KR20090076022A - Apparatus for generating a thumb-nail and multi-codec decoder apparatus including the same - Google Patents

Abstract

An apparatus for generating a thumbnail and a multi-codec decoder apparatus including the same are provided to generate a thumbnail image of high definition having a predetermined size without respect to HD(High Definition)/SD(Standard Definition) images, thereby composing a suitable list screen. A thumbnail filter unit(320) produces at least one representative pixel from a macroblock of a deblocked image. The thumbnail filter unit adjusts the produced representative pixel by a predetermined size. The thumbnail filter unit converts the extracted representative pixel into image information of RGB signals. A thumbnail buffer unit(330) stores one or more pixels for configuration of the produced thumbnail image. A thumbnail controller(310) indicates thumbnail production to the thumbnail filter unit. If the thumbnail production is completed, the thumbnail controller controls the produced thumbnail image to be stored in the thumbnail buffer unit.

Description

Apparatus for generating a thumb-nail and multi-codec decoder apparatus including the same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thumbnail generation device and a multicodec decoder device including the same, and more particularly, to a thumbnail generation device and a multicodec decoder device including the same that can be commonly used in a multicodec decoder of a high definition image.

Video compression has evolved in many directions, depending on the application. The basic framework of the video compression method is to divide the continuous video frames constituting the video into blocks of a certain size (macroblock) to remove spatial and temporal redundancy at each block position.

That is, to remove spatial redundancy, a method of converting an image frame into a frequency domain in units of blocks divided within the same image frame and quantizing the same to reduce transmission burden on high frequency components, and to remove temporal redundancy. It uses motion estimation and compensation technique between image frames.

Widely used video compression is represented by the Moving Picture Expert Group (MPEG) and is classified into several standards according to the needs of the times and applications.

MPEG-1 has been used as a method of compressing a video by an early progressive scanning method and storing it in a storage medium such as a VCD (Video Compact Disk) or compressing a small video.

In order to compress high quality video, MPEG-2 used a variety of techniques by adding an interlaced scanning method. The MPEG-2 is most widely used in various fields such as storage devices such as DVD (Digital Versatile Disk), DTV broadcasting such as satellite, cable, terrestrial wave, personal video recorder (PVR), and video transmission on a network. It is one of the video standards.

MPEG-4 is a compression standard used for a video streaming service or a wireless video service in a network environment by applying new techniques such as a moving picture, a still picture, a graphic picture, and an object model.

In order to support more complex and diverse applications and to facilitate the production and distribution of video content, the need for a better video compression standard has been raised after the MPEG-4 video compression standard. , A new compression scheme such as VC-1 (Video Coding-1) has been proposed.

H.264 is also referred to as MPEG-4 Part 10-AVC (Advanced Video Coding), and is an efficient video compression method that reduces the amount of compression bits by half while maintaining the same image quality as compared to MPEG-2.

As described above, the video compression method is developed in various ways, and the demand for a new method is constantly generated. In addition, the necessity of restoring various kinds of moving images in one receiver has emerged due to the large capacity, simplicity of digital storage media, the high quality, diversification of digital TV services, and the interconnection of various media through a network.

Accordingly, a multi-codec decoder for restoring various kinds of videos has been developed and distributed, and one video decoder can be adaptively designed to cope with various video compression standards.

In addition, an indexing function that makes good use of additional data service information, for example, program guide information, has been developed to efficiently search for information on digital broadcasting.

In this case, when not only the stored data information but also a thumbnail image of the broadcast is provided, the user may more easily search / view the stored broadcast content.

Recently, as digital broadcasting is activated, a personal video recorder (PVR) for storing high-definition video and watching it again is being used as a built-in type in a separate digital set-top box or TV.

As the recording / reproduction of digital video through the PVR is implemented, the video is stored as a scaled down image of several frames as a means of managing the recorded video and displayed together with the recorded video list.

The thumbnail image is scaled back to a smaller image for the entire decoded image after decoding, and in the case of MPEG-2, a thumbnail image is formed by collecting only DC values of Macroblocks (MBs) generated in an intermediate stage of decoding. do.

However, the scaling method is very inefficient in terms of memory, bandwidth, and computation, and in the codec such as H.264 or VC-1, secondary coding of DC values through prediction is performed, and due to the complicated slice / picture structure, etc. The method of constructing a thumbnail image by collecting only the DC value of the macroblock used in -2 has become inappropriate.

Accordingly, an object of the present invention is to propose an apparatus for generating a thumbnail image in a multicodec decoder capable of supporting various codecs, and a multicodec decoder device including the same.

In order to solve the above problems, the present invention does not collect DC values of macroblocks in the middle of the inverse transformation, but calculates and collects the representative pixels using a deblocked image and clips the desired thumbnail image to a predetermined size. Can be generated.

According to the present invention, a multi-codec decoder device capable of obtaining high-quality thumbnails can be implemented by adding a thumbnail generating device having a low complexity.

In addition, the present invention can be applied to a multi-codec decoder to generate thumbnail images regardless of the compression method, so the utility of the PVR is large.

In addition, the present invention can generate a high-quality thumbnail image having a constant size irrespective of the HD / SD image, it is possible to configure an appropriate list screen by applying to a high-definition display.

In addition, the present invention makes it possible to generate thumbnails while minimizing the use of a processor.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thumbnail generation device and a multicodec decoder device including the same, and more particularly, to a thumbnail generation device and a multicodec decoder device including the same that can be commonly used in a multicodec decoder of a high definition image.

An apparatus for generating a thumbnail according to an embodiment of the present invention calculates one or more representative pixels from a macroblock of a deblocked image, adjusts them to a predetermined size, and converts them into image information of an RGB signal using the calculated representative pixels. A thumbnail filter unit; A thumbnail buffer unit for storing one or more pixels for constructing a thumbnail image generated by the thumbnail filter unit; And a thumbnail controller for instructing the thumbnail filter unit to generate a thumbnail and storing the thumbnail in the thumbnail buffer unit when the thumbnail generation is completed.

Preferably, the thumbnail filter unit includes: a subblock filter for calculating at least one representative pixel from a macroblock; An average filter which obtains an average value of constant pixel values of each of the calculated pixels and replaces the current pixel value; A clipping unit to cut a predetermined area on the left, right, or top and bottom sides of the image to reduce the input image to an image having a predetermined size; And a color space converter configured to convert the image output from the clipping unit to image information of an RGB signal.

Preferably, the average filter reduces the horizontal and vertical sizes of the input image by 50% and outputs them.

Preferably, the thumbnail controller instructs the thumbnail filter unit to generate a thumbnail when the deblocked image is an instant decoded refresh (IDR) picture, or the thumbnail controller controls the thumbnail at every predetermined period of the deblocked image. Instructs the thumbnail filter unit to generate thumbnails.

Preferably, the average filter is bypassed when the input image is an SD (Standard Definition) image.

Preferably, the thumbnail buffer unit is configured to enable double buffering, and when the macroblock processing preset to the thumbnail buffer unit is completed, the thumbnail control unit controls to store the completed thumbnail on the external storage device and notifies the host to the host. do.

According to another aspect of the present invention, there is provided a multi-codec decoder including: a decoder configured to receive a video signal compressed by at least one encoder method and to restore the same; A deblocking unit for deblocking filtering the image reconstructed by the decoding unit and outputting the deblocking filter; A thumbnail generator configured to generate a predetermined thumbnail from the image output from the deblocking unit; And a memory unit configured to store a reference image used to restore an image signal of the decoding unit and a thumbnail generated by the thumbnail generator.

Preferably, the deblocking unit comprises: a deblocking filter unit for performing a deblocking process of an input image; A deblocking buffer unit for storing an image of which the deblocking process is completed by the deblocking filter unit; And a deblocking control unit configured to provide an image stored in the deblocking buffer unit to the thumbnail generator, and instruct generation of a thumbnail in the thumbnail generator.

Preferably, the thumbnail generation unit may include: a thumbnail filter unit configured to calculate one or more representative pixels from macroblocks of the deblocked image, adjust them to a predetermined size, and convert the converted representative image into image information of an RGB signal using the calculated representative pixels; A thumbnail buffer unit for storing one or more pixels for constructing a thumbnail generated by the thumbnail filter unit; And a thumbnail controller for instructing the thumbnail filter unit to generate thumbnails and storing the thumbnails in the thumbnail buffer unit when the thumbnails are generated.

Preferably, the thumbnail buffer unit is configured to enable double buffering, and when the macroblock processing preset in the thumbnail unit is completed, the thumbnail control unit controls to store the completed thumbnail in the memory unit and notifies the host to the memory unit. .

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily understand and implement the present invention.

1 is a block diagram illustrating a configuration of a multicodec decoder device according to an embodiment of the present invention.

As shown in FIG. 1, the multicodec decoder includes a memory unit 400, a control unit 500, an entropy decoder 110, an inverse scan / inverse quantization unit 120, an inverse transform unit 130, and an intra prediction unit. 140, a motion compensator 150, a deblocking unit 200, a thumbnail generator 300, and the like.

A video elementary stream (VES) bitstream corresponding to a program selected by a system decoder or a transport demux (not shown) is input to the entropy decoder 110.

The bitstream is an encoded format of video data and is encoded in an entropy encoding format. Accordingly, the entropy decoder 110 decodes each syntax element encoded by a variable length code (VLC) or a context adaptive binary arithmetic code (CABAC) and provides the decoded syntax block to a corresponding block.

Each syntax information includes picture header information, prediction information, residual information, and the like.

The picture header information indicates information such as a picture structure, a picture coding type, a frame size, a reference frame, and the like, and the information is transmitted to the controller 500 and used to control other blocks.

The prediction information is a reference frame index and a motion for compensating an intra prediction mode, which is information used to compensate a block value prediction value, or a block value prediction value from another frame within the same frame. Contains a motion vector. The intra prediction mode is provided to the intra predictor 140, and the reference frame index and the motion vector are provided to the motion compensator 150.

The difference information is expressed in the form of coefficients obtained by converting a difference value compensated for an intra or inter prediction value into a frequency domain, and is provided to the inverse scan / inverse quantizer 120.

The inverse scan / inverse quantization unit 120 performs inverse quantization while scanning the transform coefficients that are input by a zigzag scan in a reverse scan, that is, a raster scan method, and outputs the inverse quantization unit 130 to the inverse transform unit 130. The inverse transform unit 130 performs an inverse discrete cosine transform (IDCT) on the inverse quantized transform coefficients and outputs them to an adder.

The adder reconstructs the complete block by adding the predicted value output through the IDCT signal and the switch and outputs the complete block to the deblocking unit 200.

Meanwhile, when the macroblock to be decoded is an intra mode, the intra prediction unit 140 receives an intra prediction mode signal from the entropy decoder 110 and compensates the prediction value of the current block from adjacent pixel values in the same frame. Output to the switch.

When the macroblock to be decoded is the inter mode, the motion compensation unit 150 receives the reference frame index and the motion vector from the entropy decoder 110 to calculate a corresponding position of the reference frame to compensate for the prediction value, and then switches to the switch. Output

The switch selects the output of the intra predictor 140 or selects the output of the motion compensator 150 according to the predicted pixel value and outputs the output to the adder. The switch is switched under the control of the controller 500.

The image fully reconstructed through the above process may be output for display and stored in the memory unit 400 when the currently reconstructed image frame is later used as a reference frame. It may not be stored in the unit 400 and may be output only for display.

The image stored in the memory unit 400 may be stored through the deblocking unit 200 or may be directly stored without passing through the deblocking unit 200 according to an embodiment.

The thumbnail generator 300 generates a predetermined thumbnail image for the image that has passed through the deblocking unit 200.

The thumbnail generator 300 starts to generate a thumbnail image when a predetermined condition is established for the deblocked image. The detailed configuration of the thumbnail generator 300, the thumbnail image generation condition, and the deblocking unit are performed. Interrelation with 200 will be described in detail with reference to FIGS. 3 and 4.

The thumbnail generation unit 300 does not use a method of generating thumbnails by collecting DC values of the dequantized macroblocks as in the related art, and is suitable for a predetermined condition on the deblocked image as shown in FIG. 1. Extract only the image and use it to create thumbnail images. Accordingly, a suitable thumbnail generation device can be implemented in a multicodec decoder supporting all codecs.

The thumbnail image generated by the thumbnail generator 300 may be stored in an internal buffer unit and finally stored in the memory unit 400 to be displayed together with video content.

2 is a block diagram illustrating a simplified configuration of a multicodec decoder device according to an embodiment of the present invention.

The block diagram illustrated in FIG. 2 is a simplified representation of the block diagram illustrated in FIG. 1, and the multicodec decoder device according to an embodiment of the present invention receives and decodes a video signal compressed by one or more encoding schemes. The deblocking unit 200 for deblocking and filtering the image reconstructed by the decoding unit 100 and outputting the image for display, and a predetermined thumbnail from the image output from the deblocking unit 200. And a thumbnail generator 300 to generate a reference image, and a memory unit 400 to store a reference image used to restore an image signal of the decoder 100 and a thumbnail generated by the thumbnail generator 300.

The decoding unit 100 restores a bitstream compressed by a specific encoding scheme, for example, MPEG, H.264, VC-1, etc., and entropy decoder 110 of FIG. 1, inverse scan / dequantization. The unit 120, an inverse transform unit 130, an intra predictor 140, a motion compensator 150, and the like.

The image reconstructed by the decoding unit 100 is reduced by the block blocking between the macroblocks by the deblocking unit 200, and is predetermined by the thumbnail generator 300 by using the image from which the block distortion is reduced. Create thumbnail images.

The predetermined thumbnail image generated by the thumbnail generator 300 is stored in the memory 400. In addition, since the reference image is stored in the memory unit 400, the decoding unit 100 is used as data for restoring the compressed image.

The memory unit 400 may include a storage device such as a double data rate SDRAM (SDRAM), an SDRAM, an SRAM, and a NAND FLASH.

3 is a block diagram showing the configuration of a thumbnail generator 300 according to an embodiment of the present invention.

The thumbnail generation apparatus 300 according to an embodiment of the present invention calculates one or more representative pixels from the macroblocks of the deblocked image, adjusts them to a predetermined size, and uses the calculated representative pixels to image the RGB signal. A thumbnail filter unit 320 for converting the information into information; A thumbnail buffer unit 330 for storing one or more pixels for constructing a thumbnail image generated by the thumbnail filter unit 320; And a thumbnail controller 310 for instructing the thumbnail filter unit 320 to generate thumbnails and storing the thumbnails in the thumbnail buffer unit 330 when the thumbnail generation is completed.

When an external control signal, for example, a control signal from the deblocking unit, that is, a thumbnail generation enable signal, is received, the thumbnail controller 310 instructs the thumbnail filter unit 320 to generate a thumbnail image using the deblocked image. do.

The thumbnail filter unit 320 serves to generate a predetermined thumbnail image when a thumbnail generation instruction is received from the thumbnail controller 310. The thumbnail filter unit 320 is a subblock filter unit 321. , An average filter 322, a clipping 323, and a color space converter CSC 324.

When the thumbnail control unit 310 receives the thumbnail generation enable signal, the thumbnail control unit 310 processes the thumbnail filter unit 320 through picture type (eg, IDR picture) and picture size (eg, HD or SD) information, and performs a thumbnail filter. Generates an address for reading the contents of the deblocking buffer unit for input to the unit 320, controls to store the filtered result in the thumbnail buffer unit 330, and generates an appropriate address.

The unit of the block requesting the generation of the thumbnail image may have various sizes such as 4 × 4, 8 × 8, and 16 × 8, and may be implemented to efficiently process each. In addition, a thumbnail image may be generated in units of a macroblock or subblocks constituting the macroblock, and in this specification, a method of generating a thumbnail image in units of 4 × 4 subblocks will be described.

The subblock filter unit 321 calculates one or more representative pixels from the subblocks constituting the macroblock. The representative pixel is a pixel representing an average value of luminance (luminance, Y) of the subblock, and the thumbnail generation device according to an embodiment of the present invention may calculate one or more representative pixels from a single subblock.

The representative pixel calculation method may be equally applied to Cr and Cb values representing color values.

For example, as described above, in the case of a 4x4 subblock, for example, one pixel may be calculated as a representative pixel, or a representative pixel of 2x2 pixels may be calculated. The method of calculating 2 × 2 representative pixels from the 4 × 4 subblocks may vary. For example, one representative pixel may be calculated from four 2 × 2 blocks constituting the 4 × 4 subblocks.

In addition, a thumbnail image generation method may vary according to the type of picture. For example, when the input image is a high definition (HD) image, the macroblock may be set as 8 × 8 as a thumbnail generation unit, and the input image may be SD (Standard). Definition) In the case of an image, the macroblock may be set to 4 × 4.

Therefore, when the input image is an HD image, in order to generate a thumbnail image having a size substantially the same as that of the thumbnail image in the SD image, an average filter that calculates an average of constant peripheral pixel values of the calculated pixels and replaces the current pixel values. Pass through portion 322.

Since the average filter unit 322 reduces the horizontal and vertical sizes of the input image by 50%, the average filter unit 322 bypasses the thumbnail image of the HD image passed through the average filter unit 322 and the average filter unit 322. The thumbnail image of the SD image may have a similar size. This will be described in detail with reference to FIG. 5.

As described above, the thumbnail image of the HD image passing through the average filter unit 322 and the SD image not passing through the average filter unit 322 have a similar size, and the image size of the thumbnail image must be equally adjusted. If there is a request, the clipping unit 323 processes the two images to have the same size.

The clipping unit 323 cuts predetermined areas on the top, bottom, left, and right sides of the image to reduce the input image to an image having a predetermined size. Since the image to be displayed in one picture or frame is mostly concentrated in the center, there is no big problem in identifying the image even when cutting a certain area on the top, bottom, left and right. The clipping unit 323 will be described in detail with reference to FIG. 6.

As described above, the image may be reduced by passing through the average filter unit 322, and then a predetermined area may be cut by the clipping unit 323. Alternatively, according to an embodiment, the predetermined area may be predetermined by the clipping unit 323. After cutting the region, the average filter unit 322 may reduce the image.

Next, the image output from the clipping unit 323 passes through a color space conversion unit 324 for converting the image information of the RGB signal. The encoding / decoding process of an image is performed using Y / C units, that is, Y representing luminance values and Cr, Cb representing color values, which can be converted into image information of an RGB signal to be realized as an actual image. Make sure

The pixels constituting the thumbnail image converted by the color space converter 324 into the image information of the RGB signal are stored in the thumbnail buffer unit 330.

Here, the thumbnail buffer unit 330 is configured to enable double buffering, and may be configured to read in advance a content to be processed next in another buffer while processing a given content in one buffer. .

That is, when the processing (eg, four) of the macroblocks preset in the thumbnail buffer unit 330 is completed, the thumbnail controller 310 transmits the processed thumbnails to an external storage device such as the memory unit 400. Control to save and notify host.

4 is a block diagram illustrating in more detail a relationship between a deblocking unit and a thumbnail generator of a multicodec decoder according to an embodiment of the present invention.

As described above, the processed images such as inverse quantization, inverse transformation, and motion compensation are stored in the MC buffer 410. Next, under the control of the deblocking control unit 210, the image stored in the MC buffer 410 is sequentially deblocked by the deblocking filter unit 220 to remove image distortion between macroblocks. The images of which the image distortion elimination processing is completed are stored in the deblocking buffer unit 230.

In addition, the deblocking control unit 210 may enable a thumbnail generation instruction to the thumbnail control unit 310. In this case, a condition for enabling the generation instruction of the thumbnail may vary according to embodiments.

For example, when the deblocked image is an instant decoded refresh (IDR) picture, the deblocking control unit 210 may enable thumbnail generation in the thumbnail control unit 310, and accordingly, the thumbnail control unit 310 may be used. May instruct the thumbnail filter unit 320 to generate a thumbnail image for the IDR picture.

The IDR (Instantaneous Decoding Refresh) picture is a leading picture of an image sequence. In the IDR picture, it is necessary to demodulate a picture bit string such as a state of a reference picture buffer made from an I slice or an SI slice (switch I slice), a frame number, a picture order count (POC), and information indicating an output order of a picture). All states are initialized. Therefore, it may be desirable to use the IDR picture as a reference picture for thumbnail generation.

Alternatively, as described above, a thumbnail may be generated by extracting an image every predetermined period without generating a thumbnail image for a specific type of picture. For example, when it is preset to extract one thumbnail image per 20 frames or per picture, the deblocking controller 210 enables thumbnail generation to the thumbnail controller 310 whenever a preset period arrives. The thumbnail filter unit 320 causes the thumbnail image to be generated, and the generated thumbnail is stored in the thumbnail buffer unit 330.

In addition, the thumbnail image stored in the thumbnail buffer unit 330 may be stored in an external storage device, for example, the memory unit 400, and may control direct memory access through the DMA controller 510.

In addition, as described above, the thumbnail image stored in the thumbnail buffer unit 330 may be simultaneously stored in the external memory unit 400, or may be configured to enable double buffering to simultaneously store the memory unit 400. You can save a new thumbnail image.

5 is an exemplary view illustrating a thumbnail image generation process according to an embodiment of the present invention.

In FIG. 5, the Y values are filtered in 8 × 8 macroblocks in 4 × 4 units and the C values are filtered in 4 × 4 units for the HD image. Although FIG. 5 illustrates an image of a 4: 2: 0 format of YCrCb, this is merely an example for easy description of the present invention and the present invention is not limited thereto.

As described above, one or more representative pixels are calculated from the 4x4 subblock by the subblock filter included in the thumbnail filter unit. In addition, with respect to the Y value in which four pixels are collected, it may be further reduced to a single pixel through the processing of an average filter.

Therefore, for an HD image, an 8x8 image is reduced to a single pixel (1/8 in each side), and a 4x4 image is reduced to a single pixel in an SD image because no average filter is processed. / 1/4 each length).

6 is an exemplary view illustrating a process of adjusting the size of a thumbnail image according to an embodiment of the present invention.

(a) shows a thumbnail image generation process for a high definition (HD) image, and (b) shows a thumbnail image generation process for a standard definition (SD) image.

HD images generally have a size of 1080 × 1920, and the horizontal / vertical size is reduced to 1/8 through the processing of the subblock filter and the average filter as described above to generate a thumbnail image having a size of 136 × 240.

An SD image generally has a size of 480 × 720, and is processed by the subblock filter as described above, but bypasses the average filter to reduce the width / length to a quarter, so that the thumbnail image has a size of 120 × 180. Create

As described above, since the same size thumbnail image is also requested in some embodiments, a predetermined clipping portion of the image may be cut off by additionally performing a clipping unit on the thumbnail image of the HD image. Can be.

For example, as shown in FIG. 6, thumbnail images having a size of 120 × 180 may be generated by symmetrically cutting up, down, left, and right regions of the image passing through the average filter.

So far, the present invention has been described with reference to the preferred embodiments, and those skilled in the art to which the present invention pertains to the detailed description of the present invention and other forms of embodiments within the essential technical scope of the present invention. Could be implemented.

Here, the essential technical scope of the present invention is shown in the claims, and all differences within the equivalent range will be construed as being included in the present invention.

1 is a block diagram showing a configuration of a multicodec decoder device according to an embodiment of the present invention.

2 is a block diagram briefly illustrating a configuration of a multicodec decoder device according to an embodiment of the present invention.

3 is a block diagram showing the configuration of a thumbnail generator 300 according to an embodiment of the present invention.

4 is a block diagram illustrating in more detail a relationship between a deblocking unit and a thumbnail generating unit of a multicodec decoder according to an embodiment of the present invention.

5 is an exemplary view showing a thumbnail image generation process according to an embodiment of the present invention.

6 is an exemplary view illustrating a process of adjusting the size of a thumbnail image according to an embodiment of the present invention.

      ※ Description of the main parts of the drawings ※

Decoding unit 110: entropy decoder

120: inverse scan / inverse quantization unit 130: inverse conversion unit

140: intra prediction unit 150: motion compensation unit

200: deblocking unit 210: deblocking control unit

220: deblocking filter unit 230: deblocking buffer unit

300: thumbnail generator 310: thumbnail controller

320: thumbnail filter unit 321: subblock filter unit

322: average filter unit 323: clipping unit

324: color space conversion unit 330: thumbnail buffer unit

400: memory

Claims (13)

A thumbnail filter unit for calculating one or more representative pixels from the macroblocks of the deblocked image, adjusting them to a predetermined size, and converting the extracted representative pixels into image information of an RGB signal using the extracted representative pixels; A thumbnail buffer unit for storing one or more pixels for constructing a thumbnail image generated by the thumbnail filter unit; And And a thumbnail controller for instructing the thumbnail filter unit to generate thumbnails and storing the thumbnails in the thumbnail buffer unit when the thumbnails are generated. The method of claim 1, The thumbnail filter unit, A subblock filter for calculating at least one representative pixel from the macroblock; An average filter which obtains an average value of constant pixel values of each of the calculated pixels and replaces the current pixel value; A clipping unit which cuts a predetermined area on the top, bottom, left and right sides of the image to reduce the input image to a predetermined size image; And And a color space converter for converting the image output from the clipping unit into image information of an RGB signal. The method of claim 2, And the average filter reduces and outputs the horizontal and vertical sizes of the input image by 50%. The method of claim 1, And the thumbnail controller instructs the thumbnail filter unit to generate thumbnails when the deblocked video is an instant decoded refresh (IDR) picture. The method of claim 1, And the thumbnail controller instructs the thumbnail filter unit to generate thumbnails every predetermined period of the deblocked image. The method of claim 2, And bypassing the average filter when the input image is an SD (Standard Definition) image. The method of claim 1, And the thumbnail buffer unit is configured to enable double buffering. The method of claim 7, wherein And when the macroblock processing preset in the thumbnail buffer unit is completed, the thumbnail controller controls to store the completed thumbnail in an external storage device and notifies the host of the thumbnail block. A decoding unit for receiving and reconstructing a video signal compressed by one or more encoding schemes; A deblocking unit for deblocking filtering the image reconstructed by the decoding unit and outputting the deblocking filter; A thumbnail generator configured to generate a predetermined thumbnail from the image output from the deblocking unit; And And a memory unit configured to store a reference image used to restore an image signal of the decoding unit and a thumbnail generated by the thumbnail generator. The method of claim 9, The deblocking unit, A deblocking filter unit for performing a deblocking process of the input image; A deblocking buffer unit for storing an image of which the deblocking process is completed by the deblocking filter unit; And And a deblocking control unit configured to provide an image stored in the deblocking buffer unit to the thumbnail generation unit, and to instruct generation of thumbnails in the thumbnail generation unit. The method of claim 9, The thumbnail generator, A thumbnail filter unit which calculates one or more representative pixels from the macroblocks of the deblocked image, adjusts them to a predetermined size, and converts them into image information of the RGB signal using the calculated representative pixels; A thumbnail buffer unit for storing one or more pixels for constructing a thumbnail generated by the thumbnail filter unit; And And a thumbnail controller for instructing the thumbnail filter unit to generate a thumbnail and storing the thumbnail in the thumbnail buffer unit when the thumbnail generation is completed. The method of claim 11, And the thumbnail buffer unit is configured to enable double buffering. The method of claim 12, And when the macroblock processing preset to the thumbnail buffer unit is completed, the thumbnail control unit controls to store the completed thumbnail in the memory unit and notifies the host to the host.

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