________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of Prabhaharan R-TLS,Chennai Sent: Sunday, March 22, 2009 2:08 AM To: davinci-linux-open-source Subject: CMEM Issue in Decode Demo Application
Hello All, We are working on DM355 to play the live streamed video from an external source frame by frame. For achieving this, we are modifying the TI's Decode Demo application in the DM355 EVM in such a way that the streamed video frame is read from the custom kernel driver node instead of reading from the file. While doing this, we see that the memory allocated in CMEM pool is not accessible by the kernel driver that we have developed. How are you trying to access CMEM memory from your kernel driver? The kernel already has mappings to the CMEM memory, as established in the CMEM kernel driver. How is your kernel driver mapping to CMEM memory? To resolve this, we allocated memory for the "loader" module statically instead of CMEM memory pools. When we do like this, the Decode demo application is not all running. We assume that the Decode Demo application can't access memory area other than CMEM pools, whereas the kernel driver can't access the CMEM pools. Because of this, we are not able to feed the frame by frame received video data to the Decode Demo application. CMEM serves the needs of codecs that need physically contiguous memory, such as codecs that acccess data through physical addresses (either through the CPU or some HW accelerator). That's really the only difference between CMEM memory and other memory. Statically allocated buffers are probably not physically contiguous. Regards, - Rob Could anyone please suggest some ways to resolve this issue? Thanks a lot in advance. Thanks, Prabha. DISCLAIMER: ----------------------------------------------------------------------------------------------------------------------- The contents of this e-mail and any attachment(s) are confidential and intended for the named recipient(s) only. It shall not attach any liability on the originator or HCL or its affiliates. Any views or opinions presented in this email are solely those of the author and may not necessarily reflect the opinions of HCL or its affiliates. Any form of reproduction, dissemination, copying, disclosure, modification, distribution and / or publication of this message without the prior written consent of the author of this e-mail is strictly prohibited. If you have received this email in error please delete it and notify the sender immediately. Before opening any mail and attachments please check them for viruses and defect. -----------------------------------------------------------------------------------------------------------------------
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