CN1283931A

CN1283931A - Captions superposing method

Info

Publication number: CN1283931A
Application number: CN 99111318
Authority: CN
Inventors: 黄天; 张明; 朱雄羽
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 1999-08-05
Filing date: 1999-08-05
Publication date: 2001-02-14
Anticipated expiration: 2019-08-05
Also published as: CN1133324C

Abstract

A caption superposing method for video conference system includes superposing the caption on the image at transmitting end before the image is encoded, encoding the caption and image, transmitting, decoding at receiving end and display.

Description

A kind of stacking method of captions

The present invention relates to video pre-process and post-process technical field, be specifically related to be applied to the stacking method of a kind of captions in the video conferencing.

In the application of video conferencing, the subtitle superposition technology is a kind of very useful technology.In the process that meeting is carried out, often need pass through the mode of broadcast subtitle and point out some information relevant with meeting.Show that its meeting-place name is necessary as each meeting-place in session, which meeting-place what can allow the participant be clear that like this to show on the screen is.In addition in session in, making each terminal can both broadcast some information also is of great use.

Normally used subtitle superposition technology is to adopt the mode of a title insert to realize.The mode of this title insert overlapping text is before video shows subtitle superposition to be gone to image, that is to say, each terminal is just subtitle superposition to be got on after receiving the image that far-end sends here.Such result is, when terminal shows the picture that remote site sends here, needs know it is that meeting-place in advance in allocation list, could get on the meeting-place name displayed image that is added to.In case it is wrong that this mode allocation list upgrades, perhaps allocation list can not upgrade in time, all will cause the meeting-place name to show mistake.In addition, in this manner, each meeting-place also can't be with the information broadcast wanting the to send terminal to other.

In view of the defective that above prior art is used, purpose of the present invention just is to provide a kind of stacking method of captions, to solve the deficiency of title insert overlapping text in video conferencing is used, make TV conference system can be more flexibly, overlapping text easily.

The stacking method of a kind of captions of the present invention is applied in the system of video conferencing, it is characterized in that this method comprises following steps at least:

The caption content that superposes superposeed with image before the image encoding of transmitting terminal; Captions after the stack are encoded with image, and the terminal that re-sends to receiving terminal is carried out decoding and displaying.

According to above technical scheme, described stack may further comprise the steps:

A) by the caption content that sends the stack of terminal background interface input desire;

B) this caption content is written in the middle buffer memory that sends terminal;

C) a captions buffer area that will this centre data in buffer writes transmitting terminal image processing template;

D) carry out supercomposed coding with the view data that sends.

Above-mentioned steps c) captions buffer memory adopts first in first out (FIFO) buffer memory, and the mode that writes by block operations realizes.

Writing above-mentioned steps b) comprising: if the caption content of desiring to write has converted the CIF form to, then only need write this centre buffer memory in proper order; If the caption content of desiring to write is the latticed form by row format, the address that then will calculate the picture element in each dot matrix according to the CIF form writes corresponding address then.

Above-mentioned steps is a) before or after the step a), more may further comprise the steps before the step b):

One captions controlled flag is set and is changed to effectively this buffer zone, centre of initialization; And

Above-mentioned steps c) afterwards, it is invalid putting this captions controlled flag.

In the stacking method technical scheme of a kind of captions of the present invention, the captions that superpose superposeed before picture coding, and captions are delivered to each meeting-place terminal again and gone decoding and displaying after image is encoded.Caption content can be passed through terminal backstage, stackable captions whenever and wherever possible.The resolution of captions is CIF (352 * 288), and Y/C (brightness/chroma) is all 8bit.The captions buffer memory adopts first-in first-out (FIFO) buffer memory, and FIFO does not have the notion of address, can only take the mode that refreshes entirely, is raising speed, the mode of buffer memory in the middle of adopting.FIFO does not have the notion of address, therefore can save address resource.

After adopting technical solution of the present invention, any one terminal of video conferencing, as long as apply to become chairman, all easily overlapping text to picture, captions can be delivered to distal displayed easily with picture, to solve the deficiency of title insert overlapping text in video conferencing is used, make TV conference system can be more flexibly, overlapping text easily.In addition, in this manner, each meeting-place can realize that the information that will send superposes whenever and wherever possible, to be broadcast to other terminal.Because the method for this overlapping text is digital-to-analogue conversion (AD) part of handling in the video front and back end, therefore this subtitle superposition mode is also referred to as the AD captions.

The present invention is further described in more detail below in conjunction with drawings and the specific embodiments.

Fig. 1 is the subtitle superposition process schematic diagram before the image encoding of the present invention.

Fig. 2 is the stack schematic flow sheet of the embodiment of the invention.

At first, see also shown in Figure 1ly, caption content is after terminal background interface input, to be put into earlier in the middle buffer memory on terminal foreground, for example, one section region of memory Ox700000～Ox73FFFF of PC is as the middle buffer memory of AD captions, and earlier this section zone is initialized as OxFF.Here, the input of terminal background interface can be keyboard input, or the input of alternate manner such as touch-screen.

When caption content is write the middle buffer memory of this section region of memory,, corresponding Y or C value are write high-end (buffer memory in the middle of this part of 7M～8M) as long as calculate the side-play amount that corresponding address (through the CIF format conversion) adds 7M.

After all having write, utilize piece to move again, middle data in buffer is write among the AD subtitle region address FIFO that Ox840000 begins on the image processing plate ADA plate.The captions of depositing among the FIFO, and are seen coding off and are sent in image with regard to stackable.

It is as follows to see also detailed process shown in Figure 2, above-mentioned:

(1) captions controlled flag register is set, and it is changed to 0.

(2) zone of the 256byte of region of memory Ox700000～Ox73FFFF is warded off be middle buffer memory, and be initialized as OxFF.

(3), then only need write in proper order in the top middle buffer memory if the caption content that will write has converted the CIF form to.If press the latticed form of row format, then to calculate the address of the picture element in each dot matrix according to the CIF form, write appropriate address then.

(4) after Shang Mian process is finished, zero clearing captions buffer memory write pointer.The captions buffer memory that the content block copy of middle buffer memory is begun to the Ox840000 of image processing plate then.

(5) this caption data and view data are carried out supercomposed coding.

(6) writing captions controlled flag register is 1.

Caption superposition method in a kind of TV conference system of the present invention superposeed the captions that will superpose to get on before picture coding, and captions are delivered to each meeting-place terminal again and gone decoding and displaying after image is encoded.Make that the subtitle superposition of TV conference system is more flexible, and the caption information that each meeting-place can will send superposes whenever and wherever possible, to be broadcast to other terminal.

Claims

1, a kind of stacking method of captions is applied in the system of video conferencing, it is characterized in that this method comprises following steps at least:

2, the stacking method of captions according to claim 1 is characterized in that described stack may further comprise the steps:

D) carry out supercomposed coding with the view data that sends.

3, the stacking method of captions according to claim 2 is characterized in that: captions buffer memory in the described step c) adopts first in first out (FIFO) buffer memory, and writing is that mode by block operations realizes.

4, the stacking method of captions according to claim 2 is characterized in that writing of described step b) comprises: if the caption content of desiring to write has converted the CIF coded format to, then only need write this centre buffer memory in proper order; If the caption content of desiring to write is the latticed form by row format, the address that then will calculate the picture element in each dot matrix according to the CIF coded format writes corresponding address then.

5, the stacking method of captions according to claim 2 is characterized in that: before the described step a) or after the step a), more may further comprise the steps before the step b), a captions controlled flag is set and is changed to effectively this buffer zone, centre of initialization; And after the described step c), it is invalid putting this captions controlled flag.