Ipad app, v2.4, impact of transcoding on CPU

[gifty74]

Hi all. I had been playing around with the older Wintv Extend streaming to my Ipad 2 through Safari. Everything is set up, and works as expected as far as the channels, logging in, etc. My issue is that I can't stream anything, with any form of action (sports, etc), over 512 kbps. If I set it at 1024 kbps my CPU (dual core) peg at 100% and it just can't keep up. The stream has short glitches every 3 seconds or so, which I assume is the CPU choking at the limit of it's power. I have a dual core AMD, 3800+, running at 64-bit on Windows 7. 2 gb of dual channel RAM. It can handle most any other task I throw at it (video editing, encoding, etc) but the stream transcoding seems to really take a hit on it. Is anyone else experiencing this? What horsepower does everyone else have? Any suggestions?

[gr8sho]

You're streaming to iPad, right? On my iPhone 4 with max settings my quad core 3.8GHz (also AMD) is less than 20% utilized. If you suspect the CPU is maxed out, validate that using task manager to see if the CPUs are indeed running at 100%. My one concern is the 2GB of RAM you're running with. You might want to double that.

[gifty74]

So you have max settings, meaning 2048 kbps and you're fine? Yes, I'm having the issues on my Ipad. I also have an iphone 4 and when viewing that I can crank up the bit rate and it seems to do fine. I'm not sure how high I took it, but it didn't choke at nearly as low of a setting as it does on the Ipad. I guess there's a larger frame size on the Ipad to make it look halfway decent. The larger frame size with the higher bit rate and my PC just can't handle it. I do have my task manager open, and as soon as the feed starts playing through the Ipad the usage jumps right up to 100% on both cores. Even at 512 kbps it's in the mid 90's, and often hitting 100% on both of the cores for a split second, but not enough I guess to make the feed skip. As soon as I bump it up to 1024 though it pegs the CPU and the skipping starts. I thought the 1600 like I have has hardware encoding? Does that not apply to streaming?

[TheNewGuy]

I thought the 1600 like I have has hardware encoding? Does that not apply to streaming?The hardware encoding does already help you, but not as much as you'd need. If you'd had a software encoder device instead, the CPU would have been a lot higher and your would have had a much worse experience.

Unfortunately this live on-the-fly transcoding to the format required by the iPad/iPhone requires quite a bit of CPU work and your AMD 3800+ is probably not up to the task. In realtime it's having to decode the MPEG2 stream coming from your 1600 (either highdef or standard def), then resize each frame, then reencode the video as H.264. That's a lot of work to be done, and it needs to be done in realtime to ensure you can watch smoothly. Most modern CPUs released in the last few years (like Core 2 Duo's etc) would have no problems with this, but unfortunately it sounds like your 6 year old AMD 3800+ is struggling.

[gifty74]

I was fearing that! I was hoping it was a driver issue (which I believe I have ruled out). I believe my PC is about 5 years old now. Home built with some of the best components and it has worked great for me through all of this time. Maybe time for a MB, CPU & RAM upgrade, but not in the financial cards right now. I guess I'll just be stuck with 512 kbps. What's a not-so-expensive CPU that could handle maxed out settings streaming to the Ipad?

[TheNewGuy]

I guess I'll just be stuck with 512 kbps. What's a not-so-expensive CPU that could handle maxed out settings streaming to the Ipad?Sorry, I dont know. Its been years since I bought a processor. The faster the better though.

[gr8sho]

So you have max settings, meaning 2048 kbps and you're fine? Yes, I'm having the issues on my Ipad. I also have an iphone 4 and when viewing that I can crank up the bit rate and it seems to do fine. I'm not sure how high I took it, but it didn't choke at nearly as low of a setting as it does on the Ipad. I guess there's a larger frame size on the Ipad to make it look halfway decent. The larger frame size with the higher bit rate and my PC just can't handle it. I do have my task manager open, and as soon as the feed starts playing through the Ipad the usage jumps right up to 100% on both cores. Even at 512 kbps it's in the mid 90's, and often hitting 100% on both of the cores for a split second, but not enough I guess to make the feed skip. As soon as I bump it up to 1024 though it pegs the CPU and the skipping starts. I thought the 1600 like I have has hardware encoding? Does that not apply to streaming?

I can do 4096 kbps @ 1440x1080 on the host machine with about 75% CPU utilization.

By 1600 do you mean an ATI X1600? If yes, way too old. I had that same discussion about my X1900GT and was told same.


I was fearing that! I was hoping it was a driver issue (which I believe I have ruled out). I believe my PC is about 5 years old now. Home built with some of the best components and it has worked great for me through all of this time. Maybe time for a MB, CPU & RAM upgrade, but not in the financial cards right now. I guess I'll just be stuck with 512 kbps. What's a not-so-expensive CPU that could handle maxed out settings streaming to the Ipad?

We're in a similar place. At least the part about the age of the machine. If you started with high-end components back at that time, you may be able to do a reasonable upgrade that will put you on your way to a better machine.

When I started down this path I had an AMD 4200+ along with that X1900GT I was talking about. The thing that's allowed me to go more of the incremental upgrade path is the motherboard, an ASUS M2N32-SLI Deluxe, a real gem and apparently the first of its kind to introduce a split power distribution scheme along with the Nvidia 590 chipset.

On this board I've been able to upgrade to a Phenom X4 965BE for around 126USD, so something of that ilk if your motherboard is capable of such an upgrade. You should also consider finding some additional memory to bump to 4GB for that Windows 64-bit OS.

Hope that helps.

[gifty74]

No, I meant that I have the Hauppauge HVR-1600 tuner card. It's an older model, but still a 1600. I didn't think the video card has much to do with the performance of the steaming unless you're playing it on your PC. I might have to look at a MB upgrade and CPU. That Asus sounds good, I know they make a good one. So did you try the live streaming on your old AMD 4200+ and could it not keep up?

[gr8sho]

No, I meant that I have the Hauppauge HVR-1600 tuner card. It's an older model, but still a 1600. I didn't think the video card has much to do with the performance of the steaming unless you're playing it on your PC. I might have to look at a MB upgrade and CPU. That Asus sounds good, I know they make a good one. So did you try the live streaming on your old AMD 4200+ and could it not keep up?

Ha, well by comparison I'm only running a 1250 and it does just fine for everything I throw at it.

About my old setup, I had upgraded the CPU well before Extend was offered so I never had tested that configuration. However WinTV itself worked just fine as you already know. I bought the card initially just for local usage and didn't understand at the time or have an expectation the card would eventually act like a Slingbox. Since I will be upgrading to a SLI configuration, I may need to find a different solution for the TV tuner hardware. The 1250 fits fine, but its contribution to heat inside the case might be enough to push it out. Right now there's no worry.

I do suggest considering upgrade path. AMD AM3 based components should be very reasonably priced now that Bulldozer is out. Asus has always worked well for me but there are other companies that make good product too. In my situation if you followed the progression, the only thing I have left to do if I decide to make a next step is a motherboard and memory purchase since all other components including my 965BE would move over to the new mobo. The main benefit do making the move is to get DDR3 memory, but frankly I'm not clear how much real benefit I will see other than at the benchmarking level.

[gifty74]

Yes, so it sounds like the conclusion to this dilemma is a faster PC with an updated processor. For now I guess I'm stuck with 512kbps on streaming to the Ipad.