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 Payload consists of multiple DIF blocks –Payload length will be multiple of 80 bytes Uses 90khz clock for RTP timestamp

Updates From draft-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 –Payload identifier m=video RTP/AVP 111 a=rtpmap:111 DV/90000

Video Encoding Format Description Using SDP a=fmtp: v-encode : –SD-VCR/ –SD-VCR/ –HD-VCR/ –HD-VCR/ –SDL-VCR/ –SDL-VCR/625-50

Unbundled Stream Example v=0 o=mhandley IN IP s=SDP Seminar i=A Seminar on the session description protocol u= (Mark Handley) c=IN IP /127 t= m=audio RTP/AVP 112 a=rtpmap:112 L16/32000/2 m=video RTP/AVP 113 a=rtpmap:113 DV/90000 a=fmtp:113 v-encode:SD-VCR/525-60

DV Format Specific Parameters (Overview of fmtp Parameters) DV format Video Audio 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: a-encode:\ {...} <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, Frame lock –Locked, unlocked

Audio Encoding Description (2) Stereo mode –Multi, lumped Sub channel number –1, 2 Channel pair –Pair, independent Audio mode – Language –0 - 7

Audio Encoding Description (3) Emphasis(optional) –Emphasis Time constant(optional) –

Bundled Stream Example v=0 o=mhandley IN IP s=SDP Seminar i=A Seminar on the session description protocol u= (Mark Handley) c=IN IP /127 t= m=video RTP/AVP 112 a=rtpmap:112 DV/90000 a=fmtp:112 v-encode:SD-VCR/ 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 RTP/AVP 112 a=rtpmap:112 L16/32000/2 m=video 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 RTP/AVP 113 a=rtpmap:113 DV/90000 a=fmtp:113 video:SD-VCR/ audio

Minor modification a=fmtp: video : [audio] optional parameter “audio” shows that it is bundled stream –includes audio within RTP/DV stream