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<div class="moz-cite-prefix">On 10/14/14 6:46 PM, Ben Mesander
wrote:<br>
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cite="mid:CANgFRXCKjZY8cSx33Xt74Rm1hY461M7xdXFozWX=o+KT+zV0gg@mail.gmail.com"
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<div class="gmail_quote">On Tue, Oct 14, 2014 at 1:50 PM,
Sethuraman V <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:techmail.sethu@gmail.com" target="_blank">techmail.sethu@gmail.com</a>></span>
wrote:<br>
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<div style="color:rgb(0,0,153)">I can't understand why
an 'I' frame read from a video file can't be
written/encoded back to the video file. For other
frames 'P' and 'B' there are dependencies, so
writing/encoding the complete frame can't be done,
but why this applies to 'I' frame too, which is a
separate frame on its own.</div>
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<div>Hi,</div>
<div><br>
</div>
<div> The P and B frames depend on nearby I frames. Also,
when you re-encode an I frame, there is no reason to
expect it to be the same size as it was before.</div>
<div><br>
</div>
<div> So in the general case, you have to re-encode every
frame after the I frame in addition to the I frame. This
can of course vary based on GOP structure.</div>
<div><br>
</div>
<div> It's not a practical thing to do.</div>
<div><br>
</div>
<div>Regards,</div>
<div>Ben</div>
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-- <br>
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<div style="vertical-align:bottom;display:inline"><span
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</blockquote>
why does the differing size of the new I frame matter?<br>
<pre class="moz-signature" cols="72">Joshua Kordani
LSA Autonomy</pre>
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