JP2020022082A - Stream distribution system with segment file division function and program - Google Patents

Abstract

To provide a stream distribution system capable of exchanging a specific content such as advertisement for distribution in real time without causing content disorder.SOLUTION: A content distribution system 200 receives a broadcasting audio stream and a control signal at a broadcasting station and executes content data division (preparation of segment file) using timing of content exchange in a media center executing IP radio distribution, thereby achieving exchange in real time without causing content disorder in exchange distribution of a specific content such as advertisement.SELECTED DRAWING: Figure 1

Description

  The present invention relates to time management and a segment file division method in a stream distribution system. Specifically, in an HLS (HTTP Live Streaming) stream distribution system, when performing a streaming distribution based on a segment file described in a meta file (playlist or the like), the streaming distribution is interrupted at a designated time. The present invention relates to an HLS stream distribution system and a program having a segment file division function, which enables another content such as a CM to be inserted.

  A service for simultaneously distributing radio broadcasts in the same time zone via an IP network such as the Internet is called IP simulcast. In the case of radio, it is also called IP simul radio. For example, as shown in FIG. 6, in a media center that relays and distributes live content (for example, a radio audio signal) provided by a content provider of a broadcasting station (radio station or the like), audio and video data is encoded by an encoder. Then, the content is distributed to viewers (listeners), which may be called users, via the distribution server. Audio and video data can be converted into data every several seconds (segmented) and transmitted to the server by a segmenter.

  In a broadcast content distribution system such as an IP simul radio, a service for replacing specific content such as an advertisement is required. In particular, when distributing to an area different from an area where a broadcasting station exists, an initially created advertisement is distributed. There is a high need to replace and distribute to the one suitable for the destination area. As a conventional technique for meeting such needs, for example, there is a technique of replacing a radio program in an automatic program control device in a radio station (Patent Document 1). This method can reduce replacement work by sharing table information in program production.

  In addition, an IP radio distribution system that can insert and replace an advertisement at a specified time based on a schedule table (Patent Literature 2), or replace a content whose distribution time is unknown without the need for a schedule table or the like Content distribution system (Patent Document 3).

JP-A-6-112912 Japanese Patent No. 4647879 Japanese Patent No. 6254500

  However, in the prior art, the content is replaced in advance at each of the original broadcasting stations (transmission facilities), and the media center relays and distributes the content as it is (for example, Patent Document 1), so that the media center determines the content in real time. And couldn't replace it.

  Also, in the case of contents such as dramas, each broadcasting station can set in advance when to insert a CM, and can perform replacement based on the time schedule data. There was a problem that the time could not be set in advance. For example, the IP radio distribution system described in Patent Literature 2 cannot deal with such a problem because a schedule table including a distribution time is required to detect a content to be replaced.

  Furthermore, in a media center that relays and distributes, after encoding audio and video data, it is segmented and distributed to a viewer (listener) via a distribution server (for example, described in Patent Document 3). The data is summarized for each degree. Therefore, if segmentation is performed normally, it will be cut at a place other than the break of the CM, and unnecessary screens and sounds will be seen or heard at the joint of content switching, switching will occur in the middle of the content, etc. A trouble such as a situation may occur. Hereinafter, description will be made by taking an IP simultaneous radio as an example, and the same applies to moving image distribution and television broadcasting if audio is replaced with video.

  In order to solve the above-described problems, in the present invention, a media center that performs IP radio distribution receives a data stream obtained by converting a broadcast audio signal into IP and information obtained by converting a control signal from a broadcast station into IP, and performs content switching. By performing content data division (segment file creation) using the timing of (1), segmentation in accordance with content control during broadcasting is realized, and in replacement delivery of specific content such as advertisements, replacement without disruption of content. A content distribution system and a program (hereinafter referred to as a content distribution system, etc.) that can be executed in real time.

As one embodiment of the content distribution system according to the present invention, the content distribution system encodes stream data to generate encoded data;
A segmenter that divides the encoded data at a constant segment duration to generate a segment file;
A delay circuit that receives the stream data or the encoded data as input data, and delays and outputs the input data;
Including
The segmenter receives content control data,
The stream data and the content control data are provided with a time stamp by the same clock function,
The segmenter, when finding encoded data corresponding to a baseband signal generated at the same time as the occurrence time of the content control data, divides the encoded data at a timing based on the content control data, and divides the segment file. It is characterized by generating.

  As a preferred embodiment of the content distribution system according to the present invention, the delay circuit is provided before the encoder, and receives the stream data as the input data.

  As a preferred embodiment of the content distribution system according to the present invention, the delay circuit is provided between the encoder and the segmenter, and receives the encoded data as the input data.

  As a preferred embodiment of the content distribution system according to the present invention, the content control data is an ignition signal indicating a timing for replacing content in the stream data or CM ON / OFF data in the stream data. And

  As a preferred embodiment of the content distribution system according to the present invention, the segmenter generates a segment generated before the timing based on the content control data when the encoded data is divided at the timing based on the content control data. The file is merged with the previous segment file.

  As a preferred embodiment of the content distribution system according to the present invention, the segmenter, at the timing based on the content control data, when the encoded data is divided, until the next content control data is received, the subsequent encoded data It is characterized in that a segment file is generated by dividing at a fixed segment duration time.

As a preferred embodiment of the content distribution system according to the present invention, the segmenter generates a segment generated before the timing based on the content control data when the encoded data is divided at the timing based on the content control data. Merge the file with the previous segment file,
The segmenter, at the timing based on the content control data, when dividing the encoded data, delays the fixed division timing by the time of the segment file generated before the timing based on the content control data,
The encoding data after the timing based on the content control data is divided at the fixed division timing delayed to generate a segment file.

  As a preferred embodiment of the content distribution system according to the present invention, the segmenter generates a segment file generated after the timing based on the content control data when the encoded data is divided at the timing based on the content control data. Is merged with the segment file immediately after the segment file.

  In a preferred embodiment of the content distribution system according to the present invention, the segmenter generates a metafile in which a time length and a URL of one or more generated segment files are recorded.

  As a preferred embodiment of the content distribution system according to the present invention, the URL of one or more segment files recorded in the meta file is rewritten to a new URL pointing to another segment file, so that one of the contents in the stream data is rewritten. It is characterized in that the part is replaced with another content.

  As one embodiment of the program according to the present invention, the program is executed by a computer so that the computer functions as the content distribution system.

  The content distribution system and the like according to the present invention enables replacement without disturbing content in replacement delivery of specific content such as an advertisement in real time. Thereby, the media center (IP radio distribution company) can perform a service of automatically replacing and distributing contents such as advertisements.

1 is a conceptual diagram illustrating a configuration of a content distribution system according to an embodiment of the present invention. FIG. 3 is a conceptual diagram showing an outline of segmentation of an audio stream using content control data. FIG. 3 is a diagram showing the contents of a metafile (playlist) of a segment file generated by the segmentation of FIG. 2. FIG. 9 is a sequence diagram illustrating an operation of a program that performs a process of segmenting an audio stream using content control data. It is a conceptual diagram which shows the modification of segmentation of an audio stream. It is a conceptual diagram which shows another modification of segmentation of an audio stream. FIG. 11 is a conceptual diagram showing a configuration of a content distribution system that performs segmentation without replacing the content of an audio stream in conventional streaming distribution. FIG. 9 is a conceptual diagram showing a problem of segmentation that may occur when an attempt is made to replace the content of an audio stream based on an ignition signal in conventional streaming distribution.

  An embodiment of the present invention will be described below with reference to the drawings. In all the drawings for describing the embodiments, the same components are denoted by the same reference numerals in principle, and the repeated description thereof will be omitted. The individual embodiments of the present invention are not independent, and can be appropriately implemented in combination with each other.

  FIG. 7 conceptually shows a configuration of a content distribution system that performs segmentation without replacing the content of an audio stream in conventional streaming distribution. 2. Description of the Related Art Conventionally, a radio station, which is a content provider, flows a baseband signal (digital or analog electric signal) of audio, which is distribution content, into a station side distribution device 800, thereby transmitting a wide area IP network (Internet, dedicated Transmission to the media center via a wire. The station side distribution device 800 includes a signal remote transmission unit 805 having a signal remote transmission function. The baseband signal is transmitted as stream data by the signal remote transmission function of the signal remote transmission unit 805.

  The media center receives the stream data corresponding to the baseband signal (audio) by the content distribution system 900, and distributes and provides the viewer almost simultaneously via the Internet without changing the content of the program or the like. Distributing the same content as broadcast by radio waves over an IP network such as the Internet is called simultaneous parallel broadcasting (simultaneous broadcasting), particularly IP simultaneous broadcasting.

  The provision of multimedia contents such as sound and video via the Internet is a method that uses the HTTP protocol that is compressed and converted (encoded) into a format suitable for computers and smartphones and that is widely used for information distribution. RFC 8216) is commonly used. In the HLS, encoded minute stream data is packed on a time axis to generate a large chunk file in seconds and distributed by HTTP.

  Here, creating this block is called segmentation, and each generated file is called a segment file. The length (length) of the signal stored in the segment file is constant and is a file of several seconds to several tens of seconds. Since the generality is not lost even if the length of the segment file is set to 10 seconds, the length of the segment file is assumed to be 10 seconds for convenience unless otherwise specified.

  Content distribution system 900 includes an encoder 910 and a segmenter 920. A program that performs encoding (or a functional block or system in the program) is called an encoder, and a program that performs segmentation (or a functional block or system in the program) is called a segmenter. Stream data transmitted from a broadcast station is encoded by an encoder 910 and segmented by a segmenter 920.

  In the conventional example of streaming distribution as shown in FIG. 7, the content distribution system 900 in the media center cannot distribute and provide a part of the provided broadcast content such as a CM or a program on the Internet as it is. In order to perform the replacement, timing information of the switching point is required, and therefore, it is necessary to receive, from the broadcasting station as the content provider, an ignition signal indicating the timing separately from the baseband signal.

  In the conventional example shown in FIG. 7, the delay occurs due to the IP stream transmission in the wide area IP network by the signal remote transmission function of the signal remote transmission unit 805 and each processing of the encoder 910 and the segmenter 920, and the original baseband signal is generated. There is a problem that the time is lost in the segment file. Therefore, even if the content distribution system 900 of the media center acquires the replacement timing from the broadcasting station that is the content provider, it is difficult to identify the replacement point on the segment file.

  In order to solve such a problem, it is considered that when a signal is generated at a broadcasting station which is a content provider, the time is stamped on the signal (with a time stamp added) and the signal is transmitted remotely. Can be FIG. 8 shows an example of an attempt to replace the content of an audio stream based on an ignition signal in conventional streaming distribution.

  In the conventional example shown in FIG. 8, the station side distribution device 800 has a time stamp having a stamped signal remote transmission function for adding a time stamp to a baseband signal (voice) and transmitting the signal instead of the signal remote transmission function. Stamp-added signal remote transmission unit 810 and additional information transmission unit 820 having an additional information transmission function for adding a time stamp to content control data and transmitting the content control data so that the replacement timing of audio content in the baseband signal can be specified. And a clock unit 830 having a clock function for generating the time of the time stamp. The timer 830 provides the same time stamp to the time stamp additional signal remote transmitter 810 and the additional information transmitter 820 so that the replacement timing of the content can be specified.

  Since the baseband signal is generated from time to time in real time, the timestamp-added signal remote transmission unit 810 performs time-stamping based on the time generated by the clock unit 830 (adds a timestamp). In the content distribution system 900 that has received the stream data corresponding to the baseband signal, since the time information is lost by the encoder 910, the data at which point the data encoded by arbitrating between the encoder 910 and the segmenter 920 is data. Is required.

  The segmenter 920 generates an HLS based on a set of arbitrated and linked time stamps and encoded data (called “encoded data”) (a minute time). In HLS, *. Time information can be described by m3u8 (meta file) or the file name of a segment file.

  The time information of the segment file is the first time and the last time of the signal in the file. These are called start time and end time. Further, the information may be two sets of information from which two points such as a start time and an end time can be derived and specified.

  In the conventional example shown in FIG. 8, replacement can be attempted based on a segment file having accurate time information and replacement firing information included in content control data such as a firing signal or CM ON / OFF data. A break in the segment file whose start time (end time) is closest to the replacement timing is the replacement location. The segment file group sandwiched between the replacement portions may be replaced with a file having another content.

  However, since the length of a segment file is, for example, 10 seconds (at least several seconds), a deviation from the ideal replacement point in units of seconds often occurs. As shown in FIG. 7, this deviation is generated at the joint of content switching. Unnecessary sounds can be heard or necessary sounds are missing, resulting in a fatal shift in viewing. In order to prevent such a fatal deviation, there is a method of editing a file including an ideal replacement point, calculating the ideal replacement point in the file, and writing another content to be replaced. It is not realistic considering the amount and processing time.

  In order to solve the problem of the gap between the segment file breaks (splits) and the replacement timing as shown in FIG. 8, the segmenter is provided with a function of dividing the segment file at an arbitrary time, as shown in FIG. A distribution system is required. FIG. 1 conceptually shows a configuration of a content distribution system according to an embodiment of the present invention.

  The radio station, which is a content provider, transmits an audio baseband signal, which is distribution content, and content control data (for example, an ignition signal, CM ON / OFF data) including information for designating a replacement part in the distribution content. It can be transmitted to a media center via a wide area IP network (Internet / dedicated line) by IP stream transmission.

  The station-side distribution apparatus 100 of the content provider has the same configuration as the station-side distribution apparatus 800 shown in FIG. 8, and transmits a baseband signal (voice) with a time stamp added thereto instead of the signal remote transmission function. A time stamp added signal remote transmission unit 110 having a stamp added signal remote transmission function for transmitting a time stamp added to the content control data so as to be able to designate an audio replacement timing in the baseband signal. It includes an additional information transmission unit 120 having an additional information transmission function and a clock unit 130 having a clock function for generating a time of a time stamp. The timer 130 provides the same timestamp time to the timestamp-added signal remote transmission unit 110 and the additional information transmission unit 120 so that the replacement timing of the content can be specified.

  In the media center, it is necessary to receive firing information from the outside and prepare a segmenter for dividing the segment file at the timing. Specifically, the segmenter 230 included in the content distribution system 200 of the media center always observes the generation time of the signal corresponding to the encoded data (encoded data).

  The segmenter 230 divides the encoded data, which is a broadcast audio stream, by a predetermined fixed segment duration (for example, 10 seconds) to generate a segment file. The segmenter 230 can divide the encoded data and generate a segment file based on the timing specified by the content control data in addition to the fixed segment duration.

  That is, the segmenter 230 uses the content control data (ignition signal, CM ON / OFF data) measured by a content provider such as a broadcasting station, and responds to the baseband signal generated at the same time as the content control data. When the encoded data is found, the encoded data is divided at a timing based on the content control data to generate a segment file.

  Here, since the stream data (in other words, the IP stream transmission data) that transmitted the baseband signal and the content control data such as the ignition signal arrive separately, their order and synchronization are not guaranteed. Therefore, the content distribution system 200 includes a delay circuit 210 such as a buffer for delaying the timing of inputting stream data to the encoder 220 or the segmenter 230.

  The content distribution system 200 divides the encoded data by using the delay circuit 210 to ensure that the firing information included in the content control data arrives at the segmenter 230 first and observes the delayed encoded data based on the ignition information. Thus, a segment file can be generated.

  In one embodiment of the present invention shown in FIG. 1, a delay circuit is provided as a delay circuit 210 before an encoder 220 to receive stream data as input data and output the input data with a delay of a predetermined time. However, the present invention is not limited to this. The location of the delay circuit is not limited as long as it is before the generation of the segment file, such as before and after the encoder or inside the segmenter. For example, the delay circuit is provided between the encoder and the segmenter, and may receive encoded data, that is, encoded data, as input data, and output the input data with a delay of a predetermined time.

  In the media center, the content distribution system 200 according to one embodiment of the present invention specifies a segment file replacement section and performs replacement of the segment file in the replacement section in comparison with editing the contents of the segment file. When performing the replacement, accurate replacement can be performed by a simple and efficient method of detecting a target segment file and replacing the file in file units.

  In addition to rewriting and exchanging files for replacement, another file corresponding to the replacement section is prepared in advance, and *. It is also possible to replace the segment file in the replacement section with another segment file by changing the file name indicated by the m3u8 metafile to the file name of the different file, and to deliver the replacement file to the viewer. It is a target.

  Here, each function and each configuration in one embodiment of the present invention shown in FIG. 1 will be described. The time stamp added signal remote transmission function of the time stamp added signal remote transmission unit 110 receives a baseband signal (voice) as an input. The baseband signal (audio) is an analog or digital signal (such as a PCM signal) or the like. The output of the timestamp-added signal remote transmission function is an IP packet, and the packet includes an audio signal for a fixed short period of time and the time when the signal is generated. The generation time is recorded in the RTP header using the RTP protocol. May be described.

  The additional information transmission function of the additional information transmission unit 120 receives content control data such as a firing signal and CM ON / OFF data as inputs. The content control data is main part cut / return control information (ON / OFF of a main part cut / return manual switch). The output of the additional information transmission function is an IP packet, which includes the time when the switch was turned ON / OFF.

  The timekeeping function of the timekeeping unit 130 is a system call such as a system clock or a real-time clock of the OS, which receives a time request command as input and returns time as output.

  The delay circuit 210 can be realized by, for example, a FIFO buffer in a program. The input to the delay circuit is the contents of an IP packet group (stream) output by the time stamp-added signal remote transmission function, and is a set of time information and an audio signal for a certain minute period. The output from the delay circuit 210 is an input after a predetermined period of time (for example, one second to several minutes) has elapsed.

  Encoder 220 receives a digital signal as input. The output of the encoder 220 is audio data after compression conversion.

  The content distribution system 200 includes a time stamp information linking function. The time stamp information linking function measures or compensates for the delay of the encoder 220, and synchronizes the encoder data with the generation time (time stamp) of the corresponding signal. Function. This function receives time information and a set of audio signals for a certain minute period, etc., which are the contents of an IP packet group (stream) output by the time stamp added signal remote transmission function, and synchronizes the encoded data with the corresponding time stamp. And hand over the pair to the segmenter.

  The segmenter with division control function 230 at an arbitrary timing receives the encoded data and the time stamp as the first input, and receives the firing information as the second input. The output of the segmenter 230 is an HLS file group (* .m3u8 and a segment file group). However, the HLS file group reflects a time stamp generated at a broadcasting station and, as shown in FIG. The file is divided at the time according to the firing information (timing based on the content control data) in addition to the normal segmenter division pace (constant segment duration).

FIG. 2 shows an outline of segmentation of an audio stream using content control data. Although an audio stream is used as the stream data in FIG. 2, the present invention is not limited to this, and may be a video stream or the like. As shown in FIG. 2, in segmentation in the conventional streaming, encoded data, which is a broadcast audio stream, is divided by only a fixed segment duration, and the segment duration ΔT (for example, 10 seconds) is used. Can be generated. The horizontal axis shown in FIG. 2 is a time axis, and the broadcast audio stream is divided by segment file start times ST _m , ST _{m + 1} , ST _{m + 2} , and ST _{m + 3} (m is a natural number).

In the segmentation using the content control data of the present invention shown in FIG. 2, the encoded data is divided at a timing based on the content control data in addition to the fixed segment duration time ΔT, and the segment file (for example, SG104) Can be generated. 2, the content control data, in the case of ON / OFF data of the CM divides the broadcast audio stream CM start time TT _x (x is a natural number), shorter than the normal length ( generating a segment file (SG105) of TT _x) from ST _m. TT _x subsequent broadcast audio stream is divided at a certain segment duration [Delta] T, segment file (SG106) is generated from TT _x at scale of ST m _{+ 1.} Also, at the CM end time TT _{x + 1} , similarly, the broadcast audio stream is divided, and a segment file is generated from ST _{m + 3} to TT _{x + 1} .

FIG. 3 shows the content of a metafile (playlist) of an audio stream when segmented using the content control data. The information on the segment file SG _n (n is a natural number) in the playlist (m3u8 file) is composed of two lines. It represents. “/ Ts / audio / xxx / ts / SG102” on the second line is the URL of the segment file. Although not shown in FIG. 3, in the embodiment using the m3u8 file, the start time (dataTs) of the segment file can be described in the m3u8 file.

“#EXTINF: TTx-STm” “/ ts / audio / xxx / ts / SG105” and “#EXTINF: ΔT- (TTx-STm)” “/ ts / audio / xxx / ts / SG106” in the playlist , received a firing signal at segment file SG105 generated _{(ST m <TT x <ST} m + ΔT) example represents a (see FIG. 2), CM start time (ignition signal generation time) TTx in divided segment files SG105 And the length and URL of the SG 106 (see FIG. 2). By rewriting the URL in the playlist, for example, “/ ts / audio / xxx / ts / SG106” is changed to another URL, and the subsequent segment file before the CM end time TT _x +1 is similarly changed. By changing the URL, it is possible to replace a content such as a CM with another content. That is, by replacing the URL of one or more segment files recorded in the metafile with a new URL indicating another segment file, a part of the content in the audio stream (stream data) is replaced with another content. Can be.

  FIG. 4 is a sequence diagram of a process of segmenting the audio stream using the content control data. This processing is executed by the segmenter 230 of the content distribution system 200, for example. In the sequence diagram of FIG. 4, the segment controller (Segment Controller) confirms whether or not the segment file can be continued with the time keeper (TimeKeeper) (executes canContinue (ts)). Add encoded data (write (mmData) execution). If not continued (OPT continue = no), incrementHls (dataTs, mmData) instruction is sent to the HLS handler (HlsHandler) to cut the segment file, and then add the encoded data to the new segment file (write (mmData) execution) .

  The time keeper (TimeKeeper) divides the segment file in response to the segment file continuation confirmation (canContinue (ts)) from the segment controller (if the time data corresponding to the firing time of the content control data is found or the segment No is returned for the duration ΔT), and yes is returned when the segment file is continued without division. TimeKeeper always accepts registration of firing time (desired time of segment file cutting) by setCutTiming (cutTs).

  When dividing the segment file (OPT continue = no), the segment controller sends an incrementHls (dataTs, mmData) instruction to the HLS handler.

  The HLS handler executes updateM3u8 (dataTs, FileName) to write the information of the segment file currently being written to the playlist, and sends an increment (newFileName) instruction to the file handler (FileHandler).

  The file handler executes closeOld () to close the open segment file, and then executes createNew () to open the next segment file. By the process shown in FIG. 4, as shown in FIG. 2, a plurality of segment files in which the broadcast audio stream (encoded data) is divided and stored is generated.

  FIG. 5 is a conceptual diagram showing a modification of the segmentation of the audio stream. The first and second stages from the top, that is, the segmentation in the conventional streaming and the segmentation (a1) using the content control data of the present invention are the same as the segmentation shown in FIG. 2 and have already been described. It is as follows.

One variation of segmentation using the content control data (ignition signal) of the present invention (a2) includes a base and made division timing (ST _m), broadcast audio stream in both the firing signal (TT _x) ( encoded data) is divided and can be merged small files made before TT _x to the previous segment file (SG104). In other words, variation (a2) at the timing (TT _x) based on the content control data, upon dividing the encoded data, the segment files generated before the timing (TT _x) based on the content control data, It can be merged with the immediately preceding segment file (SG104).

Another modification (b1) is that, when the broadcast audio stream (encoded data) is divided by the firing signal (TT _x ), the broadcast audio stream (TT _x ) is kept constant until the next firing signal (TT _{x + 1} ) is received. Subsequent encoded data can be divided into segment files (SG106, SG107, etc.) for each segment duration ΔT, which is the time interval of the division timing. In other words, another modified example (b1) has a timing (TT _x ) based on the content control data (ignition signal), and when the encoded data is divided, before the timing (TT _x ) based on the content control data. only generated segment file (SG105) time (TT _x -ST _m), certain segments duration _{((TT x -ST m) +} ST m + 1) a delayed timing based on the content control data (TT _x encoded data later than), it is divided at a certain segment duration delayed _{((TT x -ST m) +} ST m + 1), can generate a segment file (SG106, SG107, etc.).

Still another modification (b2) is a combination of the modification (a2) and the modification (b1). That is, the broadcast audio stream (encoded data) is divided by both the base division timing (ST _m ) and the firing signal (TT _x ), and the small file created before TT _x is divided into the previous segment file (SG104). ), And when the broadcast audio stream (encoded data) is divided by the firing signal (TT _x ), thereafter, a fixed division timing is received until the next firing signal (TT _{x + 1} ) is received. For each segment continuation time ΔT, which is the time interval of, the subsequent encoding data is divided to generate segment files (SG105, SG106, etc.).

FIG. 6 is a conceptual diagram showing still another modification of the segmentation of the audio stream. Another modification (c) is that the broadcast audio stream (encoded data) is divided by both the base division timing (ST _m ) and the firing signal (TT _{x + 1} ), and the division is made after TT _{x + 1.} The small file can be merged with the segment file (SG109) immediately after the small file. In other words, when the segment file (main part file, SG109 shown in the middle) generated at the base division timing (ST _{m + 3} ) after the CM end timing (TT _{x + 1} ) is small (for example, The file (main file) has a segment duration less than half of the normal segment duration ΔT, and is merged with the immediately following segment file (SG110 shown in the middle) to form a large segment file (shown in the lower). SG109) can be generated.

  As described above, the content distribution system of the present invention can flexibly change the length of the segment file in accordance with the section requiring replacement in the replacement delivery of specific content such as advertisements in real time. At the point when there is no such content, the content can be replaced. As a result, the media center (for example, an IP radio distribution company) can perform a service of automatically replacing and distributing contents such as advertisements, and the broadcasting company can replace a content such as CM at a broadcasting station. It is not necessary to perform the operations individually, and the operation work can be made efficient.

  In the embodiments shown in FIGS. 2, 5 and 6, switching of CMs is described as an example, but the present invention can be applied to switching between a relay program and a local station program in addition to CMs. In addition, the system configuration, the configuration of the remote station, the type of digital broadcast signal to be handled, the switching procedure, and the like can be variously modified without departing from the scope of the present invention. The content control data is the information on the ON and OFF of the CM. However, since the OFF time of the CM can be known from the ON time of the CM and the time of the CM content, division using this may be performed.

  The firing signal is a signal generated by an electrical switch (contact) generally used in a broadcasting station, but is not essential and is not limited to this method. A content provider such as a broadcasting station may transmit an IP packet containing ignition information. Alternatively, the broadcast station may embed an invisible or inaudible mark in the sound or the switching timing of the switchable section, detect the timing somewhere along the route to the segmenter, and pass it to the segmenter. In this case, an arbitration circuit (function) for integrating and converting various types of firing information is provided at the preceding stage so that information can be delivered in the form of a firing signal suitable for the segmenter with the division control function at an arbitrary timing.

  In the content distribution system according to one embodiment of the present invention, for example, various programs related to content distribution are stored in a storage device, and these programs are controlled by a control unit (CPU), a memory, or the like as necessary. The data is read and transferred to the RAM, and read and executed by the CPU. In this way, by causing a computer to execute various programs related to content distribution, the computer can function as a content distribution system. Further, at least a part of the function of the content distribution system can be implemented in hardware by an application specific integrated circuit (ASIC) or the like.

  A content distribution system or the like according to the present invention relies on a system unique to each broadcast station in a media center that relays and distributes content (for example, radio content) transferred from a content provider of a broadcast station (radio station or the like). Instead, it is used to replace a specific part (for example, a CM part) of the content.

REFERENCE SIGNS LIST 100 Station-side distribution device 110 Time stamp-added signal remote transmission unit 120 Additional information transmission unit 130 Clock unit 200 Content distribution system 210 Delay circuit 220 Encoder 230 Segmenter 800 Station-side distribution device 805 Signal remote transmission unit 810 Time stamp-added signal remote transmission unit 820 additional information transmission unit 830 clock unit 900 content distribution system 910 encoder 920 segmenter

Claims (11)

An encoder that encodes the stream data to generate encoded data;
A segmenter that divides the encoded data at a constant segment duration to generate a segment file;
A delay circuit that receives the stream data or the encoded data as input data, and delays and outputs the input data;
Including
The segmenter receives content control data,
The stream data and the content control data are provided with a time stamp by the same clock function,
The segmenter, when finding encoded data corresponding to a baseband signal generated at the same time as the occurrence time of the content control data, divides the encoded data at a timing based on the content control data, and divides the segment file. A content distribution system characterized by generating. The content distribution system according to claim 1, wherein the delay circuit is provided before the encoder, and receives the stream data as the input data. The content delivery system according to claim 1, wherein the delay circuit is provided between the encoder and the segmenter, and receives the encoded data as the input data. The content according to any one of claims 1 to 3, wherein the content control data is an ignition signal for replacing content in the stream data or ON / OFF data of a CM in the stream data. Delivery system. When the encoded data is divided at a timing based on the content control data, the segmenter merges a segment file generated before the timing based on the content control data with a previous segment file. The content distribution system according to any one of claims 1 to 4, wherein: When the encoded data is divided at the timing based on the content control data, the segmenter generates a segment file by dividing subsequent encoded data at the fixed segment duration until receiving the next content control data. The content distribution system according to any one of claims 1 to 4, wherein The segmenter, at the timing based on the content control data, when the encoded data is divided, the segment file generated before the timing based on the content control data, merged with the previous segment file,
The segmenter, at the timing based on the content control data, when dividing the encoded data, delays the fixed division timing by the time of the segment file generated before the timing based on the content control data,
5. The segment file according to claim 1, wherein the encoded data after the timing based on the content control data is divided at the constant divided timing that is delayed to generate a segment file. Content distribution system. When the encoded data is divided at a timing based on the content control data, the segmenter merges a segment file generated after the timing based on the content control data into a segment file immediately after the segment file. The content distribution system according to any one of claims 1 to 4, wherein: The content distribution system according to any one of claims 1 to 8, wherein the segmenter generates a metafile in which a time length and a URL of one or more generated segment files are recorded. A part of the content in the stream data is replaced with another content by rewriting the URL of one or more segment files recorded in the metafile to a new URL pointing to another segment file. The content distribution system according to claim 9.   A program that causes a computer to function as the content distribution system according to any one of claims 1 to 10 by being executed by the computer.

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