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Autres articles (111)
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Gestion générale des documents
13 mai 2011, parMédiaSPIP ne modifie jamais le document original mis en ligne.
Pour chaque document mis en ligne il effectue deux opérations successives : la création d’une version supplémentaire qui peut être facilement consultée en ligne tout en laissant l’original téléchargeable dans le cas où le document original ne peut être lu dans un navigateur Internet ; la récupération des métadonnées du document original pour illustrer textuellement le fichier ;
Les tableaux ci-dessous expliquent ce que peut faire MédiaSPIP (...) -
Les vidéos
21 avril 2011, parComme les documents de type "audio", Mediaspip affiche dans la mesure du possible les vidéos grâce à la balise html5 .
Un des inconvénients de cette balise est qu’elle n’est pas reconnue correctement par certains navigateurs (Internet Explorer pour ne pas le nommer) et que chaque navigateur ne gère en natif que certains formats de vidéos.
Son avantage principal quant à lui est de bénéficier de la prise en charge native de vidéos dans les navigateur et donc de se passer de l’utilisation de Flash et (...) -
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 (...)
Sur d’autres sites (8046)
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Segfault while trying to fill the yuv image for rtsp streaming
21 septembre 2016, par tankyxI am capturing the video stream from a window, and I want to restream it to my rtsp proxy server. However, it seems I can’t write the frame properly, but I can show the said frame in a SDL window. Here is my code :
int StreamHandler::storeStreamData()
{
// Allocate video frame
pFrame = av_frame_alloc();
// Allocate an AVFrame structure
pFrameRGB = av_frame_alloc();
if (pFrameRGB == NULL)
throw myExceptions("Error : Can't alloc the frame.");
// Determine required buffer size and allocate buffer
numBytes = avpicture_get_size(AV_PIX_FMT_YUV420P, pCodecCtx->width,
pCodecCtx->height);
buffer = (uint8_t *)av_malloc(numBytes * sizeof(uint8_t));
// Assign appropriate parts of buffer to image planes in pFrameRGB
avpicture_fill((AVPicture *)pFrameRGB, buffer, AV_PIX_FMT_YUV420P,
pCodecCtx->width, pCodecCtx->height);
//InitSdlDrawBack();
// initialize SWS context for software scaling
sws_ctx = sws_getContext(pCodecCtx->width,
pCodecCtx->height,
pCodecCtx->pix_fmt,
pCodecCtx->width,
pCodecCtx->height,
pCodecCtx->pix_fmt,
SWS_LANCZOS,
NULL,
NULL,
NULL
);
SetPixelArray();
FfmpegEncoder enc("rtsp://127.0.0.1:1935/live/myStream");
i = 0;
while (av_read_frame(pFormatCtx, &packet) >= 0) {
if (packet.stream_index == videoindex) {
// Decode video frame
avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);
if (frameFinished) {
i++;
//DrawFrame();
sws_scale(sws_ctx, (uint8_t const * const *)pFrame->data,
pFrame->linesize, 0, pCodecCtx->height,
pFrameRGB->data, pFrameRGB->linesize);
enc.encodeFrame(pFrameRGB, i);
}
}
// Free the packet that was allocated by av_read_frame
av_free_packet(&packet);
}
// Free the RGB image
av_free(buffer);
av_frame_free(&pFrameRGB);
// Free the YUV frame
av_frame_free(&pFrame);
// Close the codecs
avcodec_close(pCodecCtx);
avcodec_close(pCodecCtxOrig);
// Close the video file
avformat_close_input(&pFormatCtx);
return 0;
}
void StreamHandler::SetPixelArray()
{
yPlaneSz = pCodecCtx->width * pCodecCtx->height;
uvPlaneSz = pCodecCtx->width * pCodecCtx->height / 4;
yPlane = (Uint8*)malloc(yPlaneSz);
uPlane = (Uint8*)malloc(uvPlaneSz);
vPlane = (Uint8*)malloc(uvPlaneSz);
if (!yPlane || !uPlane || !vPlane)
throw myExceptions("Error : Can't create pixel array.");
uvPitch = pCodecCtx->width / 2;
}Here I fill the YUV image and write the packet.
void FfmpegEncoder::encodeFrame(AVFrame * frame, int frameCount)
{
AVPacket pkt = { 0 };
int got_pkt;
av_init_packet(&pkt);
frame->pts = frameCount;
FillYuvImage(frame, frameCount, this->pCodecCtx->width, this->pCodecCtx->height);
if (avcodec_encode_video2(this->pCodecCtx, &pkt, frame, &got_pkt) < 0)
throw myExceptions("Error: failed to encode the frame. FfmpegEncoder.cpp l:61\n");
//if the frame is well encoded
if (got_pkt) {
pkt.stream_index = this->st->index;
pkt.pts = av_rescale_q_rnd(pkt.pts, this->pCodecCtx->time_base, this->st->time_base, AVRounding(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
if (av_write_frame(this->outFormatCtx, &pkt) < 0)
throw myExceptions("Error: failed to write video frame. FfmpegEncoder.cpp l:68\n");
}
}
void FfmpegEncoder::FillYuvImage(AVFrame * pict, int frame_index, int width, int height)
{
int x, y, i;
i = frame_index;
for (y = 0; y < height; y++)
{
for (x = 0; x < width / 2; x++)
pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;
}
for (y = 0; y < height; y++)
{
for (x = 0; x < width / 2; x++)
{
pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
pict->data[2][y * pict->linesize[2] + x] = 64 + y + i * 5; //segault here
}
}
}The "FillYuvImage" method is copied from a FFMPEG example, but It does not work for me. If I don’t call it, the "av_write_frame" function won’t work (segfault too).
EDIT : Here is my output context and codec initialization.
FfmpegEncoder::FfmpegEncoder(char *url)
{
AVRational tmp_time_base;
AVDictionary* options = NULL;
this->pCodec = avcodec_find_encoder(AV_CODEC_ID_H264);
if (this->pCodec == NULL)
throw myExceptions("Error: Can't initialize the encoder. FfmpegEncoder.cpp l:9\n");
this->pCodecCtx = avcodec_alloc_context3(this->pCodec);
//Alloc output context
if (avformat_alloc_output_context2(&outFormatCtx, NULL, "rtsp", url) < 0)
throw myExceptions("Error: Can't alloc stream output. FfmpegEncoder.cpp l:17\n");
this->st = avformat_new_stream(this->outFormatCtx, this->pCodec);
if (this->st == NULL)
throw myExceptions("Error: Can't create stream . FfmpegEncoder.cpp l:22\n");
av_dict_set(&options, "vprofile", "main", 0);
av_dict_set(&options, "tune", "zerolatency", 0);
tmp_time_base.num = 1;
tmp_time_base.den = 60;
//TODO : parse these values
this->pCodecCtx->bit_rate = 3000000;
this->pCodecCtx->width = 1280;
this->pCodecCtx->height = 720;
//This set the fps. 60fps at this point.
this->pCodecCtx->time_base = tmp_time_base;
//Add a intra frame every 12 frames
this->pCodecCtx->gop_size = 12;
this->pCodecCtx->pix_fmt = AV_PIX_FMT_YUV420P;
//Open Codec, using the context + x264 options
if (avcodec_open2(this->pCodecCtx, this->pCodec, &options) < 0)
throw myExceptions("Error: Can't open the codec. FfmpegEncoder.cpp l:43\n");
if (avcodec_copy_context(this->st->codec, this->pCodecCtx) != 0) {
throw myExceptions("Error : Can't copy codec context. FfmpegEncoder.cpp : l.46");
}
av_dump_format(this->outFormatCtx, 0, url, 1);
if (avformat_write_header(this->outFormatCtx, NULL) != 0)
throw myExceptions("Error: failed to connect to RTSP server. FfmpegEncoder.cpp l:48\n");
} -
can write frames to rtsp server, but can't display them in the ffplay or live555 client
11 octobre 2016, par tankyxI am working on a zero latency streaming server, using ffmpeg libraries and I am facing a problem.
My server is working when using nvenc, I can streaming successfully to my client, which is another computer on LAN. But if I change my encoder to use the libx264 (in order to reduce the latency), the server still write the frames, but the client is facing problems with the sdp header, and more specifically, the media subsession does not seem to be initialized. Therefore, the client crashes.The thing is, when I dump the sdp header when using nvenc and libx264, it is actually the same in both case.
Here is the code I have done to initialize my encoder :
/*
Init the codec that is used to encode the video.
Init the output format context (aka RTSP uri).
*/
FfmpegEncoder::FfmpegEncoder(char *url)
{
AVRational tmp_time_base;
AVDictionary* options = NULL;
this->pCodec = avcodec_find_encoder_by_name("libx264");
if (this->pCodec == NULL)
throw myExceptions("Error: Can't initialize the encoder. FfmpegEncoder.cpp l:9\n");
this->pCodecCtx = avcodec_alloc_context3(this->pCodec);
//Alloc output context
if (avformat_alloc_output_context2(&outFormatCtx, NULL, "rtsp", url) < 0)
throw myExceptions("Error: Can't alloc stream output. FfmpegEncoder.cpp l:17\n");
this->st = avformat_new_stream(this->outFormatCtx, this->pCodec);
this->st->id = this->outFormatCtx->nb_streams - 1;
if (this->st == NULL)
throw myExceptions("Error: Can't create stream . FfmpegEncoder.cpp l:22\n");
//Define the framerate of the output. The numerator should stay 1. Denumerator is the framerate we are aiming for.
tmp_time_base.num = 1;
tmp_time_base.den = 60;
//TODO : parse these values
this->pCodecCtx->bit_rate = 5000000;
this->pCodecCtx->width = 1280;
this->pCodecCtx->height = 720;
//This set the fps. 60fps at this point.
this->pCodecCtx->time_base = tmp_time_base;
this->st->time_base = tmp_time_base;
//Add a intra frame every 12 frames
this->pCodecCtx->gop_size = 10;
this->pCodecCtx->pix_fmt = AV_PIX_FMT_YUV420P;
av_opt_set(this->pCodecCtx, "tune", "zerolatency", 0);
av_opt_set(this->pCodecCtx, "vprofile", "main", 0);
av_opt_set(this->pCodecCtx, "preset", "faster", 0);
//Open Codec, using the context + x264 options
if (avcodec_open2(this->pCodecCtx, this->pCodec, &options) < 0)
throw myExceptions("Error: Can't open the codec. FfmpegEncoder.cpp l:43\n");
if (avcodec_copy_context(this->st->codec, this->pCodecCtx) != 0) {
throw myExceptions("Error : Can't copy codec context. FfmpegEncoder.cpp : l.46");
}
av_dump_format(this->outFormatCtx, 0, url, 1);
//write the header needed to start the stream.
if (avformat_write_header(this->outFormatCtx, NULL) != 0)
throw myExceptions("Error: failed to connect to RTSP server. FfmpegEncoder.cpp l:48\n");
} -
can write frames to rtsp server, but can't display them in the ffplay or live555 client
11 octobre 2016, par tankyxI am working on a zero latency streaming server, using ffmpeg libraries and I am facing a problem.
My server is working when using nvenc, I can streaming successfully to my client, which is another computer on LAN. But if I change my encoder to use the libx264 (in order to reduce the latency), the server still write the frames, but the client is facing problems with the sdp header, and more specifically, the media subsession does not seem to be initialized. Therefore, the client crashes.The thing is, when I dump the sdp header when using nvenc and libx264, it is actually the same in both case.
Here is the code I have done to initialize my encoder :
/*
Init the codec that is used to encode the video.
Init the output format context (aka RTSP uri).
*/
FfmpegEncoder::FfmpegEncoder(char *url)
{
AVRational tmp_time_base;
AVDictionary* options = NULL;
this->pCodec = avcodec_find_encoder_by_name("libx264");
if (this->pCodec == NULL)
throw myExceptions("Error: Can't initialize the encoder. FfmpegEncoder.cpp l:9\n");
this->pCodecCtx = avcodec_alloc_context3(this->pCodec);
//Alloc output context
if (avformat_alloc_output_context2(&outFormatCtx, NULL, "rtsp", url) < 0)
throw myExceptions("Error: Can't alloc stream output. FfmpegEncoder.cpp l:17\n");
this->st = avformat_new_stream(this->outFormatCtx, this->pCodec);
this->st->id = this->outFormatCtx->nb_streams - 1;
if (this->st == NULL)
throw myExceptions("Error: Can't create stream . FfmpegEncoder.cpp l:22\n");
//Define the framerate of the output. The numerator should stay 1. Denumerator is the framerate we are aiming for.
tmp_time_base.num = 1;
tmp_time_base.den = 60;
//TODO : parse these values
this->pCodecCtx->bit_rate = 5000000;
this->pCodecCtx->width = 1280;
this->pCodecCtx->height = 720;
//This set the fps. 60fps at this point.
this->pCodecCtx->time_base = tmp_time_base;
this->st->time_base = tmp_time_base;
//Add a intra frame every 12 frames
this->pCodecCtx->gop_size = 10;
this->pCodecCtx->pix_fmt = AV_PIX_FMT_YUV420P;
av_opt_set(this->pCodecCtx, "tune", "zerolatency", 0);
av_opt_set(this->pCodecCtx, "vprofile", "main", 0);
av_opt_set(this->pCodecCtx, "preset", "faster", 0);
//Open Codec, using the context + x264 options
if (avcodec_open2(this->pCodecCtx, this->pCodec, &options) < 0)
throw myExceptions("Error: Can't open the codec. FfmpegEncoder.cpp l:43\n");
if (avcodec_copy_context(this->st->codec, this->pCodecCtx) != 0) {
throw myExceptions("Error : Can't copy codec context. FfmpegEncoder.cpp : l.46");
}
av_dump_format(this->outFormatCtx, 0, url, 1);
//write the header needed to start the stream.
if (avformat_write_header(this->outFormatCtx, NULL) != 0)
throw myExceptions("Error: failed to connect to RTSP server. FfmpegEncoder.cpp l:48\n");
}