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Médias (1)
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Spitfire Parade - Crisis
15 mai 2011, par
Mis à jour : Septembre 2011
Langue : English
Type : Audio
Autres articles (62)
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Websites made with MediaSPIP
2 mai 2011, parThis page lists some websites based on MediaSPIP.
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Creating farms of unique websites
13 avril 2011, parMediaSPIP platforms can be installed as a farm, with a single "core" hosted on a dedicated server and used by multiple websites.
This allows (among other things) : implementation costs to be shared between several different projects / individuals rapid deployment of multiple unique sites creation of groups of like-minded sites, making it possible to browse media in a more controlled and selective environment than the major "open" (...) -
Problèmes fréquents
10 mars 2010, parPHP et safe_mode activé
Une des principales sources de problèmes relève de la configuration de PHP et notamment de l’activation du safe_mode
La solution consiterait à soit désactiver le safe_mode soit placer le script dans un répertoire accessible par apache pour le site
Sur d’autres sites (6228)
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Merge commit ’e0046bc9c96150fa06146ace9093f06857dd7b23’
23 mars 2015, par Michael Niedermayer -
ffmpeg library performance for decoding h.264 for embedded device
2 avril 2015, par pasifusI have some confuse when tried to compile and run decode h.264 on ARM and MIPS architecture.
I have two embedded devices. I tired to run simple code that read h264 format from file and decode it to h264 in loop in maximum speed (without sleep between frames)
I found that it too slow in there devices.
I tested HD video (720p/25fps)- MIPS32® 1004K (700MHz) it was 4 fps average.
- Raspberry Pi Model B (700MHz) it also was 4 fps average. (i know that raspberry have GPU to decoding/encoding)
A also check it on my virtual machine on ubuntu i686 (1300MHz) and it was 200 fps average.
The question : why it so different preference ? Somebody know how to increase decoding preference on MIPS32® 1004K architecture ?
#include
#include
#include
#include
#include <sys></sys>time.h>
#include
#include "libavcodec/avcodec.h"
#include "libavutil/mathematics.h"
#define INBUF_SIZE 80000
static long get_time_diff(struct timeval time_now) {
struct timeval time_now2;
gettimeofday(&time_now2,0);
return time_now2.tv_sec*1.e6 - time_now.tv_sec*1.e6 + time_now2.tv_usec - time_now.tv_usec;
}
int main(int argc, char **argv)
{
AVCodec *codec;
AVCodecContext *c= NULL;
AVCodecParserContext *parser = NULL;
int frame, got_picture, len2, len;
const char *filename;
FILE *f;
AVFrame *picture;
char *arghwtf = malloc(INBUF_SIZE);
uint64_t in_len;
int pts, dts;
struct timeval t,t2;
float inv_fps = 1e6/23.98;
AVPacket avpkt;
// register all the codecs
avcodec_register_all();
// log level
av_log_set_level(AV_LOG_PANIC|AV_LOG_FATAL|AV_LOG_ERROR|AV_LOG_WARNING);
filename = argv[1];
av_init_packet(&avpkt);
printf("Decoding file %s...\n", filename);
// find the H.264 video decoder
codec = avcodec_find_decoder(CODEC_ID_H264);
if (!codec)
{
fprintf(stderr, "codec not found\n");
exit(1);
}
c = avcodec_alloc_context3(codec);
picture = avcodec_alloc_frame();
// skiploopfilter=all
c->skip_loop_filter = 48;
AVDictionary* dictionary = NULL;
if (avcodec_open2(c, codec, &dictionary) < 0)
{
fprintf(stderr, "could not open codec\n");
exit(1);
}
// the codec gives us the frame size, in samples
parser = av_parser_init(c->codec_id);
parser->flags |= PARSER_FLAG_ONCE;
f = fopen(filename, "rb");
if (!f)
{
fprintf(stderr, "could not open %s\n", filename);
exit(1);
}
frame = 0;
gettimeofday(&t, 0);
if(fread(arghwtf, 1, INBUF_SIZE, f) == 0)
{
exit(1);
}
in_len = 80000;
gettimeofday(&t2, 0);
while (in_len > 0 && !feof(f))
{
len = av_parser_parse2(parser, c, &avpkt.data, &avpkt.size, arghwtf, in_len, pts, dts, AV_NOPTS_VALUE);
len2 = avcodec_decode_video2(c, picture, &got_picture, &avpkt);
if (len2 < 0) {
fprintf(stderr, "Error while decoding frame %d\n", frame);
exit(1);
}
if (got_picture)
{
fprintf(stderr, "\rDisplaying %c %dx%d :frame %3d (%02d:%03d)...", av_get_picture_type_char(picture->pict_type), c->width, c->height, frame, (int)(get_time_diff(t)/1000000), (int)((get_time_diff(t)/1000)%1000));
fflush(stderr);
frame++;
}
memcpy(arghwtf, arghwtf + len, 80000-len);
fread(arghwtf + 80000 - len, 1, len, f);
}
fclose(f);
avcodec_close(c);
av_free(c);
av_free(picture);
printf("\n");
printf("Avarage fps: %d\n", (int)(((double)frame)/(double)(get_time_diff(t)/1000)*1000));
return 0;
} -
Revision bfc27bb614 : tx-skip experiment : improve entropy coding of coeff tokens This patch allows th
31 mars 2015, par hui suChanged Paths :
Modify /vp9/common/vp9_entropy.c
Modify /vp9/common/vp9_entropy.h
Modify /vp9/common/vp9_onyxc_int.h
Modify /vp9/common/vp9_quant_common.c
Modify /vp9/decoder/vp9_detokenize.c
Modify /vp9/encoder/vp9_encodemb.c
Modify /vp9/encoder/vp9_rdopt.c
Modify /vp9/encoder/vp9_tokenize.c
tx-skip experiment : improve entropy coding of coeff tokensThis patch allows the prediction residues of tx-skipped blocks
to use probs that are different from regular transfrom
coefficients for token entropy coding. Prediction residues are
assumed as in band 6.The initial value of probs is obtained with stats from limited
tests. The statistic model for constrained token nodes has not
been optimized. The probs for token extra bits have not been
optimized. These can be future work.Certain coding improvment is observed :
derflr with all experiments : +6.26% (+0.10%)
screen_content with palette : +22.48% (+1.28%)Change-Id : I1c0d78178ee9f3655febb6f30cdaef8ee9f8e3cc