How-to postencode Audio AAC (Dolby Pro Logic II)

[jbjoret]

Hi, I have encoded a long and complex movie (RAN) in HD and realized too late that the DTS audio convertion to AAC+AC3 had a bad mapping. I have reencoded the AC3 track and was able to replace it using eac3to (Windows) and Subler (Mac), but now I would like to be able to convert the DTS track to a AAC 160kbps (Dolby Pro Logic II) track as well to replace the first audio track for my movie since the mapping of the current AAC track is wrong. The tools embedded in Handbrake are capable of that but there don't seem to be any way to do this withour reencoding the whole movie incl the video track. Any suggestions ? I tried to do this with NeroEncAAC but there is no option to set the bitrate and the Dolby Pro Logic Encoding.

[rhester]

NeroAACEnc definitely supports bitrates (in one or two passes), but does not do DPL(2).

You can use HandBrake to encode the video track to a crazy-low resolution and bitrate using the ffmpeg codec (to minimize time waste) and then pull out the AAC track and remux.

Rodney

[jbjoret]

NeroAACEnc definitely supports bitrates (in one or two passes), but does not do DPL(2).

You can use HandBrake to encode the video track to a crazy-low resolution and bitrate using the ffmpeg codec (to minimize time waste) and then pull out the AAC track and remux.

Rodney

Thx Rodney. Do you by chance happen to know what parameter to use with eac3to for NeroAACEnc, because the documentation only specifies a value between 0 and 1. SO I have no Idea how to tell Nero to map the 5.1 channels to a 2 channel Dolby Pro Logic II. I was also thinking of creating a file with video, but that would have been too easy . Actually I could also leave it like this since the AC3 track is good. But I am curious, and like to solve those kind of issues.

[rhester]

0-1 is the encoding quality, which means eac3to doesn't support Nero's bitrate mode, only CQ.

As stated previously, Nero knows nothing about Dolby Pro Logic - if eac3to doesn't offer that downmix, it won't be possible with that toolchain.

Rodney