OpenWrt编译的mjpg-streamer软件包与官方编译的不一致
OpenWrt编译的mjpg-streamer软件包居然与官方编译的是不一样的版本。不管是当前trunk还是barrier breaker版都是有这个问题。自行编译的不支持yuv格式输出，也就是说如果挂载的摄像头不支持jpeg格式直接输出那就没戏了。但是官方的mjpg-streamer就没有这个问题。先看看自己编译出来的与官方的版本在input_uvc.so模块帮助上的区别。
官方版本：
root@OpenWrt:/tmp# mjpg_streamer -i "input_uvc.so --help"
MJPG Streamer Version: svn rev: exported
---------------------------------------------------------------
Help for input plugin..: UVC webcam grabber
---------------------------------------------------------------
The following parameters can be passed to this plugin:
[-d | --device ].......: video device to open (your camera)
[-r | --resolution ]...: the resolution of the video device,
can be one of the following strings:
QSIF QCIF CGA QVGA CIF VGA
SVGA XGA SXGA
or a custom value like the following
example: 640x480
[-f | --fps ]..........: frames per second
[-y | --yuv ]..........: enable YUYV format and disable MJPEG mode
[-q | --quality ]......: JPEG compression quality in percent
(activates YUYV format, disables MJPEG)
[-m | --minimum_size ].: drop frames smaller then this limit, useful
if the webcam produces small-sized garbage frames
may happen under low light conditions
[-n | --no_dynctrl ]...: do not initalize dynctrls of Linux-UVC driver
[-l | --led ]..........: switch the LED "on", "off", let it "blink" or leave
it up to the driver using the value "auto"
---------------------------------------------------------------
input_init() return value signals to exit
root@OpenWrt:~# mjpg_streamer -i "input_uvc.so --help"
MJPG Streamer Version: svn rev: exported
---------------------------------------------------------------
Help for input plugin..: UVC webcam grabber
---------------------------------------------------------------
The following parameters can be passed to this plugin:
[-d | --device ].......: video device to open (your camera)
[-r | --resolution ]...: the resolution of the video device,
can be one of the following strings:
QSIF QCIF CGA QVGA CIF VGA
SVGA XGA SXGA
or a custom value like the following
example: 640x480
[-f | --fps ]..........: frames per second
(activates YUYV format, disables MJPEG)
[-m | --minimum_size ].: drop frames smaller then this limit, useful
if the webcam produces small-sized garbage frames
may happen under low light conditions
[-n | --no_dynctrl ]...: do not initalize dynctrls of Linux-UVC driver
[-l | --led ]..........: switch the LED "on", "off", let it "blink" or leave
it up to the driver using the value "auto"
---------------------------------------------------------------
[-t | --tvnorm ] ......: set TV-Norm pal, ntsc or secam
---------------------------------------------------------------
input_init() return value signals to exit
# # Copyright (C) 2006-2014 OpenWrt.org # # This is free software, licensed under the GNU General Public License v2. # See /LICENSE for more information. # include $(TOPDIR)/rules.mk PKG_NAME:=mjpg-streamer PKG_REV:=182 PKG_VERSION:=r$(PKG_REV) PKG_RELEASE:=1 PKG_MAINTAINER:=Roger D <[email protected]> PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).1.tar.bz2 PKG_SOURCE_URL:=https://svn.code.sf.net/p/mjpg-streamer/code/mjpg-streamer-experimental PKG_SOURCE_SUBDIR:=$(PKG_NAME)-$(PKG_VERSION) PKG_SOURCE_VERSION:=$(PKG_REV) PKG_SOURCE_PROTO:=svn PKG_LICENSE:=GPL-2.0 PKG_LICENSE_FILE:=LICENSE
https://svn.code.sf.net/p/mjpg-streamer/code/点击进去
发现mjpg-streamer有带不带“experimental”版本的区别。进一步进去查看代码带“experimental”是不支持y参数的，不带“experimental”版支持y参数，并且input_uvc插件的帮助说明与官方的一样。想不通官方为什么这么整。决定自己切换到不带“experimental”版本。
首先删除openwrt源码目录下的mjpg-streamer**.tar.gz文件。修改mjpg-streamer包路径./feeds/packages/multimedia/mjpg-streamer/下的Makefile文件，将PKG_SOURCE_URL:=https://svn.code.sf.net/p/mjpg-streamer/code/mjpg-streamer-experimental改成PKG_SOURCE_URL:=https://svn.code.sf.net/p/mjpg-streamer/code/mjpg-streamer。删除patches下的010-enable_additional_plugins.patch和020-remove_gcc_debug_options.patch补丁文件。
然后重新编译mjpg-streamer软件包：
make package/mjpg-streamer/prepare V=s make package/mjpg-streamer/install V=s
再重新安装mjpg-streamer软件包，ok。