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RTP Payload Format for DV Format Video draft-ietf-avt-dv-video-00.txt. Akimichi ogawa Keio university. Overview. RTP payload format for DV(digital video) Payload format for NTSC, PAL(SD-VCR, HD-VCR, SDL-VCR) DV data comes directly after RTP header Without payload specific header
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RTP Payload Format forDV Format Videodraft-ietf-avt-dv-video-00.txt Akimichi ogawa Keio university
Overview • RTP payload format for DV(digital video) • Payload format for • NTSC, PAL(SD-VCR, HD-VCR, SDL-VCR) • DV data comes directly after RTP header • Without payload specific header • Payload consists of multiple DIF blocks • Payload length will be multiple of 80 bytes • Uses 90khz clock for RTP timestamp
Updates Fromdraft-kobayashi-dv-video-00.txt • Cleaned up some phrases • Section for SDP format for DV encoding information is added • DV specific encoding parameter notification in SDP • unbundled stream • bundled stream
SDP Description for RTP Format for DV Format Video • Example of “m=“ line and “a=“ line • Video stream • Port 31394 • Payload identifier m=video 31394 RTP/AVP 111 a=rtpmap:111 DV/90000
Video Encoding Format Description Using SDP • a=fmtp:<payload type> v-encode :<dv-video encoding> • SD-VCR/525-60 • SD-VCR/625-50 • HD-VCR/1125-60 • HD-VCR/1250-50 • SDL-VCR/525-60 • SDL-VCR/625-50
Unbundled Stream Example v=0 o=mhandley 2890844526 2890842807 IN IP4 126.16.64.4 s=SDP Seminar i=A Seminar on the session description protocol u=http://www.cs.ucl.ac.uk/staff/M.Handley/sdp.03.ps e=mjh@isi.edu (Mark Handley) c=IN IP4 224.2.17.12/127 t=2873397496 2873404696 m=audio 49170 RTP/AVP 112 a=rtpmap:112 L16/32000/2 m=video 50000 RTP/AVP 113 a=rtpmap:113 DV/90000 a=fmtp:113 v-encode:SD-VCR/525-60
Video Audio DV Format Specific Parameters(Overview of fmtp Parameters) DV format v-encode (SD-VCR/525-60, SD-VCR/625-50) a-encode Channel ID Quantization Sampling Rate
Audio Encoding Format Description Using SDP • Please see draft for further information • Used for bundled stream • Bundled stream carries both video and audio using DV format a=fmtp:<payload type> a-encode:\ <channel id>{<channel id>...} <quantization/\ sampling rate/frame lock/stereo mode/sub channel number/\ channel pair/audiomode/language{/emphasis/time constant}>
Audio Encoding Description • Channel id • Specifies channel that is described • Quantization • 16L, 12NL, 20L • Sampling rate • 48000, 44100, 32000 • Frame lock • Locked, unlocked
Audio Encoding Description (2) • Stereo mode • Multi, lumped • Sub channel number • 1, 2 • Channel pair • Pair, independent • Audio mode • 0 - 15 • Language • 0 - 7
Audio Encoding Description (3) • Emphasis(optional) • Emphasis • Time constant(optional) • 50 - 15
Bundled Stream Example v=0 o=mhandley 2890844526 2890842807 IN IP4 126.16.64.4 s=SDP Seminar i=A Seminar on the session description protocol u=http://www.cs.ucl.ac.uk/staff/M.Handley/sdp.03.ps e=mjh@isi.edu (Mark Handley) c=IN IP4 224.2.17.12/127 t=2873397496 2873404696 m=video 49170 RTP/AVP 112 a=rtpmap:112 DV/90000 a=fmtp:112 v-encode:SD-VCR/525-60 a=fmtp:112 a-encode:abcd 12NL/32000/locked/lumped/2/independent/9/0
Minor modification • parameter notification will be changed • v-encode -> video • a-encode -> audio • for example, unbundled stream will be like….. m=audio 49170 RTP/AVP 112 a=rtpmap:112 L16/32000/2 m=video 50000 RTP/AVP 113 a=rtpmap:113 DV/90000 a=fmtp:113 video:SD-VCR/525-60
ISSUES • Is description with SDP of audio encoding parameters when using bundled stream really useful ? • AAUX data also includes audio encoding parameters • AAUX is included in AUDIO DIF block • AUDIO DIF block is sent when bundled stream • Audio information can be known by the AUDIO data in the stream
Minor modification • Audio present <-> audio not present • bundled stream, if “audio” is included • when unbundled stream, it will be defined sperately • example of an bundled stream….. m=video 50000 RTP/AVP 113 a=rtpmap:113 DV/90000 a=fmtp:113 video:SD-VCR/525-60 audio
Minor modification • a=fmtp:<payload type> video :<dv-video encoding> [audio] • optional parameter “audio” shows that it is bundled stream • includes audio within RTP/DV stream