How to convert motion jpeg frames from ip camera(rtp stream) to valid jpg image

Question

I have received motion jpeg frames from a ip camera by RTP stream, and I try to convert the frames to valid jpg images. My camera model is Secubest PXN-0512P. It multicast the video of motion jpeg data by RTP stream. Now, I have decode the RTP stream and got each frames in memory, and i try to convert it to valid jpg image.

Do you know so tools to complete this function? And what are the steps to deal with m-jpeg frame? (such as add jpeg-header, huffman table). I am a new programer in this field.

I program it in C++ language.

Thank you very much.

Update 1 I try to directly write the recieved frame data to jpg, when i open it at ubuntu, it show warning "Error interpreting JPEG image file (Not a JPEG file: starts with 0x00 0x00)". Then I add a JFIF header to it, it shows warning"Error interpreting JPEG image file (Unsupported marker type 0xf0". Jpeg_header is

char jpg_header1[] = {
        0xff, 0xd8,                          // SOI
        0xff, 0xe0,                          // APP0
        0x00, 0x10,                          // APP0 Hdr size
        0x4a, 0x46, 0x49, 0x46, 0x00, // ID string
        0x01, 0x01,                          // Version
        0x00,                               // Bits per type
        0x00, 0x00,                         // X density
        0x00, 0x00,                         // Y density
        0x00,                               // X Thumbnail size
        0x00                                // Y Thumbnail size
        };

My code is

m_FileStream.write(jpg_header1, sizeof(jpg_header1)); int skip_bytes = 2; m_FileStream.write(mem_buffer.pData+skip_bytes, mem_buffer.DataSize-skip_bytes);

How could i solve it? Thank you very much!

Answer 1

JPEG image is broken into parts according to RFC 2435 "RTP Payload Format for JPEG-compressed Video". You need to merge parts back into valid JPEG following this C# library/method: Saving JPEG file coming from Network Camera RTP Stream