<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On 20/08/2008, at 4:45 PM, Robin Gilks wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div><blockquote type="cite">The H264 decode flatlines all OSs if done in software due to the<br></blockquote><blockquote type="cite">complexity of the decode when dealing with our broadcast streams.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">I've compared Linux and Mac software decode on the same hardware,<br></blockquote><blockquote type="cite">EyeTV vs MPlayer, and they appear to use similar amounts of CPU.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">The best windows codec for software decode is CoreAVC which is a<br></blockquote><blockquote type="cite">proprietary commercial codec.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Until we get a way to accelerate some of the decode on the GPU we are<br></blockquote><blockquote type="cite">going to lag behind Windows users who have hardware accelerated decode<br></blockquote><blockquote type="cite">via the main graphics card vendors.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">As to STBs, as mentioned they have chips designed to accelerate the<br></blockquote><blockquote type="cite">decode in hardware. If you have had a play with the Zinwell STB you<br></blockquote><blockquote type="cite">would notice that it can get very hot due to the load.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Steve<br></blockquote><br>So if all the work is done in the CPU, would a mother board such as the<br>"Asus M2A-VM HDMI Motherboard" with an ATI embedded video controller do<br>the job or is it still better to spend another $40 or so and use an nvidia<br>based board such as the "Asus M3A78-EMH HDMI Motherboard".</div></blockquote><div><br></div><div><br></div><div>The pay off with the GPU will come in with the new Google Summer of Code projects to perform GPU based acceleration.</div><br><blockquote type="cite"><div><br><span class="Apple-style-span" style="-webkit-text-stroke-width: -1; ">c</span><br>In either case, what would be the minimum spec CPU required (assuming<br>these m/b will support the required speed that is!!) to handle both TV1<br>and TV3 HD?<br><br></div></blockquote><br></div><div>I did a bunch of performance comparison tests on an X2 3600+ test rig today. I looked at the CPU load for both H.264 and MPEG 2 playback of the same channels, and locked the CPU to its max frequency of 2GHz.</div><div><br></div><div>I also used the CPU++ profile and allocated a max of 2 cores to video decode. It appears that some of the frames are slice compatible so there is a benefit in enabling dual CPU, but until FFMPEG can do true multi cpu decode we really need a CPU fast enough to decode on a single core. This is a shame given the drop in price of triple and quad core processors</div><div><br></div><div><br></div><div><div>Channel <span class="Apple-tab-span" style="white-space:pre"> </span> Resolution<span class="Apple-tab-span" style="white-space:pre"> </span>Load H.264<span class="Apple-tab-span" style="white-space:pre"> </span>Load MPEG2</div><div>freeview|HD <span class="Apple-tab-span" style="white-space:pre"> </span> 720p<span class="Apple-tab-span" style="white-space:pre"> </span> 95-100+</div><div>TV One <span class="Apple-tab-span" style="white-space:pre"> </span>720p<span class="Apple-tab-span" style="white-space:pre"> </span>98-108<span class="Apple-tab-span" style="white-space:pre"> </span>11-15</div><div>TV 2<span class="Apple-tab-span" style="white-space:pre"> </span>720p<span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>100+<span class="Apple-tab-span" style="white-space:pre"> </span>11-15</div><div>TV 3<span class="Apple-tab-span" style="white-space:pre"> </span>1080i<span class="Apple-tab-span" style="white-space:pre"> </span>130+<span class="Apple-tab-span" style="white-space:pre"> </span>12-15</div><div>C4<span class="Apple-tab-span" style="white-space:pre"> </span>576i<span class="Apple-tab-span" style="white-space:pre"> </span>45<span class="Apple-tab-span" style="white-space:pre"> </span>13-15</div><div>TVNZ 6<span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>576i<span class="Apple-tab-span" style="white-space:pre"> </span>26-35<span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>9-10</div><div>Sports Extra<span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>576i<span class="Apple-tab-span" style="white-space:pre"> </span>25-40<span class="Apple-tab-span" style="white-space:pre"> </span>10-12</div><div>Maori<span class="Apple-tab-span" style="white-space:pre"> </span>576i<span class="Apple-tab-span" style="white-space:pre"> </span>37-40<span class="Apple-tab-span" style="white-space:pre"> </span>9-10 </div></div><div><br></div><div>Now the CPU load for C4 on freeview|HD is a little higher than the other channels, which might be explained by the higher bit rate they are using compared with TVNZ 6+7 etc.</div><div><br></div><div>For SD it appears we need 3.5 - 4x the CPU of SD and the X2 3600+ copes</div><div><br></div><div>For 720p the CPU is borderline and occasionally copes.</div><div><br></div><div>For 1080i I'm well out of power.</div><div><br></div><div>Right now I'd look at the fastest 65W processor I can buy. Sadly the only X2 5600s in the market are still 89W units, so it would be a 5400 which runs a 2.8 GHz. The question is will this be enough?</div><div><br></div><div><br></div><div>In the Intel space I've been playing with a MacBook and EyeTV on a 2.4 GHz T8300. Eye TV runs both cores at 90% when running TV3. I need to do a reboot and try mplayer native under Ubuntu to see how it compares.</div><div><br></div><div>Steve</div><div><br></div><br><div> <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Steven Ellis - Technical Director<br>OpenMedia Limited<br>email - <a href="mailto:steven@openmedia.co.nz">steven@openmedia.co.nz</a><br>website - <a href="http://www.openmedia.co.nz/">http://www.openmedia.co.nz</a><br></div></div></span> </div><br></body></html>