System and method for sending video data over a wireless channel
A system and method for transmitting video. Each frame of video is divided into a number of regions, that are transmitted in order beginning with a region of most importance. The region of most importance may be different from one frame to the next. When the video is transmitted over a channel with limited channel capacity, so that some frames are not transmitted completely, the region of most importance in a current frame may be selected to be the first region not transmitted in the previous frame. The system and method may be useful for the transmission of video data over a wireless link having variable or limited channel capacity.
1. A method for transmitting video for a display panel comprising N regions, numbered 1 through N, wherein N is a positive integer, the method comprising:
identifying, for a first frame of video, a first region of most importance, from among the N regions;
transmitting data from the first frame of video, one region at a time, beginning with the first region of most importance, until a first frame transmission interval corresponding to the first frame of video has elapsed;
identifying, for a second frame of video, a second region of most importance, from among the N regions, the second region of most importance being different from the first region of most importance, wherein the identifying of the second region of most importance comprises:
identifying a region from among the N regions for which a measure of a difference between data for the first frame and data for the second frame is greatest, when during the first frame transmission interval all N regions were transmitted; and
selecting the region having a next region number following, in cyclic order, a region number of a last region transmitted during the first frame transmission interval, when during the first frame transmission interval not all N regions were transmitted; and
transmitting data from the second frame of video, one region at a time, beginning with the second region of most importance, until a second frame transmission interval corresponding to the second frame of video has elapsed.
2. The method of claim 1 , wherein the identifying of the second region of most importance comprises identifying a region from among the N regions for which a measure of the difference between data for the first frame and data for the second frame is greatest, when during the first frame transmission interval all N regions were transmitted.
3. The method of claim 2 , wherein the first frame of video comprises sub-pixel data, the second frame of video comprises sub-pixel data, and the measure of the difference is a sum, over the sub-pixel data in the region, of:
a square of:
the difference between:
a value of the sub-pixel data of the first frame of video, and
a value of the sub-pixel data of the second frame of video.
4. The method of claim 1 , wherein the identifying of the second region of most importance comprises receiving from a user an indication of which region is the region of most importance.
5. The method of claim 1 , wherein:
the transmitting of data from the first frame of video further comprises transmitting an identifier for the first region of most importance.
6. The method of claim 1 , wherein:
the transmitting of data from the first frame of video, one region at a time, comprises encoding the data from the first frame of video, one region at a time; and
the transmitting of data from the second frame of video, one region at a time, comprises encoding the data from the second frame of video, one region at a time.
7. The method of claim 6 , further comprising:
receiving data from the first frame of video, one region at a time;
decoding the data from the first frame of video, one region at a time;
receiving data from the second frame of video, one region at a time; and
decoding the data from the second frame of video, one region at a time.
8. The method of claim 7 , further comprising:
supplementing the decoded data from the second frame of video with corresponding data from the first frame of video, when during the second frame transmission interval not all N regions were transmitted.
9. The method of claim 1 , wherein the transmitting of data from the first frame of video, one region at a time, beginning with the first region of most importance, comprises transmitting data by region number in cyclic order.
10. The method of claim 1 , wherein the transmitting of data from the first frame of video, one region at a time, beginning with the first region of most importance, comprises transmitting data by region number in order of decreasing importance.
11. A transmitter for transmitting video for a display panel comprising N regions, numbered 1 through N, wherein N is a positive integer, the transmitter being configured to:
identify, for a first frame of video, a first region of most importance, from among the N regions;
transmit data from the first frame of video, one region at a time, beginning with the first region of most importance, by region number in cyclic order, until a first frame transmission interval corresponding to the first frame of video has elapsed;
identify, for a second frame of video, a second region of most importance, from among the N regions, the second region of most importance being different from the first region of most importance wherein the identifying of the second region of most importance comprises:
identifying a region from among the N regions for which a measure of a difference between data for the first frame and data for the second frame is greatest, when during the first frame transmission interval all N regions were transmitted, and
selecting the region having a next region number following, in cyclic order, a region number of a last region transmitted during the first frame transmission interval, when during the first frame transmission interval not all N regions were transmitted; and
transmit data from the second frame of video, one region at a time, beginning with the second region of most importance, by region number in cyclic order, until a second frame transmission interval corresponding to the second frame of video has elapsed.
12. The transmitter of claim 11 , wherein the first frame of video comprises sub-pixel data, the second frame of video comprises sub-pixel data, and the measure of the difference is a sum, over the sub-pixel data in the region, of:
a square of:
the difference between:
a value of the sub-pixel data of the first frame of video, and
a value of the sub-pixel data of the second frame of video.
13. The transmitter of claim 11 , wherein the identifying of the second region of most importance comprises receiving from a user an indication of which region is the region of most importance.
14. The transmitter of claim 11 , wherein:
the transmitting of data from the first frame of video further comprises transmitting an identifier for the first region of most importance.
15. A method for transmitting video over a wireless link, the method comprising:
storing a first frame of video data in a buffer;
dividing the first frame into N regions, N being a positive integer;
identifying, for the first frame of video data, a first region of most importance, from among the N regions;
sending, over the wireless link, beginning with the first region of most importance, by region number in cyclic order, until a first frame transmission interval corresponding to the first frame of video has elapsed;
storing a second frame of video data in a buffer; dividing the second frame into the N regions;
identifying, for the second frame of video data, a second region of most importance, from among the N regions, the second region of most importance being different from the first region of most importance wherein the identifying of the second region of most importance comprises:
identifying a region from among the N regions for which a measure of a difference between data for the first frame and data for the second frame is greatest, when during the first frame transmission interval all N regions were transmitted, and
selecting the region having the next region number following, in cyclic order, a region number of a last region transmitted during the first frame transmission interval, when during the first frame transmission interval not all N regions were transmitted; and
sending, over the wireless link, video data from second frame of video, one region at a time, beginning with the second region of most importance, by region number in cyclic order, until a second frame transmission interval corresponding to the second frame of video has elapsed.
16. The method of claim 15 , wherein the regions in the fourth subset are in the first subset.
17. The method of claim 15 further comprising:
before the sending of the video data from a first subset of the N regions, encoding the video data from the first subset one region at a time; and
before the sending of the video data from a third subset of the N regions, encoding the video data from the third subset one region at a time.
18. The method of claim 15 further comprising:
receiving the video data from a first subset of the N regions;
displaying a first image including the video data from a first subset of the N regions;
receiving the video data from a third subset of the N regions; and
displaying a second image including:
the video data from a third subset of the N regions; and
video data from regions, of the first subset of the N regions, corresponding to the fourth subset of the N regions.