7
1. Acquiring JPEG from VN-E4 via HTTP _
1.3. Response
When API is successfully received
VN-E4 will return 200 OK. Content-length indicates file size of first JPEG in bytes. The x-vne4_response line indicates current values of all
parameters used for JPEG encoding.
Example
HTTP/1.1 200 OK<CRLF>
Connection: Keep-Alive<CRLF>
Content-Length: 27616<CRLF>
Content-Type: image/jpeg<CRLF>
Date: Fri, 13 MAY 2005 07:33:12 GMT<CRLF>
Server: VN-E4 Jpeg & Audio Server/1.0.0<CRLF>
Keep-Alive: timeout=5, max=5<CRLF>
x-vne4_response:
input=1&framesize=vga&framerate=30&header=0&assured=0&sendbuffer=16<CRLF>
<CRLF>
When VN-E4 fails to realize the requested frame rate
Depending on the frame rate settings of VN-E4, transmission may not be possible at the frame rate requested by API. For example, when VN-
E4 is set to 15 fps, transmission will only be possible at 15 fps even if the client requests for 30 fps. When VN-E4 is set to 15 fps and 10 fps is
requested by the client, transmission will be carried out at 7.5 fps to enable transmission at equal time intervals.
The actual transmission frame rate is stated in the x-vne4_response line.
Example
HTTP/1.1 206 Partial Content<CRLF>
Connection: Keep-Alive<CRLF>
Content-Length: 27616<CRLF>
Content-Type: image/jpeg<CRLF>
Date: Fri, 13 MAY 2005 07:33:12 GMT<CRLF>
Server: VN-E4 Jpeg & Audio Server/1.0.0<CRLF>
Keep-Alive: timeout=5, max=5<CRLF>
x-vne4_response:
input=1&framesize=vga&framerate=15&header=0&assured=0&sendbuffer=16<CRLF>
<CRLF>
Frame rate encoded by VN-E4 can be changed using the web setting page or API for setting. Frame rate of data
that are currently being transmitted will remain unchanged even if the frame rate to encode is increased. When
the frame rate to encode is reduced, however, this value will become the upper limit of the transmission frame
rate.
When the specified input channel and frame size are not available
For example, when QVGA encoding of CH4 is set to off at VN-E4, transmission will fail if the client requests for QVGA of CH4. When this
occurs, VN-E4 will return an error response together with a PNG file. "Not Encoded" image is written in the PNG file.
Example
HTTP/1.1 456 Header Field Not Valid for Resource<CRLF>
Connection: Keep-Alive<CRLF>
Content-Length: 27616<CRLF>
Content-Type: image/png<CRLF>
Date: Fri, 13 MAY 2005 07:33:12 GMT<CRLF>
Server: VN-E4 Jpeg & Audio Server/1.0.0<CRLF>
Keep-Alive: timeout=5, max=5<CRLF><CRLF>
(This is followed by a PNG file which includes the "Not Encoded" message.)
1.3. Response
