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View Full Version : Winamp reads this AAC file, FAAD doesn't

Rain_1
21st March 2012, 04:30
Hey there.

I've been capturing some ISDB-T International streams and I'm getting some .AAC files that nothing can read properly.

After making a fool of myself on the "HDTV / DVB / TiVo" forum and reading the Audio FAQ here, I managed to get the .AAC file to be read on Winamp, after installing CoreAAC and the AAC Parser. However, the file is not read on other players (DirectShow enabled or not), EXCEPT for Winamp.

FAAD tells me that there was an "Error initializing decoder library." Winamp, which plays the file, on the other hand tells me:

Payload Size: 672225 bytes
Format: AAC
MPEG-4 HE-AAC (Implicitly Signalled)
Sample Rate: 24000 (Output: 48000)
SBR: Present
Channels: 2 Mode: Stereo
Bitrate: VBR (51)

I tried to manually input the Sample Rate (-s 24000 on FAAD), but I still get the error.

Here's the .AAC file.

Sample 1 Audio 1 (http://rain01.free.fr/ISDBT/test_1min%20PID%20112%20DELAY%20-165ms.aac)

I'd be fine with using Winamp to convert the file to .WAV, however a command-line solution (like FAAD) would make the video encoding faster. Also, I'm worried about what will happen when I stumble upon a multi-channel Audio Stream. I don't think "Disk Out Plugin" on winamp will treat that well.

The Video Stream had another Audio Track, also in AAC (I believe), but Neither winamp or FAAD managed to read that one.

I'll throw the untouched .MPG file that my Tuner spits out and the other audio stream, which I think is messed up (as not even my tuner plays the second audio). Any help is appreciated!

Sample 1 (http://rain01.free.fr/ISDBT/test_1min.mpg) - Sample 1 Audio 2 (http://rain01.free.fr/ISDBT/test_1min%20PID%20113%20DELAY%2012067ms.aac)
Midzuki
21st March 2012, 05:44
"Sample 1" is a LATM stream (according to MediaInfo)

ffmpeg decodes it fine :)

( so you are from Brazil alright ;) )
Rain_1
21st March 2012, 06:00
Yes, I'm from Brazil. :D

ffmpeg did decode it properly, thanks!

There's no Avisynth plugin compatible with LATM, right?

Knowing it's actual name makes everything much easier. Thank you.

Edit: hey, it decoded the second audio stream too!
Midzuki
21st March 2012, 06:36
Thank you.

De nada. ;)

Edit: hey, it decoded the second audio stream too!

But of course. :)
tebasuna51
21st March 2012, 10:38
You have also other option using vlc:

vlc.exe -I dummy aud_latm.aac --sout #std{access=file,mux=mp4,dst="aud_nolatm.mp4"} vlc://quit

See http://forum.doom9.org/showthread.php?t=157467

and you obtain a standard AAC audio, without recode but now without problems to play, ready to be muxed in mp4 or mkv container.
pandy
21st March 2012, 12:02
ffmpeg did decode it properly, thanks!

There's no Avisynth plugin compatible with LATM, right?


http://forum.doom9.org/showthread.php?t=127037
Rain_1
21st March 2012, 15:49
You have also other option using vlc:

vlc.exe -I dummy aud_latm.aac --sout #std{access=file,mux=mp4,dst="aud_nolatm.mp4"} vlc://quit

See http://forum.doom9.org/showthread.php?t=157467

and you obtain a standard AAC audio, without recode but now without problems to play, ready to be muxed in mp4 or mkv container.
That's very interesting. I'll try to stick using ffmpeg for a while, mostly because AC3 is my final encoding target (I know, re-encoding sucks), but I also need to import the audio stream into AviSynth, because I cut up commercials in AviSynth with Trim().

But it's great to have options.

http://forum.doom9.org/showthread.php?t=127037
For some reason, FFAudioSource() doesn't recognize audio sources neither on the original .mpg or the demuxed .aac..

I can't find any mention of LATM on the thread either...