2.编译:
如果有编译错误,修改源码
#if defined(ARCH_ARMV4L)
typedef int32_t intptr_t ; /* Add by Andrew Huang*/
#endif
否则会产生如下编译错误,intptr_t在标准C中有定义,但在这里死活找不到,因此直接定义:
arm-linux-gcc -I../libswscale -I../libavcodec -DHAVE_AV_CONFIG_H -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_ISOC9X_SOURCE -I.. -I.. -I../libavutil -Wdisabled-optimization -Wno-pointer-sign -Wdeclaration-after-statement -I. -I.. -I../libavutil -Wall -Wno-switch -Wpointer-arith -Wredundant-decls -O4 -pipe -ffast-math -fomit-frame-pointer -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE -DHAVE_CONFIG_H -I/usr/X11R6/include -c -o cyuv.o cyuv.c
cc1: warning: include location "/usr/X11R6/include" is unsafe for cross-compilation
In file included from mpegvideo.h:32,
from cyuv.c:38:
bitstream.h: In function ''put_bits'':
bitstream.h:233: error: ''intptr_t'' undeclared (first use in this function)
bitstream.h:233: error: (Each undeclared identifier is reported only once
bitstream.h:233: error: for each function it appears in.)
bitstream.h:233: error: expected '')'' before ''s''
bitstream.h: In function ''init_get_bits'':
bitstream.h:777: error: ''intptr_t'' undeclared (first use in this function)
bitstream.h:777: error: expected '')'' before ''buffer''
bitstream.h:778: error: expected '')'' before ''buffer''
make[1]: *** [cyuv.o] Error 1
修改源码 libavcodec\armv4l\dsputil_arm_s.S, libmpeg2\motion_comp_arm_s.S
在其开始的加入,这段代码意思是定义一个空的ARM汇编宏 pld,这样当代码出现pld指令,就变成一条空指令
#ifndef HAVE_PLD
.macro pld reg
.endm
#endif
预读取PLD指令
功能:cache预读取(PLD,PreLoad),使用PLD指示存储系统从后面几条指令所指定的存储器地址读取,存储系统可使用这种方法加速以后的存储器访问。
格式:
PLD[Rn,{offset}]
其中:
Rn 存储器的基址寄存器。
Offset 加在Rn上的偏移量。含义同3。2。3节第1条指令。
如果不取消,将会产生如下错误
arm-linux-gcc -I../libswscale -I../libavcodec -DHAVE_AV_CONFIG_H -D_FILE_OFFSET _BITS=64 -D_LARGEFILE_SOURCE -D_ISOC9X_SOURCE -I.. -I.. -I../libavutil -Wdisable d-optimization -Wno-pointer-sign -Wdeclaration-after-statement -I. -I.. -I../lib avutil -Wall -Wno-switch -Wpointer-arith -Wredundant-decls -O4 -pipe -ffast-ma th -fomit-frame-pointer -D_REENTRANT -DHAVE_CONFIG_H -I/home/workspace/MPlayer/M Player-1.0rc2/../output/linux_arm/include -I/usr/X11R6/include -c -o armv4l/dsp util_arm_s.o armv4l/dsputil_arm_s.S
cc1: warning: include location "/usr/X11R6/include" is unsafe for cross-compilat ion
armv4l/dsputil_arm_s.S: Assembler messages:
armv4l/dsputil_arm_s.S:79: Error: selected processor does not support `pld [r1]''
armv4l/dsputil_arm_s.S:90: Error: selected processor does not support `pld [r1]''
armv4l/dsputil_arm_s.S:100: Error: selected processor does not support `pld [r1] ''
armv4l/dsputil_arm_s.S:111: Error: selected processor does not support `pld [r1] ''
armv4l/dsputil_arm_s.S:122: Error: selected processor does not support `pld [r1] ''
armv4l/dsputil_arm_s.S:141: Error: selected processor does not support `pld [r1]
make
修改make install的bug
执行make install时会提示
install -m 755 -s mplayer /home/hxy/MPlayer/
MPlayer-1.0rc2/../output/arm_linux/bin
strip: Unable to recognise the format of the input file
`/home/hxy/MPlayer/MPlayer-1.0rc2/../output/arm_linux/bin/mplayer'
查资料看install带-s 参数时会自动调用strip来strip应用程序。但是arm编译时要调用arm-linux-strip才有正确处理。解决办法是取消-s参数,查看Makefile可以发现-s是如下
$(INSTALL) -m 755 $(INSTALLSTRIP) mplayer$(EXESUF) $(BINDIR)
的INSTALLSTRIP设置的,它默认是-s,因此只要简单在Makefile的前面(95行)加入
INSTALLSTRIP := #将其置为空即可惟
4.执行:
export LD_LIBRARY_PATH=${LIB};./mplayer -ac mad demo.mpg
其中$LIB是保存有Mplayer所需的库的路径 -ac mad 是必须,表示强制用libmad解码.
这是我的成功执行一段脚本:
export APP_ROOT=/mnt/nfs/MPlayer/output/arm_linux
export LD_LIBRARY_PATH=$APP_ROOT,OOT/lib;./mplayer -ac mad 2.mpg
测试mpg,avi,mp3,mp4均可播放,默认是按视频的原始分辨率播放的。如果想让MPlayer完整在LCD上显示,可以用video filter 参数 scale来设置
./mplayer -vf scale=240:320
另外有人测试发现在有一些开发板下.Mplayer播放后,输出会干扰后续shell的执行行.用下面比较长的参数一般没事
export APP_ROOT=/mnt/nfs/MPlayer/output/arm_linux
export LD_LIBRARY_PATH=$APP_ROOT,OOT/lib;./mplayer -ac mad 2.mpg -quiet \ -vf scale=320:240 2>&1 1>/dev/null &&
如果搞不清自己分辩率的,可在MPlayer用 -fullscreen参数 .或者执行busybox shell命令fbset查看自n己板的分辩率
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