CN1239630A - Appts. and method for generating on-screen-display messages using true color mode - Google Patents

Abstract

An apparatus and concomitant method for generating an OSD message by constructing an OSD bitstream defining a plurality of "true color" pixels. The OSD bitstream contains an OSD header and OSD data. An OSD unit retrieves pixel control information from the OSD header which is programmed by a processor of a decoding/displaying system. The SOD header contains information that is used to program a color palette of the OSD unit and to provide instructions as to the treatment of the OSD data. If the "True Color Mode" is enabled in the OSD header, then the OSD unit will bypass the palette and treat the OSD data as true color pixels. Since the same chrominance components are shared between a pair of successive pixels, each successive set of four OSD data bytes represents the actual chrominance and luminance levels for two OSD pixels.

Description

Adopt true color mode to produce the equipment and the method for on-screen-display messages

The present invention relates to adopt true color mode to produce the method and apparatus of screen display (OSD) message.More particularly, the present invention relates to by osd data is replaced the pointer of whole OSD palette is increased the method and apparatus of available colored quantity as the true color pixel.

On-screen-display messages plays an important role in consumer electronic products, the user is provided the structure of the finger menus that they all use and this product.The ability that provides closed-caption (Closed Captioning) and channel logo (logos) to show is provided other key character of OSD.

Yet the variation of digital video technology standard has caused the problem that produces and show the increase of OSD message total amount.For example, special high definition TV (HDTV) specification is compared with the present National Television Systems Committee specification of maximum 128 characters in a window, and HDTV must show up to 216 characters in four windows.These new specifications to be used for decoding and show TV signal (such as, HDTV, NTSC, MPEG, Deng) decoding/display system be provided with great pressure, they must be to the encoded data stream decoding of input, and the data that will decipher with the delay of minimum offer display system.Because OSD message must show (overlapping) with video data, the microprocessor of this decoding/display system must be specified the portions of bandwidth of a memory, with the execution osd function, thereby the memory bandwidth that has increased decoding/display system needs and total computing cost.

Therefore, the OSD unit of decoding/display system comprises the palette of a limited size, so that reduce hsrdware requirements and memory access.That is, this OSD unit adopts and uses one group of register (inlet).Wherein each inlet comprises the expression of the colourity and the intensity level of an OSD pixel.Arrive this palette as osd data by these addresses (catalogue) of encoding, decoding/display system can reduce memory access and hardware needs.

Yet there is the restriction for the available colored quantity of demonstration of OSD message in these systems.Because this palette has fixing size, can not well be applicable to the standards change that may need to the support that increased colored quantity afterwards.For example, for the quantity of colour is increased to 256 (standard VGA) from 16,240 extra yard devices of posting need be added on the palette, and only support 16 inlets now.

The quantity that this palette is increased register is possible really, but and do not meet cost benefit, may cause timing problems (particularly for high palette access rate) and other integrated circuit (IC) design problem (for example, having increased the area on the IC).And upgrading existing decoding/display system with the palette of fixed size is difficulty and costliness.

Therefore, need a kind of method and apparatus, be used to increase quantity, and do not increase the hardware needs of decoding/display system, such as the size of OSD palette for the available colour of OSD message.

The present invention relates to, have effective osd bitstream of one group of " true color " pixel, produce the equipment of OSD message and the method for following thereof by formation.

More particularly, according to the present invention, an OSD unit recovers osd bitstream from storage device.This osd bitstream comprises OSD head and osd data.This OSD head comprises the color palette of this OSD unit that is used to programme and the control information of the instruction of handling about osd data is provided.This control information is to be programmed by the processor of decoding/display system.Be somebody's turn to do " true color mode " if start in the OSD head, then this palette is walked around in this OSD unit, and this osd data is handled as the true color pixel.That is, the group of each 3 osd data byte is in succession represented the actual colourity and the intensity level of an OSD pixel.

In order further to reduce the needs of memory bandwidth, repeat same chromatic component for next pixel.Therefore, each OSD pixel is only represented effectively by 16 bit data.

Now these and other aspect of the present invention will be described with reference to the accompanying drawings.

In the accompanying drawings:

Fig. 1 is the block diagram of the decoding/display system that comprises the OSD unit according to an aspect of the present invention;

Fig. 2 is to use true color mode to show the block diagram of the structure of sampling OSD pixel bit stream; With

Fig. 3 is expression constitutes the method for effective osd bitstream with true color mode a flow chart.

Fig. 1 represents for the decoding/display system of TV signal 100 block diagram of (being called decoding system later on).This decoding system comprises processor 130, random access memory (RAM) (RAM) 140, read-only memory (ROM) 142, OSD unit 150, video decoder 160 and blender 170.The output of blender 170 180 is coupled to display unit 190 through the path.

According to mpeg standard, ISO/IEC international standard 11172 (1991) (being commonly referred to as the MPEG-1 form) and 13818 (1995) (being commonly referred to as the MPEG-2 form) are described the present invention below.Yet, person of skill in the art will appreciate that, the present invention can be applied to or be used to realize other decoding system of other coding/decoding form.

In this most preferred embodiment, 100 pairs of various data flow of decoding system (bit stream) 120 carry out real-time audio frequency and video goes compression.This bit stream 120 can comprise audio frequency and the video-frequency basic flow according to MPEG-1 and Moving Picture Experts Group-2 coding.Produce this coding stream 120 by the encoder (not shown), and send to this decoding system by communication channel.This coding stream comprises the coded representation of one group of image, and can comprise the audio-frequency information relevant with these images, such as, multimedia data stream.This multimedia sources can be the HDTV platform, optic disk, cable TV station etc.Successively, the decoding of 100 pairs of these coding streams of decoding system is producing one group of decoding image, so that synchronously show with relevant audio-frequency information on display 190.Yet for purpose of the present invention, the audio frequency decoding function of decoding system 100 is incoherent, does not therefore discuss.

More particularly, processor 130 reception bit streams 120 and bit stream 11O are as input.Bit stream 110 can comprise various control signals and not be included in other data bit stream in the bit stream 120.For example, channel decoder or transmission unit (not shown) can be configured between transmission channel and the decoding system 100, with the syntactic analysis that realizes packet with to the transmission of data flow or control flows.

In this most preferred embodiment, processor 130 is carried out various controlled function, comprises but is not limited to, and provides control data to video decoder 160 and OSD unit 150, and management is to the visit of memory and control the demonstration of this decoding image.Although the invention describes single processor, those skilled in the art can know that this processor 130 can comprise the device of various special uses to manage specific function, for example, and memory controller, Microprocessor Interface unit etc.

Processor 130 receives bit stream 120, and through video decoder 160 these packets is write memory 140.Before being sent to memory through the memory data bus, this bit stream is selectively by first in first out [First-In-First-out (FIFO)] buffer.Generally also have another memory (not shown) in addition, it is only used by processor 130.

Memory 140 is used to store the data that one group of data comprises compression, decoding image and OSD bit table.Like this, the various buffers of generally this memory being videoed for example, are used for the position buffer of stores compressed data, are used to store the OSD buffer of OSD bit table, are used to store the various frame buffers of picture frame and are used to store the Display Register of deciphering image.

According to mpeg standard, video decoder 160 decodings this packed data in memory 140 is so that rebuild this coded image in this memory.In certain situation, this decoding image is a difference signal, and it is added to the standard picture of storage, so that produce actual image (for example, being convenient to decipher motion compensated image) according to the used compress technique of this image of coding.In case rebuild image, before demonstration, be stored in the Display Register through blender 170.

Equally, OSD unit 150 uses memory 140 so that store this OSD bit table or OSD standard.This OSD unit makes user (producer) for overlapping onto each the definition bit table on this decoding image.This OSD bit table can comprise be stored among storing apparatus such as the ROM about the structure of specific user's electronic product and the information of selection.On the other hand, this OSD bit table can comprise relevant to cable TV, the closed-caption that optic disk etc. send and the information of channel information element.The OSD bit table is defined as position able to programme and big or small one group of district (being generally rectangle), and wherein each has the palette of a unique available colour.

This OSD bit table is write the OSD buffer of memory 140 for the purpose of user's appointment.Yet, person of skill in the art will appreciate that ROM142 or other equivalent storage device also can be used for this function.

When the specific image that is a frame started this osd function, processor 130 operated in the data in the memory 140, to produce osd bitstream.This osd bitstream comprises OSD head and osd data (defining the data of this OSD pixel).

More particularly, the OSD head of processor 130 programmings (format and storage) in memory 140.This OSD head comprises the position of relevant top and bottom OSD field bit table, palette data, and to the pointer of next header block with comprise OSD resolution, the information of the various display modes of colored and compression.This OSD head in case programmed, this processor 130 can operate in the osd data in the memory 140 according to specific embodiment.For example, format this osd data according to the pattern of selecting, such as the true color mode of discussing below.In addition, this processor can be used simply to the pointer of the osd data in this memory this OSD head of programming, and has the ground of modification here and has not recovered the osd data of this storage to form this osd bitstream.

Then, processor 130 report starting states, for example, OSD unit 150 is given in the OSD starting, and it responds at the osd bitstream of 140 li storages of memory by request processor 130 visits.When this OSD head is read in this OSD unit, when each follows their relevant osd datas, just form and recovered this osd bitstream.After receiving this osd bitstream, this OSD pixel data is handled according to instruction or the preference pattern in this OSD head in this OSD unit.A pair of display counter (not shown) is waited in this OSD unit then, to obtain to be identified at the tram that is used to insert this osd information on the display.On this position, blender 170 is delivered to its output in this OSD unit.The output of this OSD unit 150 is stream or sequences of the numeric word of the separately brightness of representative on display screen and colourity.The memory access that can look for novelty when needs keep flowing through the necessary data (osd bitstream) of this OSD unit shows to generate comprehensive OSD.When last byte of the OSD pixel data of from this memory, reading present OSD zone, read next OSD head, repeat this processing up to last the OSD district that comprises this frame.

Those skilled in the art will appreciate that the order of above-mentioned formation and recovery osd bitstream is changeable.For example, when processor is just formaing this osd data, can from memory, read this OSD head, perhaps not recover under the situation of whole osd bitstream, or OSD message be handled and be shown as in this OSD unit can with this osd data.

Because the OSD pixel data is overlapped onto on this decoding image, this blender 170 will be deciphered selectively that image mixes with this OSD pixel data or be multiplexed.That is, this blender has at each pixel location demonstration OSD pixel, the pixel of this decoding image, or the ability of the combination of two kinds of pixels (mixing).This ability makes the channel logotype can show closed-caption (having only the OSD pixel data) or to show transparency (OSD pixel and decoding image pixel the two combination) on the decoding image.

The stream or the sequence of the numeric word of brightness and chromatic component respectively organized in video decoder 160 and 150 the two the formation representative of OSD system.The sequence of these video components being represented numeric word is coupled to D-A converter (DAC) 185 through blender 170.DAC by separately partly is converted to analoging brightness and carrier chrominance signal with this brightness and chrominance representation numeric word.

The bit table that this OSD unit 150 can be used for the definition of on any part of displayable screen explicit user, and with the size and the location independent of the video area of starting.Can define this bit table independently for each, be defined as the set in an OSD zone.The rectangle region that the zone is normally stipulated by its border is by its content of bit table definition.There is an associated palette in each zone, has defined one group of colour that can use in this district (such as 4 or 16 colours).If desired, one of these colours can be transparent, makes to show the background that it is whole as mentioned above.

Although the use of palette provides significant saving for the computing cost that low resolution OSD implements, it can not provide necessary display resolution according to the requirement that high-resolution OSD implements.For example, compare with available colour on palette, this OSD message can need more colored, and so-called available colour in the spring is defined as whole quantity (or actual register) on this palette.

Fig. 2 represents to adopt the structure of the sampling osd bitstream 200 of true color mode.This osd bitstream comprises one group of OSD head 210, and each has followed osd data 220.In one embodiment, this head is to be made of 5 64 words, is following any amount of 64 osd datas (bit table) word.This OSD head 210 comprises the information that interrelates with this OSD district coordinate 214, for the various inlets 216 and the various function code (position) 212 of the palette in specific OSD district.Those skilled in the art will appreciate that this OSD head is any length.Long head can provide more information and selection, for example, has the more palette of multiple entry, but is cost with higher computing cost, that is, need the more read and write cycle implement osd function.In fact, the content of this OSD head is the expression of specific embodiment, and is not limited to the concrete device shown in Fig. 2.

This OSD district coordinate 214 comprises the left side in OSD district and the position of right hand edge, that is, row beginning and arresting stop, the row start and stop bit is put.Show that for interlacing this district's coordinate comprises the position (pointer) of the top and bottom field pixel bit table in corresponding OSD district.At last, the pointer that comprises the next header block in the memory of this OSD district coordinate 214.

Palette information 216 comprises one group of inlet, and its each inlet comprises the expression of the colourity and the intensity level of OSD pixel.With palette information 216 this OSD palette that is used to programme.Because each OSD head comprises palette information 216, so selectively change its available colour for each OSD head and its relevant osd data byte.Each palette inlet can comprise 16 bit data, that is, and and 6 brightness Y, 4 colourities (color difference signal) C _bAnd 4 brightness (color difference signal) C _rBeing used to carry out various demonstrations related to the present invention with remaining two selects.In one embodiment, 16 inlets are arranged on the palette of needs 4 each inlet of bit addressing.

Function code (position) 212 comprises the information relevant with various patterns, includes but not limited to, shows to select and the osd bitstream selection.In this most preferred embodiment, this function digit comprises that a single position is used for expression " true color mode " and whether starts.

Osd data 220 comprises the bit table data, with from left to right and order from the top to bottom.Generally this osd data is used for being defined in the colour index (index) of each pixel of this bit table imaging.In this most preferred embodiment, if started " true color mode ", then osd data 220 comprises true color pixel (true color form) rather than to the index (indices) of palette.In this true color form, this osd data stream is made up of a byte (r) 222 of luminance component, and two byte (color difference signal C of chromatic component are and then arranged _b224 and C _r226), heel has another byte (228) of luminance component.As shown in Figure 2, repeat this pattern in succession pixel.The length of each byte generally is made as 8, thereby supports millions of possible color combinations.

For this operator scheme, as mentioned above, OSD unit 150 is walked around this OSD palette simply and is directly sent the true color pixel to blender 170.In addition, in order to support " transparent pixel " (illustrating), the Y component all is set to " 0 " from the decoding image of video decoder rather than the OSD pixel in the OSD zone.This set makes blender 17O use the corresponding pixel from the decoding image to replace this OSD pixel.

And this true color mode makes and has reduced the memory bandwidth requirement by repeating this identical chromatic component for the next pixel in this bit table.That is the public same chromatic component of a pair of pixel in succession.

In order to illustrate, Fig. 2 shows data byte (pixel data) 231-234 of one group of definition pixel, and wherein each pixel data structure is 24 long (8 Y, 8 C _bAnd 8 C _r).Yet, pixel 231 and 232 public same chromatic components 224 and 226.For in succession pixel to repeating this pattern, thereby only need 16 bit data represent a single pixel (representing 2 pixels) effectively with 32 bit data.

This operator scheme makes processor 130 obtain to be sent to from memory 33% saving of the data volume of this OSD unit,, has reduced the size of this osd bitstream that is.The more important thing is, under the situation of the size that does not increase this OSD palette, increased quantity widely for the utilized colour in each OSD zone.In fact, even increase on the hsrdware requirements is arranged, also be few.

Fig. 3 represents to constitute with true color mode the method 300 of osd bitstream.This method is usually from a storage device, and for example, memory calls again, and is carried out by processor 130.Produce this osd bitstream by processor 130, and handle by OSD unit 150.Method 300 has the OSD head of a true color position by generation, and the data byte of one group of true color pixel is and then arranged.Constitute osd bitstream.

Referring to Fig. 3, method 300 is in step 305 beginning and enter step 310, is appointed as the true color mode position with one in this OSD head here.If this true color mode of starting in this OSD head, the osd data byte of then following this head defines the true color pixel.If this true color mode of unstart is then handled this osd data byte with normal format, it may be 4 bit address (perhaps any other bit stream format, such as, mpeg standard) to palette.

In step 320, method 300 determines whether to have started this true color mode.If to this inquiry is a negative answer, method 300 enters step 325, uses achromaticity form true to nature to produce this osd data byte.This method 300 enters step 340 then.

If the inquiry to step 320 is an affirmative reply, method 300 enters step 330, here with one group of true color configuration of pixels in these osd data bytes.Each true color pixel comprises 3 osd data bytes, wherein each osd data byte have 8 long.Because repeat this chromatic component (perhaps deletion) for pixel in succession, two OSD pixels can be placed in four osd data bytes every a chromatic component group.

In step 340, method 300 has determined whether that another OSD head follows the handled osd data in front.If revise various patterns, the OSD head that must look for novelty by function digit 212 representatives.Equally, need a new head for each the new OSD district on the frame.If the answer is in the negative for this inquiry, method 300 enters step 350, and method 300 finishes here.If to this inquiry is affirmative reply, method 300 enters step 320, wherein for each other OSD head repeating step 320-330.By this way, this osd bitstream can comprise true color osd data byte and achromaticity osd data byte true to nature.

Represented and described the new method and apparatus of the osd bitstream that constitutes definition true color pixel like this.After this specification of having considered the open embodiment of the invention and accompanying drawing, be that significantly the present invention can have many variations to those skilled in the art, modification and other use and use.All these does not break away from the spirit and scope of the present invention, and scope of the present invention is only limited by the following claim book.

Claims (19)

1. method that is used to constitute screen display (OSD) bit stream, described method comprises step:

In the OSD head, be provided with one, institute's rheme is used to represent true color mode; With

Produce the osd data of one group of true color pixel of definition.

2. according to the process of claim 1 wherein that each of described one group of true color pixel comprises a luminance component and a chromatic component.

3. according to the method for claim 2, a pair of public same chromatic component of wherein said one group of true color pixel.

4. according to the method for claim 3, wherein said a pair of true color pixel comprises two true color pixels in succession.

5. according to the method for claim 4, the arrangement of wherein said a pair of true color pixel comprises first luminance component, follows described public chromatic component, and the back is second luminance component.

6. according to the method for claim 2, wherein with all resets of described luminance component of true color pixel, so that carry out transparent mode.

7. according to the process of claim 1 wherein that carrying out described osd data without palette produces step.

8. according to the method for claim 1, also comprise the step of the osd data that produces one group of achromaticity pixel true to nature of definition.

9. osd bitstream that stores in storage medium comprises:

A head has one and represents true color mode;

One group of osd data byte is coupled to described head, defines one group of true color pixel.

10. according to the osd bitstream of claim 9, each of wherein said one group of true color pixel comprises a luminance component and a chromatic component.

11. according to the osd bitstream of claim 10, a pair of public same chromatic component of wherein said one group of true color pixel.

12. according to the osd bitstream of claim 11, wherein said a pair of true color pixel comprises two true color pixels in succession.

13. according to the osd bitstream of claim 12, the arrangement of wherein said a pair of true color pixel comprises first luminance component, follows described public chromatic component, the back is second luminance component.

14. according to the osd bitstream of claim 10, wherein the luminance component with described true color pixel all is set to " 0 ", so that carry out transparent mode.

15. according to the osd bitstream of claim 9, wherein said osd data byte also defines achromaticity pixel true to nature.

16. an equipment that is used to produce osd bitstream comprises:

Storage medium is used to store OSD head and osd data;

Processor is coupled to described storage medium, is used for being enabled in the true color mode of described OSD head, and is used to read the described osd data of described OSD head and one group of true color pixel of definition, so that form osd bitstream.

17. according to the equipment of claim 16, wherein said storage medium is read-only memory (ROM).

18. according to the equipment of claim 16, wherein said storage medium is random access memory (RAM) (RAM).

19. an equipment that is used to produce OSD message comprises:

Storage medium is used to store the osd bitstream with head and osd data;

Processor is coupled to described storage medium, is used for being programmed in the true color mode position of described OSD head, and is used to format the described osd data of one group of true color pixel of definition; With

Described processor is coupled in OSD unit, is used to handle described osd bitstream to form this OSD message.

Images