Copy Video box missing in Video Converter

[kevinfritz]

(I had this attached to an old post in the feature requests forum, but decided it probably belongs here).

I want to convert an H264 encoded MP4 file with AC3 audio to an MP4 with AAC audio so my Roku 4 box will decode the audio versus passing it through like it does with AC3. I'm using DVDFAB 10 and when I choose the MP4 profile in "converter" mode, it will allow me to copy the audio from the source, but not the video. The box to copy video from source is missing, which means that video needs to be re-encoded. I tried the MP4 pass through mode and that copies video from source, but the copy audio (the AC3 I don't want) is pre-selected and cannot be un-selected. Essentially DVDFAB is just rebuilding the same movie from the source video and audio streams. The box to check "copy video" is missing. See the attached graphic for the advanced settings dialog box. I confirmed that the same issue exists in DVDFab 9.

Thanks,
kevinfritz

[ludicree]

Not sure if I am on the issue... but AC3 is 640kbit max.
Therefore an already highly compressed format from what would be a master stream at several mbit.

Re-compressing AC3 to AAC will result in very poor quality because of double reduction. Unless you can compress from the source again, which would make sense because AAC multichannel holds much more information at a smaller size than AC3.

Also the passthru of AC3 or the decoding to PCM and not passing it on... is mostly defined by a single switch in the player appliance. You might want to check that.

[kevinfritz]

Not sure if I am on the issue... but AC3 is 640kbit max.
Therefore an already highly compressed format from what would be a master stream at several mbit.

Re-compressing AC3 to AAC will result in very poor quality because of double reduction. Unless you can compress from the source again, which would make sense because AAC multichannel holds much more information at a smaller size than AC3.

Also the passthru of AC3 or the decoding to PCM and not passing it on... is mostly defined by a single switch in the player appliance. You might want to check that.

The quality of the sound is not an issue for me. I need AAC to be decoded by my Roku 4. I'm only outputting it to my TV which is also outputting to a subwoofer... 2.1 channel sound. My purpose of posting this was to point out that DVDFab was missing the ability to copy video, which was suggested by a developer to another user in the "Feature Requests" forum, who wanted to do the same thing. I do care about the video quality, and I"d like to "remux" the existing video with the new AAC audio, which DVDFab should be able to do per the developer.