Magic Music Visuals

hi,

sorry to dig this up this again, i just want to be sure. do i remember that correctly that videos in the video module are decompressed on the fly from disk and not stored in the vram? but pictures (so far) are stored in their uncompressed form in the vram (resolution*bitdepth=size in bits)?

Every image is stored more-or-less uncompressed in VRAM, whether it is a temporary video frame that gets subsequently overwritten, or a picture which lasts indefinitely.

The difference between video and pictures is that video is decompressed for every new frame, thus it keeps happening. For pictures, the decompression only happens when the file is initially loaded.

okay. so in terms of budgeting vram, i can go on the premise that a 1280x720 movie and 1280x720 picture need the same significant amount of vram? which would be 1280*720*24bit=22Mbyte for regular pic/movie and 1280*720*32bit=29.4Mbyte for pics/movies with a fourth alpha channel?

Yep that's basically correct, but the math is actually 1280*720*3 bytes = 2.8 Mbyte, and 1280*720*4 = 3.7 Mbyte. So a little bit smaller than what you had calculated (8 bits in a byte).

can I jump in and ask...

regarding playing video in magic, what would be the optimal video type for minimising processing power? Specifically, are smaller video files (whether due to bit rate or resolution) consequently easier for magic/computer to work with?

I have a load of .avi files which I could convvert to .mp4 but only if it would help

In general, to minimize processing requirements, you would want to use a codec that has a larger file size, because it uses less compression, and is therefore faster to decode. Examples would be M-Jpeg, QtRle, HuffYuv, etc. But you need a fast hard drive, such as an SSD, to read big files and maintain 30fps playback.

On the other hand, formats that compress heavily, such as .mp4, are fast to read from the hard drive because they are smaller files, but they use more processing power because they are more complex to decode. However, an SSD usually isn't necessary.

So unfortunately the answer isn't the same for everyone . It depends on what hardware you have. My personal recommendation is that it probably isn't worthwhile to convert your .avi's to .mp4 unless you are really noticing some playback issues (low fps, high cpu usage, etc), because the conversion process will lower the video quality. Do you know what codec the .avi's use?

Also, there are a few topics on here in which people have discussed similar things. Here are some examples:
viewtopic.php?f=2&t=87
viewtopic.php?f=2&t=129
viewtopic.php?f=2&t=88

Hopefully those will help a bit. Let me know if you have any questions though.

thanks for the info, I had a brief look at the links you sent me... there is still a lot for me to learn

actually I haven't been experiencing problems with video playback but I just wanted to know what is the most efficient setup as I move forward with my work. Your reply has answered my question.

The video files I'm using are mostly clips captured from miniDV (good old days) but I'm not sure the specific codec - DV avi? Or perhaps some intel based codec, I can't remember or see the info in the file properties, but nevermind; as I wrote, I haven't had any problems. Also I have my files on an SSD drive so I'll follow your advice and use minimal compression.