Buffer used for Gstreamer output

[Jack-Cha]

Hi NXP

Please let me know which physical buffer is used in hardware when you output the display to the pipeline through the gstreamer.

A customer asked what buffers are physically used on the Gstremer pipeline when the camera is being inputted in BT656 format and output to LVDS Dual Display. Can you explain whether the physical device used as a buffer is DRAM, DMA, mmap, etc., including Data Path?

Thanks.

Regards, 

Arrow

[Jack-Cha]

Hi. 

i.MX 8 QuadXPlus (auto grade) is used for my customer's platform. 

Thanks.

[joanxie]

you can refer to reserved-memory of

the https://github.com/nxp-imx/linux-imx/blob/lf-6.1.y/arch/arm64/boot/dts/freescale/imx8x-mek.dtsi

[Jack-Cha]

Hi Joanxie

Thanks for your kind reply.

Can you tell me how that reserved memory works in conjunction with Gstremaer?

We don't know which memory areas were engaged with GStremaer?

reserved-memory {
	#address-cells = <2>;
	#size-cells = <2>;
	ranges;
	gpu_reserved: gpu_reserved@880000000 {
	no-map;
	reg = <0x8 0x80000000 0 0x10000000>;
	};
	decoder_boot: decoder-boot@84000000 {
	reg = <0 0x84000000 0 0x2000000>;
	no-map;
	};
	encoder_boot: encoder-boot@86000000 {
	reg = <0 0x86000000 0 0x200000>;
	no-map;
	};
	decoder_rpc: decoder-rpc@92000000 {
	reg = <0 0x92000000 0 0x100000>;
	no-map;
	};
	dsp_reserved: dsp@92400000 {
	reg = <0 0x92400000 0 0x1000000>;
	no-map;
	};
	dsp_reserved_heap: dsp_reserved_heap {
	reg = <0 0x93400000 0 0xef0000>;
	no-map;
	};
	dsp_vdev0vring0: vdev0vring0@942f0000 {
	reg = <0 0x942f0000 0 0x8000>;
	no-map;
	};
	dsp_vdev0vring1: vdev0vring1@942f8000 {
	reg = <0 0x942f8000 0 0x8000>;
	no-map;
	};
	dsp_vdev0buffer: vdev0buffer@94300000 {
	compatible = "shared-dma-pool";
	reg = <0 0x94300000 0 0x100000>;
	no-map;
	};
	encoder_rpc: encoder-rpc@94400000 {
	reg = <0 0x94400000 0 0x700000>;
	no-map;
	};
	/* global autoconfigured region for contiguous allocations */
	linux,cma {
	compatible = "shared-dma-pool";
	reusable;
	size = <0 0x3c000000>;
	alloc-ranges = <0 0xc0000000 0 0x3c000000>;
	linux,cma-default;
	};
	};

[joanxie]

gstreamer is just a framework, depends on what you need, you can add vpu or gpu plugin in the gstreamer, then you can find related gpu or vpu(encoder/decoder) from the memory map

[Jack-Cha]

Hi

Customer need to write project report for this. Hence they would like to understand IMX8X' internal data path when using Gstreamer for dual lvds display output in addition to MIPI Camera Input,

It would be appreciate if you are able to provide us with more details about data path regarding Gstreamer Test Use case.

Thanks.

Regards, 

Jack

[joanxie]

what processor are you talking about?