Connecting RPi cam v1 with Raspberry Pi CM4 using waveshare Nano baseboard

Question

I am trying to connect my RPi cam with RPi CM4 and waveshare nano baseboard. I updated the config file:

# For more options and information see
# http://rptl.io/configtxt
# Some settings may impact device functionality. See link above for details
Uncomment some or all of these to enable the optional hardware interfaces
#dtparam=i2c_arm=on
#dtparam=i2s=on
#dtparam=spi=on
Enable audio (loads snd_bcm2835)
dtparam=audio=on
Additional overlays and parameters are documented
/boot/firmware/overlays/README
Automatically load overlays for detected cameras
camera_auto_detect=1
Automatically load overlays for detected DSI displays
display_auto_detect=1
Automatically load initramfs files, if found
auto_initramfs=1
Enable DRM VC4 V3D driver
dtoverlay=vc4-kms-v3d
max_framebuffers=2
Don't have the firmware create an initial video= setting in cmdline.txt.
Use the kernel's default instead.
disable_fw_kms_setup=1
Run in 64-bit mode
arm_64bit=1
Disable compensation for displays with overscan
disable_overscan=1
Run as fast as firmware / board allows
arm_boost=1
[cm4]
Enable host mode on the 2711 built-in XHCI USB controller.
This line should be removed if the legacy DWC2 controller is required
(e.g. for USB device mode) or if USB support is not required.
otg_mode=1
[cm5]
dtoverlay=dwc2,dr_mode=host
[all]
dtoverlay=ov5647,cam0
gpu_mem=128
start_x=1

Libcamera commands are working perfectly but the ffmpeg commands are giving errors. I listed my camera devices and /dev/video0 is listed under unicam. Here it is:

bcm2835-codec-decode (platform:bcm2835-codec):
        /dev/video10
        /dev/video11
        /dev/video12
        /dev/video18
        /dev/video31
        /dev/media3
bcm2835-isp (platform:bcm2835-isp):
        /dev/video13
        /dev/video14
        /dev/video15
        /dev/video16
        /dev/video20
        /dev/video21
        /dev/video22
        /dev/video23
        /dev/media1
        /dev/media2
unicam (platform:fe800000.csi):
        /dev/video0
        /dev/media4
rpivid (platform:rpivid):
        /dev/video19
        /dev/media0

Here is the ffmpeg error:

[video4linux2,v4l2 @ 0x558c9e5490] ioctl(VIDIOC_G_PARM): Inappropriate ioctl for device
[video4linux2,v4l2 @ 0x558c9e5490] Time per frame unknown
[video4linux2,v4l2 @ 0x558c9e5490] ioctl(VIDIOC_STREAMON): Invalid argument
/dev/video0: Invalid argument

Basically, I am trying to use the legacy camera stack to use ffmpeg.

Ps: I am really a newbie with RPi so really sorry for any mistakes and kindly let me know if any other config details are needed to debug my error.