Recherche avancée

Médias (3)

Mot : - Tags -/image

Autres articles (51)

  • Les autorisations surchargées par les plugins

    27 avril 2010, par

    Mediaspip core
    autoriser_auteur_modifier() afin que les visiteurs soient capables de modifier leurs informations sur la page d’auteurs

  • Publier sur MédiaSpip

    13 juin 2013

    Puis-je poster des contenus à partir d’une tablette Ipad ?
    Oui, si votre Médiaspip installé est à la version 0.2 ou supérieure. Contacter au besoin l’administrateur de votre MédiaSpip pour le savoir

  • Création définitive du canal

    12 mars 2010, par

    Lorsque 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 (...)

Sur d’autres sites (9264)

  • MP4 file data structure

    16 décembre 2015, par man-r

    i have an mp4 video byte array and i need to generate a thumbnail for it using its middle frame (e.g. if the video length is 10 seconds then i need to get the picture from 5th second).

    i managed to parse through the file and extract its boxes (atom). i have also managed to get the video length from the mvhd box. also i managed to extract
    1. the time-To-Sample table from stts box,
    2. the sample-To-Chunk table from stcs box,
    3. the chunk-Offset table from stco box,
    4. the sample Size table from stsz box,
    5. the Sync Sample table from stss box

    i know that all the actual media are available in the mdat box and that i need to correlate the above table to find the exact frame offset in the file but my question is how ? the tables data seems to be compressed (specially the time-To-Sample table) but i don’t know how decompress them.

    any help is appreciated.

    below are code samples

    code to convert byte to hex

    public static char[] bytesToHex(byte[] bytes) {
    
    char[] hexChars = new char[bytes.length * 2];
    
    for ( int j = 0; j < bytes.length; j++ ) {
    
        int v = bytes[j] & 0xFF;
    

    
        hexChars[j * 2] = hexArray[v >>> 4];
    
        hexChars[j * 2 + 1] = hexArray[v & 0x0F];            
    
    }
    
    return hexChars;
    
}

    code for getting the box offset

    final static String MOOV                          = "6D6F6F76";
    
final static String MOOV_MVHD                     = "6D766864";
    
final static String MOOV_TRAK                     = "7472616B";
    
final static String MOOV_TRAK_MDIA                = "6D646961";
    
final static String MOOV_TRAK_MDIA_MINF           = "6D696E66";
    
final static String MOOV_TRAK_MDIA_MINF_STBL      = "7374626C";
    
final static String MOOV_TRAK_MDIA_MINF_STBL_STSD = "73747364";
    
final static String MOOV_TRAK_MDIA_MINF_STBL_STTS = "73747473";
    
final static String MOOV_TRAK_MDIA_MINF_STBL_STSS = "73747373";
    
final static String MOOV_TRAK_MDIA_MINF_STBL_STSC = "73747363";
    
final static String MOOV_TRAK_MDIA_MINF_STBL_STCO = "7374636F";
    
final static String MOOV_TRAK_MDIA_MINF_STBL_STSZ = "7374737A";
    

    
static int getBox(char[] s, int offset, String type) {
    
    int typeOffset = -1;
    
    for (int i = offset*2; i-1) {
    
                break;
    
            } 
    
        }
    
        i+=(size*2);
    
    }
    

    
    return typeOffset;
    
}

    code for getting the duration and timescale

    static int[] getDuration(char[] s) {
    
    int mvhdOffset = getBox(s, 0, MOOV_MVHD);
    
    int timeScaleStart = (mvhdOffset*2) + (4 + 4 + 1 + 3 + 4 + 4)*2;
    
    int timeScaleEnd   = (mvhdOffset*2) + (4 + 4 + 1 + 3 + 4 + 4 + 4)*2;
    

    
    int durationStart  = (mvhdOffset*2) + (4 + 4 + 1 + 3 + 4 + 4 + 4)*2;
    
    int durationEnd    = (mvhdOffset*2) + (4 + 4 + 1 + 3 + 4 + 4 + 4 + 4)*2;
    

    
    String timeScaleHex = new String(Arrays.copyOfRange(s, timeScaleStart, timeScaleEnd));
    
    String durationHex = new String(Arrays.copyOfRange(s, durationStart, durationEnd));
    

    
    int timeScale = Integer.parseInt(timeScaleHex, 16);
    
    int duration = Integer.parseInt(durationHex, 16);
    

    
    int[] result = {duration, timeScale};
    
    return result;
    
}

    code to get the time-To-Sample table

    static int[][] getTimeToSampleTable(char[] s, int trakOffset) {
    
    int offset = getBox(s, trakOffset, MOOV_TRAK_MDIA_MINF_STBL_STTS);
    
    int sizeStart = offset*2;
    
    int sizeEnd   = offset*2 + (4)*2;
    

    
    int typeStart = offset*2 + (4)*2;
    
    int typeEnd   = offset*2 + (4 + 4)*2;
    

    
    int noOfEntriesStart = offset*2 + (4 + 4 + 1 + 3)*2;
    
    int noOfEntriesEnd   = offset*2 + (4 + 4 + 1 + 3 + 4)*2;
    

    
    String sizeHex = new String(Arrays.copyOfRange(s, sizeStart, sizeEnd));
    
    String typeHex = new String(Arrays.copyOfRange(s, typeStart, typeEnd));
    
    String noOfEntriesHex = new String(Arrays.copyOfRange(s, noOfEntriesStart, noOfEntriesEnd));
    

    
    int size = Integer.parseInt(sizeHex, 16);
    
    int noOfEntries = Integer.parseInt(noOfEntriesHex, 16);
    

    
    int[][] timeToSampleTable = new int[noOfEntries][2];
    

    
    for (int i = 0; icode>

  • Decompressing time-To-Sample table (STTS) in an MP4 file

    30 mai 2016, par man-r

    i have an mp4 video byte array and i need to generate a thumbnail for it using its middle frame (e.g. if the video length is 10 seconds then i need to get the picture from 5th second).

    i managed to parse through the file and extract its boxes (atom). i have also managed to get the video length from the mvhd box. also i managed to extract
    1. the time-To-Sample table from stts box,
    2. the sample-To-Chunk table from stcs box,
    3. the chunk-Offset table from stco box,
    4. the sample Size table from stsz box,
    5. the Sync Sample table from stss box

    i know that all the actual media are available in the mdat box and that i need to correlate the above table to find the exact frame offset in the file but my question is how ? the tables data seems to be compressed (specially the time-To-Sample table) but i don’t know how decompress them.

    any help is appreciated.

    below are code samples

    code to convert byte to hex

    public static char[] bytesToHex(byte[] bytes) {
    
    char[] hexChars = new char[bytes.length * 2];
    
    for ( int j = 0; j < bytes.length; j++ ) {
    
        int v = bytes[j] & 0xFF;
    

    
        hexChars[j * 2] = hexArray[v >>> 4];
    
        hexChars[j * 2 + 1] = hexArray[v & 0x0F];            
    
    }
    
    return hexChars;
    
}

    code for getting the box offset

    final static String MOOV                          = "6D6F6F76";
    
final static String MOOV_MVHD                     = "6D766864";
    
final static String MOOV_TRAK                     = "7472616B";
    
final static String MOOV_TRAK_MDIA                = "6D646961";
    
final static String MOOV_TRAK_MDIA_MINF           = "6D696E66";
    
final static String MOOV_TRAK_MDIA_MINF_STBL      = "7374626C";
    
final static String MOOV_TRAK_MDIA_MINF_STBL_STSD = "73747364";
    
final static String MOOV_TRAK_MDIA_MINF_STBL_STTS = "73747473";
    
final static String MOOV_TRAK_MDIA_MINF_STBL_STSS = "73747373";
    
final static String MOOV_TRAK_MDIA_MINF_STBL_STSC = "73747363";
    
final static String MOOV_TRAK_MDIA_MINF_STBL_STCO = "7374636F";
    
final static String MOOV_TRAK_MDIA_MINF_STBL_STSZ = "7374737A";
    

    
static int getBox(char[] s, int offset, String type) {
    
    int typeOffset = -1;
    
    for (int i = offset*2; i-1) {
    
                break;
    
            } 
    
        }
    
        i+=(size*2);
    
    }
    

    
    return typeOffset;
    
}

    code for getting the duration and timescale

    static int[] getDuration(char[] s) {
    
    int mvhdOffset = getBox(s, 0, MOOV_MVHD);
    
    int timeScaleStart = (mvhdOffset*2) + (4 + 4 + 1 + 3 + 4 + 4)*2;
    
    int timeScaleEnd   = (mvhdOffset*2) + (4 + 4 + 1 + 3 + 4 + 4 + 4)*2;
    

    
    int durationStart  = (mvhdOffset*2) + (4 + 4 + 1 + 3 + 4 + 4 + 4)*2;
    
    int durationEnd    = (mvhdOffset*2) + (4 + 4 + 1 + 3 + 4 + 4 + 4 + 4)*2;
    

    
    String timeScaleHex = new String(Arrays.copyOfRange(s, timeScaleStart, timeScaleEnd));
    
    String durationHex = new String(Arrays.copyOfRange(s, durationStart, durationEnd));
    

    
    int timeScale = Integer.parseInt(timeScaleHex, 16);
    
    int duration = Integer.parseInt(durationHex, 16);
    

    
    int[] result = {duration, timeScale};
    
    return result;
    
}

    code to get the time-To-Sample table

    static int[][] getTimeToSampleTable(char[] s, int trakOffset) {
    
    int offset = getBox(s, trakOffset, MOOV_TRAK_MDIA_MINF_STBL_STTS);
    
    int sizeStart = offset*2;
    
    int sizeEnd   = offset*2 + (4)*2;
    

    
    int typeStart = offset*2 + (4)*2;
    
    int typeEnd   = offset*2 + (4 + 4)*2;
    

    
    int noOfEntriesStart = offset*2 + (4 + 4 + 1 + 3)*2;
    
    int noOfEntriesEnd   = offset*2 + (4 + 4 + 1 + 3 + 4)*2;
    

    
    String sizeHex = new String(Arrays.copyOfRange(s, sizeStart, sizeEnd));
    
    String typeHex = new String(Arrays.copyOfRange(s, typeStart, typeEnd));
    
    String noOfEntriesHex = new String(Arrays.copyOfRange(s, noOfEntriesStart, noOfEntriesEnd));
    

    
    int size = Integer.parseInt(sizeHex, 16);
    
    int noOfEntries = Integer.parseInt(noOfEntriesHex, 16);
    

    
    int[][] timeToSampleTable = new int[noOfEntries][2];
    

    
    for (int i = 0; icode>

  • Xuggler can't open IContainer of icecast server [Webm live video stream]

    9 juin 2016, par Roy Bean

    I’m trying to stream a live webm stream.

    I tested some server and Icecast is my pic.

    With ffmpeg capturing from an IP camera and publishing in icecast server I’m able to see video in html5

    using this command :

    ffmpeg.exe -rtsp_transport tcp -i "rtsp ://192.168.230.121/profile ?token=media_profile1&SessionTimeout=60" -f webm -r 20 -c:v libvpx -b:v 3M -s 300x200 -acodec none -content_type video/webm -crf 63 -g 0 icecast ://source:hackme@192.168.0.146:8001/test

    I’m using java and tryed to make this with xuggler, but I’m getting an error when opening the stream

     final String urlOut = "icecast://source:hackme@192.168.0.146:8001/agora.webm";
    
    final IContainer    outContainer = IContainer.make();
    

    
    final IContainerFormat outContainerFormat = IContainerFormat.make();
    
    outContainerFormat.setOutputFormat("webm", urlOut, "video/webm");
    

    
    int rc = outContainer.open(urlOut, IContainer.Type.WRITE, outContainerFormat);
    

    
    if(rc>=0) {
    
    }else  {
    
        Logger.getLogger(WebmPublisher.class.getName()).log(Level.INFO, "Fail to open Container " + IError.make(rc));
    
    }

    Any help ?
    I’m getting the error -2 :
    Error : could not open file (../../../../../../../csrc/com/xuggle/xuggler/Container.cpp:544)

    It’s is also very importatn to set the content type as video/webm because icecast by default set the mime type to audio/mpeg

Navigation