h.264 and text

[Tero Ahlfors]

If you have strong color edges they will get compressed and it will show in formats that compress color information. See this for more info: https://en.wikipedia.org/wiki/Chroma_subsampling

[Jerry Smith]

Thanks Tero.

Well, I’m talking about text specifically. So a mixture of vertical lines and curves. Imagine a font size between 60 and 300 on a 1920×1080 composition. Red text, white background. Or white text, red background.

$64,000question: Should I expect shadows in h.264 for iPad, youtube, etc.? Or should I work hard to eliminate them?

I like my question because it is very clear. ☺ Unlike my text. ☹

[Tero Ahlfors]

[Jerry Smith] “Well, I’m talking about text specifically. So a mixture of vertical lines and curves.”

This would count into strong color edges it doesn’t matter if it’s a shape or text. When you’re compressing color information that will happen and internet streaming services don’t use 4:4:4 chroma subsampling.

[Jerry Smith]

Is there a trick or work around for h.264? If I were willing to settle for half resolution, could I get rid of the shadow? I could maybe even scale up the project in AE to 3840×2160 first. That would give me potentially a factor of 4 vertically and horizontally to play with.

Thanks

[Jerry Smith]

It doesn’t seem that there is any format that people actually consume that doesn’t subsample chroma information. I’m looking at this list. Is that true??

https://en.wikipedia.org/wiki/Bit_rate#Video

16 kbit/s – videophone quality (minimum necessary for a consumer-acceptable “talking head” picture using various video compression schemes)
128–384 kbit/s – business-oriented videoconferencing quality using video compression
400 kbit/s YouTube 240p videos (using H.264)[20]
750 kbit/s YouTube 360p videos (using H.264)[20]
1 Mbit/s YouTube 480p videos (using H.264)[20]
1.15 Mbit/s max – VCD quality (using MPEG1 compression)[21]
2.5 Mbit/s YouTube 720p videos (using H.264)[20]
3.5 Mbit/s typ – Standard-definition television quality (with bit-rate reduction from MPEG-2 compression)
3.8 Mbit/s YouTube 720p (at 60fps mode) videos (using H.264)[20]
4.5 Mbit/s YouTube 1080p videos (using H.264)[20]
6.8 Mbit/s YouTube 1080p (at 60 fps mode) videos (using H.264)[20]
9.8 Mbit/s max – DVD (using MPEG2 compression)[22]
8 to 15 Mbit/s typ – HDTV quality (with bit-rate reduction from MPEG-4 AVC compression)
19 Mbit/s approximate – HDV 720p (using MPEG2 compression)[23]
24 Mbit/s max – AVCHD (using MPEG4 AVC compression)[24]
25 Mbit/s approximate – HDV 1080i (using MPEG2 compression)[23]
29.4 Mbit/s max – HD DVD
40 Mbit/s max – 1080p Blu-ray Disc (using MPEG2, MPEG4 AVC or VC-1 compression)[25]

So colored text will always suffer???

[Roei Tzoref]

If your playback supports mov container, you could try one of the virtually lossless formats like JPEG2000. Reduce the quality to 60-70 percent and you can get an uncompressed look with a relatively decent file size

Roei Tzoref
After Effects Artist & Instructor
♫ Ae Blues Tutorials

[Tero Ahlfors]

[Jerry Smith] “https://en.wikipedia.org/wiki/Bit_rate#Video”

Bit rate value isn’t comparable to chroma subsampling. Although you’d want the bitrate to match the needs (resolution, frame rate, possible limitations of the playback system) of the exported file.

[Jerry Smith] “So colored text will always suffer???”

That depends on what colors you use.

[Jerry Smith]

The JPEG2000 was interesting to try. The file size is still very big and basically the same as the Animation codec that I’ve been using. Results were quite nice. I could have tried to drop the quality a bunch more.

The problem though is that it doesn’t play in the iPhone’s native AVPlayer.

[Jerry Smith]

Yes Tero, I know a bit about bit rate. But that was a nice list for a dummy like me.

Your comment about the color was interesting. I’ve been wondering whether there is some shade of red that is least noticeable. The BBC’s lower third has the bright red for the logo, but they use a much more purplish red for most of it. That seems to mitigate the problem. I went right up to the TV today and the logo does look quite crappy, while the rest looks noticeably better albeit far from perfect.

With text you get the whole range at the edges ranging from white to the red I guess normally blended.

I’m a bit shocked that there is no codec that will get me out of this jam.

It’s really frustrating too because the amount of information in my stuff is minimal. Many many frames are repeated 100 times. But the compressors don’t take advantage of that.

Suppose you had a video of single stop sign drawn in illustrator over 5 minutes + audio. It seems you’d have to take on all these ugly fringing effects and still have a file size proportional to the time.

I would have thought the codec geniuses would have done better by text. Not happy about this.

[Jerry Smith]

Actually, MJPEG has 4:4:4 that I can use. Albeit at 1280×720 only.

The file sizes are really nice.

But I’d like to up the quality. Do you guys know if I can make it near lossless?