CN106817588B - Transcoding control method and device, net cast method and system - Google Patents

Abstract

The invention discloses a transcoding control method and device, a video live broadcast method and system, and belongs to the technical field of Internet streaming media. The transcoding control method includes the following steps: detecting the video frame rate of the current detection time segment of the video stream, obtaining the current video frame rate, and setting the current video frame rate to the transcoding frame rate, according to the transcoding frame rate The frame rate is used to transcode the video stream; the next detection time segment of the video stream is determined according to the current video frame rate and the previous video frame rate; the video frame rate of the next detection time segment of the video stream is determined The detection is performed to obtain the next video frame rate, the transcoding frame rate is updated to the next video frame rate, and the video stream is transcoded according to the updated transcoding frame rate. The present invention ensures the accuracy of the transcoding frame rate in the video stream transcoding process by detecting the frame rate of the video stream in real time.

Description

Transcoding control method and device, video live broadcast method and system

technical field

The present invention relates to the technical field of Internet streaming media, and in particular, to a transcoding control method and device, and a video live broadcast method and system.

Background technique

With the development of Internet technology and the continuous acceleration of my country's bandwidth, the dominant content of the Internet has gradually developed from text and pictures to audio and video-based content. The explosive development of the mobile Internet in recent years has made the Internet more closely related to people's lives. People increasingly expect to obtain multimedia information from the Internet to meet their various needs. As a result, a large number of audio and video content providers have been born, and the development of the Content Delivery Network (CDN) industry has been greatly promoted. Simple audio and video no longer meet people's needs. What people need is whether they are on the PC side or on a variety of mobile terminals, whether the network quality is good or the network quality is poor. High-quality high-quality audio and video content.

In the field of Internet streaming media, due to the existence of video source providers of many sizes, these video source providers cannot guarantee the accuracy of the audio and video formats provided, such as video frame rate information. At the same time, the video source may also change the frame rate information of the video stream in real time during the video transcoding process. As a result, the video stream cannot be transcoded according to the accurate video frame rate. Transcoding according to the inaccurate frame rate will result in:

1. The bit rate after transcoding is uncontrollable. An incorrect frame rate setting that is too large may cause the bit rate after transcoding to be too large, resulting in wasted bandwidth.

2. The frame rate during transcoding is inconsistent with the real frame rate of the video before transcoding. During the transcoding process, video transcoding is performed according to the wrong frame rate, which will extract or copy some frames of the video, which will affect the playback of the video. Effect.

SUMMARY OF THE INVENTION

In order to solve the problems in the prior art, the embodiments of the present invention provide a transcoding control method and device, and a video live broadcast method and system. The technical solution is as follows:

In one aspect, a transcoding control method is provided, comprising the following steps:

Detect the video frame rate of the current detection time segment of the video stream, obtain the current video frame rate, set the current video frame rate to the transcoding frame rate, and transcode the video stream according to the transcoding frame rate ;

Determine the next detection time segment of the video stream according to the current video frame rate and the previous video frame rate;

Detect the video frame rate of the next detection time segment of the video stream, obtain the next video frame rate, and update the transcoding frame rate to the next video frame rate, according to the updated The video stream is transcoded at the transcoding frame rate.

Further, the video frame rate of the current detection time segment of the video stream is detected, the current video frame rate is obtained, the current video frame rate is set, and the transcoding frame rate is set, and the transcoding frame rate is The steps of transcoding the video stream specifically include:

Detect the video frame rate of the current detection time segment according to the frame rate detection algorithm, and obtain the current video frame rate;

The current video frame rate is set as the transcoding frame rate, and the current detection time segment and the video stream between the current detection time segment and the next detection time segment are analyzed according to the transcoding frame rate. Transcode.

Further, the step of determining the next detection time segment of the video stream according to the current video frame rate and the previous video frame rate specifically includes:

Calculate the difference between the current video frame rate and the previous video frame rate;

If the difference is greater than the set difference, shortening the time interval between the current detection time segment and the next detection time segment;

If the difference is less than or equal to the set difference, the time interval between the current detection time segment and the next detection time segment is extended.

Further, detecting the video frame rate of the next detection time segment of the video stream, obtaining the next video frame rate, and updating the transcoding frame rate to the next video frame rate, The step of transcoding the video stream according to the updated transcoding frame rate specifically includes:

Detect the video frame rate of the next detection time segment according to the frame rate detection algorithm, and obtain the next video frame rate;

The transcoding frame rate is updated to the next video frame rate, and the next detection time segment and the next detection time segment are compared to the next detection time segment according to the updated transcoding frame rate. The video stream is transcoded.

In another aspect, a video live broadcast method is provided, including the transcoding control method.

In yet another aspect, a transcoding control device is provided, comprising:

The first detection module is used to detect the video frame rate of the current detection time segment of the video stream, obtain the current video frame rate, and set the current video frame rate to the transcoding frame rate, and set the transcoding frame rate according to the transcoding frame rate. the video stream is transcoded;

a control module, configured to determine the next detection time segment of the video stream according to the current video frame rate and the previous video frame rate;

The second detection module is configured to detect the video frame rate of the next detection time segment of the video stream, obtain the next video frame rate, and update the transcoding frame rate to the next video frame rate, and transcode the video stream according to the updated transcoding frame rate.

Further, the first detection module includes a first detection sub-module and a first setting sub-module;

The first detection sub-module is configured to detect the video frame rate of the current detection time segment according to a frame rate detection algorithm, and obtain the current video frame rate;

The first setting sub-module is used to set the current video frame rate to the transcoding frame rate, and set the current detection time segment and the current detection time segment to the next detection time segment according to the transcoding frame rate. The video stream between probe time segments is transcoded.

Further, the control module includes a calculation submodule and a judgment submodule;

The calculation submodule is used to calculate the difference between the current video frame rate and the previous video frame rate;

The judging submodule is used to judge:

If the difference is greater than the set difference, shorten the time interval between the current detection time segment and the next detection time segment; or

If the difference is less than or equal to the set difference, the time interval between the current detection time segment and the next detection time segment is extended.

Further, the second detection module includes a second detection sub-module and a second setting sub-module;

The second detection submodule is configured to detect the video frame rate of the next detection time segment according to the frame rate detection algorithm, and obtain the next video frame rate;

The second setting submodule is configured to update the transcoding frame rate to the next video frame rate, and set the next detection time segment and the next video frame rate according to the updated transcoding frame rate. Transcoding is performed on the video stream before the detection time segment to the detection again.

In another aspect, a live video system is provided, including the transcoding control device.

The beneficial effects brought by the technical solutions provided in the embodiments of the present invention are:

Through real-time detection of the frame rate of the video stream, the accuracy of the transcoding frame rate during the video stream transcoding process is ensured, avoiding the waste of bandwidth caused by the wrong frame rate that is too large, and the degradation of the picture quality caused by the wrong frame rate that is too small. , to ensure the consistency of picture quality and bit rate before and after transcoding. This ensures the quality and effect of video stream transcoding.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a flowchart of a transcoding control method provided in Embodiment 1 of the present invention;

2 is a flowchart of a transcoding control method provided in Embodiment 1 of the present invention;

3 is a flowchart of a transcoding control method provided in Embodiment 1 of the present invention;

4 is a flowchart of a transcoding control method provided in Embodiment 1 of the present invention;

5 is a transcoding flow chart provided by Embodiment 1 of the present invention;

6 is a schematic structural diagram of a transcoding control device provided in Embodiment 2 of the present invention;

7 is a schematic structural diagram of a first detection module provided in Embodiment 2 of the present invention;

8 is a schematic structural diagram of a control module provided by Embodiment 2 of the present invention;

FIG. 9 is a schematic structural diagram of a second detection module according to Embodiment 2 of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

Example 1

An embodiment of the present invention provides a transcoding control method. Referring to FIG. 1 , the method includes the following steps:

S101: Detect the video frame rate of the current detection time segment of the video stream, obtain the current video frame rate, set the current video frame rate to a transcoding frame rate, and perform a transcoding frame rate on the video stream according to the transcoding frame rate Transcode.

In the live broadcast scenario, the video source provider provides the video stream and decides the format of the provided video stream. Since the formats of these video sources are different, the video source needs to be transcoded in real time, and then the transcoded video stream needs to be transcoded. output to the user terminal. During the transcoding process, due to different reasons, such as inaccurate video frame rate information carried by the video stream or no video frame rate information, the video frame rate obtained by directly parsing the video stream will be inaccurate, resulting in abnormal transcoding. Or the transcoded video cannot be displayed normally.

The method ensures the quality of the transcoding by detecting the video frame rate of the video stream in real time, and transcoding the video stream according to the video frame rate obtained by the real-time detection.

In this embodiment, the video frame rate of the current detection time segment of the video stream is detected to obtain the current video frame rate, and the current video frame rate is set to the transcoding frame rate, according to the transcoding frame rate The step S101 of transcoding the video stream specifically includes two sub-steps S1011-S1012, as shown in FIG. 2 .

S1011: Detect the video frame rate of the current detection time segment according to a frame rate detection algorithm, and obtain the current video frame rate.

Frame rate is a measure used to measure the number of displayed frames, and its measurement unit is the number of displayed frames per second (Frames per Second, FPS). For example, if 30 frames are displayed in one second, the frame rate is 30FPS. For the detection of frame rate, there are various detection algorithms. The higher the detection accuracy, the higher the computational complexity of the algorithm. Therefore, different detection algorithms are selected in consideration of the accuracy and computational complexity.

In the live broadcast scenario, the processing of the video stream is extremely fast due to the consideration of the delay and the device performance. Therefore, the selected detection time segments are very short, and the selection is made within the range of several hundred milliseconds. , although the detection time segment is very short, the length of the selected detection time segment determines the accuracy of the frame rate detection of this time segment. Since there is more data in the longer detection time segment, the detection result is more accurate.

In this embodiment, at the beginning of receiving and processing the video stream, the above-mentioned current detection time segment is the first selected detection time segment, and the video frame rate detection is performed on the detection time segment through the frame rate detection algorithm to obtain the current video frame rate.

S1012: Set the current video frame rate as a transcoding frame rate, and perform a comparison between the current detection time segment and the time period between the current detection time segment and the next detection time segment according to the transcoding frame rate. The video stream is transcoded.

In this embodiment, the detected current video frame rate is used as the transcoding frame rate for transcoding. By setting the current video frame rate in the transcoding device, for example, setting the context parameters of the decoder and the context of the encoder Among the parameters, the transcoding device transcodes the current detection time segment and the video stream between the current detection time segment and the next detection time segment according to the transcoding frame rate, that is, the detected current video frame rate.

It can be seen that the detected current video frame rate is limited, and it is only used as the transcoding frame rate of the video stream in a specific time segment. This is because the detection process of the video stream is real-time. The video frame rate of the video stream can well overcome the problem of changing the video frame rate caused by the jitter of the video stream caused by the unstable network.

S102: Determine the next detection time segment of the video stream according to the current video frame rate and the previous video frame rate.

In this embodiment, after each detection is completed, the next detection will be performed until the transcoding process ends. During the transcoding process, detecting the video frame rate will occupy system resources. Frequent detection will greatly increase the system burden. Therefore, it is necessary to properly set the detection timing to balance the transcoding quality and system performance.

In this embodiment, the step S102 of determining the next detection time segment of the video stream according to the current video frame rate and the previous video frame rate specifically includes two sub-steps S1021-S1022, as shown in FIG. 3 .

S1021: Calculate the difference between the current video frame rate and the previous video frame rate.

In the early stage of video stream transcoding, the current video frame rate is the video frame rate obtained by the first detection, so there is no previous video frame rate. In this case, the current detection time segment and the next detection time segment are set in advance. .

When the second video frame rate detection is completed, the current video frame rate is the video frame rate obtained by the second detection, and at this time, the previous video frame rate is the video frame rate obtained by the first detection.

When the third video frame rate detection is completed, the current video frame rate is the video frame rate obtained by the third detection. At this time, there are multiple ways to set the previous video frame rate.

A setting method of the previous video frame rate is that the previous video frame rate is the video frame rate obtained by the second detection, that is, the previous video frame rate is the video frame rate obtained by the previous detection of the current detection. In the fixed mode, the previous video frame rate does not need to count the video frame rate obtained from previous detections, and can reflect the frame rate change of the current video stream in real time.

Another way of setting the previous video frame rate is that the previous video frame rate is the reference video frame rate obtained by synthesizing the video frame rate obtained by the first detection and the video frame rate obtained by the second detection, that is, The previous video frame rate is the reference video frame rate obtained by synthesizing the video frame rates of the previous detections of the current detection. For example, the weight of the first detection value and the second detection value is set, and the weight of the first detection value is assumed. is 40%, the weight of the second detection value is 60%, and the reference video frame rate is calculated according to the weight calculation method. In this setting mode, the previous video frame rate refers to the previous detection data, which is closer to the actual frame rate of the video stream.

In the case that two video frame rate detections have been performed, the next detection time segment is determined by calculating the difference between the current video frame rate and the previous video frame rate.

S1022: If the difference is greater than a set difference, shorten the time interval between the current detection time segment and the next detection time segment; if the difference is less than or equal to a set difference, lengthen the current detection time segment The time interval between the probe time segment and the next probe time segment.

In this embodiment, the smaller the difference between the current video frame rate and the previous video frame rate, the better the stability of the current video stream, and the applicable time of the current video frame rate as the transcoding frame rate can be extended. Properly extend the time interval for the next probe. If the difference between the current video frame rate and the previous video frame rate is larger, the stability of the current video stream is poor. At this time, it is necessary to appropriately shorten the time interval for the next detection and increase the number of detections. rate as the transcoding frame rate.

It should be noted that the above-mentioned set difference reflects the acceptability of the stability of the video stream after transcoding. For example, when the set difference is small, the obtained video stream has a higher degree of stability, and the acceptability is higher at this time; When the set difference value is large, the obtained video stream has a low degree of stability and a low degree of acceptability.

S103: Detect the video frame rate of the next detection time segment of the video stream, obtain the next video frame rate, and update the transcoding frame rate to the next video frame rate, according to the updated The transcoding frame rate of the video stream is transcoded.

Since the detection process of the video frame rate is carried out continuously, it is necessary to continuously adjust the transcoding frame rate to better transcode the video stream.

In this embodiment, the video frame rate of the next detection time segment of the video stream is detected to obtain the next video frame rate, and the transcoding frame rate is updated to the next video frame rate, the step S103 of transcoding the video stream according to the updated transcoding frame rate specifically includes two sub-steps S1031-S1032, as shown in FIG. 4 .

S1031: Detect the video frame rate of the next detection time segment according to the frame rate detection algorithm, and obtain the next video frame rate.

In this embodiment, the frame rate detection algorithm used in the entire transcoding process is the same, and the next video frame rate is obtained by detecting the video frame rate of the next detection time segment according to the frame rate detection algorithm. It should be noted that when detecting the video frame rate of the next detection time segment, the process is the same as step S101, and when detecting the next detection time segment, the next detection time segment is the current time segment. The naming of the current detection time segment and the next detection time segment in this method is for the purpose of distinguishing the sequence of frame rate detection.

S1032: Update the transcoding frame rate to the next video frame rate, and analyze the next detection time segment and the next detection time segment to the time before re-detection according to the updated transcoding frame rate The video stream is transcoded.

When the next video frame rate is detected, the previous transcoding frame rate is stopped, and the transcoding frame rate is updated to the next video frame rate. According to the updated transcoding frame rate, the next detection time segment and the next Transcoding is performed on the video stream in the time interval from the detection of the time segment to the time before re-detection.

It should be noted that the current video frame rate and the previous video frame rate jointly determine the timing of the next video detection, that is, the video frame rate detection of the video stream is performed cyclically until the video stream transcoding ends.

Through real-time detection of the frame rate of the video stream, the accuracy of the transcoding frame rate during the video stream transcoding process is ensured, avoiding the waste of bandwidth caused by the wrong frame rate that is too large, and the degradation of the picture quality caused by the wrong frame rate that is too small. , to ensure the consistency of picture quality and bit rate before and after transcoding. This ensures the quality and effect of video stream transcoding.

It can be seen that the transcoding control method described in this embodiment controls the transcoding process through the real-time detection of the transcoding frame rate. Referring to Fig. 5, Fig. 5 shows a specific flowchart of transcoding applying the present transcoding control method.

First, read the input audio and video stream, and obtain the encapsulation format, audio and video parameters, and codec parameter information of the audio and video stream.

After that, the audio and video streams are decapsulated to separate the audio and video data.

For video data, after obtaining the video frame rate through the transcoding control method of this embodiment, the video frame rate is set to the decoder context parameter and the encoder context parameter, and then the video data is decoded, the video filter is processed, and the encoding filter is performed. mirrored video data.

For audio data, decode the audio data, filter the audio data, and encode the filtered audio data.

Finally, encapsulate the audio and video data according to the output file type, and output the transcoded audio and video.

FIG. 5 shows an implementation of the transcoding control method for transcoding a video stream during a live video broadcast, which is not a limitation of other implementations of the transcoding control method.

Embodiment 2

Referring to FIG. 6 , an embodiment of the present invention provides a transcoding control apparatus, which can execute the transcoding control method provided in Embodiment 1, including:

The first detection module 210 is configured to detect the video frame rate of the current detection time segment of the video stream, obtain the current video frame rate, set the current video frame rate to the transcoding frame rate, and perform the video stream processing according to the transcoding frame rate. transcoding;

The control module 220 is used to determine the next detection time segment of the video stream according to the current video frame rate and the previous video frame rate;

The second detection module 230 is configured to detect the video frame rate of the next detection time segment of the video stream, obtain the next video frame rate, and update the transcoding frame rate to the next video frame rate, according to the updated transcoding frame rate. Frame rate to transcode the video stream.

In this embodiment, when the above-mentioned transcoding control device detects the video frame rate of the video stream, it also needs the cooperation of other devices, such as a device for obtaining the encapsulation mode of a video stream, a device for decapsulating processing, an encoder, a decoder, and the like. The device completes the transcoding process of the existing video stream, and the transcoding control device is a device for detecting the video frame rate of the video stream added on the basis of the existing transcoding process.

Referring to FIG. 7 , in this embodiment, the first detection module 210 includes a first detection sub-module 211 and a first setting sub-module 212 .

The first detection sub-module 211 is configured to detect the video frame rate of the current detection time segment according to the frame rate detection algorithm, and obtain the current video frame rate.

The first setting submodule 212 is used to set the current video frame rate as the transcoding frame rate, and transcode the current detection time segment and the video stream between the current detection time segment and the next detection time segment according to the transcoding frame rate .

Referring to FIG. 8 , in this embodiment, the control module 220 includes a calculation sub-module 221 and a judgment sub-module 222 .

The calculation sub-module 221 is configured to calculate the difference between the current video frame rate and the previous video frame rate.

Judging sub-module 222, for judging:

If the difference is greater than the set difference, shorten the time interval between the current detection time segment and the next detection time segment; or

If the difference is less than or equal to the set difference, the time interval between the current detection time segment and the next detection time segment is extended.

Referring to FIG. 9 , in this embodiment, the second detection module 230 includes a second detection sub-module 231 and a second setting sub-module 232 .

The second detection sub-module 231 is configured to detect the video frame rate of the next detection time segment according to the frame rate detection algorithm, and obtain the next video frame rate.

The second setting sub-module 232 is used to update the transcoding frame rate to the next video frame rate, and perform the next detection time segment and the next detection time segment to the video stream before re-detection according to the updated transcoding frame rate. Transcode.

Embodiment 3

An embodiment of the present invention provides a video live broadcast method, including the transcoding control method provided in the first embodiment.

In the existing video live broadcast method, the transcoding of the video stream relies on the video format information provided by the video source provider, including the video resolution, bit rate, and frame rate. The above video format information is transcoded. When the above video format information is inaccurate, the transcoding quality will be poor and the live broadcast effect will be affected.

In this embodiment, referring to FIG. 5 again, in the live broadcast process, first, read the input live audio and video stream, and obtain the encapsulation format, audio and video parameters, and codec parameter information of the audio and video stream.

After that, the audio and video streams are decapsulated to separate the audio and video data.

For video data, after obtaining the video frame rate through the transcoding control method of the first embodiment, the video frame rate is set to the decoder context parameter and the encoder context parameter, and then the video data is decoded, the video filter is processed, and the encoding filter is performed. mirrored video data.

For audio data, decode the audio data, filter the audio data, and encode the filtered audio data.

Finally, encapsulate the audio and video data according to the output file type, and output the transcoded audio and video to various receiving terminals that receive the live broadcast, such as the user's mobile phone, personal computer, etc.

By implementing the transcoding control method provided in the first embodiment in the live broadcast method, an accurate video frame rate of the video stream is obtained, and the live broadcast effect is better improved.

Embodiment 4

An embodiment of the present invention provides a live video system, including the transcoding control device provided in the second embodiment.

In this embodiment, the live video system includes:

The encapsulation mode acquiring device is used for acquiring encapsulation format information, audio and video parameters and codec parameter information from the audio and video stream.

The decapsulation processing device is used to decapsulate and separate audio and video.

Transcoding control device for detecting video frame rate.

The audio and video decoding device is used to decode video into YUV data and audio into PCM data.

The filter processing device is used for audio and video filter processing.

The audio and video encoding device is used for encoding the audio and video data processed by the filter.

The encapsulation processing device is used to encapsulate the encoded audio and video data according to the required encapsulation format.

The video live broadcast system outputs the encapsulated audio and video to various receiving terminals that receive the live broadcast.

The above-mentioned serial numbers of the embodiments of the present invention are only for description, and do not represent the advantages or disadvantages of the embodiments.

The device embodiments described above are only illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in One place, or it can be distributed over multiple network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution in this embodiment. Those of ordinary skill in the art can understand and implement it without creative effort.

From the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and certainly can also be implemented by hardware. Based on this understanding, the above-mentioned technical solutions can be embodied in the form of software products in essence or the parts that make contributions to the prior art, and the computer software products can be stored in computer-readable storage media, such as ROM/RAM, magnetic A disc, an optical disc, etc., includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform the methods described in various embodiments or some parts of the embodiments.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims (8)

1. a transcoding control method, is characterized in that, comprises the steps: Detect the video frame rate of the current detection time segment of the video stream, obtain the current video frame rate, set the current video frame rate to the transcoding frame rate, and transcode the video stream according to the transcoding frame rate ; Determine the next detection time segment of the video stream according to the current video frame rate and the previous video frame rate; Detect the video frame rate of the next detection time segment of the video stream, obtain the next video frame rate, and update the transcoding frame rate to the next video frame rate, according to the updated Transcoding the video stream at the transcoding frame rate; The step of determining the next detection time segment of the video stream according to the current video frame rate and the previous video frame rate specifically includes: Calculate the difference between the current video frame rate and the previous video frame rate; If the difference value is greater than the set difference value, shortening the time interval between the current detection time segment and the next detection time segment; If the difference is less than or equal to the set difference, the time interval between the current detection time segment and the next detection time segment is extended. 2. The transcoding control method according to claim 1, wherein the video frame rate of the current detection time segment of the video stream is detected, the current video frame rate is obtained, and the current video frame rate is set. Transcoding frame rate, the step of transcoding the video stream according to the transcoding frame rate specifically includes: Detect the video frame rate of the current detection time segment according to the frame rate detection algorithm, and obtain the current video frame rate; The current video frame rate is set to the transcoding frame rate, and the current detection time segment and the video stream between the current detection time segment and the next detection time segment are analyzed according to the transcoding frame rate. Transcode. 3. The transcoding control method according to claim 2, wherein the video frame rate of the next detection time segment of the video stream is detected, the next video frame rate is obtained, and the The transcoding frame rate is updated to the next video frame rate, and the steps of transcoding the video stream according to the updated transcoding frame rate specifically include: Detect the video frame rate of the next detection time segment according to the frame rate detection algorithm, and obtain the next video frame rate; The transcoding frame rate is updated to the next video frame rate, and the next detection time segment and the next detection time segment are compared to the next detection time segment according to the updated transcoding frame rate. The video stream is transcoded. 4. A method for live video broadcasting, comprising the transcoding control method according to any one of claims 1 to 3. 5. A transcoding control device, characterized in that, comprising: The first detection module is used to detect the video frame rate of the current detection time segment of the video stream, obtain the current video frame rate, and set the current video frame rate to the transcoding frame rate, and set the transcoding frame rate according to the transcoding frame rate. the video stream is transcoded; a control module, configured to determine the next detection time segment of the video stream according to the current video frame rate and the previous video frame rate; The second detection module is configured to detect the video frame rate of the next detection time segment of the video stream, obtain the next video frame rate, and update the transcoding frame rate to the next video frame rate, and transcode the video stream according to the updated transcoding frame rate; The control module also includes a calculation submodule and a judgment submodule: The calculation submodule is used to calculate the difference between the current video frame rate and the previous video frame rate; The judging submodule is used to judge: If the difference is greater than the set difference, shorten the time interval between the current detection time segment and the next detection time segment; or If the difference is less than or equal to the set difference, the time interval between the current detection time segment and the next detection time segment is extended. 6. The transcoding control device according to claim 5, wherein the first detection module comprises a first detection sub-module and a first setting sub-module; The first detection sub-module is configured to detect the video frame rate of the current detection time segment according to a frame rate detection algorithm, and obtain the current video frame rate; The first setting sub-module is used to set the current video frame rate to the transcoding frame rate, and set the current detection time segment and the current detection time segment to the next detection time segment according to the transcoding frame rate. The video stream between probe time segments is transcoded. 7. The transcoding control device according to claim 6, wherein the second detection module comprises a second detection submodule and a second setting submodule; The second detection submodule is configured to detect the video frame rate of the next detection time segment according to the frame rate detection algorithm, and obtain the next video frame rate; The second setting submodule is configured to update the transcoding frame rate to the next video frame rate, and set the next detection time segment and the next video frame rate according to the updated transcoding frame rate. Transcoding is performed on the video stream before the detection time segment to the detection again. 8. A live video system, comprising the transcoding control device according to any one of claims 5 to 7.