libasf.c

来自「VLC媒体播放程序」· C语言 代码 · 共 852 行 · 第 1/2 页

            for( i = 0; i < i_len; i++ )
            {
                codec.psz_name[i] = GetWLE( p_data + 2*i );
            }
            codec.psz_name[i_len] = '\0';
            p_data += 2 * i_len;

            /* description */
            i_len = GetWLE( p_data ); p_data += 2;
            codec.psz_description = calloc( sizeof( char ), i_len + 1);
            for( i = 0; i < i_len; i++ )
            {
                codec.psz_description[i] = GetWLE( p_data + 2*i );
            }
            codec.psz_description[i_len] = '\0';
            p_data += 2 * i_len;

            /* opaque information */
            codec.i_information_length = GetWLE( p_data ); p_data += 2;
            if( codec.i_information_length > 0 )
            {
                codec.p_information = malloc( codec.i_information_length );
                memcpy( codec.p_information, p_data, codec.i_information_length );
                p_data += codec.i_information_length;
            }
            else
            {
                codec.p_information = NULL;
            }
#undef  codec
        }
    }
    else
    {
        p_cl->codec = NULL;
    }

#ifdef ASF_DEBUG
    msg_Dbg( (vlc_object_t*)s,
            "read \"codec list object\" reserved_guid:" GUID_FMT " codec_entries_count:%d",
            GUID_PRINT( p_cl->i_reserved ),
            p_cl->i_codec_entries_count );

    for( i_codec = 0; i_codec < p_cl->i_codec_entries_count; i_codec++ )
    {
#define codec p_cl->codec[i_codec]
        msg_Dbg( (vlc_object_t*)s,
                 "read \"codec list object\" codec[%d] %s name:\"%s\" description:\"%s\" information_length:%d",
                 i_codec,
                 ( codec.i_type == ASF_CODEC_TYPE_VIDEO ) ? "video" : ( ( codec.i_type == ASF_CODEC_TYPE_AUDIO ) ? "audio" : "unknown" ),
                 codec.psz_name,
                 codec.psz_description,
                 codec.i_information_length );
    }
#endif
    return VLC_SUCCESS;
}

static void ASF_FreeObject_codec_list( asf_object_t *p_obj )
{
    asf_object_codec_list_t *p_cl = (asf_object_codec_list_t*)p_obj;
    unsigned int i_codec;

    for( i_codec = 0; i_codec < p_cl->i_codec_entries_count; i_codec++ )
    {
#define codec p_cl->codec[i_codec]
        FREE( codec.psz_name );
        FREE( codec.psz_description );
        FREE( codec.p_information );

#undef  codec
    }
    FREE( p_cl->codec );
}

/* Microsoft should go to hell. This time the length give number of bytes
 * and for the some others object, length give char16 count ... */
static int ASF_ReadObject_content_description(stream_t *s, asf_object_t *p_obj)
{
    asf_object_content_description_t *p_cd =
                                    (asf_object_content_description_t*)p_obj;
    int     i_peek;
    uint8_t *p_peek, *p_data;

    int i_len;
    int i_title;
    int i_author;
    int i_copyright;
    int i_description;
    int i_rating;

#define GETSTRINGW( psz_str, i_size ) \
   psz_str = calloc( i_size/2 + 1, sizeof( char ) ); \
   for( i_len = 0; i_len < i_size/2; i_len++ ) \
   { \
       psz_str[i_len] = GetWLE( p_data + 2*i_len ); \
   } \
   psz_str[i_size/2] = '\0'; \
   p_data += i_size;

    if( ( i_peek = stream_Peek( s, &p_peek, p_cd->i_object_size ) ) < 34 )
    {
       return VLC_EGENERIC;
    }
    p_data = p_peek + 24;

    i_title = GetWLE( p_data ); p_data += 2;
    i_author= GetWLE( p_data ); p_data += 2;
    i_copyright     = GetWLE( p_data ); p_data += 2;
    i_description   = GetWLE( p_data ); p_data += 2;
    i_rating        = GetWLE( p_data ); p_data += 2;

    GETSTRINGW( p_cd->psz_title, i_title );
    GETSTRINGW( p_cd->psz_author, i_author );
    GETSTRINGW( p_cd->psz_copyright, i_copyright );
    GETSTRINGW( p_cd->psz_description, i_description );
    GETSTRINGW( p_cd->psz_rating, i_rating );

#undef  GETSTRINGW

#ifdef ASF_DEBUG
    msg_Dbg( (vlc_object_t*)s,
             "Read \"content description object\" title:\"%s\" author:\"%s\" copyright:\"%s\" description:\"%s\" rating:\"%s\"",
             p_cd->psz_title,
             p_cd->psz_author,
             p_cd->psz_copyright,
             p_cd->psz_description,
             p_cd->psz_rating );
#endif
    return VLC_SUCCESS;
}

static void ASF_FreeObject_content_description( asf_object_t *p_obj)
{
    asf_object_content_description_t *p_cd =
                                    (asf_object_content_description_t*)p_obj;

    FREE( p_cd->psz_title );
    FREE( p_cd->psz_author );
    FREE( p_cd->psz_copyright );
    FREE( p_cd->psz_description );
    FREE( p_cd->psz_rating );
}

static struct
{
    const guid_t  *p_id;
    int     i_type;
    int     (*ASF_ReadObject_function)( stream_t *, asf_object_t *p_obj );
    void    (*ASF_FreeObject_function)( asf_object_t *p_obj );
} ASF_Object_Function [] =
{
    { &asf_object_header_guid,            ASF_OBJECT_TYPE_HEADER,             ASF_ReadObject_Header, ASF_FreeObject_Null },
    { &asf_object_data_guid,              ASF_OBJECT_TYPE_DATA,               ASF_ReadObject_Data,   ASF_FreeObject_Null },
    { &asf_object_index_guid,             ASF_OBJECT_TYPE_INDEX,              ASF_ReadObject_Index,  ASF_FreeObject_Index },
    { &asf_object_file_properties_guid,   ASF_OBJECT_TYPE_FILE_PROPERTIES,    ASF_ReadObject_file_properties,  ASF_FreeObject_Null },
    { &asf_object_stream_properties_guid, ASF_OBJECT_TYPE_STREAM_PROPERTIES,  ASF_ReadObject_stream_properties,ASF_FreeObject_stream_properties },
    { &asf_object_header_extention_guid,  ASF_OBJECT_TYPE_EXTENTION_HEADER,   ASF_ReadObject_header_extention, ASF_FreeObject_header_extention},
    { &asf_object_codec_list_guid,        ASF_OBJECT_TYPE_CODEC_LIST,         ASF_ReadObject_codec_list,       ASF_FreeObject_codec_list },
    { &asf_object_marker_guid,            ASF_OBJECT_TYPE_MARKER,             NULL,                  NULL },
    { &asf_object_content_description_guid, ASF_OBJECT_TYPE_CONTENT_DESCRIPTION, ASF_ReadObject_content_description, ASF_FreeObject_content_description },

    { &asf_object_null_guid,   0,                      NULL,                  NULL }
};

static int ASF_ReadObject( stream_t *s,
                           asf_object_t *p_obj, asf_object_t *p_father )
{
    int i_result;
    int i_index;

    if( !p_obj )
    {
        return( 0 );
    }
    if( ASF_ReadObjectCommon( s, p_obj ) )
    {
        msg_Warn( (vlc_object_t*)s, "cannot read one asf object" );
        return VLC_EGENERIC;
    }
    p_obj->common.p_father = p_father;
    p_obj->common.p_first = NULL;
    p_obj->common.p_next = NULL;
    p_obj->common.p_last = NULL;


    if( p_obj->common.i_object_size < 24 )
    {
        msg_Warn( (vlc_object_t*)s, "found a corrupted asf object (size<24)" );
        return VLC_EGENERIC;
    }
    /* find this object */
    for( i_index = 0; ; i_index++ )
    {
        if( ASF_CmpGUID( ASF_Object_Function[i_index].p_id,
                     &p_obj->common.i_object_id )||
            ASF_CmpGUID( ASF_Object_Function[i_index].p_id,
                     &asf_object_null_guid ) )
        {
            break;
        }
    }
    p_obj->common.i_type = ASF_Object_Function[i_index].i_type;

    /* Now load this object */
    if( ASF_Object_Function[i_index].ASF_ReadObject_function == NULL )
    {
        msg_Warn( (vlc_object_t*)s, "unknown asf object (not loaded)" );
        i_result = VLC_SUCCESS;
    }
    else
    {
        /* XXX ASF_ReadObject_function realloc *pp_obj XXX */
        i_result =
          (ASF_Object_Function[i_index].ASF_ReadObject_function)( s, p_obj );
    }

    /* link this object with father */
    if( p_father )
    {
        if( p_father->common.p_first )
        {
            p_father->common.p_last->common.p_next = p_obj;
        }
        else
        {
            p_father->common.p_first = p_obj;
        }
        p_father->common.p_last = p_obj;
    }

    return( i_result );
}

static void ASF_FreeObject( stream_t *s, asf_object_t *p_obj )
{
    int i_index;
    asf_object_t *p_child;

    if( !p_obj )
    {
        return;
    }

    /* Free all child object */
    p_child = p_obj->common.p_first;
    while( p_child )
    {
        asf_object_t *p_next;
        p_next = p_child->common.p_next;
        ASF_FreeObject( s, p_child );
        p_child = p_next;
    }

    /* find this object */
    for( i_index = 0; ; i_index++ )
    {
        if( ASF_CmpGUID( ASF_Object_Function[i_index].p_id,
                     &p_obj->common.i_object_id )||
            ASF_CmpGUID( ASF_Object_Function[i_index].p_id,
                     &asf_object_null_guid ) )
        {
            break;
        }
    }

    /* Now free this object */
    if( ASF_Object_Function[i_index].ASF_FreeObject_function == NULL )
    {
        msg_Warn( (vlc_object_t*)s,
                  "unknown asf object " GUID_FMT,
                  GUID_PRINT( p_obj->common.i_object_id ) );
    }
    else
    {
#ifdef ASF_DEBUG
        msg_Dbg( (vlc_object_t*)s,
                  "free asf object " GUID_FMT,
                  GUID_PRINT( p_obj->common.i_object_id ) );
#endif
        (ASF_Object_Function[i_index].ASF_FreeObject_function)( p_obj );
    }
    free( p_obj );
    return;
}

/*****************************************************************************
 * ASF_ReadObjetRoot : parse the entire stream/file
 *****************************************************************************/
asf_object_root_t *ASF_ReadObjectRoot( stream_t *s, int b_seekable )
{
    asf_object_root_t *p_root = malloc( sizeof( asf_object_root_t ) );
    asf_object_t *p_obj;

    p_root->i_type = ASF_OBJECT_TYPE_ROOT;
    memcpy( &p_root->i_object_id, &asf_object_null_guid, sizeof( guid_t ) );
    p_root->i_object_pos = 0;
    p_root->i_object_size = stream_Tell( s );
    p_root->p_first = NULL;
    p_root->p_last  = NULL;
    p_root->p_next  = NULL;
    p_root->p_hdr   = NULL;
    p_root->p_data  = NULL;
    p_root->p_fp    = NULL;
    p_root->p_index = NULL;

    for( ; ; )
    {
        p_obj  = malloc( sizeof( asf_object_t ) );

        if( ASF_ReadObject( s, p_obj, (asf_object_t*)p_root ) )
        {
            break;
        }
        switch( p_obj->common.i_type )
        {
            case( ASF_OBJECT_TYPE_HEADER ):
                p_root->p_hdr = (asf_object_header_t*)p_obj;
                break;
            case( ASF_OBJECT_TYPE_DATA ):
                p_root->p_data = (asf_object_data_t*)p_obj;
                break;
            case( ASF_OBJECT_TYPE_INDEX ):
                p_root->p_index = (asf_object_index_t*)p_obj;
                break;
            default:
                msg_Warn( (vlc_object_t*)s, "unknow object found" );
                break;
        }
        if( p_obj->common.i_type == ASF_OBJECT_TYPE_DATA &&
            p_obj->common.i_object_size <= 50 )
        {
            /* probably a dump of broadcasted asf */
            break;
        }
        if( !b_seekable && p_root->p_hdr && p_root->p_data )
        {
            /* For unseekable stream it's enouth to play */
            break;
        }

        if( ASF_NextObject( s, p_obj ) ) /* Go to the next object */
        {
            break;
        }
    }

    if( p_root->p_hdr != NULL && p_root->p_data != NULL )
    {
        p_root->p_fp = ASF_FindObject( p_root->p_hdr,
                                       &asf_object_file_properties_guid, 0 );

        if( p_root->p_fp )
        {
            return p_root;
        }
        msg_Warn( (vlc_object_t*)s, "cannot find file properties object" );
    }

    /* Invalid file */
    ASF_FreeObjectRoot( s, p_root );
    return NULL;
}

void ASF_FreeObjectRoot( stream_t *s, asf_object_root_t *p_root )
{
    asf_object_t *p_obj;

    p_obj = p_root->p_first;
    while( p_obj )
    {
        asf_object_t *p_next;
        p_next = p_obj->common.p_next;
        ASF_FreeObject( s, p_obj );
        p_obj = p_next;
    }
    free( p_root );
}

int  __ASF_CountObject( asf_object_t *p_obj, const guid_t *p_guid )
{
    int i_count;
    asf_object_t *p_child;

    if( !p_obj )
    {
        return( 0 );
    }

    i_count = 0;
    p_child = p_obj->common.p_first;
    while( p_child )
    {
        if( ASF_CmpGUID( &p_child->common.i_object_id, p_guid ) )
        {
            i_count++;
        }
        p_child = p_child->common.p_next;
    }
    return( i_count );
}

void *__ASF_FindObject( asf_object_t *p_obj, const guid_t *p_guid, int i_number )
{
    asf_object_t *p_child;

    p_child = p_obj->common.p_first;

    while( p_child )
    {
        if( ASF_CmpGUID( &p_child->common.i_object_id, p_guid ) )
        {
            if( i_number == 0 )
            {
                /* We found it */
                return( p_child );
            }

            i_number--;
        }
        p_child = p_child->common.p_next;
    }
    return( NULL );
}