Buriedcode
Full Member level 6
Hi,
I posted in the 'digital comms' forum a few days ago, but no results.....I guess thats because I was asking about high quality audio compression for music/voice
the original post:
Ultimately, its a for a wireless headset, so high quality stereo audio being recieved, and mono medium quality audio transmitted. My limitation in RF bandwidth is about 1-1.5MB/s, so no 'major' compression needed. 2:1 would be fine, but 4:1 would be perfect.
As mentioned in the other post, the main points are low latency (hopefully<30ms for both encode and decode) and high quality. In the same vein as bluetooths SBC, or apt-x...I have also looked at CELT.
I am also limited in hardware, since I really don't want to go down the DSP route (although it looks highly likely) so perhaps an ARM7 processor limiting the code to fixed point math?
I have seen fairly fast MP3 decoders on the arm7 achitecture, which use 'similar' principles to sub band coding, only with more processes, so I am hoping that there is a fairly simple codec out there which can work at low latency, and provide very high quality with a small compression ratio (2-4:1). Obviously source code would be a godsend But I have yet to see any SBC (sub band coding) source code for anything, as its usually integrated into bluetooth baseband processors.
Any help would be appreciated
Buriedcode
I posted in the 'digital comms' forum a few days ago, but no results.....I guess thats because I was asking about high quality audio compression for music/voice
the original post:
Ultimately, its a for a wireless headset, so high quality stereo audio being recieved, and mono medium quality audio transmitted. My limitation in RF bandwidth is about 1-1.5MB/s, so no 'major' compression needed. 2:1 would be fine, but 4:1 would be perfect.
As mentioned in the other post, the main points are low latency (hopefully<30ms for both encode and decode) and high quality. In the same vein as bluetooths SBC, or apt-x...I have also looked at CELT.
I am also limited in hardware, since I really don't want to go down the DSP route (although it looks highly likely) so perhaps an ARM7 processor limiting the code to fixed point math?
I have seen fairly fast MP3 decoders on the arm7 achitecture, which use 'similar' principles to sub band coding, only with more processes, so I am hoping that there is a fairly simple codec out there which can work at low latency, and provide very high quality with a small compression ratio (2-4:1). Obviously source code would be a godsend
But I have yet to see any SBC (sub band coding) source code for anything, as its usually integrated into bluetooth baseband processors.Any help would be appreciated
Buriedcode