Max file size with 140 MBits/second Long GOP at DVinfo.net

Gints Klimanis · February 2nd, 2010, 07:51 PM

Even with Sandisk Extreme Pro 90 MByte/second flash cards, the Nanoflash uses only the maximum file size for Long GOP MPEG2 at 140 MBits/second. Is this something that will disappear with the detection of faster flash cards, or is the Nanoflash processor maxed out ?

Dan Keaton · February 3rd, 2010, 02:27 PM

Dear Gints,

As I understand your question, you are asking if we can increase the maximum file size from around 3.5 GB to something higher, for when you are using 140 Mbps per second.

We may be able to increase this some.

We have allowed ourselves a little extra room, for safety reasons, due to all of the work we have to do when we reach the "maximum file size".

We may be able to increase this closer to 4.0GB.

Gints Klimanis · February 3rd, 2010, 03:27 PM

Dan, I'm interested in using a smaller file sizes overall, even at higher bitrates. Your previous posts and Nanoflash FAQ indicate that it is difficult for the Nanoflash to keep up with file creation with at higher bitrates.

Dan Keaton · February 3rd, 2010, 06:04 PM

Dear Gints,

This gets complicated.

At lower bit rates, we can create smaller files, via the "Maximum File Size" parameter in the menu system.

When we reach this threshold, when the file is at the specified Maximum File Size, we open a new file, start writing to the new file, then, while all of this is happening, go back and close the previous file, and write out an index to every single frame in the previous file.

In simple language, we are very busy.

With higher bit rates, especially the very high bit rates, the nanoFlash is very busy.

We have to guarantee that all of this happens before the next file needs to be closed.

We just have to stay ahead of the game.

But, of course, there may be room for improvement in what we are doing.

Piotr Wozniacki · February 4th, 2010, 01:45 AM

Interestingly, even the Sony EX's own files (35mbps, 420) are written onto SxS in some 3.6GB chunks - quite a bit lower than the FAT32 size limit.

February 2nd, 2010, 07:51 PM	#1
Gints Klimanis Inner Circle Join Date: Jun 2003 Location: San Jose, CA Posts: 2,222	Max file size with 140 MBits/second Long GOP Even with Sandisk Extreme Pro 90 MByte/second flash cards, the Nanoflash uses only the maximum file size for Long GOP MPEG2 at 140 MBits/second. Is this something that will disappear with the detection of faster flash cards, or is the Nanoflash processor maxed out ?

February 3rd, 2010, 02:27 PM	#2
Dan Keaton Inner Circle Join Date: Dec 2002 Location: Augusta Georgia Posts: 5,421	Dear Gints, As I understand your question, you are asking if we can increase the maximum file size from around 3.5 GB to something higher, for when you are using 140 Mbps per second. We may be able to increase this some. We have allowed ourselves a little extra room, for safety reasons, due to all of the work we have to do when we reach the "maximum file size". We may be able to increase this closer to 4.0GB. __________________ Dan Keaton Augusta Georgia

February 3rd, 2010, 06:04 PM	#4
Dan Keaton Inner Circle Join Date: Dec 2002 Location: Augusta Georgia Posts: 5,421	Dear Gints, This gets complicated. At lower bit rates, we can create smaller files, via the "Maximum File Size" parameter in the menu system. When we reach this threshold, when the file is at the specified Maximum File Size, we open a new file, start writing to the new file, then, while all of this is happening, go back and close the previous file, and write out an index to every single frame in the previous file. In simple language, we are very busy. With higher bit rates, especially the very high bit rates, the nanoFlash is very busy. We have to guarantee that all of this happens before the next file needs to be closed. We just have to stay ahead of the game. But, of course, there may be room for improvement in what we are doing. __________________ Dan Keaton Augusta Georgia

February 4th, 2010, 01:45 AM	#5
Piotr Wozniacki Inner Circle Join Date: Aug 2006 Location: Poland Posts: 4,086	Interestingly, even the Sony EX's own files (35mbps, 420) are written onto SxS in some 3.6GB chunks - quite a bit lower than the FAT32 size limit. __________________ Sony PXW-FS7 \| DaVinci Resolve Studio; Magix Vegas Pro; i7-5960X CPU; 64 GB RAM; 2x GTX 1080 8GB GPU; Decklink 4K Extreme 12G; 4x 3TB WD Black in RAID 0; 1TB M.2 NVMe cache drive

February 3rd, 2010, 03:27 PM	#3
Gints Klimanis Inner Circle Join Date: Jun 2003 Location: San Jose, CA Posts: 2,222	Dan, I'm interested in using a smaller file sizes overall, even at higher bitrates. Your previous posts and Nanoflash FAQ indicate that it is difficult for the Nanoflash to keep up with file creation with at higher bitrates.