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Autres articles (80)

  • Use, discuss, criticize

    13 avril 2011, par

    Talk to people directly involved in MediaSPIP’s development, or to people around you who could use MediaSPIP to share, enhance or develop their creative projects.
    The bigger the community, the more MediaSPIP’s potential will be explored and the faster the software will evolve.
    A discussion list is available for all exchanges between users.

  • Le profil des utilisateurs

    12 avril 2011, par

    Chaque utilisateur dispose d’une page de profil lui permettant de modifier ses informations personnelle. Dans le menu de haut de page par défaut, un élément de menu est automatiquement créé à l’initialisation de MediaSPIP, visible uniquement si le visiteur est identifié sur le site.
    L’utilisateur a accès à la modification de profil depuis sa page auteur, un lien dans la navigation "Modifier votre profil" est (...)

  • Configurer la prise en compte des langues

    15 novembre 2010, par

    Accéder à la configuration et ajouter des langues prises en compte
    Afin de configurer la prise en compte de nouvelles langues, il est nécessaire de se rendre dans la partie "Administrer" du site.
    De là, dans le menu de navigation, vous pouvez accéder à une partie "Gestion des langues" permettant d’activer la prise en compte de nouvelles langues.
    Chaque nouvelle langue ajoutée reste désactivable tant qu’aucun objet n’est créé dans cette langue. Dans ce cas, elle devient grisée dans la configuration et (...)

Sur d’autres sites (12342)

  • 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>

  • 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>

  • FFmpegKit in Flutter fails with configuration output on Android

    15 décembre 2024, par ashvin jadav

    I am using ffmpeg_kit_flutter in my Flutter app to add a text overlay to a video. However, when I try to execute the FFmpeg command, I get an output similar to this :

    


    configuration : --cross-prefix=aarch64-linux-android- --sysroot=/Users/sue/Library/Android/sdk/ndk/22.1.7171670/toolchains/llvm/prebuilt/darwin-x86_64/sysroot --prefix=/Users/sue/Projects/arthenica/ffmpeg-kit/prebuilt/android-arm64/ffmpeg --pkg-config=/opt/homebrew/bin/pkg-config --enable-version3 --arch=aarch64 --cpu=armv8-a --target-os=android --enable-neon --enable-asm --enable-inline-asm --ar=aarch64-linux-android-ar --cc=aarch64-linux-android24-clang --cxx=aarch64-linux-android24-clang++ --ranlib=aarch64-linux-android-ranlib --strip=aarch64-linux-android-strip --nm=aarch64-linux-android-nm --extra-libs='-L/Users/sue/Projects/arthenica/ffmpeg-kit/prebuilt/android-arm64/cpu-features/lib -lndk_compat' --disable-autodetect --enable-cross-compile --enable-pic --enable...

    


    Here is my code :

    


    final command = '-i $_videoPath -vf "drawtext=text=\'Live Score: 10 - 5\':fontcolor=white:fontsize=24:x=10:y=10" $_processedVideoPath';

await FFmpegKit.execute(command).then((session) async {
  final returnCode = await session.getReturnCode();
  final output = await session.getOutput();
  final errorOutput = await session.getFailStackTrace();

  print('Return Code: $returnCode');
  print('Output: $output');
  print('Error Output: $errorOutput');
});


    


    Dependencies :
ffmpeg_kit_flutter: ^6.0.3

    


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