<br><br><div><span class="gmail_quote">On 18/09/2007, <b class="gmail_sendername">Paul Mason</b> <<a href="mailto:latepaul@gmail.com">latepaul@gmail.com</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<span class="q"><br><br><div><span class="gmail_quote">On 18/09/2007, <b class="gmail_sendername">jack snodgrass</b> <<a href="mailto:mrlinuxgroups@gmail.com" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">
mrlinuxgroups@gmail.com</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
I'm using this mencoder command to re-encode a HDTV show to something<br>smaller... something<br>I can stream to my office over the internet or something I can put on<br>a usb drive....<br><br>mencoder -srate 22050 -vf scale=720:400 -oac mp3lame -lameopts
<br>preset=15:mode=3 -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=900 -sws 2<br>-o /tmp/1005_20070914190000_720x400x900.avi<br>/mnt/store/1005_20070914190000.mpg<br><br>This command takes 22 minutes or so to re-encode a 30 minute, 4GB HDTV
<br>show down to<br>101Meg at a reasonable quality ( compared to the original HD stream ).<br><br>22 minutes seems a bit excessive to me for a 30 minute show.... this<br>is on a E6600 Core Duo.<br>It takes 2-3 more minutes to do this same command on a AMD x86_64
<br>3800+ box... quite<br>a bit slower than the E6600 box.<br></blockquote></div><br></span>I was thinking 22 minutes was quite impressive. My AMD 3800+ (non-dual) box was taking ~80mins to convert a 2Gb, 45min DVD ripped VOB file to h264. That's with an IVTC filter and then resize (720:480 -> 512:384). That was before I decided that it was a background task anyway and so I'd do a two-pass transcode which is now taking 2h15m per file.
<br><br>I'm using avidemux2_cli. I'd heard mencoder was quicker but I didn't think it was that much quicker. I might have a go with mencoder tonight. </blockquote><div><br><br>Well that was a useful exercise, thank you. So after a little playing I discovered that:
<br><br>1) like-for-like[1] mencoder is slightly faster but only slightly so.<br><br>2) the x264 is significantly more cpu-hungry than FFmpeg4<br><br>3) for the same bitrate[2] x264 encodes a noticeably[3] nicer video but
<br><br>4) for only a little (25%) more filesize I can have a similar quality FFmpeg4-encoded file in less than half the time.<br><br>So, since disk is cheap and time is less so, I'm going to switch to using FFmpeg. Though stick with avidemux2_cli as I prefer it, and mencoder did some funny things with sound on one of my tests[4]
<br><br>Oh and when testing with Jack's options above, this also re-inforced something I already knew, namely that I can cope much more easily with lower picture quality than audio. Seriously, it sounded like it was being played underwater!
<br><br><br><br>[1]or as close as I could get.<br>[2]my loose definition of 'same bitrate' is 'same resolution and target file size'<br>[3]to me. YMMV. <br>[4]I'm sure I could've fixed it given time and enough googling -but why bother when I have an alternative that already works fine?
<br></div><br></div><br>-- <br>Paul Mason