JP2014230178A - Ts smoothing output method in ip encapsulation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an IP encapsulation method capable of suppressing instantaneous bit rate increase of a TS by solving the problem that, in a conventional IP rate smoothing method, when encapsulating one IP packet into a plurality of TS packets, a bit rate of the TS in that moment is increased.SOLUTION: The IP encapsulation method is characterized in that TS packets are not outputted in a burst manner but are outputted at a fixed bit rate within a fixed period of time.

Description

  The present invention relates to an apparatus (IP encapsulation apparatus) that encapsulates an IP (Internet Protocol) packet into a TS (Transport Stream) packet. Even when “encapsulated in TS packet”, the present invention relates to a method capable of smoothing and outputting the output after encapsulating in TS packet.

  When the input IP packet stream is received in a burst manner, the conventional IP encapsulation apparatus is affected by this and the TS packet output also becomes a burst. When the packet length of an IP packet is large, one IP packet is encapsulated into a plurality of TS packets and output, but the plurality of TS packets at that time are output in bursts.

  When connecting an IP-encapsulated TS stream to a multiplexer, a modulator, or the like, if the TS packet is output in a burst manner as described above, the TS bit rate instantaneously increases, and another TS (for example, (Video / Audio) may be adversely affected (TS packet loss due to buffer failure, etc.).

  A conventional IP shaper (IP rate smoothing device) is a device that suppresses bursts of an IP packet stream, and thus is not effective when one IP packet is encapsulated into a plurality of TS packets and output.

JP 2003-273915 A

  However, the conventional IP rate smoothing apparatus has a problem that when one IP packet is encapsulated in a plurality of TS packets, the TS bit rate at that moment increases.

  An object of the present invention is to provide an IP encapsulation method capable of solving the above problems and suppressing an instantaneous TS bit rate increase.

  In order to solve the above problem, the IP encapsulation method of the present invention is characterized in that TS packets are output at a constant bit rate in a certain period without being output in bursts.

  According to the present invention, even when one IP packet is encapsulated into a plurality of TS packets for smoothing when TS packets are output, the TS bit rate at that moment does not increase. It is possible to transmit without affecting the TS.

  According to the present invention, even when one IP packet is encapsulated in a plurality of TS packets, the output TS stream is smoothed, so that it may adversely affect other TS streams when connected to a subsequent device. There is no effect.

It is a figure of the packet output timing of the IP encapsulation process using the conventional IP shaper. It is a figure of the transmission TS rate after the reception IP rate and smoothing by this invention. It is a flowchart figure of TS smoothing function by the present invention.

  The present invention will be described below with reference to the drawings.

  First, in the IP encapsulation process using the conventional IP shaper, in FIG. 1, the IP packets 102a to 102c received in a burst form by the IP reception 101 are smoothed by the IP shaper, and the IP packets 112a to 112a of the IP transmission 111 are smoothed. A non-burst IP packet is transmitted as in 112c.

  The IP packets 112a to 112c transmitted by IP are encapsulated in TS in units of received IP packets in the TS transmission 121 after IP encapsulation, and received as TS packets 122a to 122c, 122d to 122e, 122f to 122i. There is a possibility that the bit rate of TS is instantaneously increased because the IP packet is output in bursts.

  Here, in the present invention, when the received IP packet is encapsulated in the TS packet, the transmission TS packet in the smoothing period is buffered and transmitted at an average interval calculated from the number of packets. This makes it possible to transmit TS at a constant bit rate within the smoothing period.

  In FIG. 2, the IP packet received in the smoothing period A201 is encapsulated in TS packets and smoothed, and then TS is transmitted in the output period A211. At that time, the TS transmission is delayed by a fixed delay 214 considering the CPU processing time.

  Similarly, TS output is performed during the smoothing period B202 during the output period B212 and during the smoothing period C203 during the output period C213.

  In FIG. 3, the IP packet received by the IP receiving unit 301 is encapsulated by the IP encapsulation processing unit 302 and converted into a TS packet. The TS packet is transferred to the ring buffer of the TS buffer memory 303.

  The smoothing period notification processing unit 304 notifies the TS buffer memory 303 at intervals of the smoothing period. The TS packet number acquisition processing unit 305 counts the number of TS packets on the TS buffer memory 303. The TS packet transmission interval calculation processing unit 306 calculates the TS packet transmission interval using the number of TS packets and the smoothing period.

  The TS packet transmission time stamp setting processing unit 307 uses the TS packet transmission interval calculated by the TS packet transmission interval processing unit 306 and the current time stamp counter value of the time stamp counter 310 to transmit a transmission time stamp to each TS packet. In addition, the data is transferred to the TS transmission buffer 308.

  The time stamp comparison processing unit 309 compares the current time stamp counter of the time stamp counter 310 with the transmission time stamp added to the TS packet, and the current time stamp counter determines the transmission time stamp added to the TS packet. When exceeding, the TS transmission unit 311 transmits a TS packet.

101 IP reception 102a to 102c reception IP packet 111 IP transmission 112a to 112c transmission IP packet 121 TS transmission 122a to 122i transmission TS packet 201 Smoothing period A
202 Smoothing period B
203 Smoothing period C
211 Output period A
212 Output period B
213 Output period C
214 Fixed delay 301 IP reception unit 302 IP encapsulation processing unit 303 TS buffer memory 304 Smoothing period notification processing unit 305 TS packet number acquisition processing unit 306 TS packet transmission interval calculation processing unit 307 TS packet transmission time stamp setting processing unit 308 TS Transmission buffer 309 Time stamp comparison processing unit 310 Time stamp counter 311 TS transmission unit

Claims (3)

In encapsulation of IP input signal,
An IP receiver for receiving IP packets;
An IP encapsulation processing unit that encapsulates an IP packet into a TS packet;
A smoothing period notification processing unit for notifying the smoothing timing;
A TS buffer memory for buffering TS packets converted by the IP encapsulation processing unit;
A TS packet number acquisition processing unit for acquiring the number of TS packets buffered within the smoothing period;
A TS packet transmission interval calculation processing unit that calculates an average transmission interval from the smoothing period and the number of packets acquired by the TS packet number acquisition processing unit;
A time stamp counter that counts up at a fixed frequency,
A TS packet transmission time stamp setting processing unit that calculates and sets a transmission time stamp from the time stamp counter and the TS packet transmission interval calculation processing unit;
A TS transmission buffer for buffering TS packets set with a time stamp in the TS packet transmission time stamp setting processing unit;
A time stamp comparison processing unit that compares a time stamp of the TS packet in the TS transmission buffer with the time stamp counter and performs a transmission process when a transmission time comes;
A TS transmission unit that transmits a TS packet after performing transmission processing in the time stamp comparison processing unit,
A TS smoothing output method characterized in that TS packets are output at a constant bit rate for a certain period without being output in bursts.   2. The TS smoothed output method according to claim 1, wherein the TS buffer memory stores the IP-encapsulated TS packets in a ring buffer and transfers each TS packet buffered in a smoothing period. 3. The time stamp comparison processing unit compares a transmission time stamp set in the TS packet buffered in the TS transmission buffer with a previous time stamp counter, and transmits the TS packet at a specified transmission timing. The TS smoothing output method according to claim 1.