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  • MediaSPIP 0.1 Beta version

    25 avril 2011, par

    MediaSPIP 0.1 beta is the first version of MediaSPIP proclaimed as "usable".
    The zip file provided here only contains the sources of MediaSPIP in its standalone version.
    To get a working installation, you must manually install all-software dependencies on the server.
    If you want to use this archive for an installation in "farm mode", you will also need to proceed to other manual (...)

  • MediaSPIP version 0.1 Beta

    16 avril 2011, par

    MediaSPIP 0.1 beta est la première version de MediaSPIP décrétée comme "utilisable".
    Le fichier zip ici présent contient uniquement les sources de MediaSPIP en version standalone.
    Pour avoir une installation fonctionnelle, il est nécessaire d’installer manuellement l’ensemble des dépendances logicielles sur le serveur.
    Si vous souhaitez utiliser cette archive pour une installation en mode ferme, il vous faudra également procéder à d’autres modifications (...)

  • Submit bugs and patches

    13 avril 2011

    Unfortunately a software is never perfect.
    If you think you have found a bug, report it using our ticket system. Please to help us to fix it by providing the following information : the browser you are using, including the exact version as precise an explanation as possible of the problem if possible, the steps taken resulting in the problem a link to the site / page in question
    If you think you have solved the bug, fill in a ticket and attach to it a corrective patch.
    You may also (...)

Sur d’autres sites (10971)

  • Using ffmpeg to capture frames at intervals from a video

    25 octobre 2011, par TheShaggyBeard

    So here is what I am trying to do - I want to automate creating animated gif previews from a video file (in this case I know they will always be a specific format). Here is what I have :

    echo 'Make a folder named "filenamemp4"'
    folderName=$(find . -type f -name "*.mp4" | grep -o [[:alnum:]] | tr -d '\n' | cat)

    echo 'Grab the frame rate and total number of frames and put them into xaa and xab'
    qtinfo asa.mp4 | awk 'NR = 1 { print $2 }' | grep -o "^[0-9]*" | split -l 1

    echo 'Assign values to variable'
    frameRate=$(cat xaa)
    frameTotal=$(cat xab)
    videoLength=$(expr $frameTotal / $frameRate)

    echo 'Take a screenshot at 10% intervals - this is the part that gives me a bitrate error.  It says that the -r option has an invalid input being 1 / value of videoLength'
    ffmpeg -i asa.mp4 -y -ss $videoLength -an -sameq -f image2 -s 'qcif' -r $(expr 1/$videoLength) preview%02d.jpg

    echo 'Take the jpgs and mash them into an animated gif'
    convert -delay 50 -loop 10 preview*.jpg preview.gif

    echo 'Move the gif to the specified folder'
    mv preview.gif $folderName/preview.gif

    echo 'Clean Up'
    find . -type f -name "*.jpg" -exec rm -rf {} \;

    So perhaps there is a better way of doing this, or I am understanding how to use the -r option of ffmpeg wrong. In the tutorial I read on ffmpeg for a similar scenario, they used -r 1/5 to produce frames with a 5 second interval. My assumption is that for the desired interval you want, you just slap it in the denominator for the -r option.

  • Why doesn't this FFmpeg code create a video from a series of images ?

    20 octobre 2011, par user551117

    I have successfully compiled the FFmpeg library for use in an iOS application. I would like to use it for encoding a video from a series of images, but I can't seem to make it work.

    The following is the code that I am using to encode this video :

    AVCodec *codec;
    AVCodecContext *c= NULL;
    int i, out_size, size, outbuf_size;
    FILE *f;
    AVFrame *picture;
    uint8_t *outbuf;

    printf("Video encoding\n");

    /// find the mpeg video encoder
    codec=avcodec_find_encoder(CODEC_ID_MPEG4);
    //codec = avcodec_find_encoder(CODEC_ID_MPEG4);
    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 = 320;
    c->height = 480;
    //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);
    }

    f = fopen([[NSTemporaryDirectory() stringByAppendingPathComponent:filename] UTF8String], "w");
    if (!f) {
       fprintf(stderr, "could not open %s\n",[filename UTF8String]);
       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);

    #pragma mark -  
    for(i=1;i<48;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 imageNamed:[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_RGB24, 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_RGB24,
                                                      c->width, c->height,
                                                      PIX_FMT_YUV420P,
                                                      SWS_FAST_BILINEAR, NULL, NULL, NULL);

       //perform the conversion
       sws_scale(fooContext, picture->data, picture->linesize, 0, c->height, outpic->data, outpic->linesize);
       // Here is where I try to convert to YUV

       // 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);

       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, 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);
    free(outbuf);

    avcodec_close(c);
    av_free(c);
    av_free(picture);
    printf("\n");

    What could be wrong with this code ?

  • how to improve the quality of resultant video when merging audio-video with ffmpeg ?

    6 novembre 2015, par R.S

    When merging an audio and video with ffmpeg, the quality of the resultant video goes down. How to we improve the quality(esp. the audio quality) ?

    The audio quality gets degraded to quite an extent with random screeches in between.
    I’ve tried converting the audio to mp3 and video to mp4 before merging them, tried various audio-video parameters like bitrate, sample-rate, qscale etc but still unsuccessful.
    Any help would be greatly appreciated !