If you were using simply 16/32bit 2ch input, you might not have met any troubles so far (like me). In this case, sample size (in bytes) is multiple of 2, and probably there's less possibility of partial read breaking in the middle of sample boundary.
Long awaited qaac 2.5 is out!
[qaac] release 2.08 (refalac 1.08)posted 1 minute ago by nu 774Now copy chapters from ALAC/m4a input (when available).Delay Nero style chapter point as much as the encoder delay (2112 samples). It seems that Nero AAC encoder was previously using Nero style chapter to signal encoder delay this way, and fb2k is in honor of it.Note that Nero style chapter is a list of <title, start time> pairs, therefore first chapter can start at arbitrary point, while last chapter goes until the end of the track.On the other hand, QuickTime style chapter is a list of <title, duration> pairs, therefore first chapter always starts from the beginning of the track, while last chapter can end at arbitrary point.qaac will write both style chapters (for the sake of compatibility), but these two have subtle difference and incompatibility.Now writes actual duration into edts. This is done mainly for QuickTime which doesn't look iTunSMPB thingy. Now QuickTime can trim zero-padding and decode sample accurately (whole song / each sub-chapters).Technically, there's no way to tell the value of encoder delay to QuickTime player. It just silently assumes implicit AAC delay of 2112 samples, and automatically crops that amount from the beginning --- it just works with qaac because qaac is using their encoder. edts is used here in order to just let them trim the trailing zero paddings.
If qaac were to also use edts for trimming the encoder delay, would that break the gapless playback in QuickTime, since it always skips 2112 samples?
foo_abx 1.3.4 reportfoobar2000 v1.1.182012/12/25 12:36:05File A: C:\Users\Olav\Desktop\3929430_Lessons_In_Love_feat__Neon_Trees_Headhunterz_Remix.wavFile B: C:\Users\Olav\Desktop\QAAC TVBR 127\3929430_Lessons_In_Love_feat__Neon_Trees_Headhunterz_Remix.m4a12:36:05 : Test started.12:37:08 : 01/01 50.0%12:38:06 : 02/02 25.0%12:38:57 : 03/03 12.5%12:39:42 : 04/04 6.3%12:42:34 : 05/05 3.1%12:43:14 : Test finished. ---------- Total: 5/5 (3.1%)
BTW, new qaac uploaded, 2.10https://sites.google.com/site/qaacpage/cabinetNo changelog yet
Changed --delay option spec. --delay now accepts either duration in time or number of samples. If you are used to timespec of sox, you should be already familiar with it. The format is as following:--delay=[hh:[mm:]]ss[.sss]...--delay=<integer>sIn the first case, parts surrounded by brackets can be omitted. So, --delay=100 means 100 seconds, --delay=-10.72 means -10.72 seconds, --delay=02:53.1 means 2 minutes and 53.1 seconds, and so on.Second case is for number of samples. You just put an integer followed by "s" (means "samples"). --delay=-2112s or something.HTOA support. Now index 00 of first track in cue sheet is encoded into track 0.Fixed a bug of cue sheet parser. Last line of cue was ignored if the last line is ending with a white space character other than LF.
I was wondering why you have no example for the mp3 conversion syntax to preserve the quality of the input as much as possible.
Well, if you want higher quality, just raise bitrate or something. Period.However, if you encode 64kbps MP3 into 320kbps AAC, the result gets 5 times larger than input in file size, but is still worse than input in quality. Lossy to lossy conversion works like that. Sounds ridiculous?..
What's great about qaac is that, unlike ffmpeg which sometimes defaults to ADTS, it produces real QT/Itunes compatible m4a on the spot!
I wonder how QAAC encoder compares to libvo_aacenc?
qaac -v256 --verbose audio.ac3 -o audio.m4a
qaac does not support AC3 input. So, you have to decode it before passing it to qaac (by ffmpeg, avconv or something). As for 5.1ch -> stereo mixdown by qaac, read the following:https://github.com/nu774/qaac/wiki/Matrix-mixer
MeGUI supports transcoding from AC3 to AAC using QAAC if you enable its support in the latest development update (and restart it). It also supports downmix with e.g. Dolby ProLogic II matrix.Please note that MeGUI won't ensure the presence of the Apple CoreAudioToolbox DLLs; the user will be responsible to fulfill this prerequisite.
Quality of libvo_aacenc is not comparable to state-of-the-art commercial encoders of Apple or FhG. If you can, use libfdk_aac instead on ffmpeg (although you have to make it yourself).