How to get the least loss of video quality when recoding MKV file

[dave in or]

First of all thanks for the replies to my other posts. This is a great forum.

I've got an MKV file that plays poorly on my blu ray player. Through trying various things I've determined the only thing that needs to be altered is the reference frame number. The file has ref frame 8 and my player can only handle ref frame of 5.

So I need to recode and I want to have as little quality loss as possible. The only thing I can think of is to increase the video bitrate during the coding process. The file has a bitrate of about 9000 KB and I've tried increasing to 12mb 14mb 16mb with 30 sec. clips. I'm wondering if this would help keep video quality high. Since I only used such small clips to test I wonder if there could be some glitches if I recode the whole thing with a higher bitrate. Also curious if the audio could get out of sync with the higher bitrates.

Any ideas? will increasing video bitrate help, is there a noticeable difference between 12mb and 16mb?

Any other things that could help keep quality high with a recode?

[aedipuss]

i'd just re-encode the video. either use a program that allows passthrough of the audio or use mkvextract gui to get just the video and then put it back together with mkvmerge gui. you could probably get good enough results sticking with the 9mbps rate, if the source is good quality. going higher isn't really going to do all that much, if you use high quality settings for the encode.

[jagabo]

Use an encoder that supports constant quality encoding. Select the quality you want, encode.

[dave in or]

A couple of questions: What are the "high quality settings" I should use? And what encoders have a constant quality setting?

I've been using MediaCoder. Any suggestions for an encoder to use?

Thanks!

[jagabo]

In Mediacoder try x264 at CRF ~18. Use a higher value for less quality and a smaller file, or a lower for more quality and a larger file.

[dave in or]

jagabo, I haven't been able to find the setting you suggest, can you be a bit more specific as to where I can make that change, Thanks.

[jagabo]

Meidacoder doesn't let you set it directly. On the video tab, set the Encoder to h.264 (x264), Rate Mode to Variable Bitrate, above that use the pulldown to select Video Quality, then set the Quality to 64. I usually use the "Very Fast" preset with a few modifications, 2-bframes, 4 ref-frames.

[dave in or]

Is there a relationship between "CRF ~18" in your earlier post and "Quality to 64" in your recent post?

[jagabo]

Yes, setting Quality to 64 sets CRF to 18. I determined that by looking at the actual command line that Mediacoder generated. Don't worry about the CRF value, just try different quality values until you find something that you're happy with.

[dave in or]

sweet, thanks again.

[mlmiller707]

Does anyone know if AnyVideoConverter will lose any qualit going from .mkv to - .avi or .mpg. It only lists 2 channels, I want to retain the 1080p a/r and 5.1 channels with file.

[hello_hello]

Try Video To Video Converter (the installer offers to install adware but there's a portable version you can just download and run). It can copy both the audio and video, or re-encode one while copying the other, and I'm fairly sure it'll encode 5.1ch. When you open a file, select AVI from the list of conversion presets, then configure the audio and video on the right, or select "direct stream copy" if you just want to go from MKV to AVI without re-encoding anything.

I'm not very familiar with AnyVideoConverter, but I kind of remember it being limited to 2 channel. Keep in mind though, it might depend on the selected output format. There's no such thing as multi-channel MP3 (well there is, but nothing supports it and there's probably no free encoder) so if you convert to MP3 it'll have to be 2ch. AC3 and AAC support multi-channel.

[mlmiller707]

Try Video To Video Converter (the installer offers to install adware but there's a portable version you can just download and run). It can copy both the audio and video, or re-encode one while copying the other, and I'm fairly sure it'll encode 5.1ch. When you open a file, select AVI from the list of conversion presets, then configure the audio and video on the right, or select "direct stream copy" if you just want to go from MKV to AVI without re-encoding anything.

I'm not very familiar with AnyVideoConverter, but I kind of remember it being limited to 2 channel. Keep in mind though, it might depend on the selected output format. There's no such thing as multi-channel MP3 (well there is, but nothing supports it and there's probably no free encoder) so if you convert to MP3 it'll have to be 2ch. AC3 and AAC support multi-channel.

Ok Thanks for your reply. I am currently encoding with MediaCoder. I like it so far, we will see how it turns out and whether my ancient dvd player will play them.

[mlmiller707]

I have been using Mediacoder to trasncode a 4.89 gb file from mkv. to .avi.I am also making output ac3 1080p. I split the files, it has been working one file almost complete after over 10 hrs? Is that normal? Also there is no output file, it says output directory as same as input but only lists original files. I also searched whole pc for *.avi, it is not there. Does it have to wait till entire file is done until it renames it? Or doesn't produce two files one being the original and the other one the new. Or what is going on? The stats say one file skipped, but 0's for output. Thanks