US 7,321,602 B2
Apparatus and method for inserting null packet in digital broadcasting transmission system
Byungjun Bae, Daejeon (Korea, Republic of); Joonyoung Choi, Daejeon (Korea, Republic of); Jinhwan Lee, Daejeon (Korea, Republic of); Youngkwon Hahm, Daejeon (Korea, Republic of); and Chieteuk Ahn, Daejeon (Korea, Republic of)
Assigned to Electronics and Telecommunications Research Institute, (Korea, Republic of)
Filed on Apr. 04, 2003, as Appl. No. 10/407,571.
Claims priority of application No. 10-2002-0060991 (KR), filed on Oct. 07, 2002.
Prior Publication US 2004/0008736 A1, Jan. 15, 2004
Int. Cl. H04J 3/12 (2006.01)
U.S. Cl. 370—528  [386/111; 725/135] 8 Claims
OG exemplary drawing
 
1. A method for inserting a null packet in a digital broadcasting transmission system, the method comprising:
(a) removing an irregularly inserted null packet from an externally received video/audio transport stream;
(b) calculating a bit rate of the removed null packet and determining the transmission period of a periodic null packet to be newly inserted in a range not exceeding the calculated bit rate of the null packet;
(c) generating a periodic null packet according to the determined transmission period;
(d) regularly inserting the periodic null packet preferentially and then inserting the video/audio transport stream with the irregular null packet removed, and performing multiplexing;
(e) generating a non-periodic null packet and inserting the generated non-periodic null packet, when an output rate of the multiplexed transport stream is not equal to an input rate of the externally received video/audio transport stream;
(f) correcting a changed PCR (Program Clock Reference) value of the multiplexed transport stream and outputting the corrected PCR value;
(g) temporarily storing the video/audio transport stream, with the irregular null packet removed, in the units of a packet of a predetermined size, and outputting a stream flag signal when the stored video/audio transport stream exceeds at least one packet; and
(h) temporarily storing the generated periodic null packet in the units of a packet of a predetermined size, and outputting a packet flag signal when the stored null packet exceeds at least one packet.