JVC VN-E4U API Guide - Page 9

1. Acquiring JPEG from VN-E4 via HTTP _ 1.5. JPEG File Format Sent Out by VN-E4 1.5. JPEG File Format Sent Out by VN-E4 JPEG files sent out by VN-E4 are compliant with JFIF and consist of the following. FFD8 Start Code FFE0 Application Segment FFFE Comment Segment FFC0 SOF Frame Information FFDB DQT Quantization Table FFC4 DHT Huffman Table FFDA Data Start Segment FFD9 End Code The following information is stored in the comment segment. Each item has a fixed length. Item Version Information File Size Width Height Model Name Invert Flag Time Stamp Alarm Information Size Example 9 JVC V1.0 18 size = 123456 13 width = 640 14 height = 480 18 type = VN-E4 12 Stores inversion information set at VN-E4. 70 timestamp = 20050214130509123JST 13 alarm = 00000001 Camera ID 50 camera = input01 Motion Detect Setting 11 Motion Detect Result 7 Reserved 17 Reserved 32 Synchronization Time Stamp 26 Video Signal Format 20 motion = 1 md = 1 sync_timestamp = 1FDC5A34 format = NTSCU Input Channel Picture Quality 7 ch = 1 9 intp = 0 Rate Control 16 size_cntl = VFS Target Size 19 Quantization Scale 14 Firmware Version Information 12 size = 23456 q_scale = 45 ver = 01.00 Description Indicates the version of information stored in the comment segment The number of bytes of the JPEG file. Width of JPEG. Height of JPEG. Name of model that created the JPEG. Specified as reverse=1 in the case of a vertical inversion. Indicates the time at which JPEG is created. This is made up of the year/month/day, hour/minute/second, millisecond and timezone code. Indicates the alarm input status when the JPEG is created in a 4-byte binary value. (Not ASCII code.) 4 alarm inputs are assigned to 4 bits from the LSB. For example, value is alarm = 00000001when changes occur with alarm input 1, alarm = 00000008 when changes occur with alarm input 4, and alarm = 00000009 when changes occur with alarm inputs 1 and 4. Stores camera information set at VN-E4. Character code is Shift-JIS when information is stored in Japanese. Specified as 1 when the motion detect feature is ON. Specified as 1 if motion is detected at the time when JPEG is created. Indicates the 8 kHz counter value in a 4-byte binary value. (Not ASCII code.) This can be used when synchronizing with audio. Indicates the input video signal. Stated as NTSCJ for NTSC in Japan, and NTSCU for other NTSC formats. Stated as PAL for PAL format. Indicates the signal source among the 4 inputs of VN-E4. Stated as 1 when this is set to field interpolation at VN-E4, and 0 when this is set to frame processing. Describes the mode of rate control for JPEG. VFS (VariableFileSize), AFS (AverageFileSize) or CFS (ConstantFileSize). Target size of rate control. Indicates the quantization scale. Up to 3 digits. Indicates version of the firmware that is used to create JPEG. Item names and values, excluding the version information that does not include =, are stored in the following format. Item names Space = Space values 0x00 Defined fixed length by each item. Example: When width=640, the 13-byte area will be written as follows. wi d t h = 640 0x00 0x00 9