<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri",sans-serif;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="#0563C1" vlink="#954F72" style="word-wrap:break-word">
<div class="WordSection1">
<p class="MsoNormal">Hi Team ,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">We are using Live555 library as a RTSP client in our CCTV product.<o:p></o:p></p>
<p class="MsoNormal">Recently we integrated a new camera where we are getting two I/P frames with the same timestamp.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">When we further analyze, this specific camera is setting FU header end bit in middle of a frame.<o:p></o:p></p>
<p class="MsoNormal">Suppose a single I frame is sent as 90 FUs, 45th FU end bit is set and again on 90th FU end bit is set and RTP header marker bit set.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">We checked the Live555 code, in H264VideoRTPSource.cpp, processSpecialHeader() function set the fCurrentPacketCompletesFrame flag based on two condition<o:p></o:p></p>
<p class="MsoNormal">1) FU header end bit is set<o:p></o:p></p>
<p class="MsoNormal">2) Current FU is complete NAL unit<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Because of this logic we are getting two I/P frames with same timestamp.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">We noticed other third party libraries(ffmpeg) are able to decode and play this data.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">But our system depends on many places I frame logic<o:p></o:p></p>
<p class="MsoNormal">For example, we play only in reverse I frame, saving a single GOP data depends on I Frame.<o:p></o:p></p>
<p class="MsoNormal">We are not able to handle this data.<o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal">Can we set the fCurrentPacketCompletesFrame flag only if marker bit of RTP header is set ?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Any other suggestion from your side ?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Please share your input.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks and Regards,<o:p></o:p></p>
<p class="MsoNormal">Ranjith<o:p></o:p></p>
</div>
</body>
</html>