Quote:
Originally Posted by tebasuna51
@kukushka
Maybe we can open a new thread to speak about AAC and muxer/demuxer's (Mp4Muxer/Mp4Box/MkvToolnix/tsMuxeR), but the relevant questions for this thread are clear:
- The directshow Nero 7 decoder, used by eac3to to decode .aac, cut the first 1024 samples (21,333 ms in 48 KHz) in 2.0 and is broken for 5.1.
Take in mind the problem.
- The encoder NeroAacEnc.exe, user by eac3to to encode .m4a, put the correct delay to compensate and can be decoded without problems with NeroAacDec, Qaac or ffmpeg. No problem with it.
- eac3to works fine extracting AAC from MKV/TS/M2TS containers, I obtain the same aac than I muxed previously.
Then, to avoid problems, you can use eac3to to extract and Qaac or ffmpeg to decode (or LWLibavAudioSource inside AviSynth).
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Greetings tebasuna51.
Thanks for the post. I'm using eac3to to convert aac to ac3, and struggling to understanding the delay issue. Appreciate if you could assist.
1. If direct from aac to ac3, 5ms silence seems to be inserted. This appears to agree with ffmpeg. Audacity is used for comparing the two.
2. If going from ts/mkv to ac3, Nero Audio Decoder would be used. This would seem to remove 42ms if the audio begins with silence. So the resulting ac3 would be either -37ms shorter or +5ms longer, depending on the initial content.
Does this behavior look correct to you? Is there a way not to use Nero for step 2?
Many thanks and best regards.