KR100946516B1 - Encoding monitoring device and its operation method - Google Patents

Abstract

Embodiments of the present invention relate to an encoding monitoring apparatus and a method for monitoring an encoding, wherein when a problem occurs during encoding, the monitoring is detected to initialize the encoder. An embodiment of the present invention provides a first process of periodically reading a sequence number recorded in a header field of each I frame generated by a video encoder, and a second process of initializing the encoder when the sequence number has not changed for a predetermined time or more. Process. In addition, in the second process, the predetermined time is 3 seconds, and the initialization initializes the library used for encoding.

Encoder, Decoder, MPEG, H.263, Frame, Sequence Number, Initialization, Time Stamp

Description

Apparatus for encoding monitoring and method for operating the same}

Embodiments of the present invention relate to an encoding monitoring apparatus and a method for monitoring an encoding.

Most video compression standards, such as MPEG or H.26x video codecs, adopt compression based on motion estimation and compensation and transformation. In such motion compensation based encoding, motion vector information of each block must be encoded and transmitted, and the compression efficiency may vary greatly depending on how the motion vector is encoded.

In addition, a general digital video compression processing method may be divided into single image compression (INTRA Coding, I frame coding) and motion vector prediction compression (INTER Coding, P frame coding). In the case of digital video, continuous motion vector prediction compression (INTER Coding) is mainly used, and a single image compression (INTRA Coding) is used periodically. That is, the encoder (compressor) is generally streamed into I frames and P frames of the digital video encoder.

At this time, each such information is generally composed of two elements, i) video data + time stamp (visual information), ii) audio data + time stamp (visual information). Therefore, normal frames cannot be generated without a time stamp.

However, the encoder of the video uses a time stamp as described above. If an overflow occurs in one of the variables generating the time stamp, the input image is converted into a video such as MPEG4 or MPEG4 / AVC. You will not be able to compress it as a compressed file. If a normal I frame or P frame cannot be generated due to an abnormal time stamp, the decoder (decoder) which decodes the same does not output a screen normally.

Therefore, since the existing encoder does not know whether or not the normal encoding operation, there is a fear that a normal frame cannot be generated.

Embodiments of the present invention allow normal encoding to be performed at frame generation in the encoder.

An embodiment of the present invention provides a first process of periodically reading a sequence number recorded in a header field of each I frame generated by a video encoder, and a second process of initializing the encoder when the sequence number has not changed for a predetermined time or more. Process.

In the second process, the predetermined time period is 3 seconds.

The initialization initializes the library used for encoding.

According to an embodiment of the present invention, an encoding unit for compressing video data and periodically generating an I frame, which is a single image compression frame, a library for providing a function and variable initialization values necessary for encoding, and each of which is periodically generated And a monitoring unit which reads the sequence number recorded in the header field of the I frame of and initializes the library when the sequence number has not changed for a predetermined period. The apparatus may further include a buffering unit receiving and buffering video data and transmitting the same to the encoding unit.

According to an embodiment of the present invention, when an encoding is not properly performed due to a problem such as a time stamp when generating a frame of an encoder, the encoder is detected and initialized so that a normal frame may be encoded.

Hereinafter, a detailed description of embodiments of the present invention will be described with reference to the accompanying drawings. In the following description of the reference numerals to the components of the drawings it should be noted that the same reference numerals as possible even if displayed on different drawings.

1 is a block diagram of an encoding monitoring apparatus according to an embodiment of the present invention.

The encoding monitoring apparatus includes an encoder 20 having a buffering unit 11, an encoding unit 12, a library 13, and a monitoring unit 20. When the encoding is wrong, the monitoring unit 20 initializes the encoder.

The buffering unit 11 is a buffering unit that temporarily receives video data to be compressed and buffers it, and buffers the video data, which is a source, to be transmitted to the encoding unit.

The library 13 has encoding library information (including functions and variable initialization values necessary for encoding) such as a time stamp, and provides such library information to the encoding unit 12.

The encoding unit 12 encodes the video data according to a video compression standard such as MPEG (MPEG-4), H.263, and the like, and the compressed video information is a packet identified as a video packet by a packet header. It consists of

Each picture group is a frame processed only in an intra-frame compression method, and generates periodic I frames and aperiodic P frames using a time stamp, which is time information.

The I frame is an initial anchor frame and is a single image compression frame generated periodically without prediction of a motion vector. The P frame is a prediction frame predicted by extrapolation from the most recent of the previous I and P frames according to a motion vector prediction obtained by comparing blocks of the latest ones from the previous I and P frames. Frame is generated aperiodically based on the difference between the video frame and the actual video frame.

The encoding unit 12 increments and records the sequence number by 1 in the header field of each I frame when generating the I frame. For example, in the case of an MPEG4 encoder, when generating I frame once per second periodically, the sequence number which is their frame number is increased by 1 and recorded in the header field of the I frame. Therefore, the sequence number is sequentially increased and recorded like I-frame1 and I-frame2.

[Table 1] is a table showing field information in a frame of a general MPEG4 encoder.

TABLE 1

V: Version (2 bytes)

IN: I frame number (4 byte)

PN: P frame number (2 bytes)

DL: MPEG4 data length (4 bytes)

E: Motion / Sensor Event (Event, 1byte)

CH: Channel Info (2 bytes)

Yr: Year, Mt: Month, Dy: Day, Hr: Hour, Mi: Minute, Sc: Second, MS: Millisecond

VI: Video Loss Detection (1 byte)

R: Reserved (1 byte)

UT: UITIME (Upate frame time stamp)

MH: Mpeg4 header size

As shown in Table 1, a sequence number, which is a frame number such as IN and PN, is sequentially recorded in the header of each video-compressed frame.

The monitoring unit 20 monitors whether the I frame output from the encoding unit is normally output and initializes the encoder 10 when the normal I frame is not output.

Normal output can be monitored by viewing the output value of the I frame. For example, if the sequence number IN of the I frame is periodically monitored and the sequence number has not increased for a predetermined time (for example, 3 seconds), it is determined that a normal I frame is not output and the encoder 10 ) Is initialized to operate normally.

The initialization may be performed in various ways. The library may be initialized to initialize encoding library information such as a time stamp to enable normal operation. In addition, as an initialization scheme, the buffering unit 11 and the encoding unit 12 may be initialized in addition to the library 13.

2 is a flowchart illustrating an encoding monitoring process according to an embodiment of the present invention.

When encoding is started according to standards such as MPEG2, MPEG4, H.263, and H.264 (S21), the encoder receives video data, buffers it, and generates a frame (I frame, P frame) (S22).

Among the frames, the I frame is a single image compression frame continuously generated without motion vector prediction, and the sequence number is sequentially increased by 1 in the header field of the I frame generated when the I frame is generated.

When the frame is generated as described above, the monitoring unit monitors whether there is a change in the sequence number of the I frame (S24). The monitoring is performed every fixed period. When the predetermined period elapses (S23), it is monitored whether there is a change in the sequence number of the I frame.

As a result of the monitoring, when there is no change in the sequence number of the I frame, it is determined that the encoder does not operate normally for some reason, and the encoder is initialized (S25).

That is, if the sequence number of the I frame is periodically monitored and the sequence number does not increase for a predetermined time (for example, 3 seconds), it is determined that the normal I frame is not output and the encoder is initialized to operate normally. Do it.

The initialization (S25) may be a variety of methods, it is possible to initialize the library to initialize the encoding library information, such as a time stamp. In addition to the initialization method, the buffering unit and the encoding unit may be initialized in addition to the library.

After the initialization (S25) is made, it is determined whether the encoding operation is finished (S26). As a result of determination, if encoding is continued without being terminated, the process returns to the steps S22, S23, S24, and S25 to repeat normal encoding operations.

In the above description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention is not to be determined by the embodiments described above, but will be apparent in the claims as well as equivalent scope.

1 is a diagram illustrating an encoding monitoring operation according to an embodiment of the present invention.

2 is a flowchart illustrating an encoding monitoring process according to an embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

10: Encoder 11: Buffering Section

12: encoding section 13: library

20: monitoring unit

Claims (5)

Periodically reading a sequence number recorded in a header field of each I frame generated by the video encoder; A second process of initializing the encoder when the sequence number has not changed for a predetermined time Encoding monitoring method comprising a. The method of claim 1, wherein the predetermined time is 3 seconds in the second process. The encoding monitoring method of claim 1, wherein the initialization initializes a library used for encoding. An encoder for compressing video data to periodically generate I frames; A library for providing a function and a variable initialization value for encoding to the encoding unit; A monitoring unit which reads a sequence number recorded in a header field of each I frame periodically generated and initializes the library when the sequence number has not changed for a predetermined period Encoding monitoring device comprising a. The encoding monitoring apparatus of claim 4, further comprising a buffering unit configured to receive and buffer video data and transmit the video data to the encoding unit.

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