Hi there, I'm Jeff and I'm a long time lurker and first time poster.

When I was in High School, I always wanted an iMac G4 but I could never get one. Well recently, I changed that and went down the retro Mac road. I got myself a 1GHz 17" model and I absolutely love it. I put in an SSD and got the RAM up to 1.5GB (annoyingly one of the OWC RAM sticks as bad otherwise it would be 2GB, but I digress). But I live in Tokyo and my Apartment is tiny, so I can't just buy pretty things to have them take up space. I decided if I was going to buy it, I was going to put it to good use... as my accessory monitor so I can watch KPOP while I work [headphones]. But I know these old Macs cannot play H.264 barely at all and they almost can't use the internet because of TLS. So I started doing some experiments to work around this.

I think I came up with something pretty cool and so I made a full tutorial on how to set it up. It does require a second computer to do the streaming work, but what I can say is, I think the video quality is pretty epic. No, it's not a beautiful 4K stream on an OLED panel. But it's a full 720p stream at 20FPS with almost no compression artifacts. Its also completely tunable if you have an older or newer PowerPC Mac you can adjust it appropriately.

To see the quality you can get out of this old G4, take a look at this video I recorded from my phone. I have noticed that the streaming quality from Google
Drive directly is not always great, so please download it to be sure you are seeing the full 1080p quality.

Anyway, if you are interested in trying something like this please take a look at the tutorial:

And if you are an FFMPEG expert and know why I can't seem to be able to capture system audio at 44,100Hz I would love to hear your ideas!

Thanks so much,
Jeff

This is a great write up, and I appreciate you thinking through the tradeoffs and assumptions that govern video quality at any point in time.

I have plans to deploy a "composite-out from Raspberry Pi to analog AV in" to enable video streaming on a Centris 660av :)

>> PL212 said:

This is a great write up, and I appreciate you thinking through the tradeoffs and assumptions that govern video quality at any point in time. I have plans to deploy a "composite-out from Raspberry Pi to analog AV in" to enable video streaming on a Centris 660av Click to expand...

thanks for taking a look! That sounds like a fun project. Does the Centris AV have dedicated hardware to handle the AV components?

>> jeffburg said:

thanks for taking a look! That sounds like a fun project. Does the Centris AV have dedicated hardware to handle the AV components? Click to expand...

AV in older Macs is usually done by DMA into the frame buffer of a graphics controller. This reduces work required by the CPU. I'm not sure if it affects RAM bandwidth if the video data is going directly to VRAM. Benchmarks to compare with AV play-thru happening and not happening might be interesting.
I am most familiar with AV on Power Mac 8500/8600 which has a 2nd buffer for clipping (I wrote a Mac OS X driver for it). For Centris, isn't clipping handled by only replacing pixels of a certain value in the frame buffer with pixels from video input? I know some old Macs used that method.

Possibly. The ITVB worked that way (using a Pepto-Bismol shade of pink for "transparency").

I updated the tutorial to fix the main shortcoming before, which was a bug in FFMPEG when capturing from AVFoundation. Now I use a Linux VM to do the FFMPEG streaming. It is much better now because the Audio is full quality 192K AAC 44,100Hz.