daum PotPlayer when I leave the AVCodecContext::extradata empty, however, I can play the file in VLC. If I feed the extra data (probably not correctly - I just copy the first 50 bytes from the packet received from the HW encoder), the file is playable in PotPlayer, but not in VLC.
I do not know, how to prepare the extradata properly.
The code below shows the muxing.
void WriteVideo()
{
AVFormatContext* formatContext = nullptr;
AVStream* stream = nullptr;
int ret = 0;
ret = avformat_alloc_output_context2(&formatContext, nullptr, "mp4", OUTPUT_V_FILE_NAME);
if (ret < 0)
{
fprintf(stderr, "Error occurred when allocating output context: %d\n", ret);
return;
}
stream = avformat_new_stream(formatContext, nullptr);
if (!stream)
{
avformat_free_context(formatContext);
formatContext = nullptr;
fprintf(stderr, "Error occurred creating new stream");
return;
}
stream->codec->codec_tag = 0;
if (formatContext->oformat->flags & AVFMT_GLOBALHEADER)
{
stream->codec->flags |= CODEC_FLAG_GLOBAL_HEADER;
}
stream->codec->codec_type = AVMEDIA_TYPE_VIDEO;
stream->codec->codec_id = AV_CODEC_ID_H264;
stream->codec->pix_fmt = AV_PIX_FMT_YUV420P;
stream->codec->bit_rate = 4096000; // 8192000; // 4096000; // 384000;
stream->codec->width = 1920; // 352
stream->codec->height = 1080; // 288
stream->codec->gop_size = 50;
AVRational tb;
tb.num = 1;
tb.den = 25;
stream->codec->time_base = tb;
//stream->codec->field_order = AVFieldOrder::AV_FIELD_UNKNOWN;
//stream->codec->color_primaries = AVColorPrimaries::AVCOL_PRI_BT470BG;
//stream->codec->color_trc = AVColorTransferCharacteristic::AVCOL_TRC_GAMMA22;
//stream->codec->colorspace = AVColorSpace::AVCOL_SPC_BT470BG;
//stream->codec->chroma_sample_location = AVChromaLocation::AVCHROMA_LOC_CENTER;
AVRational aratio;
aratio.num = 1;
aratio.den = 1;
stream->codec->sample_aspect_ratio = aratio;
// stream->codec->delay = 0;
// stream->codec->color_range = AVColorRange::AVCOL_RANGE_MPEG;
av_dump_format(formatContext, 0, formatContext->filename, 1);
if (!(formatContext->oformat->flags & AVFMT_NOFILE))
{
if (avio_open(&formatContext->pb, formatContext->filename, AVIO_FLAG_WRITE) < 0)
{
avformat_free_context(formatContext);
formatContext = nullptr;
fprintf(stderr, "Error occurred when opening output file.");
return;
}
}
avformat_write_header(formatContext, nullptr);
int frameIdx = 0;
int pts = 0;
int dts = 0;
int pkt_pos = 0;
int size = static_cast<int>(tmpRawFrameBuffer.size());
AVPacket pkt = { 0 };
av_init_packet(&pkt);
while (frameIdx < size)
{
pkt.data = tmpRawFrameBuffer[frameIdx];
pkt.size = tmpRawFrameSizes[frameIdx];
// debug purphose start
FILE* f;
char filename[MAX_PATH];
sprintf_s(filename, MAX_PATH, OUTPUT_PACKET_FILE_PATTERN_NAME, frameIdx);
auto err = fopen_s(&f, filename, "wb");
if (err != 0)
{
fprintf(stderr, "Could not open %s\n", OUTPUT_V_FILE_NAME);
exit(1);
}
fflush(stdout);
fwrite(pkt.data, 1, pkt.size, f);
fclose(f);
// debug purphose end
if (tmpRawFrameTypes[frameIdx] == VIDEO_I_FRAME)
{
pkt.flags |= AV_PKT_FLAG_KEY;
stream->codec->extradata_size = 50;
stream->codec->extradata = (uint8_t*)av_malloc(stream->codec->extradata_size);
memcpy(stream->codec->extradata, pkt.data, stream->codec->extradata_size);
}
pkt.pts = pts++;
pkt.dts = dts++;
/* rescale output packet timestamp values from codec to stream timebase */
// av_packet_rescale_ts(&pkt, stream->codec->time_base, stream->time_base);
pkt.pts = av_rescale_q(pkt.pts, stream->codec->time_base, stream->time_base);
pkt.dts = av_rescale_q(pkt.dts, stream->codec->time_base, stream->time_base);
pkt.duration = 512; // should be calculated (derived from FPS 25, and 12800)
pkt.pos = -1;
pkt.stream_index = stream->index;
auto ret = av_write_frame(formatContext, &pkt);
if (ret < 0)
{
fprintf(stderr, "Error while writing video frame: %d\n", ret);
break;
}
av_packet_unref(&pkt);
++frameIdx;
}
if (formatContext)
{
av_write_trailer(formatContext);
if (!(formatContext->oformat->flags & AVFMT_NOFILE)) avio_close(formatContext->pb); // close the output file
avformat_free_context(formatContext);
formatContext = nullptr;
}
}
</int>It seems, the packet from camera (buffered in tmpRawFrameBuffer vector) contains some headers, but I am not able to parse them, I do not understand the meaning of the header.
The first bytes of the I-frame packet looks like the dump bellow :
00 00 01 FC 02 19 F0 87 A0 23 73 41 B6 C0 01 00
00 00 00 01 67 4D 00 2A 95 A8 1E 00 89 F9 61 00
00 03 00 01 00 00 03 00 32 84 00 00 00 01 68 EE
3C 80 00 00 00 01 06 E5 01 19 80 00 00 00 01 65
B8 00 00 08 C7 B0 23 FF F7 80 EE FE 63 B6 FB F5
...The first bytes of the first P-frame :
00 00 01 FD E5 24 00 00 00 00 00 01 61 E0 22 27
FF D6 B0 D7 A4 2B 71 6B 19 C5 87 CA BB 8B BF 60
14 59 B4 00 CC BC 0F C0 9E FD 84 B5 FB C4 83 DB
5A 8B 80 FC EC D6 33 6D DE 10 96 6F 31 41 86 5C
D4 22 F9 33 48 5B CE 77 38 17 0C D6 DD C7 6C E8
...first bytes of next P-frame :
00 00 01 FD 5E 2F 00 00 00 00 00 01 61 E0 42 2F
FF E7 06 DD 3C 66 26 15 94 93 7A F1 30 8A 6D B8
AD DD 6B 0F 38 89 1D 1B 5C AC 44 6A D7 D1 21 3B
E2 29 F8 14 BB 98 1C 06 4D B6 10 BB DB B9 CA 4F
0B ED B1 A9 06 78 8C EC 06 6D 9F 4F 79 0C 35 5B
......
begining of next I-frame :
00 00 01 FC 02 19 F0 87 A2 23 73 41 75 89 01 00
00 00 00 01 67 4D 00 2A 95 A8 1E 00 89 F9 61 00
00 03 00 01 00 00 03 00 32 84 00 00 00 01 68 EE
3C 80 00 00 00 01 06 E5 01 1B 80 00 00 00 01 65
B8 00 00 0F 07 F0 7F F6 6C 69 43 0F F0 28 DF 97
...Does anybody know, how to fill correctly the extradata ? I just made a copy of first 50 bytes, but it seems, this is not correct.
Probably the headers are (AUD)(SPS)(PPS)(I-Slice)(PPS)(P-Slice)(PPS)(P-Slice) ... (AUD)(SPS)(PPS)(I-Slice) (http://stackoverflow.com/a/20686267/1699328), however, I do not know, how to extract data for the
stream->codec->extradataI tried to get some inspiration in this post H.264 muxed to MP4 using libavformat not playing back, but I am not able to figure out what are values of spsFrameLen, ppsFrameLen and spsFrame.
The result of the muxer (first and last bytes of the mp4 file) :
00 00 00 20 66 74 79 70 69 73 6F 6D 00 00 02 00
69 73 6F 6D 69 73 6F 32 61 76 63 31 6D 70 34 31
00 00 00 08 66 72 65 65 00 26 2E 6D 6D 64 61 74
00 00 00 0D FC 02 19 F0 87 A0 23 73 41 B6 C0 01
00 00 00 00 16 67 4D 00 2A 95 A8 1E 00 89 F9 61
00 00 03 00 01 00 00 03 00 32 84 00 00 00 04 68
EE 3C 80 00 00 00 05 06 E5 01 19 80 00 01 C0 87
65 B8 00 00 08 C7 B0 23 FF F7 80 EE FE 63 B6 FB
F5 97 A8 6B 48 39 61 99 FD 99 27 41 F2 78 54 EE
D1 38 8E E8 18 DD 05 E4 BA F4 EB 69 CF 91 5C 34
...
...
...
95 B8 D8 D4 C3 AF A1 BA AC 28 F0 D4 D4 7C 48 9A
0C A6 8C 4C 98 00 00 05 1E 6D 6F 6F 76 00 00 00
6C 6D 76 68 64 00 00 00 00 00 00 00 00 00 00 00
00 00 00 03 E8 00 00 13 B0 00 01 00 00 01 00 00
00 00 00 00 00 00 00 00 00 00 01 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 01 00 00 00 00 00
00 00 00 00 00 00 00 00 00 40 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 02 00 00 04 48 74 72 61
6B 00 00 00 5C 74 6B 68 64 00 00 00 03 00 00 00
00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 13
B0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00
00 40 00 00 00 07 80 00 00 04 38 00 00 00 00 00
24 65 64 74 73 00 00 00 1C 65 6C 73 74 00 00 00
00 00 00 00 01 00 00 13 B0 00 00 00 00 00 01 00
00 00 00 03 C0 6D 64 69 61 00 00 00 20 6D 64 68
64 00 00 00 00 00 00 00 00 00 00 00 00 00 00 32
00 00 00 FC 00 55 C4 00 00 00 00 00 2D 68 64 6C
72 00 00 00 00 00 00 00 00 76 69 64 65 00 00 00
00 00 00 00 00 00 00 00 00 56 69 64 65 6F 48 61
6E 64 6C 65 72 00 00 00 03 6B 6D 69 6E 66 00 00
00 14 76 6D 68 64 00 00 00 01 00 00 00 00 00 00
00 00 00 00 00 24 64 69 6E 66 00 00 00 1C 64 72
65 66 00 00 00 00 00 00 00 01 00 00 00 0C 75 72
6C 20 00 00 00 01 00 00 03 2B 73 74 62 6C 00 00
00 93 73 74 73 64 00 00 00 00 00 00 00 01 00 00
00 83 61 76 63 31 00 00 00 00 00 00 00 01 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 07 80
04 38 00 48 00 00 00 48 00 00 00 00 00 00 00 01
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 18 FF FF 00 00 00 2D 61 76 63 43 01 4D 00 2A
FF E1 00 16 67 4D 00 2A 95 A8 1E 00 89 F9 61 00
00 03 00 01 00 00 03 00 32 84 01 00 04 68 EE 3C
80 00 00 00 18 73 74 74 73 00 00 00 00 00 00 00
01 00 00 00 7E 00 00 02 00 00 00 00 1C 73 74 73
73 00 00 00 00 00 00 00 03 00 00 00 01 00 00 00
33 00 00 00 65 00 00 00 34 73 74 73 63 00 00 00
00 00 00 00 03 00 00 00 01 00 00 00 3B 00 00 00
01 00 00 00 02 00 00 00 37 00 00 00 01 00 00 00
03 00 00 00 0C 00 00 00 01 00 00 02 0C 73 74 73
7A 00 00 00 00 00 00 00 00 00 00 00 7E 00 01 C0
C7 00 00 24 EE 00 00 2F 67 00 00 1D 83 00 00 2E
8F 00 00 30 B6 00 00 2F 44 00 00 2F 50 00 00 34
6B 00 00 30 BE 00 00 31 0C 00 00 31 E7 00 00 30
EA 00 00 31 4E 00 00 31 A8 00 00 32 21 00 00 31
E6 00 00 31 B5 00 00 31 14 00 00 31 AF 00 00 31
9D 00 00 33 60 00 00 32 11 00 00 32 4C 00 00 31
F0 00 00 32 91 00 00 43 43 00 00 44 29 00 00 44
EC 00 00 44 20 00 00 44 86 00 00 45 AD 00 00 47
47 00 00 46 9F 00 00 46 D9 00 00 47 BE 00 00 48
CD 00 00 3E 50 00 00 40 98 00 00 41 0E 00 00 40
43 00 00 41 07 00 00 41 BB 00 00 41 FF 00 00 30
5E 00 00 33 C7 00 00 34 B7 00 00 33 F1 00 00 33
0D 00 00 32 DB 00 01 89 86 00 00 3B E1 00 00 3C
55 00 00 3C 64 00 00 3C B7 00 00 3C FD 00 00 3E
54 00 00 3E C5 00 00 3E 1C 00 00 3E 94 00 00 3E
44 00 00 3E D7 00 00 3F CC 00 00 3E D6 00 00 40
00 00 00 40 4D 00 00 40 04 00 00 3F A9 00 00 40
82 00 00 41 0F 00 00 41 64 00 00 41 E5 00 00 42
1E 00 00 42 2C 00 00 42 80 00 00 42 4D 00 00 43
9F 00 00 43 DA 00 00 44 45 00 00 44 21 00 00 44
B7 00 00 45 22 00 00 45 E3 00 00 45 BF 00 00 46
18 00 00 47 4B 00 00 45 05 00 00 47 34 00 00 46
60 00 00 46 97 00 00 46 66 00 00 46 29 00 00 46
38 00 00 47 1D 00 00 47 42 00 00 47 18 00 00 47
13 00 00 46 52 00 00 47 48 00 00 46 F8 00 01 BE
E3 00 00 3F 56 00 00 3B 32 00 00 38 F8 00 00 37
56 00 00 36 2D 00 00 35 DA 00 00 34 6B 00 00 3E
BE 00 00 3E B5 00 00 3F 33 00 00 3F AC 00 00 3F
38 00 00 42 32 00 01 1B DC 00 01 80 50 00 01 14
06 00 00 C2 BB 00 00 96 12 00 00 6D EC 00 00 54
E6 00 00 3A AC 00 00 32 00 00 00 2F 0A 00 00 2D
F1 00 00 1B 7F 00 00 00 1C 73 74 63 6F 00 00 00
00 00 00 00 03 00 00 00 30 00 0F DD AB 00 1F 7D
9E 00 00 00 62 75 64 74 61 00 00 00 5A 6D 65 74
61 00 00 00 00 00 00 00 21 68 64 6C 72 00 00 00
00 00 00 00 00 6D 64 69 72 61 70 70 6C 00 00 00
00 00 00 00 00 00 00 00 00 2D 69 6C 73 74 00 00
00 25 A9 74 6F 6F 00 00 00 1D 64 61 74 61 00 00
00 01 00 00 00 00 4C 61 76 66 35 37 2E 32 33 2E
31 30 30Thanks a lot for any advices.
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