TWI721089B - Transcoding method and device - Google Patents

Abstract

The embodiment of the present invention discloses a transcoding method and device. The method includes: pre-establishing a plurality of correspondences between definitions and resolutions; selecting the first definition and the second definition from the plurality of definitions, and determining the respective The first resolution and the second resolution corresponding to the first and second resolutions; according to the first and second resolutions, the first part of the media file is transcoded according to the preset transcoding rules, and the transcoding process is recorded The first real-time quantization parameter value and the second real-time quantization parameter value in, determine whether the first real-time quantization parameter value and the second real-time quantization parameter value meet the preset detection rules; if the judgment result is no, adjust the first resolution and/ Or adjust the second resolution; transcode the untranscoded part of the media file according to the adjusted first resolution and/or second resolution. The transcoding method and device provided by the embodiments of the present invention can improve the transcoding speed of media files.

Description

Transcoding method and device

The present invention relates to the field of information processing technology, and particularly relates to a transcoding method and device.

With the continuous development of mobile communication technology, the rapid increase in network access speed, the increasingly smarter mobile terminals, and the increasing optimization of digital compression technology, mobile terminals have evolved from simple communication and contact tools to multimedia intelligence. platform. Mobile streaming media is a combination of mobile communication and streaming media transmission. Streaming media technology is used for data transmission on mobile terminals through mobile networks, providing users with services including video-on-demand, mobile video chat, and mobile video monitoring.

Transcoding is to compress high-definition super-large media files (such as video files) into certain network scenarios (such as optical fiber network, WIFI network, 3G network, etc.), and on certain terminals (such as TV, PC, The process of file/streaming played by mobile phone, PAD, etc.). Generally, the smaller the media file is compressed, the more suitable it is for transmission in a bandwidth-constrained environment, but the display quality of the media file may also be worse.

Existing transcoding methods usually include: different clarity can be set in advance The transcoding parameters corresponding to the resolution, for example, the resolution may include four types: process, SD, HD, and ultra-definition, and the resolution and bit rate corresponding to the four resolutions can be set respectively. The media files are respectively pre-encoded and transcoded according to different definitions according to the set resolution and code rate, and after the transcoding of the definitions is completed, the media files corresponding to each definition can be output.

In the process of implementing the present invention, the inventor found that there are at least the following problems in the prior art: In the existing transcoding method, the transcoding parameters of the media file need to be analyzed before transcoding to determine the appropriate resolution and bit rate, etc. Transcoding parameters, and then transcoding according to the analyzed parameters and outputting the transcoded media files. Generally, the process of analyzing the parameters takes a certain amount of time. When a media file needs to be transcoded into media files of different definitions, Parameter analysis is required for each definition, which will take a lot of time and reduce the transcoding speed.

The purpose of the embodiments of the present invention is to provide a transcoding method and device to improve the transcoding speed of media files.

In order to solve the above technical problems, the embodiments of the present invention provide a transcoding method and device that are implemented as follows: A transcoding method includes: pre-establishing a plurality of correspondences between different definitions and resolutions; Select the first resolution and the second resolution in the degree, and determine the first resolution and the second resolution corresponding to the first resolution and the second resolution, respectively; According to the first resolution and the second resolution, the first part of the content of the media file is transcoded according to a preset transcoding rule, and the data corresponding to the first resolution and the second resolution during the transcoding process are recorded. The first real-time quantization parameter value and the second real-time quantization parameter value; determine whether the first real-time quantization parameter value and the second real-time quantization parameter value both comply with the preset detection rule; if the first real-time quantization parameter does not comply with the Preset detection rule to adjust the first resolution corresponding to the first definition; and/or, if the second real-time quantization parameter does not meet the preset detection rule, adjust the first resolution corresponding to the second definition Second resolution: transcoding the untranscoded part of the media file according to the adjusted first resolution and/or adjusted second resolution.

A transcoding device, comprising: a correspondence relationship establishment module, a definition and resolution determination module, a transcoding module, a first judgment module, and a resolution first adjustment module; wherein the correspondence relationship establishment module , For pre-establishing a plurality of correspondences between different definitions and resolutions; the definition and resolution determination module is used for selecting the first definition and the second definition from the plurality of definitions, Determine the first resolution and the second resolution respectively corresponding to the first resolution and the second resolution; the transcoding module is configured to perform the first resolution and the second resolution of the media file according to the first resolution and the second resolution Part of the content is transcoded according to a preset transcoding rule, and the first real-time quantization parameter value and the second real-time quantization parameter value corresponding to the first definition and the second definition respectively in the transcoding process are recorded; The first judgment module is configured to judge whether the first real-time quantization parameter value and the second real-time quantization parameter value both comply with the preset detection rule; the preset detection rule includes: transcoding according to a resolution The number of obtained real-time quantization parameter values that are greater than the first threshold value is less than a% of the total number of real-time quantization parameters obtained by transcoding according to the resolution; the value range of a includes: 30 -70; The first resolution adjustment module is configured to adjust the first clarity when the judgment result of the first judgment module is that the first real-time quantization parameter does not meet the preset detection rule The first resolution corresponding to the degree; and/or, for adjusting the second definition when the judgment result of the first judgment module is that the second real-time quantization parameter does not meet the preset detection rule The corresponding second resolution; the transcoding module is also used to adjust the first resolution and/or the adjusted second resolution of the media file according to the first resolution adjusted by the first adjustment module The untranscoded part is transcoded.

As can be seen from the technical solutions provided by the above embodiments of the present invention, the transcoding method and device provided by the embodiments of the present invention transcode part of the content of the media file according to a predetermined resolution corresponding to the resolution, and before transcoding There is no need to analyze the transcoding parameters of each definition separately, which saves transcoding time and improves the transcoding speed. At the same time, during the transcoding process, the change of the quantization parameter value is recorded. When the quantization parameter value is too large, the resolution can be adjusted in time, and the untranscoded part of the media file can be transcoded according to the adjusted resolution. Ensure that the transcoded media files can be played clearly and smoothly.

301: Correspondence establishment module

302: Definition and resolution determination module

303: Transcoding Module

304: The first judgment module

305: The first resolution adjustment module

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are merely present For some of the embodiments described in the invention, for those skilled in the art, without creative labor, other drawings can be obtained from these drawings.

Fig. 1 is a flowchart of an embodiment of the transcoding method of the present invention; Fig. 2 is a schematic diagram of adjusting the resolution using a linear model in an embodiment of the transcoding method of the present invention; Fig. 3 is a module of an embodiment of the transcoding device of the present invention Figure.

The embodiment of the present invention provides a transcoding method and device.

In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described The embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the protection scope of the present invention.

Fig. 1 is a flowchart of an embodiment of a transcoding method of the present invention. As shown in Figure 1, the transcoding method may include:

S101: Establish a plurality of correspondence relationships between different definitions and resolutions in advance.

You can set the corresponding relationship between multiple levels of clarity and resolution. The multiple levels of clarity may be at least 2 levels of clarity. For example, the corresponding relationship between the different definitions and the resolutions may be as shown in Table 1, where the plurality of definitions may be 4 levels of definition, from the highest level of definition to the lowest level of definition The order can be: ultra-definition, high-definition, standard-definition, smooth.

S102: Select the first definition and the second definition from the plurality of definitions, and determine the first resolution and the second resolution respectively corresponding to the first definition and the second definition.

The first definition and the second definition can be selected from the plurality of levels of definition.

When the multiple levels of sharpness are two levels of sharpness, the first sharpness can be any one of the two levels of sharpness, and the second sharpness can be the other one.

When the multiple levels of clarity are 3 or more levels of clarity In terms of clarity, the first clarity and the second clarity may be any two levels of clarity excluding the highest level of clarity among the plurality of levels of clarity. For example, the multiple levels of definition, from the highest level of definition to the lowest level of definition, may be: ultra-definition, high-definition, standard-definition, and smooth. Then the first definition and the second definition may be any two levels of definition among "high definition", "standard definition" and "smooth".

Further, when the multiple levels of definition are 4 or more levels of definition, the first definition and the second definition may be two non-adjacent levels of definition. For example, you can select the definition of "High Definition" and "Smooth" levels respectively.

According to the pre-established correspondences of different definition pre-resolutions, the first resolution and the second resolution respectively corresponding to the first resolution and the second resolution can be determined.

S103: Transcode the first part of the content of the media file according to the first resolution and the second resolution according to a preset transcoding rule, and record the difference between the first resolution and the second resolution during the transcoding process. Corresponding first instant quantization parameter value and second instant quantization parameter value.

The first part of the content of the media file may be transcoded according to a preset transcoding rule according to the first resolution and the second resolution.

Wherein, the first part of the content of the media file may include: the content of the first duration of the media file. The first duration may be less than the total playback duration of the media file. For example, for a video file with a total duration of 30 minutes, the content of the first duration may be content within 2 minutes of the current time.

The preset transcoding rule may include encoding according to a fixed code rate coefficient (CRF) value or a fixed quantization parameter (QP) value. Normally, a CRF value of 18 indicates that the media file quality is basically lossless, a CRF value of 19-21.5 indicates that the media file quality is high quality, and a CRF value of 22-26 indicates that the media file quality is medium quality.

The preset code rate coefficient may be selected according to actual experimental conditions. For example, the value of the CRF may be 25.

The quantization parameter (QP) value can be used to measure the distortion/compression rate of the transcoded media file. The larger the QP value, the higher the distortion of the transcoded media file and the higher the compression rate; QP The smaller the value, the smaller the distortion of the transcoded media file and the lower the compression rate.

Generally, the value range of QP is generally 0~51. For general Internet video files, if QP>35, the quality of media files will be poor.

In the transcoding process, the first real-time quantization parameter value and the second real-time quantization parameter value corresponding to the first definition and the second definition, respectively, can be recorded.

S104: Determine whether the first real-time quantization parameter value and the second real-time quantization parameter value both comply with a preset detection rule.

It can be determined whether the first real-time quantization parameter value and the second real-time quantization parameter value both comply with a preset detection rule.

The preset detection rule may include: the number of real-time quantization parameter values obtained by transcoding according to a resolution that is greater than a first threshold value is less than the number of real-time quantization parameter values obtained by transcoding according to the resolution. A% of the total number; the value range of a can include: 30-70.

Wherein, by comparing whether the instant quantization parameter value is greater than the first threshold value, it can be determined whether the instantaneous bit rate value is too high during the transcoding process.

The first threshold value may be the fixed quantization parameter value or a quantization parameter value corresponding to the fixed code rate coefficient value. Specifically, when the preset transcoding rule is encoding according to a fixed code rate coefficient value, the first threshold value may be: the preset code rate coefficient value plus 5. In general, when the quantization parameter value obtained by the transcoding is greater than the first threshold value, it can be indicated that the instantaneous bit rate value is greater than the maximum bit rate value at which the media file can be played smoothly at the current resolution. The bit rate value is greater than the maximum bit rate value, which may cause the media file to not be played smoothly at the current resolution.

S105: If the first real-time quantization parameter value does not meet the preset detection rule, adjust the first resolution corresponding to the first definition; and/or, if the second real-time quantization parameter value does not meet all The preset detection rule is used to adjust the second resolution corresponding to the second definition.

When the number of quantization parameter values greater than the first threshold is large, it means that when transcoding is performed according to the preset transcoding rule under the current resolution, the instantaneous bit rate of multiple fragments of the media file may change Exceeding the maximum bitrate under this resolution may cause media files to not play smoothly. Therefore, the resolution corresponding to the current sharpness needs to be reduced.

The adjusting the first resolution may include: multiplying the value of the first resolution by a first coefficient. The adjusting the second resolution may include: multiplying the value of the second resolution by a first coefficient. The value of the first coefficient can be Including: greater than 0 and less than 1. For example, the first coefficient may be 0.8.

S106: Transcode the untranscoded part of the media file according to the adjusted first resolution and/or adjusted second resolution.

According to the adjusted first resolution and/or second resolution, the untranscoded part of the media file can be transcoded according to a preset transcoding rule, and it can be obtained separately from the first resolution. The new first bit rate and the new second bit rate corresponding to the degree and second definition.

In another embodiment, the method may further include: if the first real-time quantization parameter value and the second real-time quantization parameter value both conform to the preset detection rule, according to the first resolution and the second resolution Transcoding the untranscoded part of the media file. When the first instant quantization parameter value and the second instant quantization parameter value both conform to the preset detection rule, it may indicate that the number of quantization parameters greater than the first threshold value is 0 or the number is less. Then, it means that under the current resolution, when transcoding according to the preset transcoding rules, the instantaneous bit rate value of the media file with no or only a few fragments will exceed the maximum bit rate value under the resolution, which can guarantee The media file can be played smoothly, so the untranscoded part of the media file can be transcoded according to the first resolution and the second resolution.

In another embodiment, the method may further include: recording a first bit rate and a second bit rate corresponding to the first definition and the second definition respectively obtained by transcoding the first part of the content of the media file, according to The first bit rate, the second bit rate and the first resolution and the second resolution respectively corresponding to the first resolution and the second resolution establish a linear model.

Further, when the clarity of the multiple levels is at least 3 levels of clarity, according to the linear model and the multiple levels of clarity, each other than the first clarity and the second clarity The resolution corresponding to the level of clarity determines the bit rate value corresponding to the other levels of clarity.

Specifically, the linear relationship between the resolution and the bit rate can be calculated according to the first resolution, the second resolution, the first bit rate, and the second bit rate, and the linear relationship between the resolution and the bit rate can be calculated based on the linear relationship. The bit rate value corresponding to the resolution of the sharpness. Through the linear model, the code rate corresponding to the other levels of resolution can be determined directly and quickly, without the need to transcode the media files according to the resolutions corresponding to the different levels of resolution to obtain the corresponding code rate. Value to improve processing efficiency.

Further, it can be judged whether the code rate value corresponding to each level of definition is less than or equal to the preset upper limit code rate threshold value corresponding to that level of definition; if the judgment result is no, it can be determined that the multiple In the definition of the level, the definition of the target level whose bit rate value is greater than the threshold value of the upper limit bit rate; according to the threshold value of the upper limit bit rate corresponding to the definition of the target level and the linear model, it can be determined that The adjusted resolution corresponding to the definition of the target level; the untranscoded part of the media file may be transcoded according to the adjusted resolution. By controlling the code rate value in the transcoding process to not be greater than the upper limit code rate threshold, the smooth playback of media files can be ensured. At the same time, the linear model can be used to obtain a resolution that matches the code rate value of the media file that can be played smoothly at each level of definition, so as to ensure that the transcoded media file can be played clearly and smoothly.

FIG. 2 is a schematic diagram of adjusting the resolution using a linear model in an embodiment of the transcoding method of the present invention. As shown in Figure 2, in Figure 2, B and E respectively represent the first resolution and the second resolution corresponding to "HD" and "Smooth" obtained according to Table 1, where A represents the and obtained according to Table 1. The resolution corresponding to the definition "super definition", D represents the resolution corresponding to the definition "standard definition" obtained according to Table 1. b represents the first code rate value obtained during the transcoding process, and e represents the second code rate value obtained during the transcoding process.

Then, a linear model can be established based on B, E, b, and e, and the linear relationship between the resolution and the bit rate can be obtained, as shown by the line m in Figure 3. According to the linear model, the code rate value a corresponding to the resolution A and the code rate value d corresponding to the resolution D can be obtained. Assuming that a', b', d', and e'are the preset bit rate thresholds corresponding to the definitions "Ultra Definition", "HD", "SD" and "Smooth" respectively, then it can be judged that, Only d>d' means that if the resolution D of the media file is transcoded to realize the playback with the definition of "SD", the media file will not be played smoothly. At this time, according to the upper limit code rate value d'corresponding to "standard definition" and the linear model, the resolution D'corresponding to d'can be obtained, and the D'is taken as the adjusted and " When transcoding the untranscoded part of the media file according to the adjusted D', the resolution corresponding to “standard definition” can ensure the clear and smooth playback of the media file.

The transcoding method provided in the foregoing embodiment transcodes part of the content of the media file according to the predetermined resolution corresponding to the resolution, and does not need to analyze the transcoding parameters of each resolution separately before transcoding. , Which saves transcoding time and improves transcoding speed. At the same time, during the transcoding process In, the change of the quantization parameter value is recorded. When the quantization parameter value is too large, the resolution can be adjusted in time and the untranscoded part of the media file can be transcoded according to the adjusted resolution, and the transcoded media can be guaranteed Files can be played clearly and smoothly.

Fig. 3 is a module diagram of an embodiment of the transcoding device of the present invention. As shown in FIG. 3, the transcoding device may include: a correspondence relationship establishment module 301, a definition and resolution determination module 302, a transcoding module 303, a first judgment module 304, and a first resolution adjustment module. Group 305. Wherein, the corresponding relationship establishment module 301 can be used to establish a plurality of different definitions and resolutions corresponding relationships in advance.

The definition and resolution determination module 302 can be used to select a first definition and a second definition from the plurality of definitions, and determine the first definition and the second definition respectively corresponding to the first definition and the second definition. Resolution and second resolution.

The transcoding module 303 may be used to transcode the first part of the content of the media file according to the preset transcoding rules according to the first resolution and the second resolution, and record that the transcoding process is different from each other during the transcoding process. The first real-time quantization parameter value and the second real-time quantization parameter value corresponding to the first definition and the second definition.

The first judgment module 304 can be used to judge whether the first real-time quantization parameter value and the second real-time quantization parameter value both comply with the preset detection rule. The preset detection rule may include: the number of real-time quantization parameter values obtained by transcoding according to a resolution that is greater than the first threshold is less than the total number of real-time quantization parameters obtained by transcoding according to the resolution. A% of the number; the value range of a can include: 30-70.

The resolution first adjustment module 305 may be used to adjust the first clarity when the first determination module 304 determines that the first real-time quantization parameter does not meet the preset detection rule. And/or can be used to adjust the second real-time quantization parameter when the judgment result of the first judgment module 304 is that the second real-time quantization parameter does not meet the preset detection rule The second resolution corresponding to the sharpness.

The transcoding module 303 may also be used for transcoding the untranscoded content in the media file according to the first resolution adjusted by the first resolution adjustment module 305 and/or the adjusted second resolution Partially transcoded.

In another embodiment, the transcoding device may further include: a code rate recording module and a linear model establishment module. The code rate recording module may be used to record the first code rate and the second code rate corresponding to the first definition and the second definition respectively obtained by transcoding the first part of the content of the media file by the transcoding module . The linear model establishment module may be used to establish a linear model according to the first code rate, the second code rate, the first resolution and the second resolution respectively corresponding to the first resolution and the second resolution.

Further, the transcoding device may further include other code rate determination modules, which may be used to determine each other than the first definition and the second definition according to the linear model and the plurality of levels of definition. The resolution corresponding to the level of clarity, to determine the bit rate value corresponding to the other levels of clarity

In another embodiment, the transcoding device may further include: a second judgment module. The second judgment module can be used to judge each level Whether the code rate values corresponding to the definitions of, are all less than or equal to the preset upper limit code rate threshold value corresponding to the definition of the level.

Further, when the judgment result of the second judgment module is no, the transcoding device may further include: a target level definition determination module and a second resolution adjustment module; wherein, the target definition The module can be used to determine the definition of the target level whose code rate value is greater than the corresponding preset upper limit code rate threshold among the definitions of the multiple levels.

The second resolution adjustment module may be used to determine the adjusted resolution corresponding to the resolution of the target level according to the upper limit bit rate threshold corresponding to the resolution of the target level and the linear model degree.

Correspondingly, the transcoding module 303 can also be used to transcode the untranscoded part of the media file according to the resolution adjusted by the second resolution adjustment module.

The transcoding device disclosed in the foregoing embodiment corresponds to the embodiment of the transcoding method of the present invention, and can implement the method embodiment of the present invention and obtain the technical effects of the method embodiment.

In the 1990s, the improvement of a technology can be clearly distinguished from the improvement of the hardware (for example, the improvement of the circuit structure of diodes, transistors, switches, etc.) or the improvement of the software (for the process of the method). Improve). However, with the development of technology, the improvement of many methods and processes of today can be regarded as a direct improvement of the hardware circuit structure. Designers almost always get the corresponding hardware circuit structure by programming the improved method flow into the hardware circuit. Therefore, it cannot be said that the improvement of a method flow is not It can be implemented with hardware physical modules. For example, a Programmable Logic Device (PLD) (such as a Field Programmable Gate Array (FPGA)) is such an integrated circuit whose logic function is determined by the user's programming of the device. It is programmed by the designer to "integrate" a digital system on a single PLD, without requiring the chip manufacturer to design and manufacture a dedicated integrated circuit chip 2. Moreover, nowadays, instead of manually making integrated circuit chips, this kind of programming is mostly realized by using "logic compiler" software, which is similar to the software compiler used in program development and writing, but requires compilation. The original code before has to be written in a specific programming language, which is called Hardware Description Language (HDL), and HDL is not only one, but there are many, such as ABEL (Advanced Boolean Expression Language), AHDL (Altera Hardware Description Language), Confluence, CUPL (Cornell University Programming Language), HDCal, JHDL (Java Hardware Description Language), Lava, Lola, MyHDL, PALASM, RHDL (Ruby Hardware Description Language), etc., currently the most Commonly used are VHDL (Very-High-Speed Integrated Circuit Hardware Description Language) and Verilog2. It should also be clear to those skilled in the art that only a little logic programming of the method flow in the above hardware description languages and programming into the integrated circuit can easily obtain the hardware circuit that implements the logic method flow.

The controller can be implemented in any suitable way, for example, the controller can For example, a microprocessor or a processor and a computer-readable medium storing computer-readable program codes (such as software or firmware) executable by the (micro)processor, logic gates, switches, and dedicated integrated circuits (Application Specific Integrated Circuit, ASIC), programmable logic controllers and embedded microcontrollers. Examples of controllers include but are not limited to the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20 and Silicone Labs C8051F320, memory controllers also Can be implemented as part of the control logic of the memory.

Those skilled in the art also know that in addition to implementing the controller in a purely computer-readable program code, it is entirely possible to program the method steps to make the controller be controlled by logic gates, switches, dedicated integrated circuits, and programmable logic. The same function can be realized in the form of an embedded microcontroller and a microcontroller. Therefore, such a controller can be regarded as a hardware component, and the devices included in it for realizing various functions can also be regarded as a structure within the hardware component. Or even, the device for realizing various functions can be regarded as both a software module for realizing the method and a structure within a hardware component.

The systems, devices, modules, or units explained in the above embodiments may be implemented by computer chips or entities, or implemented by products with certain functions.

For the convenience of description, when describing the above device, the functions are divided into various units and described separately. Of course, when implementing the present invention, the functions of each unit can be implemented in the same or multiple software and/or hardware.

It can be seen from the description of the above embodiments that those skilled in the art It can be clearly understood that the present invention can be implemented by means of software plus the necessary universal hardware platform. Based on this understanding, the technical solution of the present invention essentially or the part that contributes to the prior art can be embodied in the form of a software product. In a typical configuration, the computing device includes one or more processors (CPU) , Input/output interface, network interface and memory. The computer software product may include a number of instructions to enable a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments of the present invention. The computer software product can be stored in memory, which may include non-permanent memory in computer-readable media, random access memory (RAM) and/or non-volatile memory, such as read-only Memory (ROM) or flash memory (flash RAM). Memory is an example of computer-readable media. Computer-readable media include permanent and non-permanent, movable and non-movable media, and information storage can be realized by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), and other types of random access memory (RAM) , Read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, CD-ROM, digital multi-function optical disc (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by computing devices. According to the definition in this article, computer-readable media does not include transitory media (transitory media), such as Modulated data signal and carrier.

The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, as for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and for related parts, please refer to the part of the description of the method embodiment.

The present invention can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld or portable devices, tablet devices, multi-processor systems, microprocessor-based systems, set-top boxes, programmable consumer electronic devices, network PCs, small computers, large Computers, distributed computing environments including any of the above systems or equipment, etc.

The invention can be described in the general context of computer-executable instructions executed by a computer, such as a program module. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The present invention can also be practiced in distributed computing environments. In these distributed computing environments, remote processing devices connected through a communication network perform tasks. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

Although the present invention has been described through the embodiments, those skilled in the art know that the present invention has many modifications and changes without departing from the spirit of the present invention. It is hoped that the scope of the appended patent application includes these modifications and changes without departing from the present invention. spirit.

Claims (17)

A transcoding method includes: establishing a plurality of different definitions and resolutions corresponding relationships in advance; selecting a first definition and a second definition from the plurality of definitions, and determining that they are respectively related to the first definition and the second definition. The first resolution and the second resolution corresponding to the two definitions; according to the first resolution and the second resolution, the first part of the content of the media file is transcoded according to a preset transcoding rule, and the transcoding is recorded During the process, the first real-time quantization parameter value and the second real-time quantization parameter value corresponding to the first definition and the second definition respectively; determine whether the first real-time quantization parameter value and the second real-time quantization parameter value meet the preset Detection rule; if the first real-time quantization parameter value does not meet the preset detection rule, adjust the first resolution corresponding to the first definition; and/or, if the second real-time quantization parameter value does not meet the The preset detection rule adjusts the second resolution corresponding to the second definition, wherein the preset detection rule includes: a real-time quantization parameter value obtained by transcoding according to a resolution is greater than a first threshold The number of quantization parameter values of is less than a% of the total number of real-time quantization parameters obtained by transcoding according to the resolution; the value range of a includes: 30-70; according to the adjusted first resolution And/or the adjusted second resolution transcodes the untranscoded part of the media file. For example, the transcoding method described in item 1 of the scope of patent application, wherein the preset transcoding rules include: according to a fixed code rate coefficient value or a fixed The quantization parameter value is encoded. The transcoding method according to item 2 of the scope of patent application, wherein the first threshold value is a quantization parameter value corresponding to the fixed code rate coefficient value or the fixed code rate coefficient value. The transcoding method according to item 3 of the scope of patent application, wherein, when the preset transcoding rule is encoding according to a fixed code rate coefficient value, the quantization parameter value includes: the fixed code rate coefficient value Add 5. The transcoding method according to item 1 of the scope of patent application, wherein the adjusting the first resolution includes: multiplying the value of the first resolution by a first coefficient, and the first coefficient is greater than 0 and less than 1. . The transcoding method according to item 1 of the scope of patent application, wherein the adjusting the second resolution includes: multiplying the value of the second resolution by a first coefficient, and the first coefficient is greater than 0 and less than 1. . The transcoding method according to item 1 of the scope of patent application, wherein the method further comprises: recording the first code corresponding to the first definition and the second definition obtained by transcoding the first part of the content of the media file The linear model is established according to the first code rate, the second code rate, the first resolution, and the second resolution corresponding to the first resolution and the second resolution, respectively. The transcoding method according to item 7 of the scope of patent application, wherein, when the multiple levels of clarity include at least 3 levels of clarity, the method further includes: according to the linear model and the multiple The resolutions corresponding to each level of clarity except the first clarity and the second clarity in each level of clarity Degree to determine the bit rate value corresponding to the other levels of clarity. For example, the transcoding method described in item 7 or 8 of the scope of patent application, wherein the method further comprises: judging whether the bit rate value corresponding to each level of definition is less than or equal to the preset corresponding to the level of definition If the judgment result is no, determine the definition of the target level whose code rate value is greater than the upper limit code rate threshold among the multiple levels of definition; according to the clarity of the target level The upper limit code rate threshold value corresponding to the degree and the linear model determine the adjusted resolution corresponding to the definition of the target level; and the untranscoded content in the media file is determined according to the adjusted resolution Partially transcoded. The transcoding method according to item 1 of the scope of patent application, wherein, when the plurality of levels of definition includes at least 3 levels of definition, the first definition is selected from the plurality of definitions And the second definition includes: selecting any two levels of definition except the highest level of definition among the plurality of levels of definition as the first definition and the second definition. The transcoding method according to item 10 of the scope of patent application, wherein, when the plurality of levels of definition are 4 or more levels of definition, the first definition is selected from the plurality of definitions The degree and the second definition include: the first definition and the second definition select two non-adjacent levels of definition. As the transcoding method described in item 1 of the scope of patent application, wherein: The first part of the content of the media file includes: the content of the first duration of the media file; the first duration is less than the total playing duration of the media file. A transcoding device, wherein the device comprises: a correspondence relationship establishment module, a definition and resolution determination module, a transcoding module, a first judgment module, and a first resolution adjustment module; wherein, the The corresponding relationship establishment module is used to establish a plurality of different definitions and resolutions corresponding relationships in advance; the definition and resolution determination module is used to select the first definition and the resolution from the plurality of definitions The second resolution determines the first resolution and the second resolution respectively corresponding to the first resolution and the second resolution; the transcoding module is used to determine the first resolution and the second resolution according to the first resolution and the second resolution Transcode the first part of the media file according to the preset transcoding rule, and record the first real-time quantization parameter value and the second real-time quantization parameter corresponding to the first definition and the second definition in the transcoding process Value; the first judgment module is used to judge whether the first real-time quantization parameter value and the second real-time quantization parameter value both comply with the preset detection rule; the preset detection rule includes: according to a resolution The number of real-time quantization parameter values obtained by transcoding that are greater than the first threshold value is less than a% of the total number of real-time quantization parameters obtained by transcoding according to the resolution; the value range of a includes : 30-70; The first resolution adjustment module is configured to adjust the first real-time quantization parameter when the judgment result of the first judgment module is that the first real-time quantization parameter does not meet the preset detection rule A first resolution corresponding to a sharpness; and/ Or, when the judgment result of the first judgment module is that the second real-time quantization parameter does not meet the preset detection rule, adjust the second resolution corresponding to the second definition; the conversion The encoding module is further configured to transcode the untranscoded part of the media file according to the first resolution adjusted by the first resolution adjustment module and/or the adjusted second resolution. The transcoding device according to item 13 of the scope of patent application, wherein the transcoding device further includes: a rate recording module and a linear model establishment module; the rate recording module is used to record the transcoding The module transcodes the first part of the content of the media file to obtain the first code rate and the second code rate respectively corresponding to the first definition and the second definition; A linear model is established for the first bit rate, the second bit rate, the first resolution, and the second resolution corresponding to the first resolution and the second resolution, respectively. The transcoding device according to item 14 of the scope of patent application, wherein the transcoding device further includes: other code rate determination modules, which are used to divide the first among the linear models and the multiple levels of clarity The resolution corresponding to each level of clarity other than the first resolution and the second resolution determines the bit rate value corresponding to the other levels of resolution. For example, the transcoding device according to item 14 of the scope of patent application, wherein the transcoding device further includes: a second judgment module; used to judge whether the bit rate value corresponding to each level of definition is less than or equal to the The level of definition corresponds to the preset upper limit bit rate threshold. For example, the transcoding device according to item 16 of the scope of patent application, wherein, when the judgment result of the second judgment module is no, the transcoding device further includes: a target level definition determining module and a resolution first 2. an adjustment module; the target definition module is used to determine the definition of the target level whose bit rate value is greater than the corresponding preset upper limit bit rate threshold among the plurality of levels of definition; The second resolution adjustment module is used to determine the adjusted resolution corresponding to the definition of the target level according to the upper limit bit rate threshold corresponding to the definition of the target level and the linear model; Preferably, the transcoding module is further configured to transcode the untranscoded part of the media file according to the resolution adjusted by the second resolution adjustment module.

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