On 09/21/2014 06:10 PM, JPT wrote:
How my I find out more about the error -12?
http://www.virtsync.com/c-error-codes-include-errno
#define ENOMEM 12 /* Out of memory */
Likely allocating USB stream buffers fails. You could try request
smaller buffers. Drop count to 1 and test. Drop framesperurb to 1 and
test. Drop framesize to 1 and test. Surely streaming will not work if
all buffers are totally wrong and too small, but you will see if it is
due to big usb buffers. Then you could try optimize buffers smaller.
Wow, that did it. Thanks Antti!
Works with count = 2, but not with count = 4.
What exactly do I learn from this?
Where are those buffers? In the RAM? or somewhere in onboard USB hardware?
VDR is now able to connect to the device, but I am not sure if it
receives anything yet.
.count = 8,
.framesperurb = 32,
.framesize = 2048,
If I didn't remember wrong, that means allocated buffers are 8 * 32 *
2048 = 524288 bytes. It sounds rather big for my taste. Probably even
wrong. IIRC USB2.0 frames are 1024 and there could be 1-3 frames. You
could use lsusb with all verbosity levels to see if it is
1024/2048/3072. And set value according to that info.
32 framesperurb sounds absolute too much. You could decrease it a lot,
under 10 should be OK. Maybe 8 is good guess. 8 is number of URBs you
use for streaming. 8 does not sound bad, but maybe 6 is OK if it works.
Smallest value depends largely device USB FIFO size vs. stream size.
Bigger the FIFO less the buffers needed. Smaller the stream, less the
buffers needed.
So I would recommend
.count = 6,
.framesperurb = 8,
.framesize = 1024,
Use some testing with error and trial to find out smallest working
buffers, then add some 20% extra for that.
regards
Antti
--
http://palosaari.fi/
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