4 ms·

Why compare with Baseline, though, and not Main or High? In e.g. the "desktop computer playing the video through Flash" scenario there's no client-side reason n

by m_eiman 17y ago

Why compare with Baseline, though, and not Main or High? In e.g. the "desktop computer playing the video through Flash" scenario there's no client-side reason not to use the more advanced modes. The iPhone is limited to Baseline to be able to use accelerated decoding, but is that also the case for other embedded systems such as set-top boxes? In the case of YouTube et al there's the server-side performance/encoding time consideration, but they should be able to encode everything in a quicker format, e.g. Baseline, and re-encode popular content in High profile as needed.

ZeroGravitas 17y ago
Well it was aw3c2 who originally made the comparison that you responded to, so you'd have to ask them to find their reasons. For myself, I'd suggest that Baseline might be the XP of H.264, good enough for most folk and with a big installed base out there. (Main profile would be Vista in this analogy as many people seem to suggest just skipping straight onto High Profile if Baseline isn't appropriate). Would you like to provide one set of images on your blog for most users and another set to iPhone users? I'd guess the same applies to video. Though of course this isn't an issue for centralised hosts like Youtube that host multiple bitrates, profiles and codecs. It will be interesting, for example, to see if the next-gen iPhone allows you to play High Profile, I think the current 3GS has got enough oomph but is software limited by Apple to baseline, presumably to keep the iPhone line a homogenous target platform to some extent (or to avoid the hit on battery life making them look bad?). Speaking of XP I'd also love to know what levels of H.264 video many existing computers, especially netbooks, can handle. I'd guess Google is the kind of company to gather this kind of info, and they have an obvious interest with Youtube, but I don't know if they've released any of it publicly. They are famous for conservatism in their encoding settings, though I believe they use High Profile for their 720p encodes now.
aw3c2 17y ago
From what I know Baseline is what is usually used for SD on the web, so it just makes sense to compare to that. Also many people say "mobile things do not have hardware support for Theora but for H264" and that, as you said, mostly means those devices have Baseline support.

by m_eiman 17y ago

ZeroGravitas 17y ago

Well it was aw3c2 who originally made the comparison that you responded to, so you'd have to ask them to find their reasons. For myself, I'd suggest that Baseline might be the XP of H.264, good enough for most folk and with a big installed base out there. (Main profile would be Vista in this analogy as many people seem to suggest just skipping straight onto High Profile if Baseline isn't appropriate). Would you like to provide one set of images on your blog for most users and another set to iPhone users? I'd guess the same applies to video. Though of course this isn't an issue for centralised hosts like Youtube that host multiple bitrates, profiles and codecs. It will be interesting, for example, to see if the next-gen iPhone allows you to play High Profile, I think the current 3GS has got enough oomph but is software limited by Apple to baseline, presumably to keep the iPhone line a homogenous target platform to some extent (or to avoid the hit on battery life making them look bad?). Speaking of XP I'd also love to know what levels of H.264 video many existing computers, especially netbooks, can handle. I'd guess Google is the kind of company to gather this kind of info, and they have an obvious interest with Youtube, but I don't know if they've released any of it publicly. They are famous for conservatism in their encoding settings, though I believe they use High Profile for their 720p encodes now.

aw3c2 17y ago

From what I know Baseline is what is usually used for SD on the web, so it just makes sense to compare to that. Also many people say "mobile things do not have hardware support for Theora but for H264" and that, as you said, mostly means those devices have Baseline support.