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Autres articles (40)
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Keeping control of your media in your hands
13 avril 2011, parThe vocabulary used on this site and around MediaSPIP in general, aims to avoid reference to Web 2.0 and the companies that profit from media-sharing.
While using MediaSPIP, you are invited to avoid using words like "Brand", "Cloud" and "Market".
MediaSPIP is designed to facilitate the sharing of creative media online, while allowing authors to retain complete control of their work.
MediaSPIP aims to be accessible to as many people as possible and development is based on expanding the (...) -
Personnaliser en ajoutant son logo, sa bannière ou son image de fond
5 septembre 2013, parCertains thèmes prennent en compte trois éléments de personnalisation : l’ajout d’un logo ; l’ajout d’une bannière l’ajout d’une image de fond ;
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MediaSPIP v0.2
21 juin 2013, parMediaSPIP 0.2 est la première version de MediaSPIP stable.
Sa date de sortie officielle est le 21 juin 2013 et est annoncée ici.
Le fichier zip ici présent contient uniquement les sources de MediaSPIP en version standalone.
Comme pour la version précédente, il est nécessaire d’installer manuellement l’ensemble des dépendances logicielles sur le serveur.
Si vous souhaitez utiliser cette archive pour une installation en mode ferme, il vous faudra également procéder à d’autres modifications (...)
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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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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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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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