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Médias (91)
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999,999
26 septembre 2011, par
Mis à jour : Septembre 2011
Langue : English
Type : Audio
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The Slip - Artworks
26 septembre 2011, par
Mis à jour : Septembre 2011
Langue : English
Type : Texte
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Demon seed (wav version)
26 septembre 2011, par
Mis à jour : Avril 2013
Langue : English
Type : Audio
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The four of us are dying (wav version)
26 septembre 2011, par
Mis à jour : Avril 2013
Langue : English
Type : Audio
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Corona radiata (wav version)
26 septembre 2011, par
Mis à jour : Avril 2013
Langue : English
Type : Audio
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Lights in the sky (wav version)
26 septembre 2011, par
Mis à jour : Avril 2013
Langue : English
Type : Audio
Autres articles (17)
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Création définitive du canal
12 mars 2010, parLorsque votre demande est validée, vous pouvez alors procéder à la création proprement dite du canal. Chaque canal est un site à part entière placé sous votre responsabilité. Les administrateurs de la plateforme n’y ont aucun accès.
A la validation, vous recevez un email vous invitant donc à créer votre canal.
Pour ce faire il vous suffit de vous rendre à son adresse, dans notre exemple "http://votre_sous_domaine.mediaspip.net".
A ce moment là un mot de passe vous est demandé, il vous suffit d’y (...) -
Selection of projects using MediaSPIP
2 mai 2011, parThe examples below are representative elements of MediaSPIP specific uses for specific projects.
MediaSPIP farm @ Infini
The non profit organizationInfini develops hospitality activities, internet access point, training, realizing innovative projects in the field of information and communication technologies and Communication, and hosting of websites. It plays a unique and prominent role in the Brest (France) area, at the national level, among the half-dozen such association. Its members (...) -
Les tâches Cron régulières de la ferme
1er décembre 2010, parLa gestion de la ferme passe par l’exécution à intervalle régulier de plusieurs tâches répétitives dites Cron.
Le super Cron (gestion_mutu_super_cron)
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 (3651)
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Is it possible to "lossless"-ly speed up a video ?
15 novembre 2020, par Synn KoMight sound like a strange question, but hear me out. I have hours of video I want to cut up and edit together, but a lot of it is just junk I don't need. I don't want to lose any quality, so I use LosslessCut.


The problem for me is that it's... A LOT of footage, and I don't need to see every single second of it. It would be nice if LosslessCut had a button to change the speed of the playback, but it doesn't have that.


So another idea would be to speed up all the videos in advance with ffmpeg, cut them up using LosslessCut, then change the remaining clips back to their original speed using ffmpeg again. Is it possible to speed up a video and change it back to its original speed without losing any quality or changing the video ?


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FFMpeg AC3 to AAC Conversion speed
28 juillet 2022, par sweetngxWhile I don't actually have a problem with conversion, I do have a direct problem with Conversion speed. With FFMpeg, I convert ac3 (175 mb) audio files to aac (70mb) format in about 2 minutes by consuming very little cpu (5%).
I couldn't find a way to achieve this even though it's really great on my computer, I guess the problem is software... Do you think there is a way to achieve this ?
I have a lot of questions in my mind, why can't FFMPeg speed up this process at the expense of consuming more cpu, What is the obstacle ?


I think I found someone having similar issue at the link below... Anyone have a better idea ?
https://forums.developer.nvidia.com/t/nvenc-with-audio-conversion-best-practice-advice/40759


ffmpeg.exe -threads 32 -i "en.ac3" -map a:0 -c:a aac -b:a 128k -vn -y output.aac


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increasing memory occupancy while recording screen save to disk with ffmpeg [on hold]
19 mai 2016, par vbtangwonder if there are any resoures i didn’t free ?or do i need to do something special so that i can free these momery ?
ps. run the demo step by step, and found it has the same problem, until it quit the main function, it still have 40MB memory occupancy. And i found the memory increase obviously in the screen capture thread,but when it increased to about 150MB, it won’t increase, until i quit the program, it will have 40MB memory left. i feel confused.
pss. i download ffmpeg dev and shared version form here https://ffmpeg.zeranoe.com/builds/,it seems a dll of debug version ? do i need a release version ?
here is my demo code.#include "stdafx.h"
#ifdef __cplusplus
extern "C"
{
#endif
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libswscale/swscale.h"
#include "libavdevice/avdevice.h"
#include "libavutil/audio_fifo.h"
#pragma comment(lib, "avcodec.lib")
#pragma comment(lib, "avformat.lib")
#pragma comment(lib, "avutil.lib")
#pragma comment(lib, "avdevice.lib")
#pragma comment(lib, "avfilter.lib")
//#pragma comment(lib, "avfilter.lib")
//#pragma comment(lib, "postproc.lib")
//#pragma comment(lib, "swresample.lib")
#pragma comment(lib, "swscale.lib")
#ifdef __cplusplus
};
#endif
AVFormatContext *pFormatCtx_Video = NULL, *pFormatCtx_Audio = NULL, *pFormatCtx_Out = NULL;
AVCodecContext *pCodecCtx_Video;
AVCodec *pCodec_Video;
AVFifoBuffer *fifo_video = NULL;
AVAudioFifo *fifo_audio = NULL;
int VideoIndex, AudioIndex;
CRITICAL_SECTION AudioSection, VideoSection;
SwsContext *img_convert_ctx;
int frame_size = 0;
uint8_t *picture_buf = NULL, *frame_buf = NULL;
bool bCap = true;
DWORD WINAPI ScreenCapThreadProc( LPVOID lpParam );
DWORD WINAPI AudioCapThreadProc( LPVOID lpParam );
int OpenVideoCapture()
{
AVInputFormat *ifmt=av_find_input_format("gdigrab");
//
AVDictionary *options = NULL;
av_dict_set(&options, "framerate", "15", NULL);
//av_dict_set(&options,"offset_x","20",0);
//The distance from the top edge of the screen or desktop
//av_dict_set(&options,"offset_y","40",0);
//Video frame size. The default is to capture the full screen
//av_dict_set(&options,"video_size","320x240",0);
if(avformat_open_input(&pFormatCtx_Video, "desktop", ifmt, &options)!=0)
{
printf("Couldn't open input stream.（无法打开视频输入流）\n");
return -1;
}
if(avformat_find_stream_info(pFormatCtx_Video,NULL)<0)
{
printf("Couldn't find stream information.（无法获取视频流信息）\n");
return -1;
}
if (pFormatCtx_Video->streams[0]->codec->codec_type != AVMEDIA_TYPE_VIDEO)
{
printf("Couldn't find video stream information.（无法获取视频流信息）\n");
return -1;
}
pCodecCtx_Video = pFormatCtx_Video->streams[0]->codec;
pCodec_Video = avcodec_find_decoder(pCodecCtx_Video->codec_id);
if(pCodec_Video == NULL)
{
printf("Codec not found.（没有找到解码器）\n");
return -1;
}
if(avcodec_open2(pCodecCtx_Video, pCodec_Video, NULL) < 0)
{
printf("Could not open codec.（无法打开解码器）\n");
return -1;
}
img_convert_ctx = sws_getContext(pCodecCtx_Video->width, pCodecCtx_Video->height, pCodecCtx_Video->pix_fmt,
pCodecCtx_Video->width, pCodecCtx_Video->height, PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL);
frame_size = avpicture_get_size(pCodecCtx_Video->pix_fmt, pCodecCtx_Video->width, pCodecCtx_Video->height);
//
fifo_video = av_fifo_alloc(30 * avpicture_get_size(AV_PIX_FMT_YUV420P, pCodecCtx_Video->width, pCodecCtx_Video->height));
return 0;
}
static char *dup_wchar_to_utf8(wchar_t *w)
{
char *s = NULL;
int l = WideCharToMultiByte(CP_UTF8, 0, w, -1, 0, 0, 0, 0);
s = (char *) av_malloc(l);
if (s)
WideCharToMultiByte(CP_UTF8, 0, w, -1, s, l, 0, 0);
return s;
}
int OpenAudioCapture()
{
//
AVInputFormat *pAudioInputFmt = av_find_input_format("dshow");
//
char * psDevName = dup_wchar_to_utf8(L"audio=virtual-audio-capturer");
if (avformat_open_input(&pFormatCtx_Audio, psDevName, pAudioInputFmt,NULL) < 0)
{
printf("Couldn't open input stream.（无法打开音频输入流）\n");
return -1;
}
if(avformat_find_stream_info(pFormatCtx_Audio,NULL)<0)
return -1;
if(pFormatCtx_Audio->streams[0]->codec->codec_type != AVMEDIA_TYPE_AUDIO)
{
printf("Couldn't find video stream information.（无法获取音频流信息）\n");
return -1;
}
AVCodec *tmpCodec = avcodec_find_decoder(pFormatCtx_Audio->streams[0]->codec->codec_id);
if(0 > avcodec_open2(pFormatCtx_Audio->streams[0]->codec, tmpCodec, NULL))
{
printf("can not find or open audio decoder!\n");
}
return 0;
}
int OpenOutPut()
{
AVStream *pVideoStream = NULL, *pAudioStream = NULL;
const char *outFileName = "test.mp4";
avformat_alloc_output_context2(&pFormatCtx_Out, NULL, NULL, outFileName);
if (pFormatCtx_Video->streams[0]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
{
VideoIndex = 0;
pVideoStream = avformat_new_stream(pFormatCtx_Out, NULL);
if (!pVideoStream)
{
printf("can not new stream for output!\n");
return -1;
}
//set codec context param
pVideoStream->codec->codec = avcodec_find_encoder(AV_CODEC_ID_MPEG4);
pVideoStream->codec->height = pFormatCtx_Video->streams[0]->codec->height;
pVideoStream->codec->width = pFormatCtx_Video->streams[0]->codec->width;
pVideoStream->codec->time_base = pFormatCtx_Video->streams[0]->codec->time_base;
pVideoStream->codec->sample_aspect_ratio = pFormatCtx_Video->streams[0]->codec->sample_aspect_ratio;
// take first format from list of supported formats
pVideoStream->codec->pix_fmt = pFormatCtx_Out->streams[VideoIndex]->codec->codec->pix_fmts[0];
//open encoder
if (!pVideoStream->codec->codec)
{
printf("can not find the encoder!\n");
return -1;
}
if (pFormatCtx_Out->oformat->flags & AVFMT_GLOBALHEADER)
pVideoStream->codec->flags |= CODEC_FLAG_GLOBAL_HEADER;
if ((avcodec_open2(pVideoStream->codec, pVideoStream->codec->codec, NULL)) < 0)
{
printf("can not open the encoder\n");
return -1;
}
}
if(pFormatCtx_Audio->streams[0]->codec->codec_type == AVMEDIA_TYPE_AUDIO)
{
AVCodecContext *pOutputCodecCtx;
AudioIndex = 1;
pAudioStream = avformat_new_stream(pFormatCtx_Out, NULL);
pAudioStream->codec->codec = avcodec_find_encoder(pFormatCtx_Out->oformat->audio_codec);
pOutputCodecCtx = pAudioStream->codec;
pOutputCodecCtx->sample_rate = pFormatCtx_Audio->streams[0]->codec->sample_rate;
pOutputCodecCtx->channel_layout = pFormatCtx_Out->streams[0]->codec->channel_layout;
pOutputCodecCtx->channels = av_get_channel_layout_nb_channels(pAudioStream->codec->channel_layout);
if(pOutputCodecCtx->channel_layout == 0)
{
pOutputCodecCtx->channel_layout = AV_CH_LAYOUT_STEREO;
pOutputCodecCtx->channels = av_get_channel_layout_nb_channels(pOutputCodecCtx->channel_layout);
}
pOutputCodecCtx->sample_fmt = pAudioStream->codec->codec->sample_fmts[0];
AVRational time_base={1, pAudioStream->codec->sample_rate};
pAudioStream->time_base = time_base;
//audioCodecCtx->time_base = time_base;
pOutputCodecCtx->codec_tag = 0;
if (pFormatCtx_Out->oformat->flags & AVFMT_GLOBALHEADER)
pOutputCodecCtx->flags |= CODEC_FLAG_GLOBAL_HEADER;
if (avcodec_open2(pOutputCodecCtx, pOutputCodecCtx->codec, 0) < 0)
{
//
return -1;
}
}
if (!(pFormatCtx_Out->oformat->flags & AVFMT_NOFILE))
{
if(avio_open(&pFormatCtx_Out->pb, outFileName, AVIO_FLAG_WRITE) < 0)
{
printf("can not open output file handle!\n");
return -1;
}
}
if(avformat_write_header(pFormatCtx_Out, NULL) < 0)
{
printf("can not write the header of the output file!\n");
return -1;
}
return 0;
}
int _tmain(int argc, _TCHAR* argv[])
{
av_register_all();
avdevice_register_all();
if (OpenVideoCapture() < 0)
{
return -1;
}
if (OpenAudioCapture() < 0)
{
return -1;
}
if (OpenOutPut() < 0)
{
return -1;
}
InitializeCriticalSection(&VideoSection);
InitializeCriticalSection(&AudioSection);
AVFrame *picture = av_frame_alloc();
int size = avpicture_get_size(pFormatCtx_Out->streams[VideoIndex]->codec->pix_fmt,
pFormatCtx_Out->streams[VideoIndex]->codec->width, pFormatCtx_Out->streams[VideoIndex]->codec->height);
picture_buf = new uint8_t[size];
avpicture_fill((AVPicture *)picture, picture_buf,
pFormatCtx_Out->streams[VideoIndex]->codec->pix_fmt,
pFormatCtx_Out->streams[VideoIndex]->codec->width,
pFormatCtx_Out->streams[VideoIndex]->codec->height);
//star cap screen thread
CreateThread( NULL, 0, ScreenCapThreadProc, 0, 0, NULL);
//star cap audio thread
CreateThread( NULL, 0, AudioCapThreadProc, 0, 0, NULL);
int64_t cur_pts_v=0,cur_pts_a=0;
int VideoFrameIndex = 0, AudioFrameIndex = 0;
while(1)
{
if (_kbhit() != 0 && bCap)
{
bCap = false;
Sleep(2000);//
}
if (fifo_audio && fifo_video)
{
int sizeAudio = av_audio_fifo_size(fifo_audio);
int sizeVideo = av_fifo_size(fifo_video);
//
if (av_audio_fifo_size(fifo_audio) <= pFormatCtx_Out->streams[AudioIndex]->codec->frame_size &&
av_fifo_size(fifo_video) <= frame_size && !bCap)
{
break;
}
}
if(av_compare_ts(cur_pts_v, pFormatCtx_Out->streams[VideoIndex]->time_base,
cur_pts_a,pFormatCtx_Out->streams[AudioIndex]->time_base) <= 0)
{
//read data from fifo
if (av_fifo_size(fifo_video) < frame_size && !bCap)
{
cur_pts_v = 0x7fffffffffffffff;
}
if(av_fifo_size(fifo_video) >= size)
{
EnterCriticalSection(&VideoSection);
av_fifo_generic_read(fifo_video, picture_buf, size, NULL);
LeaveCriticalSection(&VideoSection);
avpicture_fill((AVPicture *)picture, picture_buf,
pFormatCtx_Out->streams[VideoIndex]->codec->pix_fmt,
pFormatCtx_Out->streams[VideoIndex]->codec->width,
pFormatCtx_Out->streams[VideoIndex]->codec->height);
//pts = n * (（1 / timbase）/ fps);
picture->pts = VideoFrameIndex * ((pFormatCtx_Video->streams[0]->time_base.den / pFormatCtx_Video->streams[0]->time_base.num) / 15);
int got_picture = 0;
AVPacket pkt;
av_init_packet(&pkt);
pkt.data = NULL;
pkt.size = 0;
int ret = avcodec_encode_video2(pFormatCtx_Out->streams[VideoIndex]->codec, &pkt, picture, &got_picture);
if(ret < 0)
{
//
continue;
}
if (got_picture==1)
{
pkt.stream_index = VideoIndex;
pkt.pts = av_rescale_q_rnd(pkt.pts, pFormatCtx_Video->streams[0]->time_base,
pFormatCtx_Out->streams[VideoIndex]->time_base, (AVRounding)(AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX));
pkt.dts = av_rescale_q_rnd(pkt.dts, pFormatCtx_Video->streams[0]->time_base,
pFormatCtx_Out->streams[VideoIndex]->time_base, (AVRounding)(AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX));
pkt.duration = ((pFormatCtx_Out->streams[0]->time_base.den / pFormatCtx_Out->streams[0]->time_base.num) / 15);
cur_pts_v = pkt.pts;
ret = av_interleaved_write_frame(pFormatCtx_Out, &pkt);
//delete[] pkt.data;
av_free_packet(&pkt);
}
VideoFrameIndex++;
}
}
else
{
if (NULL == fifo_audio)
{
continue;//
}
if (av_audio_fifo_size(fifo_audio) < pFormatCtx_Out->streams[AudioIndex]->codec->frame_size && !bCap)
{
cur_pts_a = 0x7fffffffffffffff;
}
if(av_audio_fifo_size(fifo_audio) >=
(pFormatCtx_Out->streams[AudioIndex]->codec->frame_size > 0 ? pFormatCtx_Out->streams[AudioIndex]->codec->frame_size : 1024))
{
AVFrame *frame;
frame = av_frame_alloc();
frame->nb_samples = pFormatCtx_Out->streams[AudioIndex]->codec->frame_size>0 ? pFormatCtx_Out->streams[AudioIndex]->codec->frame_size: 1024;
frame->channel_layout = pFormatCtx_Out->streams[AudioIndex]->codec->channel_layout;
frame->format = pFormatCtx_Out->streams[AudioIndex]->codec->sample_fmt;
frame->sample_rate = pFormatCtx_Out->streams[AudioIndex]->codec->sample_rate;
av_frame_get_buffer(frame, 0);
EnterCriticalSection(&AudioSection);
av_audio_fifo_read(fifo_audio, (void **)frame->data,
(pFormatCtx_Out->streams[AudioIndex]->codec->frame_size > 0 ? pFormatCtx_Out->streams[AudioIndex]->codec->frame_size : 1024));
LeaveCriticalSection(&AudioSection);
if (pFormatCtx_Out->streams[0]->codec->sample_fmt != pFormatCtx_Audio->streams[AudioIndex]->codec->sample_fmt
|| pFormatCtx_Out->streams[0]->codec->channels != pFormatCtx_Audio->streams[AudioIndex]->codec->channels
|| pFormatCtx_Out->streams[0]->codec->sample_rate != pFormatCtx_Audio->streams[AudioIndex]->codec->sample_rate)
{
//
}
AVPacket pkt_out;
av_init_packet(&pkt_out);
int got_picture = -1;
pkt_out.data = NULL;
pkt_out.size = 0;
frame->pts = AudioFrameIndex * pFormatCtx_Out->streams[AudioIndex]->codec->frame_size;
if (avcodec_encode_audio2(pFormatCtx_Out->streams[AudioIndex]->codec, &pkt_out, frame, &got_picture) < 0)
{
printf("can not decoder a frame");
}
av_frame_free(&frame);
if (got_picture)
{
pkt_out.stream_index = AudioIndex;
pkt_out.pts = AudioFrameIndex * pFormatCtx_Out->streams[AudioIndex]->codec->frame_size;
pkt_out.dts = AudioFrameIndex * pFormatCtx_Out->streams[AudioIndex]->codec->frame_size;
pkt_out.duration = pFormatCtx_Out->streams[AudioIndex]->codec->frame_size;
cur_pts_a = pkt_out.pts;
int ret = av_interleaved_write_frame(pFormatCtx_Out, &pkt_out);
av_free_packet(&pkt_out);
}
AudioFrameIndex++;
}
}
}
delete[] picture_buf;
delete[]frame_buf;
av_fifo_free(fifo_video);
av_audio_fifo_free(fifo_audio);
av_write_trailer(pFormatCtx_Out);
avio_close(pFormatCtx_Out->pb);
avformat_free_context(pFormatCtx_Out);
if (pFormatCtx_Video != NULL)
{
avformat_close_input(&pFormatCtx_Video);
pFormatCtx_Video = NULL;
}
if (pFormatCtx_Audio != NULL)
{
avformat_close_input(&pFormatCtx_Audio);
pFormatCtx_Audio = NULL;
}
if (NULL != img_convert_ctx)
{
sws_freeContext(img_convert_ctx);
img_convert_ctx = NULL;
}
return 0;
}
DWORD WINAPI ScreenCapThreadProc( LPVOID lpParam )
{
AVPacket packet;/* = (AVPacket *)av_malloc(sizeof(AVPacket))*/;
int got_picture;
AVFrame *pFrame;
pFrame= av_frame_alloc();
AVFrame *picture = av_frame_alloc();
int size = avpicture_get_size(pFormatCtx_Out->streams[VideoIndex]->codec->pix_fmt,
pFormatCtx_Out->streams[VideoIndex]->codec->width, pFormatCtx_Out->streams[VideoIndex]->codec->height);
//picture_buf = new uint8_t[size];
avpicture_fill((AVPicture *)picture, picture_buf,
pFormatCtx_Out->streams[VideoIndex]->codec->pix_fmt,
pFormatCtx_Out->streams[VideoIndex]->codec->width,
pFormatCtx_Out->streams[VideoIndex]->codec->height);
// FILE *p = NULL;
// p = fopen("proc_test.yuv", "wb+");
av_init_packet(&packet);
int height = pFormatCtx_Out->streams[VideoIndex]->codec->height;
int width = pFormatCtx_Out->streams[VideoIndex]->codec->width;
int y_size=height*width;
while(bCap)
{
packet.data = NULL;
packet.size = 0;
if (av_read_frame(pFormatCtx_Video, &packet) < 0)
{
av_free_packet(&packet);
continue;
}
if(packet.stream_index == 0)
{
if (avcodec_decode_video2(pCodecCtx_Video, pFrame, &got_picture, &packet) < 0)
{
printf("Decode Error.（解码错误）\n");
continue;
}
if (got_picture)
{
sws_scale(img_convert_ctx, (const uint8_t* const*)pFrame->data, pFrame->linesize, 0,
pFormatCtx_Out->streams[VideoIndex]->codec->height, picture->data, picture->linesize);
if (av_fifo_space(fifo_video) >= size)
{
EnterCriticalSection(&VideoSection);
av_fifo_generic_write(fifo_video, picture->data[0], y_size, NULL);
av_fifo_generic_write(fifo_video, picture->data[1], y_size/4, NULL);
av_fifo_generic_write(fifo_video, picture->data[2], y_size/4, NULL);
LeaveCriticalSection(&VideoSection);
}
}
}
av_free_packet(&packet);
//Sleep(50);
}
av_frame_free(&pFrame);
av_frame_free(&picture);
//delete[] picture_buf;
return 0;
}
DWORD WINAPI AudioCapThreadProc( LPVOID lpParam )
{
AVPacket pkt;
AVFrame *frame;
frame = av_frame_alloc();
int gotframe;
while(bCap)
{
pkt.data = NULL;
pkt.size = 0;
if(av_read_frame(pFormatCtx_Audio,&pkt) < 0)
{
av_free_packet(&pkt);
continue;
}
if (avcodec_decode_audio4(pFormatCtx_Audio->streams[0]->codec, frame, &gotframe, &pkt) < 0)
{
av_frame_free(&frame);
printf("can not decoder a frame");
break;
}
av_free_packet(&pkt);
if (!gotframe)
{
continue;//
}
if (NULL == fifo_audio)
{
fifo_audio = av_audio_fifo_alloc(pFormatCtx_Audio->streams[0]->codec->sample_fmt,
pFormatCtx_Audio->streams[0]->codec->channels, 30 * frame->nb_samples);
}
int buf_space = av_audio_fifo_space(fifo_audio);
if (av_audio_fifo_space(fifo_audio) >= frame->nb_samples)
{
EnterCriticalSection(&AudioSection);
av_audio_fifo_write(fifo_audio, (void **)frame->data, frame->nb_samples);
LeaveCriticalSection(&AudioSection);
}
}
av_frame_free(&frame);
return 0;
}
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