KR20060049755A - Method for transmitting moving picture in mobile communication terminal - Google Patents

Abstract

The present invention provides a method for transmitting a video of a mobile communication terminal, the method comprising: checking whether a capacity of an original video to be transmitted exceeds a preset maximum transmission capacity when a user requests a video transmission; and the capacity of the original video is a preset maximum transmission capacity. If exceeded, the process includes editing the original video to generate a plurality of edited videos, and transmitting the generated plurality of edited videos. Therefore, the present invention can easily transmit a video exceeding the maximum transmission capacity when transmitting a video of the mobile communication terminal. In addition, by presenting an algorithm for reducing the divided video, it can be easily implemented on the mobile communication terminal.

Mobile communication terminal, DCT, video, transmission, variable length coding, variable length decoding, quantization

Description

How to send video from mobile terminal {METHOD FOR TRANSMITTING MOVING PICTURE IN MOBILE COMMUNICATION TERMINAL}

1 is a flowchart illustrating a video transmission process of a mobile communication terminal according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a process of generating an edited video in operation of FIG. 1; FIG.

FIG. 3 illustrates a functional unit that performs variable long decoding in the operation of FIG. 2.

The present invention relates to a video transmission method of a mobile communication terminal, and more particularly, to a method for transmitting a video exceeding the maximum transmission capacity when the video transmission of the mobile communication terminal.

As digital images are widely used, there is a growing need for effective tools to process these images. Image size conversion is also a basic and important image processing tool.

In particular, in order to support various image media with one digital image data, image size conversion necessarily follows. For example, video media that need to support VOD (Video On Demand) services include general computer monitors, high definition televisions (HDTVs), and liquid crystal displays of mobile phones in addition to general televisions. It is almost impossible to prepare and store all the video data. Therefore, one digital image data should be generated and stored, and only its size should be converted according to the image medium.

In general, two operations, namely, changing the sampling rate and low pass filtering, are required to convert an image size. To reduce the size of the image, lowpass filtering is performed on the image and then downsampling. In order to increase the size of the image, upsampling is performed on the image and then low pass filtering is performed.

Typically, this operation is performed in the pixel area. Most still images and moving images are stored in a compressed form. For this reason, in order to convert the size of a compressed image, it is necessary to decompress and then recompress the size. In other words, in order to reduce the size of the image, it is necessary to go through three processes of decompression, image size conversion, and compression.

In order to solve this problem, many methods for directly converting the image size of a compressed image have been proposed. Since the compressed image is mainly Discrete Cosine Transform (DCT), the image size conversion for the compressed image means that the size conversion in the DCT region.

On the other hand, mobile communication terminals having a multimedia function, which are capable of displaying moving images, have recently emerged in which IMT-2000 (International Mobile Telecommunications-2000) technology is being pushed forward. In this way, the mobile communication terminal equipped with video function is larger than before and adopts a color LCD (Liquid Crystal Display) instead of a single color to enable video on demand (VOD). You can now transfer videos to your back.

Since the video must be playable on any video terminal, a standard codec (codec / decoder) is used, mainly moving picture expert group-1 (MPEG-1), MPEG-2, MPEG-4, and H.261. Low bit rate compressed video codecs such as H.263, H.26L, and the like are used.

However, when a mobile communication terminal transmits the video to another terminal through a wireless network, the mobile communication terminal may not transmit an unlimited size video, and a certain limitation is due to the data transmission efficiency between the mobile terminal and the wireless network and difficulty in implementing a technology. Being applied. For example, Samsung's V-series terminals do not provide video transmission services for videos over 384Kbytes. This is because a video with a capacity larger than 384 Kbytes causes problems such as data loss and channel overuse when only one transmission is attempted.

Therefore, when a user wants to transmit a large video using a mobile communication terminal, there is a inconvenience in that a VOD-based streaming transmission must be performed through a separate Internet. As a result, there has been a need for a new method for the mobile communication terminal to efficiently wirelessly transmit a large video.

The present invention has been made to solve the above problems, and to provide a method for efficiently transmitting a video exceeding the capacity that can be transmitted in a mobile communication terminal.

In order to achieve the above object, the present invention provides a method for transmitting a video of a mobile communication terminal, the method comprising: checking whether a capacity of an original video to be transmitted exceeds a preset maximum transmission capacity when a user requests a video transmission; If the capacity exceeds the preset maximum transmission capacity, the method includes editing the original video to generate a plurality of edited videos, and transmitting the generated plurality of edited videos.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

In addition, the embodiment of the present invention will be described taking the MPEG-4 compression method as an example. However, in addition to the compression method, the same may be applied by various compression methods.

1 is a flowchart illustrating a video transmission process of a mobile communication terminal according to an embodiment of the present invention.

The mobile communication terminal checks whether there is a predetermined video transmission request from the user (S110). The video transmission request may be a video mail transmission request.

If there is a video transmission request, the mobile communication terminal checks whether the data capacity of the original video to be transmitted exceeds a preset maximum transmission capacity (for example, 384 Kbytes) (S120). The maximum transmission capacity is a data capacity that a mobile communication terminal can transmit once through a wireless network, and means a maximum transmission data capacity determined by each terminal manufacturer in consideration of wireless network status, transmission efficiency, and transmission capability of the mobile communication terminal. do. For example, in the case of Samsung V-series terminals, the maximum transmission capacity that can be transmitted is currently set to 384 Kbytes.

If the data capacity of the original video does not exceed a preset transmission capacity, the mobile communication terminal transmits the video over the wireless network (S130).

If the data capacity of the original video to be transmitted exceeds a preset maximum transmission capacity, the mobile communication terminal edits the original video to generate a plurality of edited videos (S140). The edited video means that the original video is data that is divided into a predetermined size and then bit-converted (bps). A process of generating the edited video will be described in detail with reference to FIG. 2.

The mobile communication terminal sequentially transmits the generated plurality of edited videos (S150).

Next, the process of S140 will be described in detail.

FIG. 2 is a flowchart illustrating a process of generating an edited video in detail in the operation of FIG. 1. That is, FIG. 1 is a diagram illustrating the S140 process of FIG. 1 in detail.

Referring to FIG. 2, when the data capacity of the original video to be transmitted exceeds the maximum transmission capacity, the mobile communication terminal outputs a message for receiving approval from the user whether to generate an edited video (S210). The message may be a voice message or a text message.

The mobile communication terminal checks whether there is a user's approval of the output message (S220).

In order to help the understanding of the description, hereinafter, a 30 Mbyte size video shot at 384 kbps bit rate will be described as an example.

The mobile communication terminal divides the original video to be transmitted in units of a size of K times the maximum transmission capacity, if the user confirms the message (S230). At this time, the proportional value of K times is applied at the same ratio in the requantization process which will be described later. That is, in the requantization process, the criterion for requantization step size is determined by K times larger than the existing quantization step size.

Therefore, when dividing the 30Mbyte size video, it is divided into about 1Mbyte form (approximately 3 times 384 Kbytes). In other words, the K value at this time is 3.

In the process (S230), the method of dividing by 1 Mbyte unit may, for example, analyze and divide the header atom based on I-frame in case of MPEG-4 compression.

When the partitioning process is performed, a total of 30 videos divided by 1 Mbyte may be generated in the case of a 30 Mbyte video.

The mobile communication terminal performs variable length decoding (VLD) on each of the divided videos using a DCT coefficient (S240). The variable length decoding method will be described in detail with reference to FIG. 3.

The mobile communication terminal requantizes the variable-length decoded video based on the quantization step size that is K times larger than the quantization calculation size of the original video (S250). That is, the mobile terminal requantizes the variable-length decoded video by three times the size of the existing quantization calculation.

The mobile communication terminal performs variable length coding (VLC) on the requantized video using a DCT coefficient (S260).

Through the above processes, 30 videos of 1 Mbyte size are requantized (S250) and variable length encoding process in the form of 3x quantization step size (QP) when the quantization step size is quantized three times larger than the existing size as described above. Through S260, an edited video having a size of 384 Kbytes having a 128 kbps bit rate is obtained.

Accordingly, through the above processes, the mobile communication terminal generates 30 edited videos having a size of 30Mbyte of 384kbps bit rate and 384Kbyte size of 128kbps bit rate, and transmits the generated edited videos through the wireless network 30 times. .

Meanwhile, the variable length encoding method may use various conventional methods.

That is, in video compression coding such as MPEG-1, MPEG-2, MPEG-4, H.261, H.263, H.26L, etc., a discrete cosine transform using an orthogonal relationship between the spatial domain and the frequency domain After the DCT), the energy of the 2D image is concentrated in the low frequency term, that is, the DC (Direct Current) coefficients, that is, the large value is concentrated at the top left and the small value is concentrated at the bottom right. Take a way to eliminate spatial redundancy. Larger values become smaller due to quantization performed after DCT, and smaller values converge to zero, so that compression can be greatly expected by variable length coding (VLC).

The variable length coding method is a U.S. Patent No. 5,708,732 (Fast DCT domain downsampling and inverse motion compensation), DCT, which implements down sampling of 1 / n by taking an average of n 8x8 DCT blocks and generating one 8x8 DCT block. US Pat. No. 5,845,015 (Method and apparatus for resizing images), which generates a 4x4 DCT block by performing a lowpass filtering operation by multiplying the coefficients by the transform coefficients of the lowpass filter, and then folding and subtracting the filtered operation coefficients. Since there are various conventional techniques such as by using the discrete cosine transform), a detailed description thereof will be omitted.

3 is a diagram illustrating a functional unit that performs variable long decoding in the operation of FIG. 2. That is, a process in which the mobile communication terminal variably decodes the divided videos using the DCT coefficient in step S240 of FIG. 2 will be briefly described with reference to FIG. 3.

The illustrated compressed video decoder 300 includes a header parser 302, a variable length decoder 304, a dequantization (DQ) block 306, and an inverse discret cosine transform (IDCT). Block 308, an MC block 310, and a frame buffer 312, which decodes the original image before compression encoding from the compressed encoding video stream.

In FIG. 3, it is assumed that a compressed encoded video stream input to the compressed video decoder 300 is a video stream compressed and encoded in an MPEG-4 simple profile format using DCT.

The compressed coded video stream is first analyzed by the header parser 302 for various information according to compression encoding, variable length decoded by the variable length decoder 304, and then dequantized by the DQ block 306 to be decoded by the IDCT block. 308 is applied.

The IDCT block 308 dequantizes the dequantized image, that is, the 8x8 block DCT images. The decoded image of the I-VOP is output as the output image and stored in the frame buffer 312, and the P-VOP is the MC block. To (310).

In this case, the I-VOP is an image obtained by encoding the entire screen, and the P-VOP is a difference image which is an image in which time redundancy indicating only a difference from the previous screen is removed.

The MC block 310 of the compressed video decoder 300 decodes the P-VOP and then plays back the picture in combination with the reference image, which is moved by a motion vector from the previous screen to read the reference block and read the image. Means to reconstruct

Therefore, the MC block 310 decodes and outputs an image according to the P-VOP by performing MC processing using the I-VOP and the P-VOP.

In the above description of the present invention, a specific embodiment such as a mobile terminal has been described, but various modifications can be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the equivalent of claims and claims.

As described above, in the present invention, even when a video having a large capacity can be divided and reduced and then transmitted, wireless transmission can be performed on a mobile communication terminal without limitation of capacity. In addition, by presenting an algorithm for reducing the divided video, there is an effect that can be easily implemented on the mobile communication terminal.

Claims (6)

In the video transmission method of the mobile communication terminal, When a user requests to send a video, the process of checking whether the capacity of the original video to be sent exceeds the preset maximum sending capacity, Generating a plurality of edited videos by editing the original video when the capacity of the original video exceeds a preset transmission capacity; And transmitting the generated plurality of edited videos. The method of claim 1, wherein the edited video A video transmission method of a mobile communication terminal, characterized in that the data is divided into a predetermined size bit-rate (bps) reduced conversion. The method of claim 1, wherein the generating process Outputting a message for acknowledging whether or not to generate the edited video when the capacity of the original video exceeds a preset transmission capacity; And if the user approves, dividing the original video into a predetermined size and then reducing and converting the bit rate (bps) to generate a plurality of edited video. The method of claim 3, wherein the generating step Dividing the original video into units of a size that is K times a preset maximum transmission capacity; Variable Length Decoding (VLD) of the divided videos using Discrete Cosine Transform (DCT) coefficients, respectively; Re-Quantization of the variable-length decoded videos based on the quantization step size of K times larger than the quantization step size of the original video, And variable length coding (VLC) each of the requantized moving pictures using a discrete cosine transform coefficient. The method of claim 4, wherein The video transmission method of the mobile terminal, characterized in that K is the same value. The method of claim 1, wherein the transmission process The video transmission method of the mobile communication terminal, characterized in that for transmitting the edited video over a wireless network.

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