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Specialist Group on Video/Audio Coding
This web page is intended for archive purposes only. Current PC activities can be found on the ATSC Enterprise site: http://members.atsc.org.
The Specialist Group on Audio and Video Coding, under the supervision and direction of the Technology and Standards Group (TSG), develops recommendations for audio and video coding for use in the ATSC television system.
TSG/S6, as directed by TSG, has the following work items:
  1. Address implementation issues:
    • Audio levels assigned to S6-3
    • Audio/video synchronization issues assigned to S6-4
    • Maintain liaison with S8 for any transport issues identified.
  2. Maintain liaison with both CEA and SMPTE work in areas of closed captions and AFD/bar data
    • Coordinate with TSG/S13 on caption related questions
  3. Maintain current Candidate Standards
    • CS-TSG-674 Amendment 2 to A/53 Part 4
  4. Resolve ballot comments, if any, on Parts 1 of A/72 and A/73
  5. Roll A/63 (50 Hz) formats into A/53 Part 4, A/72 Part 1, and A/73 Part 1 as applicable.
  6. Maintain other ATSC audio and video coding documents
  7. Maintain liaison with S4 and S4-3 on M/H codecs
Patrick Waddell (Harmonic) chairs this Specialist group.
Next Meeting
S6 meets frequently but irregularly. Please check the ATSC Web site Meetings Page for a complete list of upcoming meetings. The web page you are currently reading is typically updated less frequently than meetings actually occur.
Ad-hoc groups
S6-3 (Audio Loudness, Chaired by Jim Starzynski, NBC Universal)
S6-4 (Audio/Video Synchronization Issues, Chaired by John Henderson, Hitachi)
Minutes
2002 2003 2004 2005
October 7, 2002
October 30,2002
February 19, 2003
March 26, 2003
April 22, 2003
May 2, 2003
May 9, 2003
May 14, 2003
May 19, 2003
June 10, 2003
June 20, 2003
July 8, 2003
July 23, 2003
August 11, 2003
August 18, 2003
August 25, 2003
September 26, 2003
October 10, 2003
October 31, 2003
November 7, 2003
November 17, 2003
December 15, 2003
December 19, 2003
January 5, 2004
January 12, 2004
January 23, 2004
January 30, 2004
February 17, 2004
February 23, 2004
August 18, 2004
September 8, 2004
September 13, 2004
October 27, 2004
November 4, 2004
November 22, 2004
December 3, 2004
December 13, 2004
December 20, 2004
January 5, 2005
January 14, 2005
February 4, 2005
February 17, 2005
February 25, 2005
March 11, 2005
March 31, 2005
April 27, 2005
May 4, 2005
May 23, 2005
June 8,, 2005
June 22, 2005
August 3, 2005
August 17, 2005
August 31, 2005
October 6, 2005
November 14, 2005
November 22, 2005
December 1, 2005
2006 2007 2008
3 January 2006
23 January 2006
13 February 2006
13 March 2006
3 April 2006
1 May 2006
19 May 2006
10 July 2006
31 July 2006
15 August 2006
25 August 2006
6 October 2006
30 October 2006
28 November 2006
8 January 2007
12 February 2007
23 February 2007
21 March 2007,
continued 27 March

24 April 2007
30 April 2007
24 May 2007
25 June 2007
10 July 2007
13 August 2007
28 August 2007
8 October 2007
29 October 2007
26 November 2007
23 January 2008
29 February 2008 (draft)
14 March 2008 (draft)
4 April 2008 (future)
TSG/S6 Documents
Document Log
TSG/S6 Scope Statement
TSG/S6 Work Statement
Output Documents
TSG/S6 has, over the past several years, produced several Amendments to the ATSC Standards, as well as several Candidate Standard Amendments, affecting both video and audio coding constraints.   S6 has also worked on the subject of advanced video coding.   This lead to the creation of two Candidate Standards, one for SMPTE 421M ("VC-1") and the other for MPEG-4 Part 10 ("AVC") video compression.

    These Candidate Standards each are a Part 1 of two proposed new ATSC Standards (with Part 2 (Transport) being produced by TSG/S8).   These proposed new ATSC Standards are to be A/73 (VC-1) and A/72 (AVC).   Each Part 1 defines the coding constraints for using that new codec in the ATSC system, especially how closed captions and AFD/bar data are to be carried.   Both proposed new Standards are in the ATSC ballot process as of this writing.
Audio Coding
S6-442r2, Draft Amendment 1 to A/53-5 and A/53-6:   "Part 5 - AC-3 Audio System Characteristics," and   "Part 6 - Enhanced AC-3 Audio System Characteristics"   became CS-TSG-757r0 and CS-TSG-758r0 respectively   (see the ATSC Candidate Standards pages).

    The purpose of this amendment (to each Part) is to change the method of measuring the loudness of the average spoken program dialogue from the original "LAeq" method described in ANSI document ANSI S1.4-1983 "Specification for Sound Level Meters", to the method described by ITU-R Recommendation BS.1770, "Algorithms to measure audio programme loudness and true-peak audio level".

    The ITU measurement method agrees more closely with subjective loudness assessments than does the LAeq method.   This is one focus of AHG S6-3's work.
Video Coding
draft CS Part 1 of A/73 for VC-1 (became CS-TSG-658r3)    in the ATSC ballot process
draft CS Part 1 of A/72 for AVC (became CS-TSG-659r4)    in the ATSC ballot process
draft CS Amendment 2 to A/53, Part 4 (became CS-TSG-674r2)
See the ATSC Candidate Standards pages for these documents.
AFD and Bar Data
    Coordinated work with SMPTE and CEA resulted in current Part 4 of A/53-2007.   This Part is posted on the ATSC Standards pages.   Amendment 1 to Part 4 is currently posted as CS-TSG-744r3 (see the ATSC Candidate Standards pages) and is currently in the ATSC ballot process.
Document Archive
T3/S6 2001 Document Archive
T3/S6 2002 Document Archive
T3/S6 2003 Document Archive
T3/S6 2004 Document Archive
TSG/S6 2005 Document Archive
TSG/S6 2006 Document Archive
TSG/S6 2007 Document Archive
TSG/S6 2008 Document Archive