JP2001358799A - Data transmission system, data transmitter used in the data transmission system, data reproducing device and data transmitter method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately encode data and to transmit the data by taking data reproduction capability and storage capacity at a receiving side into consideration. SOLUTION: In this data transmission system where a video transmitter 1 and a video reproducing device 2 are connected through a transmission line 3, the reproducing device 2 of the receiving side transmits attribute information about its own data reproduction capability or storage capacity when making a request for data. The transmitter 1 of a transmitting side is provided with an image input device 11, a sound input device 12 and a video recorder 13 as data supply sources, encodes video data supplied from the data supply sources on the basis of the attribute information in an encoding part 14 and transmits the encoded data. Thus, the receiving side can reliably receive the data with quality that is suitable to its own data reproduction capability or storage capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmission system for transmitting voice data, image data, and the like from a personal computer to a portable telephone, a data transmission device, a data reproduction device, It relates to a data transmission method.

[0002]

2. Description of the Related Art Conventionally, there is a system such as a server-client system in which a server provides various data to a client via a communication line in accordance with a request from the client. In this case, in order to provide high-quality data requiring real-time properties such as voice and image to a plurality of terminal devices having different communication lines, communication transfer rates and protocols that can be used by these terminal devices are used. It is necessary to send data according to.

From such a viewpoint, for example, Japanese Patent Application No.
In the data transmitting apparatus described in Japanese Patent No. 84567, a transmitting terminal notifies a communication transfer rate usable by the terminal device and attribute information indicating a protocol used by the terminal device. 2. Description of the Related Art Data transmission is performed by changing data encoding according to information.

[0004]

As described in the above publication, the method of encoding and transmitting data based on the communication transfer rate and the attribute information of the protocol is suitable for the communication line used by the terminal device on the receiving side. The data is transmitted with the same quality. However, since the data reproduction capability and storage capacity of the terminal device itself on the receiving side are not considered at all, there is a problem that, for example, when the data reproduction capability or storage capacity on the receiving side is insufficient, the data cannot be accepted. Was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has been made in consideration of a data reproduction capability and a storage capacity at a receiving side, and is capable of data transmission capable of appropriately encoding and transmitting data. It is an object to provide a system, a data transmission device, a data reproduction device, and a data transmission method used in the data transmission system.

[0006]

A data transmission system according to the present invention comprises a first terminal device and a second terminal device connected via a transmission line, and transmits a data requested by the second terminal device. Is transmitted from the first terminal device to the second terminal device via the transmission path,
At the time of a data request from the terminal device, generates and transmits attribute information on its own data reproduction capability or storage capacity, and determines a coding method and a coding condition based on the attribute information on the first terminal device side, The data supplied from the data supply source is encoded according to the above-mentioned encoding method and encoding conditions, and the encoded data is transmitted to the second terminal device.

As described above, when the data is requested, the second
By transmitting attribute information relating to data reproduction capability or storage capacity from the terminal device, encoding the data based on the attribute information in the first terminal device on the transmitting side, and transmitting the encoded data. On the receiving side, data can be reliably received with a quality suitable for its own data reproduction capability or storage capacity.

The data supply source of the first terminal device may be a recording medium on which various data are recorded in advance or an input device for inputting data in real time, so that the data recorded on the recording medium is In addition, real-time data input from the input device can be appropriately encoded and transmitted based on the attribute information of the second terminal device.

The encoding control means encodes data in accordance with the storage capacity of the second terminal device, thereby encoding the data so as to fit in the storage capacity of the second terminal device. Can be sent. Further, if the data cannot be accommodated, it may be notified that data cannot be provided.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A data transmission system according to one embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a data transmission system according to one embodiment of the present invention. The data transmission system according to the present embodiment is intended to transmit video data including audio data and image data, for example, from a personal computer to a mobile phone.

As shown in FIG. 1, in this system, a video transmitting device 1 and a video reproducing device 2 are connected via a transmission line 3. The video transmission device 1 is, for example, a personal computer, and provides a data transmission device (first device) that provides video data including audio data and image data in accordance with a request from the video reproduction device 2.
Terminal device). The video playback device 2 is, for example, a mobile phone, and is used as a data playback device (second terminal device) that plays back data provided from the video transmission device 1. The transmission path 3 is a wireless or wired communication line that connects the video transmitting device 1 and the video reproducing device 2.

The video transmission device 1 has an information supply source including an image input device 11, an audio input device 12, and a video recording device 13. The image input device 11 and the sound input device 12 are used as input devices for inputting analog images and sounds in real time, and convert the input images and sounds into digital signals and transmit them. The video recording device 13 has a plurality of recording media, and individually records image data obtained from the recording image input device 11 and audio data obtained from the audio input device 12 on these recording media, or The audio data and the video data obtained by encoding the image data are recorded, and these data are selectively read from a recording medium and output.

The video transmitting apparatus 1 has an encoding section 14 for encoding data from the information supply source, and an attribute analysis / control for controlling the encoding section 14 based on the attribute information of the video reproducing apparatus 2. A unit 15 and a communication interface 16 for transmitting and receiving data to and from the video reproduction device 2 are provided.

The encoding unit 14 selects data input from the image input device 11 and the audio input device 12 or data read from the recording medium of the video recording device 13 from a plurality of encoding methods. The encoding is performed in accordance with the other encoding method and the encoding conditions associated with the encoding method. In the present embodiment, the encoding unit 14 includes an output unit 14a that performs only data output, and includes an MPEG1 encoder 14
b, MPEG2 encoder 14c, MPEG4 encoder 1
4d, a Motion JPEG encoder 14e and other encoders corresponding to a plurality of encoding schemes are provided, and by selecting these according to an instruction from the attribute analysis / control unit 15, data to be transmitted is encoded. Output.

When the encoded video data existing in the video recording device 13 is the information supply source, or when the unencoded video data, that is, the original signal image data and audio data are the information supply source. Has an encoding unit 1
4 selects only the output device 14a and outputs data only.

The encoding unit 14 receives from the attribute analysis / control unit 15 an instruction to select one of a plurality of encoding methods and designation of an encoding condition. The attribute analysis / control unit 15 analyzes the attribute information received from the video playback device 2, and instructs the encoding unit 14 to select one encoding method from a plurality of encoding methods according to the analysis result and an encoding condition. give.

FIG. 2 shows an example of attribute information transmitted from the video reproducing device 2 to the video transmitting device 1.

As shown in FIG. 2, the attribute information indicates the attribute of the terminal on the receiving side, and here includes an image reproduction attribute, an image reproduction capability, a sound reproduction attribute, a sound reproduction capability, and a storage capacity.

The image reproduction attribute is information on the image display device 26 (see FIG. 3) provided as a display device of the video reproduction device 2, and is composed of the number of horizontal pixels, the number of vertical pixels, and the display color. 14 is the encoding condition. The image playback capability is information on the image playback capability of the video playback device 2 and includes an encoding method, a frame rate, and a bit rate. The encoding method is a condition for selecting an encoding method for the encoding unit 14, Are encoding conditions for the encoding unit 14. The bit rate is used in equation (1) described below.

The audio reproduction attribute is information on the audio output device 25 (see FIG. 3) provided as an audio output device of the video reproduction device 2 and includes a sampling frequency and the number of channels. Condition. The audio reproduction capability is information on the audio reproduction capability of the video reproduction device 2 and includes an encoding method and a bit rate. The encoding method is a condition for selecting an encoding method for the encoding unit 14. The bit rate is used in equation (1) described below.

The storage capacity is information relating to the storage capacity of the storage device 24 (see FIG. 3) provided as a storage device of the video reproducing apparatus 2, and the current remaining capacity (unit: number of bytes)
Is shown.

The attribute analysis / control unit 15 determines that the video data satisfying the encoding method and the encoding condition indicated by the attribute information exists in the information supply source, and that the capacity of the video data is If the capacity is equal to or less than the capacity, an instruction is issued to the encoding unit 14 to perform only data output. Otherwise, the attribute analysis / control unit 15 determines the capacity (unit: number of bytes) of the encoded video data according to the following equation (1).
Is calculated.

Size = (VideoRate / 8 + AudioRate / 8) · Time (1) where Size is a trial calculation value of video data capacity, and Time is input from the image input device 11 and the audio input device 12 or the video recording device 13. Time rate (unit: second) of image data and audio data, VideoRate is bit rate (unit: bit / second) of image reproduction capability information, and AudioRate is bit rate (unit: bit / second) of audio reproduction capability information. .

If the estimated size of the video data capacity obtained by the above equation (1) is equal to or less than the remaining capacity of the video reproducing apparatus 2, the above two bit rates (VideoRate and AudioRate) are adopted and these are encoded. It is assumed that the encoding condition is set to 14. Otherwise, the value of each bit rate is gradually reduced, or the estimated value of the video data capacity Size is set to be equal to or less than the remaining capacity of the video playback device 2 assuming a low bit rate encoding method as necessary. Is calculated, and the respective bit rates and coding schemes after the calculation are adopted.

The attribute analysis / control unit 15 determines whether the encoding method for the image reproduction capability information or the encoding method for the audio reproduction capability information does not exist in the encoding unit 14, If it is expected that the value of the bit rate calculated to satisfy the condition (1) is small and the video quality is extremely impaired, the video data of the requested video data is transmitted to the video reproduction device 2 via the communication interface 16. Notify that provision is not possible.

The present invention is not limited to the encoding system, but can be applied to all the systems realized in the video transmitting apparatus 1 and the video reproducing apparatus 2.
It can be effectively applied to a variable rate coding system such as EG4.

The video data output from the encoding unit 14 is input to a communication interface 16. The communication interface 16 controls a protocol, receives attribute information, and transmits video data when communicating with the video reproduction device 2 via the transmission path 3. Since the present invention does not limit the communication interface and the transmission path,
These are not embodied in the present embodiment.

FIG. 3 is a block diagram showing the configuration of the video reproducing apparatus 2 used in the present system.

The video reproducing device 2 transmits attribute information and receives data provided from the video transmitting device 1 by communicating with the video transmitting device 1 via the transmission path 3. As shown in FIG. 2, the video playback device 2 includes a communication interface 21, a control unit 22, an attribute generation unit 23, a storage device 24, an audio output device 25, and an image display device 26.

The communication interface 21 performs data transmission / reception processing with the video transmission device 1. Control unit 22
Controls the entire video reproducing apparatus 2,
Transmission processing of attribute information generated by the attribute generation unit 23,
A series of processes such as a process of receiving data provided from the video reproduction device 2 is executed. The storage device 24 is a device for storing received data. The audio output device 25 is a device for outputting audio data. The image display device 26 is a device for displaying image data.

In the video reproducing apparatus 2 having such a configuration, a data request is issued to the video transmitting apparatus 1 and
By generating and transmitting attribute information indicating its own data reproduction capability and storage capacity, it receives video data encoded based on the attribute information from the video transmitting device 1 on the transmitting side. The received video data is stored in the storage device 24 of the video reproduction device 2 and reproduced through the audio output device 25 and the image display device 26 when the user likes.

Next, the operation of the present system will be described separately for the processing on the video transmitting apparatus 1 side and the processing on the video reproducing apparatus 2 side.

(A) Processing on the Video Transmitting Apparatus 1 Side FIG. 4 is a flowchart showing processing on the video transmitting apparatus 1 side in the present system.

On the video transmitting apparatus 1 side, the data request transmitted from the video reproducing apparatus 2 via the transmission path 3 is received by the communication interface 16 (step A1).
1) Receive attribute information sent following the data request (step A12). Here, the request data is video data. The attribute information is information unique to the video playback device 2 that has issued the data request. As described with reference to FIG. 2, the attribute information includes the image playback attribute, the image playback capability, the audio playback attribute, the audio playback capability, and the storage capacity. Shall be included.

When the video transmitting apparatus 1 receives the attribute information of the video reproducing apparatus 2 which has issued the data request, the attribute analyzing /
The control unit 15 analyzes the attribute information, and determines an encoding method and an encoding condition according to the analysis result (step A13).

More specifically, as described above, video data that satisfies the encoding method and the encoding condition indicated in the attribute information exists in the information supply source, and the capacity of the video data is If the capacity is equal to or less than the capacity,
Is determined to output only data. Otherwise, a trial calculation value of the video data capacity after encoding is calculated according to the above equation (1), and if the trial calculation value Size is equal to or less than the remaining capacity of the video playback device 2, the bit of the image playback capability information is calculated. A rate (VideoRate) and a bit rate (AudioRate) of audio reproduction capability information are adopted and these are encoded.
If not, gradually reduce the value of each bit rate, or if necessary, assuming a low bit rate coding method, the estimated value of the video data capacity Size is less than the remaining capacity Are calculated, and the respective bit rates and coding schemes after the calculation are adopted.

Here, when the encoding method of the image reproduction capability information or the encoding method of the audio reproduction capability information does not exist in the encoding unit 14, the calculation is performed to satisfy the above expression (1). In the case where the value of the set bit rate is small and the video quality is expected to be extremely impaired, provision of the requested data is impossible. As described above, when it is determined that the provision of the request data is impossible (step A
(No in 14), the attribute analysis / control unit 15 notifies the video playback device 2 that has requested the data via the communication interface 16 that the requested video data cannot be provided (step A18).

If the request data can be provided (Yes in step A14), the attribute analysis / control unit 15 gives the coding method and the coding condition determined above to the coding unit 14 (step A15). The encoding unit 14 selects an encoder corresponding to this encoding method from the output unit 14a, the MPEG1 encoder 14b, the MPEG2 encoder 14c, the MPEG4 encoder 14d, and the Motion JPEG encoder 14e. Then, using the selected encoder, the data supplied from the information supply source of the image input device 11, the audio input device 12, or the video recording device 13 is encoded according to the encoding condition (step A16).

In this manner, encoding based on the attribute information of the video reproducing apparatus 2 is performed, and the video data output from the encoding unit 14 immediately after the start of the encoding or after the encoding is completed is transmitted via the communication interface 16 to the data. The request is transmitted to the video reproducing device 2 of the request source (step A17). In this case, the quality of the video data transmitted from the video transmitting device 1 is adjusted to a quality suitable for the attribute of the video reproducing device 2 that has issued the data request.

(B) Processing on the Video Reproducing Apparatus 2 FIG. 5 is a flowchart showing processing on the video reproducing apparatus 2 side in the present system.

The video reproducing device 2 transmits a data request to the image transmitting device 1 (step B11). Here, it is assumed that the transmission of the video data is requested. This request is transmitted to the video transmission device 1 via the communication interface 21.

Here, when a data request is issued, attribute information of the video reproducing apparatus 2 is generated by the attribute generating section 23 (step B12), and the attribute information is transmitted to the video transmitting apparatus 1 via the communication interface 21. Transmitted to the user (step B13). As shown in FIG. 2, the attribute information includes an image reproduction attribute, an image reproduction capability, an audio reproduction attribute, an audio reproduction capability, and a storage capacity. In the attribute generation unit 23, the image display device 26 provided in the video reproduction device 2, The capability of the audio output device 25 and the storage device 24 are analyzed to generate the attribute information.

By transmitting such attribute information, the video transmitting apparatus 1 encodes the video data to be provided to the video reproducing apparatus 2 in accordance with an encoding method and a coding condition suitable for the attribute of the video reproducing apparatus 2. Send. In this case, in the encoding, when it is predicted that the quality of the data is extremely deteriorated, it is notified that the data cannot be provided.

When the requested video data is sent from the video playback device 2, the video playback device 2 receives the video data via the communication interface 21 (step B).
14; Yes), and store it in the storage device 24 (step B
15). Thereafter, the user reads the video data held in the storage device 24 as necessary, and reproduces the video data through the audio output device 25 and the image display device 26.

As described above, since the video data is provided based on the attribute information of the video reproduction device 2, the user can receive video data of a quality suitable for the video reproduction device 2. In this case, the attribute information of the video playback device 2 is automatically generated when a data request is issued and is transmitted to the video transmission device 1, so that the user is not conscious and suitable for the video playback device 2 owned by the user. It is possible to receive video data with high quality.

Although the above embodiment has been described on the assumption that video data including audio data and image data is transmitted, the present invention is not limited to this. For example, only audio data, only image data , Or even when transmitting other types of data.

The same method as described above can be applied not only to stored data but also to data having real-time properties. The data quality is changed according to the reproduction capability and storage capacity of the video reproduction apparatus 2 and transmitted. can do.

Further, in the above embodiment, the video transmitting device 1
Has an image reproduction attribute, an image reproduction capability, an audio reproduction attribute, an audio reproduction capability, and a storage capacity as attribute information received from the video reproduction device 2, but a part of these information is referred to as attribute information. Embodiments are possible without departing from the invention. For example, when the attribute information indicating the storage capacity is used, the video transmitting apparatus 1 encodes and sends the data according to the capacity that can be stored in the storage device 24 of the video playback apparatus 2. Is configured to provide a notification that provision is impossible.

The present invention is not limited to a personal computer as the video transmitting device 1 and a mobile phone as the video reproducing device 2, but the present invention can be applied to all devices constituting a server / client system.

In short, the present invention is not limited to the above-described embodiment, and can be variously modified in the practical stage without departing from the gist of the present invention. Further, the embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some components are deleted from all the components shown in the embodiment, the effects described in “Problems to be Solved by the Invention” can be solved,
When the effects described in the section of “Effects of the Invention” can be obtained, a configuration from which this configuration requirement is deleted can be extracted as an invention.

The method described in the above-described embodiment may be a program that can be executed by a computer such as a magnetic disk (floppy (registered trademark) disk, hard disk, etc.), an optical disk (CD
-ROM, DVD, etc.), writing to a recording medium such as a semiconductor memory and applying to various devices, or transmitting to a communication medium and applying to various devices. A computer that realizes the present apparatus reads the program recorded on the recording medium, and executes the above-described processing by controlling the operation of the program.

[0053]

As described above in detail, according to the present invention, at the time of data request, attribute information relating to data reproduction capability or storage capacity is transmitted from the terminal device on the receiving side, and the attribute information is transmitted to the terminal device on the transmitting side. Based on the encoding of the data and transmit the encoded data, the quality of the data can be changed according to the terminal attributes of the receiving side, the receiving side, its own data reproduction capability or storage Data can be reliably received and reproduced with a quality suitable for the capacity.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a data transmission system according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of attribute information in a terminal device on a receiving side used in the data transmission system.

FIG. 3 is a block diagram showing a configuration of a terminal device on the receiving side used in the data transmission system.

FIG. 4 is a flowchart showing processing of a transmitting terminal device used in the data transmission system.

FIG. 5 is a flowchart showing processing of a terminal device on the receiving side used in the data transmission system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Video transmission device 2 ... Video reproduction device 3 ... Transmission path 11 ... Image input device 12 ... Audio input device 13 ... Video recording device 14 ... Encoding part 14a ... Output device 14b ... MPEG1 encoder 14c ... MPEG2 encoder 14d ... MPEG4 encoder 14e ... Motion JPEG encoder 15 ... Attribute analysis / control unit 16 ... Communication interface 21 ... Communication interface 22 ... Control unit 23 ... Attribute generation unit 24 ... Storage device 25 ... Sound output device 26 ... Image display device

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 7/24 H04L 11/00 310B 7/173 640 H04N 7/13 Z F-term (Reference) 5C059 SS10 TA17 TA17 TA60 TB11 TC45 5C064 BA07 BB10 BC18 BC20 BC23 BC25 BD01 BD07 5K033 DA19 DB10 5K034 DD01 EE03 FF13 MM08 5K041 BB01 BB08 CC02 CC07 DD02 EE53 JJ24

Claims (7)

[Claims] 1. A first terminal device and a second terminal device are connected via a transmission line, and data requested from the second terminal device is transmitted from the first terminal device to the transmission line. A data transmission system for transmitting to the second terminal device via the data terminal, the first terminal device selecting a data supply source and data supplied from the data supply source among a plurality of encoding schemes. Encoding means for encoding according to the specified method and the encoding conditions attached thereto, data transmitting means for transmitting data encoded by the encoding means, and attribute information transmitted from the second terminal device Encoding control means for determining an encoding method and an encoding condition of the encoding means based on the information. The second terminal device transmits attribute information on its own data reproduction capability or storage capacity at the time of data request. Attribute generating means, attribute transmitting means for transmitting attribute information generated by the attribute generating means, and receiving data transmitted from the first terminal device after transmitting the attribute information by the attribute transmitting means. Data receiving means, the first terminal device side encodes data suitable for the second terminal device, and transmits the encoded data to the second terminal device. A data transmission system characterized in that: 2. A data transmission device for transmitting data to a terminal device that has requested data, comprising: a data source; and data supplied from the data source selected from a plurality of encoding methods. Encoding means for encoding according to the specified scheme and the associated encoding conditions; transmitting means for transmitting the data encoded by the encoding means; and data reproduction capability of the terminal device from the data requesting terminal device Or, an attribute acquisition unit for acquiring attribute information relating to storage capacity; and an encoding control unit for determining an encoding method and an encoding condition of the encoding unit based on the attribute information acquired by the attribute acquisition unit. A data transmission device characterized by the above-mentioned. 3. The data supply source is a recording medium on which various data are recorded in advance or an input device for inputting data in real time.
A data transmission device as described in the above. 4. The data according to claim 2, wherein said encoding control means controls said encoding means so as to encode data in accordance with the storage capacity of the terminal device requesting the data. Transmission device. 5. When the data cannot be encoded by the encoding means, or when the quality is significantly reduced by encoding, the data requesting terminal apparatus is notified that the data cannot be provided. 3. The data transmitting apparatus according to claim 2, further comprising a notifying unit that performs the notification. 6. A data reproducing apparatus for requesting data from a terminal device having a data supply source and receiving and reproducing data provided from the terminal device, wherein the data reproducing device has its own data reproducing capability or Attribute generating means for generating attribute information relating to storage capacity; attribute transmitting means for transmitting attribute information generated by the attribute generating means; data transmitted from the terminal device after transmitting the attribute information by the attribute transmitting means And a data receiving means for receiving the data. 7. A first terminal device and a second terminal device are connected via a transmission line, and data requested from the second terminal device is transmitted from the first terminal device via the transmission line. A data transmission method for transmitting to the second terminal device by transmitting attribute information relating to its own data reproduction capability or storage capacity at the time of a data request from the second terminal device; Side determines an encoding method and an encoding condition based on the attribute information, encodes data supplied from a data supply source according to the encoding method and the encoding condition, and encodes the encoded data into the second data. A data transmission method, wherein the data is transmitted to a terminal device.