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Head down (wav version)
26 septembre 2011, par
Mis à jour : Avril 2013
Langue : English
Type : Audio
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Echoplex (wav version)
26 septembre 2011, par
Mis à jour : Avril 2013
Langue : English
Type : Audio
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Discipline (wav version)
26 septembre 2011, par
Mis à jour : Avril 2013
Langue : English
Type : Audio
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Letting you (wav version)
26 septembre 2011, par
Mis à jour : Avril 2013
Langue : English
Type : Audio
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1 000 000 (wav version)
26 septembre 2011, par
Mis à jour : Avril 2013
Langue : English
Type : Audio
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999 999 (wav version)
26 septembre 2011, par
Mis à jour : Avril 2013
Langue : English
Type : Audio
Autres articles (70)
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Les tableaux ci-dessous expliquent ce que peut faire MédiaSPIP (...) -
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 (...) -
Les tâches Cron régulières de la ferme
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Cette tâche, planifiée chaque minute, a pour simple effet d’appeler le Cron de l’ensemble des instances de la mutualisation régulièrement. Couplée avec un Cron système sur le site central de la mutualisation, cela permet de simplement générer des visites régulières sur les différents sites et éviter que les tâches des sites peu visités soient trop (...)
Sur d’autres sites (10907)
-
FFmpeg - avcodec_receive_frame returns AVERROR(EAGAIN)
8 novembre 2019, par JinxI’m using an QOpenGL widget to draw frames. However, I’m struggling to get frames by using
avcodec_receive_frame. It ended within the blockelse if (ret == AVERROR(EAGAIN))and returned -11. I have no idea what made this happen. Also I checked that codecs were fine, so I guess the problem wasn’t caused by codecs.MyDemux.cpp
AVPacket* MyDemux::allocatePacket()
{
AVPacket* packet = av_packet_alloc();
return packet;
}
AVFrame* MyDemux::allocateFrame()
{
AVFrame* frame = av_frame_alloc();
return frame;
}
int MyDemux::readFrame(AVPacket* packet)
{
mux.lock();
if (!formatCtx) {
std::cout << "formaetCtx is null" << std::endl;
mux.unlock();
return -1;
}
int ret = av_read_frame(formatCtx, packet);
if (ret == AVERROR_EOF) {
return -2;
}
if (ret != 0) {
mux.unlock();
av_packet_free(&packet);
return -1;
}
media_type = packet->stream_index;
mux.unlock();
return 0;
}MyDecode.cpp
void MyDecode::decode(AVFrame* frame, AVPacket* packet)
{
int ret;
ret = avcodec_send_packet(codecCtx, packet); // this returned 0
while (ret == 0) {
ret = avcodec_receive_frame(codecCtx, frame); // this returned -11
if (ret == AVERROR(EINVAL)) {
std::cout << "codec issue" << std::endl;
av_frame_free(&frame);
return;
}
else if (ret == AVERROR(EAGAIN)) { // program ends here
std::cout << "output is not available this state" << std::endl;
av_frame_free(&frame);
return;
}
else if (ret == AVERROR(EINVAL)) {
std::cout << "no more frames" << std::endl;
av_frame_free(&frame);
return;
}
}
}main.cpp
class MyThread : public QThread
{
public:
MyDemux demux;
MyDecode video_decode;
myDecode audio_decode;
MyVideoWidget* videoWidget;
AVPacket* packet;
AVFrame* frame;
void initThread()
{
char* url = "demo.mp4";
demux.openFile(url);
video_decode.openCodec(demux.copy_video_codec_par());
audio_decode.openCodec(demux.copy_audio_codec_par());
packet = demux.allocatePacket();
frame = demux.allocateFrame();
}
void run()
{
while (demux.readFrame(packet) != -2) {
if (demux.get_media_type() == 0) {
video_decode.decode(frame, packet);
videoWidget->paintFrame(frame);
}
else if (demux.get_media_type() == 1) {
}
}
video_decode.decode(frame, nullptr);
demux.clear();
demux.close();
}
}; -
ffmpeg : libavfilter API av_buffersink_get_frame returns alway EAGAIN
29 juin 2024, par aculnaigI want to resize an image with
libavfilterC API throughzscalefilter andlibplacebofilter but no matter how I callav_buffersink_get_frame, it always returnsEAGAINand no data is filled in thefiltered_frame.

#include 
#include 
#include 
#include 
#include 

#include <libavcodec></libavcodec>avcodec.h>
#include <libavformat></libavformat>avformat.h>
#include <libavfilter></libavfilter>avfilter.h>
#include <libavfilter></libavfilter>buffersrc.h>
#include <libavfilter></libavfilter>buffersink.h>
#include <libavutil></libavutil>log.h>

int main(int argc, char **argv)
{
 if (argc != 2) {
 fprintf(stderr, "usage: %s <filename>\n", argv[0]);
 exit(EXIT_FAILURE);
 }

 const char *src_name = argv[1];
 const char *dst_name = basename(src_name);
 int ret = 0;

 const enum AVPixelFormat src_format = AV_PIX_FMT_YUV422P;

 av_log_set_level(AV_LOG_TRACE);

 AVFormatContext *fmt_ctx = avformat_alloc_context();
 if (fmt_ctx == NULL) {
 av_log(NULL, AV_LOG_TRACE, "avformat_alloc_context(): failed.\n");
 exit(EXIT_SUCCESS);
 }
 if ((ret = avformat_open_input(&fmt_ctx, src_name, NULL, NULL)) != 0) {
 av_log(NULL, AV_LOG_TRACE, "avformat_open_input(): %s.\n", av_err2str(ret));
 exit(EXIT_SUCCESS);
 }

 AVCodecContext *dec_ctx;
 AVCodec *dec;

 if ((ret = av_find_best_stream(fmt_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, &dec, 0)) < 0) {
 av_log(NULL, AV_LOG_TRACE, "av_find_best_stream(): %s.\n", av_err2str(ret));
 exit(EXIT_SUCCESS);
 }
 dec_ctx = avcodec_alloc_context3(dec);
 if (dec_ctx == NULL) {
 av_log(NULL, AV_LOG_TRACE, "avcodec_alloc_context3(): failed.\n");
 exit(EXIT_SUCCESS);
 }
 if ((ret = avcodec_open2(dec_ctx, dec, NULL)) < 0) {
 av_log(NULL, AV_LOG_TRACE, "avcodec_open2(): %s.\n", av_err2str(ret));
 exit(EXIT_SUCCESS);
 }

 AVFrame *frame = av_frame_alloc();
 if (frame == NULL) {
 av_log(NULL, AV_LOG_TRACE, "av_frame_alloc(): failed.\n");
 exit(EXIT_SUCCESS);
 }
 AVPacket *packet = av_packet_alloc();
 if (packet == NULL) {
 av_log(NULL, AV_LOG_TRACE, "av_packet_alloc(): failed.\n");
 exit(EXIT_SUCCESS);
 }

 if ((ret = av_read_frame(fmt_ctx, packet)) < 0) {
 av_log(NULL, AV_LOG_TRACE, "av_read_frame(): %s.\n", av_err2str(ret));
 exit(EXIT_SUCCESS);
 }
 ret = avcodec_send_packet(dec_ctx, packet);
 if (ret == AVERROR(EAGAIN)) {
 av_log(NULL, AV_LOG_TRACE, "avcodec_send_packet(): %s.\n", av_err2str(ret));
 avcodec_receive_frame(dec_ctx, frame);
 avcodec_send_packet(dec_ctx, packet);
 }
 
 if ((ret = avcodec_receive_frame(dec_ctx, frame)) < 0) {
 av_log(NULL, AV_LOG_TRACE, "avcodec_receive_frame(): %s.\n", av_err2str(ret));
 exit(EXIT_SUCCESS);
 }
 av_packet_unref(packet);

 av_log(NULL, AV_LOG_TRACE, "filename: %s, w: %d, h: %d, fmt: %d\n", src_name, frame->width, frame->height, frame->format);

 AVFilterGraph *filter_graph = avfilter_graph_alloc();

 char buffersrc_args[512];
 snprintf(buffersrc_args, sizeof(buffersrc_args), "video_size=%dx%d:pix_fmt=%d:time_base=1/25", frame->width, frame->height, frame->format); 

 AVFilterContext *buffersrc_ctx;
 if ((ret = avfilter_graph_create_filter(&buffersrc_ctx, avfilter_get_by_name("buffer"), NULL, buffersrc_args, NULL, filter_graph)) < 0) {
 av_log(NULL, AV_LOG_TRACE, "avfilter_graph_create_filter(): %s.\n", av_err2str(ret));
 exit(EXIT_SUCCESS);
 }

 char libplacebo_args[512];
 snprintf(libplacebo_args, sizeof(libplacebo_args), "format=yuv420p:colorspace=bt470bg:color_primaries=bt709:color_trc=iec61966-2-1:range=pc:w=(iw/2):h=(ih/2):downscaler=none:dithering=none");
 AVFilterContext *libplacebo_ctx;
 if ((ret = avfilter_graph_create_filter(&libplacebo_ctx, avfilter_get_by_name("libplacebo"), NULL, libplacebo_args, NULL, filter_graph)) < 0) {
 av_log(NULL, AV_LOG_TRACE, "avfilter_graph_create_filter(): %s.\n", av_err2str(ret));
 exit(EXIT_SUCCESS);
 }

 AVFilterContext *buffersink_ctx;
 if ((ret = avfilter_graph_create_filter(&buffersink_ctx, avfilter_get_by_name("buffersink"), NULL, NULL, NULL, filter_graph)) < 0) {
 av_log(NULL, AV_LOG_TRACE, "avfilter_graph_create_filter(): %s.\n", av_err2str(ret));
 exit(EXIT_SUCCESS);
 }

 if ((ret = avfilter_link(buffersrc_ctx, 0, libplacebo_ctx, 0)) != 0) {
 av_log(NULL, AV_LOG_TRACE, "avfilter_link(): %s.\n", av_err2str(ret));
 exit(EXIT_SUCCESS);
 }
 if ((ret = avfilter_link(libplacebo_ctx, 0, buffersink_ctx, 0)) != 0) {
 av_log(NULL, AV_LOG_TRACE, "avfilter_link(): %s.\n", av_err2str(ret));
 exit(EXIT_SUCCESS);
 }
 
 if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0) {
 av_log(NULL, AV_LOG_TRACE, "avfilter_graph_config(): %s.\n", av_err2str(ret));
 exit(EXIT_SUCCESS);
 }

 AVFrame *filtered_frame = av_frame_alloc();
 if (filtered_frame == NULL) {
 av_log(NULL, AV_LOG_TRACE, "av_frame_alloc(): failed.\n");
 exit(EXIT_SUCCESS);
 }
 if ((ret = av_buffersrc_add_frame(buffersrc_ctx, frame)) < 0) {
 av_log(NULL, AV_LOG_TRACE, "av_buffersrc_add_frame(): %s.\n", av_err2str(ret));
 exit(EXIT_SUCCESS);
 }
 
 while (1) {
 int ret = av_buffersink_get_frame(buffersink_ctx, filtered_frame);
 if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
 break;
 if (ret < 0) {
 av_log(NULL, AV_LOG_TRACE, "av_buffersink_get_frame(): %s.\n", av_err2str(ret));
 exit(EXIT_FAILURE);
 } 
 }

 av_log(NULL, AV_LOG_TRACE, "filename: %s, w: %d, h: %d, f: %d\n", dst_name, filtered_frame->width, filtered_frame->height, filtered_frame->format);

 AVCodecContext *enc_ctx;
 AVCodec *enc;
 AVPacket *enc_packet = av_packet_alloc();

 enc = avcodec_find_encoder_by_name("mjpeg");
 enc_ctx = avcodec_alloc_context3(enc);
 enc_ctx->width = filtered_frame->width;
 enc_ctx->height = filtered_frame->height;
 enc_ctx->bit_rate = dec_ctx->bit_rate * 1024;
 enc_ctx->time_base = (AVRational) {1, 25};
 enc_ctx->framerate = (AVRational) {25, 1};
 enc_ctx->pix_fmt = filtered_frame->format;
 enc_ctx->strict_std_compliance = FF_COMPLIANCE_EXPERIMENTAL;
 enc_ctx->compression_level = 0;
 enc_ctx->color_range = AVCOL_RANGE_JPEG;

 avcodec_open2(enc_ctx, enc, NULL);

 avcodec_send_frame(enc_ctx, filtered_frame);
 avcodec_receive_packet(enc_ctx, enc_packet);

 FILE *dst_file = fopen(dst_name, "wb");
 fwrite(enc_packet->data, 1, enc_packet->size, dst_file);
 fclose(dst_file);

 av_packet_unref(enc_packet);
 av_frame_free(&frame);
 av_frame_free(&filtered_frame);
 
 avfilter_graph_free(&filter_graph);

 avformat_close_input(&fmt_ctx);
 avformat_free_context(fmt_ctx);
 
 exit(EXIT_SUCCESS);
}
</filename>

and here are the logs




PS : the logs were so many I could paste in stackoverflow


-
FFmpeg - avcodec_receive_frame returns 0 but frames are invalid
9 juillet 2019, par JinxI’ve been trying to extract images from videos, but not those with PNG codec. My code works fine with those with JPEG.
avcodec_receive_frameworked successfully but the data of the frames was like trash ? Do I have to do something special to demuxing when dealing with PNG ?Exception thrown at 0x00007FFF7DF34B9A (msvcrt.dll) in Program.exe : 0xC0000005 : Access violation reading location 0x00000000000003F0 when calling
avcodec_send_framein mysaveImagefunction, which means I was accessing invalid or unalloacted memory I guess. How this happened ?
Just suppose all the function calls returned 0 until exception thrown.
Decoding :
bool ImageExtractor::decode() {
// some other code here
ret = avcodec_send_packet(codec_ctx, packet); // returned 0
ret = avcodec_receive_frame(codec_ctx, frame); // returned 0
if (ret == 0) {
if (count >= target_frame) {
snprintf(buf, sizeof(buf), "%s/%d.png", destination.toLocal8Bit().data(), count);
saveImage(frame, buf); // a function that writes images on disk
}
// some other code here
}
bool ImageExtractor::saveImage(AVFrame *frame, char *destination) {
AVFormatContext *imgFmtCtx = avformat_alloc_context();
pFormatCtx->oformat = av_guess_format("mjpeg", NULL, NULL);
// some other code here
if (!frame)
std::cout << "invalid frame \n";
if (!imgCodecCtx) // AV_CODEC_ID_MJPEG(7)
std::cout << "invalid codec ctx \n";
ret = avcodec_send_frame(imgCodecCtx, frame); // everything stopped here
}Demuxing :
avformat_open_input(&format_ctx, source.toLocal8Bit(), nullptr, nullptr);
vsi = av_find_best_stream(format_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, nullptr, 0);
codec_par = avcodec_parameters_alloc();
avcodec_parameters_copy(codec_par, format_ctx->streams[vsi]->codecpar);
AVCodec* codec = avcodec_find_decoder(codec_par->codec_id); // AV_CODEC_ID_PNG(61)
codec_ctx = avcodec_alloc_context3(codec);
avcodec_parameters_to_context(codec_ctx, codec_par);
avcodec_parameters_free(&codec_par);
avcodec_open2(codec_ctx, codec, 0);
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