search

mstorsjo / fdk-aac

A standalone library of the Fraunhofer FDK AAC code from Android.
https://sourceforge.net/projects/opencore-amr/
Other
1.18k stars 389 forks source link

Trouble with encoder test example (aac_enc.c) using AAC-ELD #102

Open fdkaaclover opened 5 years ago

fdkaaclover commented 5 years ago

I tried to use aac-enc.c example to generate AAC-ELD audio format. No problem in compilation. But when running the example using option -t 39 as indicated in Supported AOTs in help menu, I got error message " Unable to initialize the encoder". Does anyone successfully encode audio wave file in AAC-ELD format?

mstorsjo commented 5 years ago

Right, I should maybe remove that from the help text for the example. That example, aac-enc.c, writes AAC data in ADTS format, but that format only supports the simplest profiles (and requires e.g. backwards compatible signaling of HE-AAC), but AAC-ELD can only be encoded in raw form (AACENC_TRANSMUX set to TT_MP4_RAW) and then muxed e.g. into mp4, but that's out of scope for the example. If encoding via e.g. libavcodec, it should work fine.

fdkaaclover commented 5 years ago

Thank you for your quick response. If possible, could you provide AAC-ELD in aac-enc.c ? The raw form should be fine if decoder example aac-dec.c can recognize it.

mstorsjo commented 5 years ago

It's not that easy - you can't easily just write the raw form of AAC to a file and read it out, the raw form requires using some sort of container around it, and mp4/m4a is a bit too much for the small examples.