sending a jpeg image to a Client.

Question

Hello I have made this program and what I want it to do is send a Image to a client. But I dont want just to send ONE image but multiple images one after another then I want the client to accept thmem all and save them what do I do? Thanks Rob

spgilmore · Answer

In what medium are you sending these? Mailslots named pipes memory-mapped files disk files email sockets or HTTP? Did you write an automated FTP client? If you just want to know how to stuff multiple pieces of standalone data into a single stream or buffer that's easy. You need to conjure a format or protocol of your own. This can be very simple. Here's one that I like to use. I use a CRC32 for the checksum but you can eliminate that completely if you want. Some mediums need it (telephony) and others don't (tcp/ip). The size is important though. It tells you where each block begins and ends. If you put them all at the beginning of the stream you don't have to do a lot of SEEKing in the stream to find your way around. But if your stream is read-only of you write on-the-fly you can put the SIZE between the datablocks instead of all of them at the beginning. The key is that the client reads the stream the same way the server writes it. --------stream start number of blocks (one image per block) (4 bytes) block1size (4 bytes) block1checksum (4 bytes) block2size (4 bytes) block2checksum (4 bytes) ... ... blocknsize (4 bytes) blocknchecksum (4 bytes) block1data (block1size bytes) block2data (block2size bytes) ... blockndata (blocknsize bytes) -----------stream end