Video recording apparatus, video recording system and video recording method executed by video recording apparatus
The present invention enables an effective use of a ring buffer. A video recording apparatus includes a first thinning process unit which reduces a data size of camera videos transmitted from a camera to a frame rate number of the camera videos, and which stores the camera videos having undergone a thinning process in a ring buffer, and a second thinning process unit which further reduces the data size of the videos stored in the ring buffer at a frame rate number in accordance with a condition among a plurality of conditions. The first thinning process unit stores the camera videos in the ring buffer at a frame rate that is the lowest common multiple of the frame rate numbers of the plurality of conditions.
1. A video recording apparatus comprising:
a first thinning processor which reduces a data size of camera videos transmitted from a camera to a frame rate number smaller than a frame rate number of the camera videos, and which stores the camera videos having undergone a thinning process in a ring buffer; and
a second thinning processor which has a frame rate number of a thinning process set in advance for each of a plurality of conditions, and which further reduces the data size of the videos stored in the ring buffer to the frame rate number in accordance with a condition among the plurality of conditions,
the first thinning processor being configured to store the camera videos in the ring buffer at a frame rate number that is a lowest common multiple of a first frame number and a second frame number, wherein the first frame number is a frame number when the camera video is recorded in a normal condition and the second frame number is a frame number when the camera video is recorded in a case where an alarm signal is input to the video recording apparatus,
wherein the second thinning processor reduces a data size of the data-size-reduced camera videos to the first frame number when the alarm signal is not input to the video recording apparatus, and
wherein the second thinning processor reduces the data size of the data-size-reduced camera videos to the second frame number when the alarm signal is input to the video recording apparatus.
2. The video recording apparatus according to claim 1 , wherein
the video recording apparatus comprises a plurality of the cameras,
frame rate numbers in accordance with the plurality of conditions are set for each camera, and
the first thinning processor stores, for each camera, the camera videos in the ring buffer at a frame rate that is a lowest common multiple of the frame rate numbers of the plurality of conditions for each camera.
3. A video recording system comprising:
a camera; and
the video recording apparatus according to claim 1 .
4. A video recording method executed by a video recording apparatus, comprising steps of:
reducing, by a first thinninurocessor, a data size of camera videos transmitted from a camera to a frame rate number smaller than a frame rate number of the camera videos and storing the camera videos having undergone a thinning process in a ring buffer,
setting, in advance, a frame rate number of a thinning process for each of a plurality of conditions, and reducing, by a second thinning processor, the data size of the videos stored in the ring buffer to the frame rate number in accordance with a condition among the plurality of conditions,
causing the first thinning processor to store the camera videos in the ring buffer at a frame rate that is a lowest common multiple of a first frame number and a second frame number, wherein the first frame number is a frame number when the camera video is recorded in a normal condition and the second frame number is a frame number when the camera video is recorded in a case where an alarm signal is input to the video recording apparatus,
wherein the second thinning processor reduces a data size of the data-size-reduced camera videos to the first frame number when the alarm signal is not input to the video recording apparatus, and
wherein the second thinning processor reduces the data size of the data-size-reduced camera videos to the second frame number when the alarm signal is input to the video recording apparatus.
5. The video recording method according to claim 4 , wherein
frame rate numbers in accordance with the plurality of conditions are set for each of a plurality of cameras, and
the first thinning processor stores, for each camera, the camera videos in the ring buffer at a frame rate number that is a lowest common multiple of the frame rate numbers in accordance with the plurality of conditions for each camera.