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<p class="MsoNormal">Hi all,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I’m curious to understand which editing operations can be performed on an h264 stream without the<br>
need to re-encode the stream.<o:p></o:p></p>
<p class="MsoNormal">For example:<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l1 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">1.<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]><span dir="LTR"></span>Clipping from I frame to P frame can be done without re-encoding<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l1 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">2.<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]><span dir="LTR"></span>Afaik, it is possible to rotate the video (90,180,270) using some SEI packet<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l1 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">3.<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]><span dir="LTR"></span>Afaik, it is possible to clip the frames by changing the clipping parameters in the SPS<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Is there anything else that is possible?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Specifically, I’m wondering - if I have 2 video streams encoded with the same parameters (let’s say identical<br>
SPS/PPS, and aligned GOP), is it theoretically possible (not necessarily using current tools) to merge the 2 videos
<br>
so that they appear side by side without re-encoding?<o:p></o:p></p>
<p class="MsoNormal">I assume that if the macro blocks are independent, it should be possible, but not familiar enough with the<br>
internals of the codec to know if that is the case.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thank you!<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Eran<o:p></o:p></p>
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