Question on dvr device copy

Hi,

Currently when playing stream from memory through dvr device (through write calls), the written buffer is copied from user-space to kernel space. The same applies when recording a stream, the TS packets received from HW are copied to dvr ring-buffer.

I'm a bit concerned about the performance due to the copy, and whether we better have a memory mapped ring-buffer in dvr device output and/or dvr device input with user-space to cope with high bitrate streams.

Your feedback on this will be mostly appreciated.

Thanks
Hamad

Hi,

I would appreciate if anyone can feedback on this, I'm considering implementing mmap in demux/dvr devices so that user-space can access the input/output buffers directly without the need for read/write operations.

Thanks
Hamad

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Hamad Kadmany
Sent: Sunday, February 12, 2012 4:19 PM
To: [email protected]
Subject: [media][dvb-core] Question on dvr device copy

Hi,

Currently when playing stream from memory through dvr device (through write calls), the written buffer is copied from user-space to kernel space. The same applies when recording a stream, the TS packets received from HW are copied to dvr ring-buffer.

I'm a bit concerned about the performance due to the copy, and whether we better have a memory mapped ring-buffer in dvr device output and/or dvr device input with user-space to cope with high bitrate streams.

Your feedback on this will be mostly appreciated.

Thanks
Hamad

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