Video Converter Video Converter not recompressing

[mattyj2001]

Howdy -

I'm using DVDFab 9.1.7.1 for the Mac, running Yosemite.

If I rip/convert a title directly from the Bluray, it compresses the file to a little under half the size it is on disk. So far so good.

However, if I take (for example) the same track and rip it using 'mkv passthrough' or 'mp4 passthrough', then take that resulting file and feed it through the default mp4 profile, it won't compress the file.

On the video converter sidebar it displays the target file size I should expect by converting/compressing it (88 MB from a 211 MB uncompressed file) but it doesn't actually compress the video.

At the same time I'm converting the audio track to AAC, and that is working fine, but the video seems like it is doing a passthrough.

The above is just an example. My situation is that I have 100's of uncompressed mkv's lying around, and I want to play them through a Roku. This means I need to convert audio to AAC, but at the same time I thought I may as well make them smaller. HandBrake will compress them just fine but it goes incredibly slow, and the interface is clunky. I purchased the Video Converter module for DVDFab just for this purpose but it doesn't seem to recognize that I want it to compress the MP4 stream within the MKV.

I've run some mpeg and avi's through it and it compresses those wicked fast and with great quality, etc., it's just that it doesn't seem to want to compress an MKV MP4 stream into a smaller MP4 file.

I've attached my log file in case anyone from support wants to have a look. The first section is the results of trying to compress an MKV file. The second is when I ripped the same title off the disk (in which case it does compress it.)

Thanks!

[mattyj2001]

It's Mac OpenCL

I found that if you set the H.264 decoder to to Mac OpenCL, it won't work right on source files of a certain size, perhaps over 500 MB or so. If I keep the same settings and try to re-encode something smaller it works fine. Larger files end up doing passthrough for the video.

Perhaps one of the DvdFab authors can have a look, seems like a bug with the Mac OpenCL implementation/usage.

[Wilson.Wang]

Hi,

DVDFab will not reencode and passthrough video & audioif using profile "mkv.passthrough".

Please select profile "mkv" if you want a samller video size.

Wilson

[mattyj2001]

I'm still running into this on occasion, but for some reason not on all occasions.

I've double-checked that I'm not in a passthrough mode. I'm in a regular mp4 mode. I've double checked that I'm using single-pass, 'standard' quality for video.

Yet, most conversions/compressions from mkv to mp4 do a passthrough of the video without compressing it. If I leave all settings alone except for the A/V Codec settings (turning off OpenCL and setting all three dropdowns to 'software') it will work fine, albeit much slower.

I have a mix of bluray titles and regular DVD titles. Most of the bluray mkv's, which are generally 30 GB or larger, will not work properly. Though the regular DVD mkv's, which are generally around 5 GB or less, work fine. Even when I have them in the same queue with the same settings.

A telltale sign that it's not working is that the progress bar won't show any progress while it's erroneously doing the passthrough, nor will it show the fps and estimated time remaining at the bottom.

I'm wondering if it's a memory issue with OpenCL, but I've tried setting it to 'auto', 'max', etc. and it still has problems with large mkv files.

Interestingly, if I break out the original bluray disc and use the ripper on the same tittle, it works fine. The problem is that I have hundreds of mkv's that my new media player wants to re-encode as it plays, so I want to convert them all to a native format that will work without taxing the system so much on playback.

For now I'll change all the A/V Codec settings to software, but it would be nice to be able to take advantage of OpenCL on larger files.

[mattyj2001]

This is still problem with 9.1.7.9.

I've found that the problem occurs only in larger H264 MP4 AVC files in the MVK container, trying to recompress them with the MP4 profile.

I ran into a couple rips (most notable O Brother Where Art Thou?) that ripped from the Bluray in Windows Media Video VC1, and it worked fine even though it's a big file (23 GB.)

It still looks like an H264 file will not recompress unless you have OpenCL disabled.

[Dora]

mattyj2001
From you post log in thread1. You compress failed using opencl.

From log you input recode was same with the output recode. It also does not recompress sames ok. Can you give us a log that same source using Opencl and not using opencl. The same output settings, results size.

[mattyj2001]

Sure thing. Here's how I obtained the attached log.

I used what is essentially an MKV passthrough copy of the first chapter of The Mechanic, which is 1.7 GB in size. VLC reports that the video codec is "H264 - MPEG-4 AVC (part 10) (avc1)".

I drop that mkv into the corverter tab, set the MP4.Default profile (fast encode, standard video quality) and ensure that the Video Decoder H.264 setting is "Software".

The conversion takes a few minutes and produces an mp4 file that is close to the estimation on the sidebar (see attached screenshot.)

Then I change the H.264 setting to "Mac OpenCL" and run the conversion again, without touching anything else. It takes just a few seconds to run and produces an mp4 file that is about 1.5 GB in size, even though the side bar shows it should be 273 MB. Here's a file listing where you can get a better idea of the source and processed file sizes:

$ ls -lh MECHANIC__THE.Title1.*
-rw-r--r-- 1 mattyj staff 1.6G Dec 27 01:38 MECHANIC__THE.Title1.mkv
-rw-r--r-- 1 mattyj staff 1.4G Dec 27 02:05 MECHANIC__THE.Title1.opencl.mp4
-rw-r--r-- 1 mattyj staff 277M Dec 27 02:03 MECHANIC__THE.Title1.software.mp4

Thanks!