Beispiel #1
0
        /// <summary>
        /// Read the container header section. (The 'RIFF' or 'LIST' header.)
        /// This method verifies the header is well-formed and caches the
        /// container'stream FOURCC type.
        /// </summary>
        private void ReadRiffHeader()
        {
            RiffChunk header = new RiffChunk();

            // Riff chunks must be WORD aligned
            if (!IsAligned(this.containerOffset, 2))
            {
                throw new InvalidOperationException("The chunk is not aligned");
            }

            // Offset must be positive.
            if (this.containerOffset < 0)
            {
                throw new InvalidOperationException("The container offset needs to be positive");
            }

            // Seek to the start of the container.
            this.stream.Position = this.containerOffset;

            // Read the header
            header.FCC     = (FourCC)this.br.ReadUInt32();
            header.Size    = this.br.ReadUInt32();
            header.FCCList = (FourCC)this.br.ReadUInt32();

            // Make sure the header ID matches what the caller expected.
            if (header.FCC != this.fccId)
            {
                throw new InvalidOperationException("We don't have the right FourCC code");
            }

            // The size given in the RIFF header does not include the 8-byte header.
            // However, our _containerOffset is the offset from the start of the
            // header. Therefore our container size = listed size + size of header.
            this.containerSize = header.Size + SizeOfRiffChunk;
            this.fccType       = header.FCCList;

            this.currentChunkOffset = this.containerOffset + SizeOfRiffList;

            this.ReadChunkHeader();
        }
Beispiel #2
0
        /// <summary>
        /// Read the container header section. (The 'RIFF' or 'LIST' header.)
        /// This method verifies the header is well-formed and caches the
        /// container'stream FOURCC type.
        /// </summary>
        private void ReadRiffHeader()
        {
            RiffChunk header = new RiffChunk();

            // Riff chunks must be WORD aligned
            if (!IsAligned(this.containerOffset, 2))
            {
                throw new InvalidOperationException("The chunk is not aligned");
            }

            // Offset must be positive.
            if (this.containerOffset < 0)
            {
                throw new InvalidOperationException("The container offset needs to be positive");
            }

            // Seek to the start of the container.
            this.stream.Position = this.containerOffset;

            // Read the header
            header.FCC = (FourCC)this.br.ReadUInt32();
            header.Size = this.br.ReadUInt32();
            header.FCCList = (FourCC)this.br.ReadUInt32();

            // Make sure the header ID matches what the caller expected.
            if (header.FCC != this.fccId)
            {
                throw new InvalidOperationException("We don't have the right FourCC code");
            }

            // The size given in the RIFF header does not include the 8-byte header.
            // However, our _containerOffset is the offset from the start of the
            // header. Therefore our container size = listed size + size of header.
            this.containerSize = header.Size + SizeOfRiffChunk;
            this.fccType = header.FCCList;

            this.currentChunkOffset = this.containerOffset + SizeOfRiffList;

            this.ReadChunkHeader();
        }