Dear Ulrich, Thanks for your answer.>Well, today 4 GiB is about half an hour of 8-channel, 96 kHz, 24-bit >uncompressed audio, or about 0.9 % of the capacity of a modest 2 TB >HDD. Not much, in other words, and who hasn't cursed yet at artificial >4 GiB (or even 2 GiB) limitations? So I wouldn't be too sure about the >"ever", even though it does seem very far away at the moment.OK, I get the point, but even at 192 kb/s, 32 bit sample resolution and say... about 100 channels (but by the very definition of a sample count one should consider one sample per frame, even if it has 100 subframes) one would have room for a 7616 year file! It seems a bet for a long life for FLAC --and for humankind! Best regards, Federico Miyara
Federico Miyara wrote:> Thanks for your answer. > > >Well, today 4 GiB is about half an hour of 8-channel, 96 kHz, 24-bit > >uncompressed audio, or about 0.9 % of the capacity of a modest 2 TB > >HDD. Not much, in other words, and who hasn't cursed yet at artificial > >4 GiB (or even 2 GiB) limitations? So I wouldn't be too sure about the > >"ever", even though it does seem very far away at the moment. > > OK, I get the point, but even at 192 kb/s, 32 bit sample resolution > and say... about 100 channels (but by the very definition of a sample > count one should consider one sample per frame, even if it has 100 > subframes) one would have room for a 7616 year file!Its not that we need space for 7616 years, its that if we only use 32 bit offsets, then we would be limited to files of 2 Gigabytes (signed 32 bit integer) is simply not enough. For instance, at 96kHz/24 bits, recording 8 channels would chew up the 2Gigabytes in about 15 minutes. Some songs are longer than that, If 32 bits is not enough, the next logical amount is 64 bits. Erik -- ---------------------------------------------------------------------- Erik de Castro Lopo http://www.mega-nerd.com/
Dear Erik,>Its not that we need space for 7616 years, its that if we only use >32 bit offsets, then we would be limited to files of 2 Gigabytes >(signed 32 bit integer) is simply not enough. > >For instance, at 96kHz/24 bits, recording 8 channels would chew up >the 2Gigabytes in about 15 minutes. Some songs are longer than that, > >If 32 bits is not enough, the next logical amount is 64 bits.Fact is that FLAC is highly economical in items such as reserving 20 bits for sampling rate or 3 bits in the middle of the middle of a byte for number of channels (which are, in fact, currently too few for applications such as beamforming that use arrays of several dozen microphones), so the next logical amount could easily be 40 bits, which would suffice for 50 h recording at 192 kHz / 32 bits / 8 channels; or even 48 bit, which allows for 1.5 year recordings (not unlikely, however, in long-term soundscape continuous recordings). If the file turns to be that huge, an efficient search would demand probably quite a few seek points, perhaps about 0.01 % the sample count, which might involve a huge amount of extra bytes because of this choice (4 bytes per seek point, assuming 64 bit instead of 48 above). I don't find this explanation convincing enough. May be there is another reason that just reserving space for the far far future? Best regards, Federico