fre 2023-12-29 klockan 10:44 +1100 skrev glen english LIST: > Hi Tomas > "codec2 + zip makes for even smaller files" > > implying that there is still redundancy to remove in the codec2 > encoded voice files ???? > That sounds like low hanging fruit to pick.
That is not surprising. In speech you can lower the signal rate by talking more slowly. This and repetition happens often over the air. Silence doesn't require more bits to encode than the length of the silence. I think Dave posted on his blog a while back that the effective data rate of human speech is on the order of 1-10 bit/s or so As for it being low-hanging, variable bitrate may be something to consider for future modes. If there is silence, perhaps it is enough to just transmit a carrier? If 14 bits are enough for a frame rather then 28 because reasons, then maybe Manchester code those bits. Or use a lower baudrate for those bits, but I'm not sure how that interacts with modem stuff. Oh and that would require a breaking change to the .c2 file format, unless you pad with zeroes For files this isn't a huge issue I think. Might be fun to cram an entire 10 hour audio book onto a floppy though /Tomas _______________________________________________ Freetel-codec2 mailing list Freetel-codec2@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freetel-codec2
