Streaming Media East Presentations

I just got back from a wonderful trip to Streaming Media East, where I gave two presentations. The first was a 3 hour session on producing H.264 video, here's the agenda.

In particular, note the comparisons of H.264 codecs, which you'll find helpful if trying to find the best H.264 encoding tool, and the settings for common H.264 encoders, which may help you navigate through your selected program. I also addressed how to set common encoding parameters like Profiles, Levels, Entropy Encoding (CABAC/CAVLC), B-Frame intervals, reference frames and the like.

The second is, a 76 slide, 45-minute look at common mistakes made by video producers, and the agenda is below. This one was actually filmed; I'll add the link to the streaming video file once it becomes available. Note that the encoding section includes lots of useful statistics about the current streaming configurations used by broadcast and corporate sites. Have a look.

I hope you find the presentations useful. Enjoy!

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Comments (3)

Jan Petzold
Said this on 05/24/2009 At 04:41 pm
Thanks for sharing this. Very useful information. Two questions:

1. What exactly is the benefit of 2-pass-CBR Encoding? Since the encoder can't vary the bitrate, I don't see what can be done to improve quality during fast-paced sequences. Probably some frames are left out?
2. I think even the first iPod video (5G) released in 2005 is able to play H.264 encoded video in a resolution of 640*480. I have one here for testing, and it defintely works ;-)
Jan Ozer
Said this on 05/24/2009 At 10:45 pm
Jan:

Thanks for weighing in.

My assumption on 2-pass encoding is that it enables the encoder some variability in the compressed data rate, which it can then mitigate by packing the data into a more consistent bitstream. I've seen some descriptions that confirm that, and pretty much every tutorial that I've seen recommends 2-pass CBR when available. I haven't done side by side comparisons though; next time in experiment mode, I'll give it a try.

Your memory differs from mine. Apple's technical description is offline for these older models, but as I recall, the first video capable ipod maxed out (according to the specs) at 320x240 for H.264. I also know that the majority of producers on itunes still max produce their podcasts at 320x240, which seems to confirm that there are some ipods that don't play 640x480. Doesn't mean I'm correct, but that's my recollection.

Thanks for weighing in.

Jan Ozer
Jan Petzold
Said this on 05/25/2009 At 03:09 pm
Hey Jan,

that's exactly what I'm wondering about - if the encoder always uses the maximum bitrate as it would in CBR, there's not much to improve. For quality improvement it needs variability, so it's not CBR anymore. Maybe they vary the bitrate in a GOP, but I also doubt that this improves quality noticeable. Probably it needs some tool like Elecard StreamEye or similar to see the difference. I also noticed that Windows Media varies the framerate according to the complexity, but that doesn't help during fast-paced sequences either.

For the iPod, yeah, I remember the specs, I think they were a bit too cautious. I always have this old iPod 5G for testing purposes, and it definitely worked for resolutions above 320 in H.264. If you want to I can point you to some files that should work.

Cheers,

Jan

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