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Autres articles (86)
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Gestion de la ferme
2 mars 2010, parLa ferme est gérée dans son ensemble par des "super admins".
Certains réglages peuvent être fais afin de réguler les besoins des différents canaux.
Dans un premier temps il utilise le plugin "Gestion de mutualisation" -
Organiser par catégorie
17 mai 2013, parDans MédiaSPIP, une rubrique a 2 noms : catégorie et rubrique.
Les différents documents stockés dans MédiaSPIP peuvent être rangés dans différentes catégories. On peut créer une catégorie en cliquant sur "publier une catégorie" dans le menu publier en haut à droite ( après authentification ). Une catégorie peut être rangée dans une autre catégorie aussi ce qui fait qu’on peut construire une arborescence de catégories.
Lors de la publication prochaine d’un document, la nouvelle catégorie créée sera proposée (...) -
Récupération d’informations sur le site maître à l’installation d’une instance
26 novembre 2010, parUtilité
Sur le site principal, une instance de mutualisation est définie par plusieurs choses : Les données dans la table spip_mutus ; Son logo ; Son auteur principal (id_admin dans la table spip_mutus correspondant à un id_auteur de la table spip_auteurs)qui sera le seul à pouvoir créer définitivement l’instance de mutualisation ;
Il peut donc être tout à fait judicieux de vouloir récupérer certaines de ces informations afin de compléter l’installation d’une instance pour, par exemple : récupérer le (...)
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Codec not found while H.264 encoding using FFMPEG in iOS
12 juin 2013, par Sukhpal SinghI am trying to encode video in h.264 format using FFMpeg in iOS. Actually I am receiving sample buffer from iPhone Camera and then converting it AVFrame and further from AVFrame to H.264 video. But while h.264 encoding if I use :
codec = avcodec_find_encoder(CODEC_ID_MPEG1VIDEO);Then codec is found but if I use :
codec = avcodec_find_encoder(CODEC_ID_H264);Then codec is nil means codec not found. Full code is as below :
static void encode(AVFrame *picture)
{
AVCodec *codec;
AVCodecContext *c= NULL;
int i, out_size, size, outbuf_size;
uint8_t *outbuf, *picture_buf;
printf("Video encoding\n");
/* find the mpeg1 video encoder */
//avcodec_init() ; // Also tried this but giving warning and not worked
avcodec_register_all();
codec = avcodec_find_encoder(CODEC_ID_H264);
if (!codec) {
fprintf(stderr, "codec not found\n");
exit(1);
}
c= avcodec_alloc_context();
picture= avcodec_alloc_frame();
/* put sample parameters */
c->bit_rate = 400000;
/* resolution must be a multiple of two */
c->width = 352;
c->height = 288;
/* frames per second */
c->time_base= (AVRational){1,25};
c->gop_size = 10; /* emit one intra frame every ten frames */
c->max_b_frames=1;
c->pix_fmt = PIX_FMT_YUV420P;
/* open it */
if (avcodec_open(c, codec) < 0) {
fprintf(stderr, "could not open codec\n");
exit(1);
}
/* alloc image and output buffer */
outbuf_size = 100000;
outbuf = malloc(outbuf_size);
size = c->width * c->height;
picture_buf = malloc((size * 3) / 2); /* size for YUV 420 */
out_size = avcodec_encode_video(c, outbuf, outbuf_size, picture);
NSLog(@"NSdada===%@",[NSData dataWithBytes:(const void *)outbuf length:out_size]);
free(picture_buf);
free(outbuf);
avcodec_close(c);
av_free(c);
av_free(picture);
printf("\n");
} -
iOS FFMPEG encode images to video
10 avril 2013, par brad.roushI am trying to take a set of UIImages and create a video file out of them with FFMPEG. Seems there are lots of questions about this topic but non have been able to get this working correctly for me. This one was particularly helpful in giving me a starting point. This iFrameExtractor example was also very helpful but I want to do this in reverse, then add audio.
This is the closest I have gotten and it creates a short silent video with flashing colors and no images :
// Register all formats and codecs
av_register_all();
AVCodec *codec;
AVCodecContext *c= NULL;
int i, out_size, size, outbuf_size;
FILE *file;
AVFrame *picture;
uint8_t *outbuf;
NSLog(@"Video encoding");
/* find the mpeg video encoder */
codec = avcodec_find_encoder(CODEC_ID_MPEG2VIDEO);
if (!codec) {
fprintf(stderr, "codec not found\n");
exit(1);
}
c= avcodec_alloc_context3(codec);
picture= avcodec_alloc_frame();
/* put sample parameters */
c->bit_rate = 400000;
/* resolution must be a multiple of two */
c->width = 352;
c->height = 288;
/* frames per second */
c->time_base= (AVRational){1,25};
c->gop_size = 10; /* emit one intra frame every ten frames */
c->max_b_frames=1;
c->pix_fmt = PIX_FMT_YUV420P;
/* open it */
if (avcodec_open2(c, codec, nil) < 0) {
fprintf(stderr, "could not open codec\n");
exit(1);
}
// Put file in place
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docs_dir = [paths objectAtIndex:0];
NSString *filePath = [docs_dir stringByAppendingPathComponent:@"test.mpeg"];
// Seed file
NSString *sourcePath = [[NSBundle mainBundle] pathForResource:@"test" ofType:@"mov"];
NSError* error = nil;
if (![[NSFileManager defaultManager] copyItemAtPath:sourcePath toPath:filePath error:&error]) {
NSLog(@"Test Video creation failed:%@",[error userInfo]);
} else NSLog(@"Test Video Created");
const char *filename = [filePath UTF8String];
file = fopen(filename, "wb");
if (!file) {
fprintf(stderr, "could not open %s\n", "filename");
exit(1);
}
/* alloc image and output buffer */
outbuf_size = 100000;
outbuf = malloc(outbuf_size);
size = c->width * c->height;
//#pragma mark -
AVFrame* outpic = avcodec_alloc_frame();
int nbytes = avpicture_get_size(PIX_FMT_YUV420P, c->width, c->height);
//create buffer for the output image
uint8_t* outbuffer = (uint8_t*)av_malloc(nbytes);
AVPacket packet;
av_init_packet(&packet);
//#pragma mark -
for(i=1;i<50;i++) {
fflush(stdout);
int numBytes = avpicture_get_size(PIX_FMT_YUV420P, c->width, c->height);
uint8_t *buffer = (uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
UIImage *image = [UIImage imageWithContentsOfFile:[docs_dir stringByAppendingPathComponent:[NSString stringWithFormat:@"%d.png",i]]];
CGImageRef newCgImage = [image CGImage];
CGDataProviderRef dataProvider = CGImageGetDataProvider(newCgImage);
CFDataRef bitmapData = CGDataProviderCopyData(dataProvider);
buffer = (uint8_t *)CFDataGetBytePtr(bitmapData);
avpicture_fill((AVPicture*)picture, buffer, PIX_FMT_RGB8, c->width, c->height);
avpicture_fill((AVPicture*)outpic, outbuffer, PIX_FMT_YUV420P, c->width, c->height);
struct SwsContext* fooContext = sws_getContext(c->width, c->height,
PIX_FMT_RGB8,
c->width, c->height,
PIX_FMT_YUV420P,
SWS_FAST_BILINEAR, NULL, NULL, NULL);
//perform the conversion
sws_scale(fooContext, outpic->data, outpic->linesize,
0, c->height, outpic->data, outpic->linesize);
// Tried This but it didn't work
//sws_scale(fooContext, picture->data, picture->linesize, 0, c->height, outpic->data, outpic->linesize);
out_size = avcodec_encode_video(c, outbuf, outbuf_size, outpic);
// Tried this but it didn't work
//int test = 0;
//out_size = avcodec_encode_video2(c, &packet, outpic, &test);
printf("encoding frame %3d (size=%5d)\n", i, out_size);
fwrite(outbuf, 1, out_size, file);
free(buffer);
buffer = NULL;
}
/* get the delayed frames */
/*
for(; out_size; i++) {
fflush(stdout);
out_size = avcodec_encode_video(c, outbuf, outbuf_size, NULL);
printf("write frame %3d (size=%5d)\n", i, out_size);
fwrite(outbuf, 1, outbuf_size, file);
}
*/
/* add sequence end code to have a real mpeg file */
outbuf[0] = 0x00;
outbuf[1] = 0x00;
outbuf[2] = 0x01;
outbuf[3] = 0xb7;
fwrite(outbuf, 1, 4, file);
fclose(file);
free(outbuf);
avcodec_close(c);
av_free(c);
av_free(picture);
printf("\n");Any ideas will be helpful here. If anyone knows of any other good objective-c examples, this would also be great.
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FFMpeg encoded video will only play in FFPlay
8 novembre 2013, par mohMI've been debugging my program for a couple of weeks now with the output video only showing a blank screen (was testing with VLC, WMP and WMPClassic). I happened to try using FFPlay and lo and behold the video works perfectly. I've read that this is usually caused by an incorrect pixel format, and that switching to PIX_FMT_YUV420P will make it work universally...but I'm already using that pixel format in the encoding process. Is there anything else that is causing this ?
AVCodec* codec;
AVCodecContext* c = NULL;
uint8_t* outbuf;
int i, out_size, outbuf_size;
avcodec_register_all();
printf("Video encoding\n");
// Find the mpeg1 video encoder
codec = avcodec_find_encoder(CODEC_ID_H264);
if (!codec) {
fprintf(stderr, "Codec not found\n");
exit(1);
}
else printf("H264 codec found\n");
c = avcodec_alloc_context3(codec);
c->bit_rate = 400000;
c->width = 1920; // resolution must be a multiple of two (1280x720),(1900x1080),(720x480)
c->height = 1200;
c->time_base.num = 1; // framerate numerator
c->time_base.den = 25; // framerate denominator
c->gop_size = 10; // emit one intra frame every ten frames
c->max_b_frames = 1; // maximum number of b-frames between non b-frames
//c->keyint_min = 1; // minimum GOP size
//c->i_quant_factor = (float)0.71; // qscale factor between P and I frames
//c->b_frame_strategy = 20;
//c->qcompress = (float)0.6;
//c->qmin = 20; // minimum quantizer
//c->qmax = 51; // maximum quantizer
//c->max_qdiff = 4; // maximum quantizer difference between frames
//c->refs = 4; // number of reference frames
//c->trellis = 1; // trellis RD Quantization
c->pix_fmt = PIX_FMT_YUV420P;
c->codec_id = CODEC_ID_H264;
//c->codec_type = AVMEDIA_TYPE_VIDEO;
// Open the encoder
if (avcodec_open2(c, codec,NULL) < 0) {
fprintf(stderr, "Could not open codec\n");
exit(1);
}
else printf("H264 codec opened\n");
outbuf_size = 100000 + c->width*c->height*(32>>3);//*(32>>3); // alloc image and output buffer
outbuf = static_cast(malloc(outbuf_size));
printf("Setting buffer size to: %d\n",outbuf_size);
FILE* f = fopen("example.mpg","wb");
if(!f) printf("x - Cannot open video file for writing\n");
else printf("Opened video file for writing\n");
// encode 5 seconds of video
for(i=0;iwidth, c->height);
uint8_t* outbuffer = (uint8_t*)av_malloc(nbytes*sizeof(uint8_t));
AVFrame* inpic = avcodec_alloc_frame();
AVFrame* outpic = avcodec_alloc_frame();
outpic->pts = (int64_t)((float)i * (1000.0/((float)(c->time_base.den))) * 90);
avpicture_fill((AVPicture*)inpic, (uint8_t*)pPixels, PIX_FMT_RGB32, c->width, c->height); // Fill picture with image
avpicture_fill((AVPicture*)outpic, outbuffer, PIX_FMT_YUV420P, c->width, c->height);
av_image_alloc(outpic->data, outpic->linesize, c->width, c->height, c->pix_fmt, 1);
inpic->data[0] += inpic->linesize[0]*(screenHeight-1); // Flipping frame
inpic->linesize[0] = -inpic->linesize[0]; // Flipping frame
struct SwsContext* fooContext = sws_getContext(screenWidth, screenHeight, PIX_FMT_RGB32, c->width, c->height, PIX_FMT_YUV420P, SWS_FAST_BILINEAR, NULL, NULL, NULL);
sws_scale(fooContext, inpic->data, inpic->linesize, 0, c->height, outpic->data, outpic->linesize);
// encode the image
out_size = avcodec_encode_video(c, outbuf, outbuf_size, outpic);
printf("Encoding frame %3d (size=%5d)\n", i, out_size);
fwrite(outbuf, 1, out_size, f);
delete [] pPixels;
av_free(outbuffer);
av_free(inpic);
av_free(outpic);
}
// get the delayed frames
for(; out_size; i++) {
fflush(stdout);
out_size = avcodec_encode_video(c, outbuf, outbuf_size, NULL);
printf("Writing frame %3d (size=%5d)\n", i, out_size);
fwrite(outbuf, 1, out_size, f);
}
// add sequence end code to have a real mpeg file
outbuf[0] = 0x00;
outbuf[1] = 0x00;
outbuf[2] = 0x01;
outbuf[3] = 0xb7;
fwrite(outbuf, 1, 4, f);
fclose(f);
avcodec_close(c);
free(outbuf);
av_free(c);
printf("Closed codec and Freed\n");
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