Merging different bitrates

[carlmart]

I wonder if this would work, but to me sounds like a probable way to improve conversion quality.

My experience using Vidcoder to convert my mkv files is proving very good. To improve conversion times I am not processing the audio track, as I usually already convert DTS to Dolby 5.1 using AvsP/Avisynth.

So I wonder if I can split the video & audio files before conversion, leaving the final titles on a separate video.

As I target for final size, sacrificing bitrate, in that way I may increase bitrate a little on the "main" video part. The "titles" part I can process with less bitrate. Arithmetically that should work.

Then I could merge this both on MKVmerge and end up theoretically with a mixed bitrate final video.

First of all: would this work?

Second: is it worth it?

[transporterfan]

Why would you want to? Are you working to a specific file size?
The time you waste splitting files like that would take longer than the transcoding.

1st. Probably.
2nd. Probably not.

[carlmart]

Yes, I do work for a maximum target size: 8Gb.

Splitting a file with MKV merge takes just a few minutes.

[transporterfan]

Ah, right. Have you considered though that you have to 'tool up' three times?
Once for the titles bitrate, again for the main, again for the credits; then you have to check the quality is to your liking.
Then recombine. Then test joins...
Sorry. It just seems like a lot of work.

[Cornucopia]

Not only that, but you are missing out on the automation capable of being used through 2passVBR or CQ/CRF type encoding, which SPECIFICALLY address the kinds of bitrate adjustments in different sequences like you are worried about.

Don't need to reinvent the wheel here.

*Note: there is also in pro-encoding environments, a feature known as "segment-based re-encoding" that goes back to square-one for limited sections and encodes a new bitrate from the original at quality levels manually-specified and overridden from the usual automatic. But this is primarily necessary for tape-based sources. Multipass encoding usually covers all the main variations expected.

Scott

[jman98]

You're not the first guy to ever think of this. Years ago when Divx/Xvid was very common and DVD burners were extremely expensive so few people had them, people were obsessed with this very thing. One of the more popular Divx/Xvid encoding programs allowed you to do this - use a much lower bit rate on the credits. Nobody seems interested in this topic any more because it's just not all that important now that DVD burners are cheap. Even if you found a way to do it, I don't think it would really make a lot of difference.

Would your life not be a lot easier if you just bought this device instead of converting everything? (This is the Western Digital TV Live player with the page in Portuguese)
http://www.wdc.com/pt/products/products.aspx?id=320

[jagabo]

Some encoders let you apply weightings to different parts of the video. That allows you to specify a different quality for different sections. So you could, for example, have the encoder use less bitrate than it normally would on the end credits. But using half as much bitrate on a few minutes of end credits will only allow a little more for the main movie. You won't even notice the difference in the main movie.

[brusno]

As I target for final size, sacrificing bitrate, in that way I may increase bitrate a little on the "main" video part. The "titles" part I can process with less bitrate. Arithmetically that should work.

I think you can convert a film and use different bitrates at different areas in it with the parameter "zones" in x264.exe.
Example:
D:\x264.exe --output "outputfile.h264" "inputfile.avs" --bitrate 1500 --zones 0,1000,b=0.5/73000,75000,b=0.33

In this example the video will get bitrate 1500 kbps, while the beginning (0 - 1000) will get 1500/2 =750 kbps, and the end (73000 - 75000) will get 1500/3 = 500 kbps.

But then you have to use x264.exe (CLI).