Bitrate conversion question

[32768]

Okay so I have some 600KB/sec bitrate (video BR) .FLV that I'd like to convert to H.264 to play on iDevices.

If I use SUPER to convert as so, what bit rate should I set it to avoid excessive loss of quality, without "oversampling"?

I expect tiny losses, but not easily detectable.

[Baldrick]

THe flv might already be in h264 video. Check with Mediainfo. Then remux with for example avidemux, open flv, under video and audio choose copy, save as a new mp4.

Or else use about same bitrate or constant quality encoding mode.

[32768]

I have once tried to convert using the same bitrate on another movie (flv, IIRC) and found out that it was "oversampled". Does CQEM as you described negate such an issue?

[jagabo]

Yes, constant quality encoding uses exactly the right bitrate to deliver the quality you specify. If the quality can be met with a low bitrate that's what you'll get.

[32768]

So this means I'll have to make some test runs to find out which settings will produce the results desired?

I did have some Planet Earth DVDs I ripped, I figured 768Kbps was about the limit of the iDevices. I have (and Apple doesn't say) NO idea what the max bitrate they can handle. Soooo the quality is "Okay" but I have always wondered if it could be better.

[jagabo]

So this means I'll have to make some test runs to find out which settings will produce the results desired?

Yes. You don't need to encode an entire movie. Just pick out varied scenes for testing. With most codecs problems first appear in dark noisy areas and in smooth gradients. So look there carefully.

Once you've figured out what quality level you can live with you can encode all your videos with that setting. Maybe a little higher quality for important videos, lower for unimportant videos.

[32768]

Update: Yeah the MediaInfo in SUPER showed that it was AVC.

Done. I didn't see a checkbox for CQE, so maybe I missed something. (Top Quality?)

Also: A quick question: In a video (let's pick a normal video), does the file maintain keyframes (more or less just raw images) and then keep data on what changes from one keyframe to the next?

EDIT: Additionally: How much longer in time do y'all think H.264 will last? 'nother decade?

[jagabo]

I didn't see a checkbox for CQE, so maybe I missed something. (Top Quality?)

I don't use Super but in x264 it's called CRF mode. You may have to switch Super to single pass mode for it to show you the settings.

In a video (let's pick a normal video), does the file maintain keyframes (more or less just raw images) and then keep data on what changes from one keyframe to the next?

Yes, key frames are like JPEG images. All the data needed to reconstruct the image is in the key frame. Other frames only include changes from frame to frame.

How much longer in time do y'all think H.264 will last? 'nother decade?

I'm sure it will be common for at least that long. Many cable and satellite systems have switched to it. Blu-ray uses it. Youtube. Etc.

[32768]

Now another question.

How come we can't use a small handful of codecs and containers for just about everything? I mean how many do we really need? .flv doesn't need to even exist, we can embed with mp4/AVC (which, apparently I have been seeing more, or just AVC in .flv). The difference between a video you upload to YouTube that gets converted from .wmv (let's say version 8) to .flv and .mp4, and in the process murdering the bitrate (for slow internets) is needless.

If we removed all the silly licensing agreements (like .ogg Vorbis video) and just all got along, (good luck with that) couldn't we do that? Obviously you need a RAW format for dumping direct, and maybe an oddball, the rest is pointless (like RealVideo).

[jagabo]

How come we can't use a small handful of codecs and containers for just about everything?

Because every engineer was the smartest kid in his class when he was in school. Hence every engineer thinks he can do anything better than anyone else. So every engineer has to make his own codec and container because it will be better than all the others.

If we removed all the silly licensing agreements

You'll have to discuss that with MPEG LA, Apple, Microsoft, Adobe...

[jman98]

If we removed all the silly licensing agreements (like .ogg Vorbis video)

Um, Vorbis is FREE so any "licensing" agreement exists merely to keep it that way. By the way Vorbis was created out of the fear that licensing restrictions and costs for the successor to MPEG-2 would make it essentially impossible for common people to use it. That did not end up happening but it's what drove the project in the beginning.