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Autres articles (18)
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Taille des images et des logos définissables
9 février 2011, parDans beaucoup d’endroits du site, logos et images sont redimensionnées pour correspondre aux emplacements définis par les thèmes. L’ensemble des ces tailles pouvant changer d’un thème à un autre peuvent être définies directement dans le thème et éviter ainsi à l’utilisateur de devoir les configurer manuellement après avoir changé l’apparence de son site.
Ces tailles d’images sont également disponibles dans la configuration spécifique de MediaSPIP Core. La taille maximale du logo du site en pixels, on permet (...) -
Contribute to a better visual interface
13 avril 2011MediaSPIP is based on a system of themes and templates. Templates define the placement of information on the page, and can be adapted to a wide range of uses. Themes define the overall graphic appearance of the site.
Anyone can submit a new graphic theme or template and make it available to the MediaSPIP community. -
MediaSPIP Core : La Configuration
9 novembre 2010, parMediaSPIP Core fournit par défaut trois pages différentes de configuration (ces pages utilisent le plugin de configuration CFG pour fonctionner) : une page spécifique à la configuration générale du squelettes ; une page spécifique à la configuration de la page d’accueil du site ; une page spécifique à la configuration des secteurs ;
Il fournit également une page supplémentaire qui n’apparait que lorsque certains plugins sont activés permettant de contrôler l’affichage et les fonctionnalités spécifiques (...)
Sur d’autres sites (4011)
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ffmpeg : AVI to FLV conversion doubles file size
22 septembre 2012, par weekensI convert AVI to FLV with ffmpeg using -sameq parameter (same quality) :
ffmpeg -i test.avi -sameq -f flv sameq.flvThe resulting file has the same video and audio quality as the original, but it's more than twice the original file size :
84M sameq.flv
41M test.aviWhy does it happen ?
Transcoder output :
ffmpeg version N-34750-g070d2d7, Copyright (c) 2000-2011 the FFmpeg developers
built on Nov 12 2011 11:23:07 with gcc 4.6.1
configuration: --enable-gpl --enable-version3 --enable-nonfree --enable-postproc --enable-libfaac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid --enable-x11grab
libavutil 51. 24. 1 / 51. 24. 1
libavcodec 53. 33. 0 / 53. 33. 0
libavformat 53. 20. 0 / 53. 20. 0
libavdevice 53. 4. 0 / 53. 4. 0
libavfilter 2. 48. 0 / 2. 48. 0
libswscale 2. 1. 0 / 2. 1. 0
libpostproc 51. 2. 0 / 51. 2. 0
Input #0, avi, from 'test.avi':
Duration: 00:06:30.00, start: 0.000000, bitrate: 866 kb/s
Stream #0:0: Video: mpeg4 (Advanced Real Time Simple Profile) (DIVX / 0x58564944), yuv420p, 400x300 [SAR 1:1 DAR 4:3], 25 tbr, 25 tbn, 25 tbc
Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055), 44100 Hz, mono, s16, 64 kb/s
[buffer @ 0xa247ae0] w:400 h:300 pixfmt:yuv420p tb:1/1000000 sar:1/1 sws_param:
Output #0, flv, to 'sameq.flv':
Metadata:
encoder : Lavf53.20.0
Stream #0:0: Video: flv1 ([2][0][0][0] / 0x0002), yuv420p, 400x300 [SAR 1:1 DAR 4:3], q=2-31, 200 kb/s, 1k tbn, 25 tbc
Stream #0:1: Audio: mp3 ([2][0][0][0] / 0x0002), 44100 Hz, mono, s16, 128 kb/s
Stream mapping:
Stream #0:0 -> #0:0 (mpeg4 -> flv)
Stream #0:1 -> #0:1 (mp3 -> libmp3lame)
Press [q] to stop, [?] for help
frame= 9742 fps=255 q=0.0 Lsize= 85074kB time=00:06:30.00 bitrate=1787.0kbits/s
video:79163kB audio:5525kB global headers:0kB muxing overhead 0.455568% -
Capture video stream with FFmpeg
14 mars 2013, par ricksterI wrote an android app that sends a live video stream from the camera over a socket to my computer. Is it possible to use FFmpeg to decode the MPEG4 video stream and some how display what the camera is seeing in real time ? I'm guessing I would have to create a bitmap from the latest information it had from the byte stream and display it on the computer at 20+ FPS.
How would I go about doing something like this ?
C++, C# or Java is fine. From my understanding FFmpeg is written in C++ -
Video created using H263 codec and ffmpeg does not play on android device [closed]
21 mars 2013, par susheel tickooI have created a video using FFmpeg and H263 codec. But when I play the video on an Android device the player is unable to play it. I have used both the extensions .mp4 and .3gp.
void generate(JNIEnv *pEnv, jobject pObj,jobjectArray stringArray,int famerate,int width,int height,jstring videoFilename)
{
AVCodec *codec;
AVCodecContext *c= NULL;
//int framesnum=5;
int i,looper, out_size, size, x, y,encodecbuffsize,j;
__android_log_write(ANDROID_LOG_INFO, "record","************into generate************");
int imagecount= (*pEnv)->GetArrayLength(pEnv, stringArray);
__android_log_write(ANDROID_LOG_INFO, "record","************got magecount************");
int retval=-10;
FILE *f;
AVFrame *picture,*encoded_avframe;
uint8_t *encodedbuffer;
jbyte *raw_record;
char logdatadata[100];
int returnvalue = -1,numBytes =-1;
const char *gVideoFileName = (char *)(*pEnv)->GetStringUTFChars(pEnv, videoFilename, NULL);
__android_log_write(ANDROID_LOG_INFO, "record","************got video file name************");
/* find the mpeg1 video encoder */
codec = avcodec_find_encoder(CODEC_ID_H264);
if (!codec) {
__android_log_write(ANDROID_LOG_INFO, "record","codec not found");
exit(1);
}
c= avcodec_alloc_context();
/*c->bit_rate = 400000;
c->width = width;
c->height = height;
c->time_base= (AVRational){1,famerate};
c->gop_size = 12; // emit one intra frame every ten frames
c->max_b_frames=0;
c->pix_fmt = PIX_FMT_YUV420P;
c->codec_type = AVMEDIA_TYPE_VIDEO;
c->codec_id = CODEC_ID_H263;*/
c->bit_rate = 400000;
// resolution must be a multiple of two
c->width = 176;
c->height = 144;
c->pix_fmt = PIX_FMT_YUV420P;
c->qcompress = 0.0;
c->qblur = 0.0;
c->gop_size = 20; //or 1
c->sub_id = 1;
c->workaround_bugs = FF_BUG_AUTODETECT;
//pFFmpeg->c->time_base = (AVRational){1,25};
c->time_base.num = 1;
c->time_base.den = famerate;
c->max_b_frames = 0; //pas de B frame en H263
// c->opaque = opaque;
c->dct_algo = FF_DCT_AUTO;
c->idct_algo = FF_IDCT_AUTO;
//lc->rtp_mode = 0;
c->rtp_payload_size = 1000;
c->rtp_callback = 0; // ffmpeg_rtp_callback;
c->flags |= CODEC_FLAG_QSCALE;
c->mb_decision = FF_MB_DECISION_RD;
c->thread_count = 1;
#define DEFAULT_RATE (16 * 8 * 1024)
c->rc_min_rate = DEFAULT_RATE;
c->rc_max_rate = DEFAULT_RATE;
c->rc_buffer_size = DEFAULT_RATE * 64;
c->bit_rate = DEFAULT_RATE;
sprintf(logdatadata, "------width from c ---- = %d",width);
__android_log_write(ANDROID_LOG_INFO, "record",logdatadata);
sprintf(logdatadata, "------height from c ---- = %d",height);
__android_log_write(ANDROID_LOG_INFO, "record",logdatadata);
__android_log_write(ANDROID_LOG_INFO, "record","************Found codec and now opening it************");
/* open it */
retval = avcodec_open(c, codec);
if ( retval < 0)
{
sprintf(logdatadata, "------avcodec_open ---- retval = %d",retval);
__android_log_write(ANDROID_LOG_INFO, "record",logdatadata);
__android_log_write(ANDROID_LOG_INFO, "record","could not open codec");
exit(1);
}
__android_log_write(ANDROID_LOG_INFO, "record","statement 5");
f = fopen(gVideoFileName, "ab");
if (!f) {
__android_log_write(ANDROID_LOG_INFO, "record","could not open video file");
exit(1);
}
__android_log_write(ANDROID_LOG_INFO, "record", "***************Allocating encodedbuffer*********\n");
encodecbuffsize = avpicture_get_size(PIX_FMT_RGB24, c->width, c->height);
sprintf(logdatadata, "encodecbuffsize = %d",encodecbuffsize);
__android_log_write(ANDROID_LOG_INFO, "record",logdatadata);
encodedbuffer = malloc(encodecbuffsize);
jclass cls = (*pEnv)->FindClass(pEnv, "com/canvasm/mediclinic/VideoGenerator");
jmethodID mid = (*pEnv)->GetMethodID(pEnv, cls, "videoProgress", "(Ljava/lang/String;)Ljava/lang/String;");
jmethodID mid_delete = (*pEnv)->GetMethodID(pEnv, cls, "deleteTempFile", "(Ljava/lang/String;)Ljava/lang/String;");
if (mid == 0)
return;
__android_log_write(ANDROID_LOG_INFO, "native","got method id");
for(i=0;i<=imagecount;i++) {
jboolean isCp;
int progress = 0;
float temp;
jstring string;
if(i==imagecount)
string = (jstring) (*pEnv)->GetObjectArrayElement(pEnv, stringArray, imagecount-1);
else
string = (jstring) (*pEnv)->GetObjectArrayElement(pEnv, stringArray, i);
const char *rawString = (*pEnv)->GetStringUTFChars(pEnv, string, &isCp);
__android_log_write(ANDROID_LOG_INFO, "record",rawString);
picture = OpenImage(rawString,width,height);
//WriteJPEG(c,picture,i);
// encode video
memset(encodedbuffer,0,encodecbuffsize);
//do{
for(looper=0;looper<5;looper++)
{
memset(encodedbuffer,0,encodecbuffsize);
out_size = avcodec_encode_video(c, encodedbuffer, encodecbuffsize, picture);
sprintf(logdatadata, "avcodec_encode_video ----- out_size = %d \n",out_size );
__android_log_write(ANDROID_LOG_INFO, "record",logdatadata);
if(out_size>0)
break;
}
__android_log_write(ANDROID_LOG_INFO, "record","*************Start looping for same image*******");
returnvalue = fwrite(encodedbuffer, 1, out_size, f);
sprintf(logdatadata, "fwrite ----- returnvalue = %d \n",returnvalue );
__android_log_write(ANDROID_LOG_INFO, "record",logdatadata);
__android_log_write(ANDROID_LOG_INFO, "record","*************End looping for same image*******");
// publishing progress
progress = ((i*100)/(imagecount+1))+15;//+1 is for last frame duplicated entry
if(progress<20 )
progress =20;
if(progress>=95 )
progress =95;
sprintf(logdatadata, "%d",progress );
jstring jstrBuf = (*pEnv)->NewStringUTF(pEnv, logdatadata);
(*pEnv)->CallObjectMethod(pEnv, pObj, mid,jstrBuf);
if(i>0)
(*pEnv)->CallObjectMethod(pEnv, pObj, mid_delete,string);
}
/* get the delayed frames */
for(; out_size; i++) {
fflush(stdout);
out_size = avcodec_encode_video(c, encodedbuffer, encodecbuffsize, NULL);
fwrite(encodedbuffer, 20, out_size, f);
}
/* add sequence end code to have a real mpeg file */
encodedbuffer[0] = 0x00;
encodedbuffer[1] = 0x00;
encodedbuffer[2] = 0x01;
encodedbuffer[3] = 0xb7;
fwrite(encodedbuffer, 1, 4, f);
fclose(f);
free(encodedbuffer);
avcodec_close(c);
av_free(c);
__android_log_write(ANDROID_LOG_INFO, "record","Video created ");
// last updation of 100%
sprintf(logdatadata, "%d",100 );
jstring jstrBuf = (*pEnv)->NewStringUTF(pEnv, logdatadata);
(*pEnv)->CallObjectMethod(pEnv, pObj, mid,jstrBuf);
}
AVFrame* OpenImage(const char* imageFileName,int w,int h)
{
AVFrame *pFrame;
AVCodec *pCodec ;
AVFormatContext *pFormatCtx;
AVCodecContext *pCodecCtx;
uint8_t *buffer;
int frameFinished,framesNumber = 0,retval = -1,numBytes=0;
AVPacket packet;
char logdatadata[100];
//__android_log_write(ANDROID_LOG_INFO, "OpenImage",imageFileName);
if(av_open_input_file(&pFormatCtx, imageFileName, NULL, 0, NULL)!=0)
//if(avformat_open_input(&pFormatCtx,imageFileName,NULL,NULL)!=0)
{
__android_log_write(ANDROID_LOG_INFO, "record",
"Can't open image file ");
return NULL;
}
pCodecCtx = pFormatCtx->streams[0]->codec;
pCodecCtx->width = w;
pCodecCtx->height = h;
pCodecCtx->pix_fmt = PIX_FMT_YUV420P;
// Find the decoder for the video stream
pCodec = avcodec_find_decoder(pCodecCtx->codec_id);
if (!pCodec)
{
__android_log_write(ANDROID_LOG_INFO, "record",
"Can't open image file ");
return NULL;
}
pFrame = avcodec_alloc_frame();
numBytes = avpicture_get_size(PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height);
buffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t));
sprintf(logdatadata, "numBytes = %d",numBytes);
__android_log_write(ANDROID_LOG_INFO, "record",logdatadata);
retval = avpicture_fill((AVPicture *) pFrame, buffer, PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height);
// Open codec
if(avcodec_open(pCodecCtx, pCodec)<0)
{
__android_log_write(ANDROID_LOG_INFO, "record","Could not open codec");
return NULL;
}
if (!pFrame)
{
__android_log_write(ANDROID_LOG_INFO, "record","Can't allocate memory for AVFrame\n");
return NULL;
}
int readval = -5;
while (readval = av_read_frame(pFormatCtx, &packet) >= 0)
{
if(packet.stream_index != 0)
continue;
int ret = avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);
sprintf(logdatadata, "avcodec_decode_video2 ret = %d",ret);
__android_log_write(ANDROID_LOG_INFO, "record",logdatadata);
if (ret > 0)
{
__android_log_write(ANDROID_LOG_INFO, "record","Frame is decoded\n");
pFrame->quality = 4;
av_free_packet(&packet);
av_close_input_file(pFormatCtx);
return pFrame;
}
else
{
__android_log_write(ANDROID_LOG_INFO, "record","error while decoding frame \n");
}
}
sprintf(logdatadata, "readval = %d",readval);
__android_log_write(ANDROID_LOG_INFO, "record",logdatadata);
}The
generatemethod takes a list of strings (path to images) and converts them to video and theOpenImagemethod is responsible for convertign a single image toAVFrame.
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