Open laimison opened 5 years ago
I have found that removing modules-load=dwc2
from /boot/cmdline.txt
and dtoverlay=dwc2
from /boot/config.txt
seems sorted the root cause in my case. I came to idea to remove this because of [253805.452822] dwc2 3f980000.usb: dwc2_hc_halt() Channel can't be halted
error in dmesg
.
I still have two issues that
1) video quality is not good enough to see very small fonts (it's like 30+ years old TV display)
I still see the error buffer contains corrupted data
when using ffmpeg
or avconv
tools manually
2) lower corner of screen is not visible through web server (so when I'm in the Linux console, I don't see few last lines what I'm typing in) - I have also checked the jpg
file in /mnt/ramdisk
to confirm that it's not web interface and css styling issue
Not sure whether these next issues are related with original issue at the moment
I wanted to share a resolution.
An second issue solved by changing avconv -f video4linux2 ...
to avconv -f v4l2 -standard pal ...
in /var/www/html/image.php
so it fits into the screen now.
Video/image quality still could be better, but decided to not invest time on this issue.
An example with "HD Capture":
Unfortunately, analog video has a very low quality. From my past experience there are EasyCap devices that use bad qualiy ADC chip, device looks the same but different chips inside. The Amazon link provided should be the better quality one.
You can research more but I think the best way is going fully digital, you can check issue #6 for alternatives.
Thanks for useful info. Did you mean the amazon links from README.md? If I remember correctly I had some difficulties to get this in the UK with limited time and also found that "HD Capture" doesn't require a separate powering so I bought that one. Do you know whether these devices in README.md support resolution such as 1024x768 or at least 800x600?
Do you have some examples of digital solutions? Are they sold only at higher prices comparing with EasyCap devices?
I have attached the photos of "HD Capture" and lsusb
output (not sure whether this is ADC bad quality chip):
pi@raspberrypi:/var/www/html $ lsusb -D /dev/bus/usb/001/007
Device: ID 1b71:3002 Fushicai USBTV007 Video Grabber [EasyCAP]
Couldn't open device, some information will be missing
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x1b71 Fushicai
idProduct 0x3002 USBTV007 Video Grabber [EasyCAP]
bcdDevice 1.00
iManufacturer 3
iProduct 4
iSerial 2
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 83
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 500mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 4
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 0
bInterfaceProtocol 255
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x0000 1x 0 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x84 EP 4 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 4
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 1
bNumEndpoints 4
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 0
bInterfaceProtocol 255
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x1400 3x 1024 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0100 1x 256 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x84 EP 4 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 4
pi@raspberrypi:/var/www/html $
Many thanks if you have a few minutes to reply this
@laimison refer issue #14 for an interesting "hackish" way to capture HDMI signals with minimal budget if you would like to upgrade your quality.
About the cloned devices, I meant the Easycap device. But anyway you can't expect much from those cheapo product. The downscaling from HDMI resolutions, to analog TV resolutions like S-Video will give you approximately the equivalent of 640x480-800x600 resoluion. Text won't be sharp in this technology unless higher quality analog-to-digital and digital-to-analog converters are used.
Best option is to use an all-digital path as I mentioned before.
Hi,
I have tested
https://www.ebay.co.uk/itm/Mini-Portable-USB-2-0-Port-HD-1-Way-HDMI-1080P-Video-Capture-Card-For-PC-Laptop/142907175902?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
and
https://www.ebay.co.uk/itm/TV-DVD-VHS-RCA-S-Video-Video-Audio-AV-EasyCAP-Grabber-Capture-USB-2-0-Adapter/183096373306?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649 + https://www.ebay.co.uk/itm/HDMI-to-3RCA-AV-CVBS-Composite-S-Video-R-L-Audio-Converter-Adapter-Upscaler/262370360688?epid=1140068747&hash=item3d167dfd70:g:gZYAAOSwCpRbEhZ7
I've got the same result by using any of these converters and cables.
I'm using mencoder command to record test.avi and the output is almost not visible because of many green lines and glitches:
This is a mencoder command which prints some drops (
14 frames successfully processed, -10 frames dropped
):Another attempt. This time
26 frames successfully processed, 31 frames dropped.
:dmesg
information when I connect this HDMI->USB converter:mencoder version:
Can you see guys causes for an issue or do you need more details? I really appreciate any comment on that - thanks!