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View Full Version : Lame only reads part of aac file


bur
7th July 2009, 14:25
I have an m4b file that I wanted to convert to mp3 to be able to play it on my cellphone. I extracted the aac stream with YAMB and then tried to convert the aac file with lame, but the result was a small file with only about 23 min playtime instead of 8h 30min.

I also noticed that when playing the aac in Winamp the remaining playtime skips all the time and Winamp doesn't seem to know when the file will end. If just left playing it plays it to the end, you just can't fast forward to some regions.

Is that a known behaviour for aac files with variable bitrate (or do they all have variable bitrate)? And is there any way to transcode the file besides doing an "what-you-hear"-recording? Maybe the header needs fixing because the stream came from an m4b file?


edit: I told YAMB now to extract to mp4 instead of raw stream. The resulting file works in Winamp, playtime is shown properly, fast forward works, but still Lame only encodes the first 52xxx frames of the file.

buzzqw
7th July 2009, 14:30
lame support aac input ???

better to decode to wav first

BHH

smok3
7th July 2009, 14:34
or use foobar2000, afaik you should be able to go directly from mp4 to mp3.

bur
7th July 2009, 15:40
lame support aac input ???It seems so, at least it accepts the input file and also produces a sort of proper output.

or use foobar2000, afaik you should be able to go directly from mp4 to mp3. Are all the mp3 encoding options like vbr available there?

Anyway I'd rather use a small tool for converting mp4 to wav instead of installing a whole audio player. Yes, I know foobar is better than WInamp... ;)


edit 1: I saved the mp4 as wav with Winamp and am now encoding the wave file with lame. It seems like all works now.

edit 2: lame completed and the file seems okay, but it says 1142149/6734553 (17%) on the frame count. I don't know why this happened, but it doesn't seem to have any impact on the result...

Gew
14th January 2012, 15:24
I know this is somewhat a long bump, yet it seems this is still an issue. I'm sitting here with the Win32 build that comes out of lame3.98.4-libsndfile.zip (RareWares). I know this build is officially supporting FLAC input. That was also all I thought it would do. Anyway, just for kicks, I tried a fool's game:
lame.exe -v input.mp4 output.mp3I was expecting something like "Unsupported input", but it actually went on with the encode, read sample rate and all. However, my input AAC stream was almost half an hour, but the produced MP3 was less than four minutes. Any ideas why this is?

Cheers!
:thanks: