Problems with AAC LATM decoding

[marwin321]

I am working on an audio project with AAC encoding with support for both ADTS and LOAS/LATM headers/containers. Using ADTS I am able to play my encoded files with VLC. This has been tested with lots of different input files and bitrates. However, when using LOAS/LATM, VLC continously reports the following warnings/errors while glitches are heard:

faad warning: Maximum number of bitstream elements exceeded
core warning: playback way too early (-145334): playing silence
core debug: inserting 6976 zeroes
faad warning: Maximum number of bitstream elements exceeded

Note that FFMPEG has no problem decoding/playing my LOAS/LATM AAC files.

I have uploaded a sample AAC-LC file containing a single sine wave @1kHz to http://www19.zippyshare.com/v/8xztpJKX/file.html. It is a mono track with LOAS/LATM container with no advanced tools (like TNS). The first 0.6 seconds of the file is silent.

As I expect VLC is able to decode LATM, I guess there is something wrong with my implementation, but I have not been able to figure it out. I guess the faad decoder warning means that the decoder is out of synch with the bitstream, not finding the ID_FIL or ID_END tags. However, FFMPEG plays the files without errors or warnings.

It would be greatly appreciated if someone with expertice in AAC could have a look at the sample file to see what I do wrong, or if there is an issue with VLC. I realize my question might be more related to the encoder implementation than to VLC, but I still believe the VLC warnings are unexpected.

Tested with release version 2.2.1 on Windows and latest nighlty builds on Linux.

Please let me know if I have used the wrong forum...

[Lotesdelere]

Yes, I can reproduce the issue.

You should create a new ticket on the VLC Trac with the links to your file and to this thread.

[marwin321]

Problem solved Misunderstanding in the specification.