Recherche avancée
Médias (1)
-
La conservation du net art au musée. Les stratégies à l’œuvre
26 mai 2011
Mis à jour : Juillet 2013
Langue : français
Type : Texte
Autres articles (51)
-
Personnaliser les catégories
21 juin 2013, parFormulaire de création d’une catégorie
Pour ceux qui connaissent bien SPIP, une catégorie peut être assimilée à une rubrique.
Dans le cas d’un document de type catégorie, les champs proposés par défaut sont : Texte
On peut modifier ce formulaire dans la partie :
Administration > Configuration des masques de formulaire.
Dans le cas d’un document de type média, les champs non affichés par défaut sont : Descriptif rapide
Par ailleurs, c’est dans cette partie configuration qu’on peut indiquer le (...) -
HTML5 audio and video support
13 avril 2011, parMediaSPIP uses HTML5 video and audio tags to play multimedia files, taking advantage of the latest W3C innovations supported by modern browsers.
The MediaSPIP player used has been created specifically for MediaSPIP and can be easily adapted to fit in with a specific theme.
For older browsers the Flowplayer flash fallback is used.
MediaSPIP allows for media playback on major mobile platforms with the above (...) -
Support audio et vidéo HTML5
10 avril 2011MediaSPIP utilise les balises HTML5 video et audio pour la lecture de documents multimedia en profitant des dernières innovations du W3C supportées par les navigateurs modernes.
Pour les navigateurs plus anciens, le lecteur flash Flowplayer est utilisé.
Le lecteur HTML5 utilisé a été spécifiquement créé pour MediaSPIP : il est complètement modifiable graphiquement pour correspondre à un thème choisi.
Ces technologies permettent de distribuer vidéo et son à la fois sur des ordinateurs conventionnels (...)
Sur d’autres sites (8473)
-
Streaming H.264 over UDP using FFmpeg, and "dimensions not set" error
3 septembre 2015, par Baris DemirayI’m trying to stream H.264 over UDP with no luck so far. Here is a minimal code that you can reproduce the problem.
To compile,
g++ -o test -lavcodec -lavformat -lavutil test.cppExtra information, I start
ffplayas follows. Currently it’s of no use.ffplay -i udp://127.0.0.1:8554/live.sdpOutput of my code (see
avio_open()call),[libx264 @ 0x6a26c0] using mv_range_thread = 24
[libx264 @ 0x6a26c0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.1 Cache64
[libx264 @ 0x6a26c0] profile High, level 3.1
Output #0, h264, to 'udp://127.0.0.1:8554/live.sdp':
Stream #0:0, 0, 0/0: Video: h264 (libx264), -1 reference frame, none, q=-1--1
[h264 @ 0x6a2020] dimensions not set
Cannot write header to stream: SuccessAnd the code,
extern "C" {
#include <libavcodec></libavcodec>avcodec.h>
#include <libavformat></libavformat>avformat.h>
#include <libavutil></libavutil>avutil.h>
}
#include <iostream>
using namespace std;
int main() {
AVCodecContext* m_codecContext;
AVCodec* m_codec;
AVFormatContext* m_formatContext;
AVStream* m_stream;
unsigned m_outWidth = 768;
unsigned m_outHeight = 608;
av_register_all();
avcodec_register_all();
avformat_network_init();
int errorStatus = 0;
char errorLog[128] = { 0 };
av_log_set_level(AV_LOG_TRACE);
string m_output("udp://127.0.0.1:8554/live.sdp");
if (avformat_alloc_output_context2(&m_formatContext, NULL, "h264", m_output.c_str()) < 0) {
cerr << "Cannot allocate output context: "
<< av_make_error_string(errorLog, 128, errorStatus) << endl;
return -1;
}
AVOutputFormat *m_outputFormat = m_formatContext->oformat;
m_codec = avcodec_find_encoder(AV_CODEC_ID_H264);
if (!m_codec) {
cerr << "Cannot find an encoder: "
<< av_make_error_string(errorLog, 128, errorStatus) << endl;
return -1;
}
m_codecContext = avcodec_alloc_context3(m_codec);
if (!m_codecContext) {
cerr << "Cannot allocate a codec context: "
<< av_make_error_string(errorLog, 128, errorStatus) << endl;
return -1;
}
m_codecContext->pix_fmt = AV_PIX_FMT_YUV420P;
m_codecContext->width = m_outWidth;
m_codecContext->height = m_outHeight;
if (avcodec_open2(m_codecContext, m_codec, NULL) < 0) {
cerr << "Cannot open codec: "
<< av_make_error_string(errorLog, 128, errorStatus) << endl;
return -1;
}
m_stream = avformat_new_stream(m_formatContext, m_codec);
if (!m_stream) {
cerr << "Cannot create a new stream: "
<< av_make_error_string(errorLog, 128, errorStatus) << endl;
return -1;
}
av_dump_format(m_formatContext, 0, m_output.c_str(), 1);
if ((errorStatus = avio_open(&m_formatContext->pb, m_output.c_str(), AVIO_FLAG_WRITE)) < 0) {
cerr << "Cannot open output: "
<< av_make_error_string(errorLog, 128, errorStatus) << endl;
return -1;
}
if (avformat_write_header(m_formatContext, NULL) < 0) {
cerr << "Cannot write header to stream: "
<< av_make_error_string(errorLog, 128, errorStatus) << endl;
return -1;
}
cout << "All done." << endl;
return 0;
}
</iostream>For those who has even more time to spare on my problem, when I change
m_outputtortsp://127.0.0.1:8554/live.sdp, andffplaycommand toffplay -rtsp_flags listen -i rtsp://127.0.0.1:8554/live.sdpI get the error,[libx264 @ 0x1e056c0] using mv_range_thread = 24
[libx264 @ 0x1e056c0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.1 Cache64
[libx264 @ 0x1e056c0] profile High, level 3.1
Output #0, h264, to 'rtsp://127.0.0.1:8554/live.sdp':
Stream #0:0, 0, 0/0: Video: h264 (libx264), -1 reference frame, none, q=-1--1
Cannot open output: Protocol not foundAm I naive to expect that streaming protocol will be changed like this ?
-
How to modify the bit_rate of AVFormatContext ?
27 mars 2023, par Zion LiuHello，I would like to know how to modify the bit_rate of AVFormatContext.


Here is the minimal reproducible example.This is a simple process for pushing rtmp video streams.Now I want to control the bitrate of the video it pushes.


I tried modifying the bitrate like this, but it didn't work.


AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL;
int64_t bit_rate = 400*1000;
....
ofmt_ctx->bit_rate = bit_rate;


Can be compiled by
g++ -Wall -o -g -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/local/include -L/usr/local/lib simplt_push_streaming.cpp -o test.out -lavformat -lavcodec -lavutil -lgobject-2.0 -lglib-2.0 -lpthread

And my ffmpeg version :
ffmpeg version 4.4.2-0ubuntu0.22.04.1

#include 
extern "C"
{
#include <libavformat></libavformat>avformat.h>
#include <libavutil></libavutil>mathematics.h>
#include <libavutil></libavutil>time.h>
};

int main(int argc, char* argv[])
{
 AVOutputFormat *ofmt = NULL;
 //Input AVFormatContext and Output AVFormatContext
 AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL;
 AVPacket pkt;
 const char *in_filename, *out_filename;
 int ret, i;
 int videoindex=-1;
 int frame_index=0;
 int64_t start_time=0;
 int64_t bit_rate = 400*1000;
 in_filename = "/home/zion/video/mecha.flv";// Input file URL
 out_filename = "rtmp://localhost:1935/live/test";//Output URL [RTMP]
 av_register_all();
 avformat_network_init();
 avformat_open_input(&ifmt_ctx, in_filename, 0, 0);
 avformat_find_stream_info(ifmt_ctx, 0);
 for(i=0; inb_streams; i++) 
 if(ifmt_ctx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO){
 videoindex=i;
 break;
 }
 //Output
 avformat_alloc_output_context2(&ofmt_ctx, NULL, "flv", out_filename); //RTMP
 ofmt = ofmt_ctx->oformat;
 for (i = 0; i < ifmt_ctx->nb_streams; i++) {
 //Create output AVStream according to input AVStream
 AVStream *in_stream = ifmt_ctx->streams[i];
 AVStream *out_stream = avformat_new_stream(ofmt_ctx, in_stream->codec->codec);
 //Copy the settings of AVCodecContext
 ret = avcodec_copy_context(out_stream->codec, in_stream->codec);
 out_stream->codec->codec_tag = 0;
 if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
 out_stream->codec->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
 }
 //Open output URL
 if (!(ofmt->flags & AVFMT_NOFILE)) {
 ret = avio_open(&ofmt_ctx->pb, out_filename, AVIO_FLAG_WRITE);
 }
 //Write file header
 avformat_write_header(ofmt_ctx, NULL);
 start_time=av_gettime();
 while (1) {
 AVStream *in_stream, *out_stream;
 //Get an AVPacket
 ret = av_read_frame(ifmt_ctx, &pkt);
 if (ret < 0)
 break;
 //Important:Delay
 if(pkt.stream_index==videoindex){
 AVRational time_base=ifmt_ctx->streams[videoindex]->time_base;
 AVRational time_base_q={1,AV_TIME_BASE};
 int64_t pts_time = av_rescale_q(pkt.dts, time_base, time_base_q);
 int64_t now_time = av_gettime() - start_time;
 if (pts_time > now_time)
 av_usleep(pts_time - now_time);
 }
 in_stream = ifmt_ctx->streams[pkt.stream_index];
 out_stream = ofmt_ctx->streams[pkt.stream_index];
 if(pkt.stream_index==videoindex){
 printf("Send %8d video frames to output URL\n",frame_index);
 frame_index++;
 }
/*I tried modifying the bitrate here and I'm not sure if this is the correct usage.*/
 ofmt_ctx->bit_rate = bit_rate;
 av_interleaved_write_frame(ofmt_ctx, &pkt);
 av_free_packet(&pkt);
 }
 //Write file trailer
 av_write_trailer(ofmt_ctx);
end:
 avformat_close_input(&ifmt_ctx);
 /* close output */
 if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE))
 avio_close(ofmt_ctx->pb);
 avformat_free_context(ofmt_ctx);
 return 0;
}


-
ERROR "Application provided invalid, non monotonically increasing dts to muxer in stream 1 : 6874 >= 6874" while writing encoded output to an mp4 file
11 mai 2023, par lokit khemkaI have a running RTSP stream, streaming video on a loop using the following FFMPEG command :


ffmpeg -re -stream_loop -1 -i ./ffmpeg_c_test/small_bunny_1080p_60fps.mp4 -ac 2 -f rtsp -rtsp_transport tcp rtsp://localhost:8554/mystream


The video file is obtained from the github link : https://github.com/leandromoreira/ffmpeg-libav-tutorial


I keep getting error response, when I calling the function
av_interleaved_write_framecalled from the functionremuxin the attached program. The output format ismp4, output video codec isav1and output audio codec is same as input audio codec. The error is from audio stream.

I tried to create a "minimal reproducible code", however, I think it is still not completely minimal, but it reproduces the exact error.


#include <libavcodec></libavcodec>avcodec.h>
#include <libavformat></libavformat>avformat.h>
#include <libavutil></libavutil>timestamp.h>
#include <libavutil></libavutil>opt.h>
#include <libswscale></libswscale>swscale.h>
#include 
#include 
#include 

#include 
#include 

typedef struct StreamingContext{
 AVFormatContext* avfc;
 const AVCodec *video_avc;
 const AVCodec *audio_avc;
 AVStream *video_avs;
 AVStream *audio_avs;
 AVCodecContext *video_avcc;
 AVCodecContext *audio_avcc;
 int video_index;
 int audio_index;
 char* filename;
 struct SwsContext *sws_ctx;
}StreamingContext;


typedef struct StreamingParams{
 char copy_video;
 char copy_audio;
 char *output_extension;
 char *muxer_opt_key;
 char *muxer_opt_value;
 char *video_codec;
 char *audio_codec;
 char *codec_priv_key;
 char *codec_priv_value;
}StreamingParams;

void logging(const char *fmt, ...)
{
 va_list args;
 fprintf(stderr, "LOG: ");
 va_start(args, fmt);
 vfprintf(stderr, fmt, args);
 va_end(args);
 fprintf(stderr, "\n");
}

int fill_stream_info(AVStream *avs, const AVCodec **avc, AVCodecContext **avcc)
{
 *avc = avcodec_find_decoder(avs->codecpar->codec_id);
 *avcc = avcodec_alloc_context3(*avc);
 if (avcodec_parameters_to_context(*avcc, avs->codecpar) < 0)
 {
 logging("Failed to fill Codec Context.");
 return -1;
 }
 avcodec_open2(*avcc, *avc, NULL);
 return 0;
}

int open_media(const char *in_filename, AVFormatContext **avfc)
{
 *avfc = avformat_alloc_context();
 if (avformat_open_input(avfc, in_filename, NULL, NULL) != 0)
 {
 logging("Failed to open input file %s", in_filename);
 return -1;
 }

 if (avformat_find_stream_info(*avfc, NULL) < 0)
 {
 logging("Failed to get Stream Info.");
 return -1;
 }
}

int prepare_decoder(StreamingContext *sc)
{
 for (int i = 0; i < (int)sc->avfc->nb_streams; i++)
 {
 if (sc->avfc->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
 {
 sc->video_avs = sc->avfc->streams[i];
 sc->video_index = i;

 if (fill_stream_info(sc->video_avs, &sc->video_avc, &sc->video_avcc))
 {
 return -1;
 }
 }
 else if (sc->avfc->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO)
 {
 sc->audio_avs = sc->avfc->streams[i];
 sc->audio_index = i;

 if (fill_stream_info(sc->audio_avs, &sc->audio_avc, &sc->audio_avcc))
 {
 return -1;
 }
 }
 else
 {
 logging("Skipping Streams other than Audio and Video.");
 }
 }
 return 0;
}

int prepare_video_encoder(StreamingContext *encoder_sc, AVCodecContext *decoder_ctx, AVRational input_framerate,
 StreamingParams sp, int scaled_frame_width, int scaled_frame_height)
{
 encoder_sc->video_avs = avformat_new_stream(encoder_sc->avfc, NULL);
 encoder_sc->video_avc = avcodec_find_encoder_by_name(sp.video_codec);
 if (!encoder_sc->video_avc)
 {
 logging("Cannot find the Codec.");
 return -1;
 }

 encoder_sc->video_avcc = avcodec_alloc_context3(encoder_sc->video_avc);
 if (!encoder_sc->video_avcc)
 {
 logging("Could not allocate memory for Codec Context.");
 return -1;
 }

 av_opt_set(encoder_sc->video_avcc->priv_data, "preset", "fast", 0);
 if (sp.codec_priv_key && sp.codec_priv_value)
 av_opt_set(encoder_sc->video_avcc->priv_data, sp.codec_priv_key, sp.codec_priv_value, 0);

 encoder_sc->video_avcc->height = scaled_frame_height;
 encoder_sc->video_avcc->width = scaled_frame_width;
 encoder_sc->video_avcc->sample_aspect_ratio = decoder_ctx->sample_aspect_ratio;

 if (encoder_sc->video_avc->pix_fmts)
 encoder_sc->video_avcc->pix_fmt = encoder_sc->video_avc->pix_fmts[0];
 else
 encoder_sc->video_avcc->pix_fmt = decoder_ctx->pix_fmt;

 encoder_sc->video_avcc->bit_rate = 2 * 1000 * 1000;

 encoder_sc->video_avcc->time_base = av_inv_q(input_framerate);
 encoder_sc->video_avs->time_base = encoder_sc->video_avcc->time_base;

 

 if (avcodec_open2(encoder_sc->video_avcc, encoder_sc->video_avc, NULL) < 0)
 {
 logging("Could not open the Codec.");
 return -1;
 }
 avcodec_parameters_from_context(encoder_sc->video_avs->codecpar, encoder_sc->video_avcc);
 return 0;
}


int prepare_copy(AVFormatContext *avfc, AVStream **avs, AVCodecParameters *decoder_par)
{
 *avs = avformat_new_stream(avfc, NULL);
 avcodec_parameters_copy((*avs)->codecpar, decoder_par);
 return 0;
}

int encode_video(StreamingContext *decoder, StreamingContext *encoder, AVFrame *input_frame)
{
 if (input_frame)
 input_frame->pict_type = AV_PICTURE_TYPE_NONE;

 AVPacket *output_packet = av_packet_alloc();


 int response = avcodec_send_frame(encoder->video_avcc, input_frame);

 while (response >= 0)
 {
 response = avcodec_receive_packet(encoder->video_avcc, output_packet);
 if (response == AVERROR(EAGAIN) || response == AVERROR_EOF)
 {
 break;
 }

 output_packet->stream_index = decoder->video_index;
 output_packet->duration = encoder->video_avs->time_base.den / encoder->video_avs->time_base.num;

 av_packet_rescale_ts(output_packet, decoder->video_avs->time_base, encoder->video_avs->time_base);
 response = av_interleaved_write_frame(encoder->avfc, output_packet);
 }

 av_packet_unref(output_packet);
 av_packet_free(&output_packet);

 return 0;
}

int remux(AVPacket **pkt, AVFormatContext **avfc, AVRational decoder_tb, AVRational encoder_tb)
{
 (*pkt)->duration = av_rescale_q((*pkt)->duration, decoder_tb, encoder_tb);
 (*pkt)->pos = -1;
 av_packet_rescale_ts(*pkt, decoder_tb, encoder_tb);
 if (av_interleaved_write_frame(*avfc, *pkt) < 0)
 {
 logging("Error while copying Stream Packet.");
 return -1;
 }
 return 0;
}

int transcode_video(StreamingContext *decoder, StreamingContext *encoder, AVPacket *input_packet, AVFrame *input_frame)
{
 int response = avcodec_send_packet(decoder->video_avcc, input_packet);
 while (response >= 0)
 {
 response = avcodec_receive_frame(decoder->video_avcc, input_frame);
 
 if (response == AVERROR(EAGAIN) || response == AVERROR_EOF)
 {
 break;
 }
 if (response >= 0)
 {
 if (encode_video(decoder, encoder, input_frame))
 return -1;
 }

 av_frame_unref(input_frame);
 }
 return 0;
}

int main(int argc, char *argv[])
{
 const int scaled_frame_width = 854;
 const int scaled_frame_height = 480;
 StreamingParams sp = {0};
 sp.copy_audio = 1;
 sp.copy_video = 0;
 sp.video_codec = "libsvtav1";
 
 StreamingContext *decoder = (StreamingContext *)calloc(1, sizeof(StreamingContext));
 decoder->filename = "rtsp://localhost:8554/mystream";

 StreamingContext *encoder = (StreamingContext *)calloc(1, sizeof(StreamingContext));
 encoder->filename = "small_bunny_9.mp4";
 
 if (sp.output_extension)
 {
 strcat(encoder->filename, sp.output_extension);
 }

 open_media(decoder->filename, &decoder->avfc);
 prepare_decoder(decoder);


 avformat_alloc_output_context2(&encoder->avfc, NULL, "mp4", encoder->filename);
 AVRational input_framerate = av_guess_frame_rate(decoder->avfc, decoder->video_avs, NULL);
 prepare_video_encoder(encoder, decoder->video_avcc, input_framerate, sp, scaled_frame_width, scaled_frame_height);

 prepare_copy(encoder->avfc, &encoder->audio_avs, decoder->audio_avs->codecpar);
 

 if (encoder->avfc->oformat->flags & AVFMT_GLOBALHEADER)
 encoder->avfc->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;

 if (!(encoder->avfc->oformat->flags & AVFMT_NOFILE))
 {
 if (avio_open(&encoder->avfc->pb, encoder->filename, AVIO_FLAG_WRITE) < 0)
 {
 logging("could not open the output file");
 return -1;
 }
 }

 
 if (avformat_write_header(encoder->avfc, NULL) < 0)
 {
 logging("an error occurred when opening output file");
 return -1;
 }

 AVFrame *input_frame = av_frame_alloc();
 AVPacket *input_packet = av_packet_alloc();

 while (1)
 {
 int ret = av_read_frame(decoder->avfc, input_packet);
 if(ret<0)
 break;
 if (decoder->avfc->streams[input_packet->stream_index]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
 {
 if (transcode_video(decoder, encoder, input_packet, input_frame))
 return -1;
 av_packet_unref(input_packet);

 }
 else if (decoder->avfc->streams[input_packet->stream_index]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO)
 {
 
 if (remux(&input_packet, &encoder->avfc, decoder->audio_avs->time_base, encoder->audio_avs->time_base))
 return -1;
 }
 else
 {
 logging("Ignoring all nonvideo or audio packets.");
 }
 }

 if (encode_video(decoder, encoder, NULL))
 return -1;
 

 av_write_trailer(encoder->avfc);


 if (input_frame != NULL)
 {
 av_frame_free(&input_frame);
 input_frame = NULL;
 }

 if (input_packet != NULL)
 {
 av_packet_free(&input_packet);
 input_packet = NULL;
 }

 avformat_close_input(&decoder->avfc);

 avformat_free_context(decoder->avfc);
 decoder->avfc = NULL;
 avformat_free_context(encoder->avfc);
 encoder->avfc = NULL;

 avcodec_free_context(&decoder->video_avcc);
 decoder->video_avcc = NULL;
 avcodec_free_context(&decoder->audio_avcc);
 decoder->audio_avcc = NULL;

 free(decoder);
 decoder = NULL;
 free(encoder);
 encoder = NULL;

 return 0;
}



Syndiquer tout le site
