- From: <bugzilla@jessica.w3.org>
- Date: Wed, 10 Sep 2014 20:52:50 +0000
- To: public-html-bugzilla@w3.org
https://www.w3.org/Bugs/Public/show_bug.cgi?id=26778 Bug ID: 26778 Summary: Section 3 MPEG-2 TS should handle the closed captions case where the caption_services_descriptor is not signaled when caption data is present in the transport stream. Product: HTML WG Version: unspecified Hardware: PC OS: Windows NT Status: NEW Severity: normal Priority: P2 Component: Sourcing In-band Media Resource Tracks Assignee: silviapfeiffer1@gmail.com Reporter: Pat_Ladd2@cable.comcast.com QA Contact: public-html-bugzilla@w3.org CC: mike@w3.org, public-html-admin@w3.org Existing MPEG-2 TS content does not always contain the ‘caption_services_descriptor’ to signal when captions are present. Caption tracks should be sourced in this case. This can be done as follows: Section 3.2. The CEA 708 caption service [CEA708] as identified by: - A 'Caption Service Descriptor' [ATSC65] in the 'Elementary Stream Descriptors' in the PMT entry for a video stream with stream type 0x02 or 0x1B. - For stream type 0x02, the presence of caption data in the ‘user_data()’ field [ATSC52]. - For stream type 0x1B, the presence of caption data in the ‘ATSC1_data()’ field [SCTE128-1]. Section 3.3. Language: @kind is “captions”: - Content of the 'language' field for the caption service in the 'Caption Service Descriptor’. - If a ‘caption_service_descriptor()’ is not present: o @language of the audio track where @kind is “main” for the first caption service o The empty string for all other caption services [ATSC52] http://www.atsc.org/cms/standards/a53/a_53-Part-1-6-2007.pdf [SCTE128-1] http://www.scte.org/documents/pdf/Standards/ANSI_SCTE%20128-1%202013.pdf -- You are receiving this mail because: You are the QA Contact for the bug.
Received on Wednesday, 10 September 2014 20:52:53 UTC