Hi,
I was wondering if it was possible to transcode losslessly from HE-AAC to AAC. I have a peace of HE-AAC audio which I would like to listen to on a HE-AAC incompatible hardware. My understanding of HE-AAC being it's roughly AAC LC with SBR to gain over bitrate, I thought it might be possible to reconstruct the 48KHz symmetric AAC frame without loss. Would anyone here know if it is possible ?
I think it's likely that your hardware can play HE-AAC file as LC-AAC if it is implicitly signaled.
If your hardware supports ADTS playback, try it first.
If not, try remuxing like the following:
mp4box -raw input.m4a && mp4box -add input_track1.aac -new output.m4a
I think it's likely that your hardware can play HE-AAC file as LC-AAC if it is implicitly signaled.
If your hardware supports ADTS playback, try it first.
If not, try remuxing like the following:
mp4box -raw input.m4a && mp4box -add input_track1.aac -new output.m4a
AFAIK HE-AAC plays the LC-AAC part on HE incompatible software/hardware. The sample rate will probably only be 22 Khz through.
Thanks for both your answers. I'll try this.
I knew I should never have changed my avatar away from a red panda; now I’ve been usurped.
HE-AAC consists of a 22kHz LC-AAC file, with some extra info (the HE part) on how to best guess the upper 22kHz from the LC part.
Non-HE-AAC players will see and play the 22kHz LC-AAC part and simply not do the extra reconstruction.
"Lossless transcoding" is a bit of a strange concept in there.
I knew I should never have changed my avatar away from a red panda; now I’ve been usurped.
You reap what you ...