Within a Superframe, there are (depending on the usage of SBR, and of 48/32 kHz) 2 to 6 AAC frames of variable length. A Superframe is a special container defined by DAB+ (ETSI TS 102 563) that has a fixed length (for a given service). ODR-AudioEnc does not produce plain AAC frames, but the so-called Superframes. just an MP4/ISOBMFF container or an LATM stream. So for correct playback, such AAC content has to be stored in a format that contains this config. The 960/1024 samples/frame signalling is done by the frameLengthFlag within the GASpecificConfig, which in turn is contained in the AudioSpecificConfig (all defined in ISO 14496-3). But this signalling is required, as all AAC decoders (I have seen so far) otherwise default to 1024 samples/frame and the audio sounds slow and low-pitched, as described! The problem is that these streams use the ADTS format, which cannot incorporate the signalling whether 960 or 1024 was used. Stream #0:1: Audio: aac, 48000 Hz, stereoĪt least one output file must be specifiedĪll that DABMON streams are still AAC with 960 samples/frame.

If you want to help, upload a sample of this file to and contact the ffmpeg-devel mailing list. If the problem still occurs, it means that your file has a feature which has not been implemented.

Update your FFmpeg version to the newest one from Git.

An aac sample with 960/120 MDCT was uploaded by a user, mdct_error.flv is now in samples/A-codecs/AACįfmpeg version N-41284-ge00b2d2 Copyright (c) 2000-2012 the FFmpeg developersĬonfiguration: -cc=/usr/local/gcc-4.3.2/bin/gcc -enable-gpl -enable-libopenjpeg -enable-libvorbis -enable-libspeex -enable-libmp3lame -enable-libtheora -extra-ldflags=-lm -enable-libvpx -enable-libxavs

He aac v2 sample file