1，yasm：
到 http://www.tortall.net/projects/yasm/wiki/Download 下载yasm0.7.2（x264需要用到的汇编编译器）
for x86:
./configure --enable-shared --prefix=/usr/local
make
make install
for arm:
./configure --enable-shared --prefix=/usr/local/ --host=arm-linux
make
make install
2，x264：
到 ftp://ftp.videolan.org/pub/videolan/x264/snapshots/ 下载x264库
for x86:
./configure --enable-shared --prefix=/usr/local
make
make install
for arm:
./configure --enable-shared --prefix=/usr/local/ --host=arm-linux
到common/cpu.c编译不过，未定义 cpu_set_t。这里改为 返回1.
x264_cpu_num_processors().
cpu_set_t unsinged long.
3，xvid：
到 http://downloads.xvid.org/downloads/xvidcore-1.1.3.tar.gz 下载xvid
for x86:
cd build/generic
./configure --prefix=/usr/local
make
make install
for arm:
#./configure --prefix=/usr/local/ --host=arm-linux --target=arm-linux
./configure --prefix=/usr/local/ --host=arm-hismall-linux --target=arm-hismall-linux
make
make install
4，ffmpeg:
svn co svn://svn.mplayerhq.hu/ffmpeg/trunk 下载ffmpeg源码
for x86:
./configure --prefix=/usr/local/ --enable-gpl --enable-shared --enable-xvid --enable-x264 --enable-pthreads --disable-ffserver --disable-ffplay --enable-faac --enable-faad
编译不过，I changed the line (about line number 596):
static always_inline long int lrintf(float x)
in /libavcodec/dsputil.h to:
static __inline__ long int lrintf(float x)
make
make install
在x86的linux上执行：
[root@localhost ffmpeg-0.4.9-p20051216]# ffmpeg -i ../test/beijing.mp4 -b 479k -s 320x240 ../test/beijing.h264
ffmpeg version CVS, build 3342336, Copyright (c) 2000-2004 Fabrice Bellard
configuration: --prefix=/usr/local/ --enable-gpl --enable-shared --enable-xvid --enable-x264 --enable-pthreads --disable-ffserver --disable-ffplay
built on Nov 11 2008 08:48:14, gcc: 3.4.6 20060404 (Red Hat 3.4.6-8)
Input #0, mov,mp4,m4a,3gp,3g2, from '../test/beijing.mp4':
Duration: 00:06:50.2, start: 0.000000, bitrate: 479 kb/s
Stream #0.0, 23.98 fps: Video: mpeg4, yuv420p, 320x240
Stream #0.1: Audio: mp4a / 0x6134706D, 16000 Hz, stereo
File '../test/beijing.h264' already exists. Overwrite ? [y/N]
Not overwriting - exiting
[root@localhost ffmpeg-0.4.9-p20051216]# ffmpeg -i ../test/beijing.mp4 -b 479k -s 320x240 ../test/beijing.h264
ffmpeg version CVS, build 3342336, Copyright (c) 2000-2004 Fabrice Bellard
configuration: --prefix=/usr/local/ --enable-gpl --enable-shared --enable-xvid --enable-x264 --enable-pthreads --disable-ffserver --disable-ffplay
built on Nov 11 2008 08:48:14, gcc: 3.4.6 20060404 (Red Hat 3.4.6-8)
Input #0, mov,mp4,m4a,3gp,3g2, from '../test/beijing.mp4':
Duration: 00:06:50.2, start: 0.000000, bitrate: 479 kb/s
Stream #0.0, 23.98 fps: Video: mpeg4, yuv420p, 320x240
Stream #0.1: Audio: mp4a / 0x6134706D, 16000 Hz, stereo
File '../test/beijing.h264' already exists. Overwrite ? [y/N] y
Output #0, h264, to '../test/beijing.h264':
Stream #0.0, nan fps: Video: h264, yuv420p, 320x240, q=2-31, 479 kb/s
Stream mapping:
Stream #0.0 -> #0.0
[h264 @ 0x458428]using SAR=1/1
[h264 @ 0x458428]using cpu capabilities: MMX MMXEXT SSE SSE2
Press [q] to stop encoding
frame= 9835 q=9.0 Lsize= 24683kB time=410.2 bitrate= 492.9kbits/s
video:24683kB audio:0kB global headers:0kB muxing overhead 0.000000%
[h264 @ 0x458428]slice I:1007 Avg QP:22.31 size: 9162 PSNR Mean Y:43.70 U:48.20 V:47.61 Avg:44.67 Global:43.74
[h264 @ 0x458428]slice P:8828 Avg QP:25.29 size: 1815 PSNR Mean Y:41.23 U:47.00 V:46.21 Avg:42.35 Global:41.02
[h264 @ 0x458428]mb I I16..4: 23.8% 0.0% 76.2%
[h264 @ 0x458428]mb P I16..4: 3.6% 0.0% 2.0% P16..4: 41.9% 17.4% 6.5% 0.0% 0.0% skip:28.5%
[h264 @ 0x458428]final ratefactor: 21.37
[h264 @ 0x458428]SSIM Mean Y:0.9803090
[h264 @ 0x458428]PSNR Mean Y:41.484 U:47.120 V:46.353 Avg:42.588 Global:41.228 kb/s:492.37
[root@localhost ffmpeg-0.4.9-p20051216]#
共用时3分3秒45
ffmpeg -i ../test/beijing.mp4 -b 479k -s 320x240 -fs 1500 -y ../test/beijing.h264 录制1500kB的文件，用时9秒27
for arm:
./configure --prefix=/usr/local/ --enable-gpl --cpu=arm --enable-xvid --enable-x264 --enable-pthreads --disable-ffserver --disable-ffplay --cc=arm-hismall-linux-gcc --enable-shared
编译到最后报错：
arm-hismall-linux-gcc -Wl,--warn-common -rdynamic -g -o ffmpeg_g ffmpeg.o cmdutils.o -L./libavformat -lavformat -L./libavcodec -lavcodec -L./libavutil -lavutil -lm -lxvidcore -lx264 -ldl -lpthread
./libavcodec/libavcodec.so: undefined reference to `roundf'
./libavcodec/libavcodec.so: undefined reference to `log2'
collect2: ld returned 1 exit status
make: *** [ffmpeg_g] 错误 1
在Makefile中加入-I/home/ellen/compiler/gcc-3.4.3-uClibc-0.9.28/，还是报错。
更换gcc为arm-linux-gcc-3.3.2.tar.bz2，还是报错。
在 libavcodec/Makefile 中加入 -I/home/ellen/compiler/gcc-3.4.3-uClibc-0.9.28/ （roundf和log2都包含在math.h中），还是报错。
在 libavcodec/Makefile 中 定义x264.o 的地方，加入 EXTRALIBS += -lm，还是报错。
用 nm -u libavcodec.so 可以查看so中未定义的函数。
自己写log的函数：
#define M_1_SQRT2 0.70710678118654752440084436210484904
#define POLYNOM1(x, a) ((a)[1]*(x)+(a)[0])
#define POLYNOM2(x, a) (POLYNOM1((x),(a)+1)*(x)+(a)[0])
#define POLYNOM3(x, a) (POLYNOM2((x),(a)+1)*(x)+(a)[0])
double
log(double x)
{
/* Algorithm and coefficients from:
"Software manual for the elementary functions"
by W.J. Cody and W. Waite, Prentice-Hall, 1980
*/
static double a[] = {
-0.64124943423745581147e2,
0.16383943563021534222e2,
-0.78956112887491257267e0
};
static double b[] = {
-0.76949932108494879777e3,
0.31203222091924532844e3,
-0.35667977739034646171e2,
1.0
};
double znum, zden, z, w;
int exponent;
if (x errno = EDOM;
return -HUGE_VAL;
}
else if (x == 0) {
errno = ERANGE;
return -HUGE_VAL;
}
if (x }
else return x; /* for infinity and Nan */
x = frexp(x, &exponent);
if (x > M_1_SQRT2) {
znum = (x - 0.5) - 0.5;
zden = x * 0.5 + 0.5;
}
else {
znum = x - 0.5;
zden = znum * 0.5 + 0.5;
exponent--;
}
z = znum/zden; w = z * z;
x = z + z * w * (POLYNOM2(w,a)/POLYNOM3(w,b));
z = exponent;
x += z * (-2.121944400546905827679e-4);
return x + z * 0.693359375;
}
double
log10(double x)
{
if (x errno = EDOM;
return -HUGE_VAL;
}
else if (x == 0) {
errno = ERANGE;
return -HUGE_VAL;
}
return log(x) / M_LN10;
}
double log2(double x)
{
return (log10(x) / log10(2) );
}
log2编译通过。
自己写roundf的函数：
double
copysign (double x, double y)
{
if ((x 0) || (x > 0 && y return -x;
return x;
}
float
copysignf (float x, float y)
{
/* We use the double version. */
return copysign (x, y);
}
float modff(float x, float * y)
{
*y=((int)x);
return (x-*y);
}
float
roundf(float Arg)
{
float FracPart, IntPart;
FracPart = modff(Arg, &IntPart);
if (fabsf(FracPart) >= 0.5f)
IntPart += copysignf(1.0, IntPart);
return IntPart;
}
编译通过。
编译好的ffmpeg放到arm平台上，把libavcodec.so和libavformat.so放到板子上，运行，报错：
/usr/local/lib $ ls -l
-rwxrwxrwx 1 root root 4984743 Nov 10 15:02 libavcodec.so
-rwxrwxrwx 1 root root 1466472 Nov 10 15:07 libavformat.so
lrwxrwxrwx 1 root root 14 Nov 10 15:03 libavformat.so.50 -> libavformat.so
/usr/local/lib $ /ffmpeg
Can't modify /usr/local/lib/libavformat.so.50's text section. Use GCC option -fPIC for shared objects, please.
/usr/local/lib $
在libavformat和libavcodec的makefile中添加 -fPIC,还是不行。
./configure --prefix=/usr/local/ --enable-gpl --cpu=arm --enable-xvid --enable-x264 --enable-pthreads --disable-ffserver --disable-ffplay --cc=arm-hismall-linux-gcc --disable-strip
不用shared，用静态编译，把libavcodec和libavformat都编到ffmpeg中，在板子上运行，需要链接 libx264.so时，还是报错不能 -fPIC，于是想办法把libx264静态编译到ffmepg中。
重新编译x264，不用shared。把libx264.a 和libxvidcore.a 拷贝到libavcodec和libavformat目录下，修改 ffmpeg/Makefile，添加：
LIBSUF += libx264.a libxvidcore.a
放在arm上运行时，还是会报错：
[h264 @ 0x3705fc]no ratecontrol method specified
Error while opening codec for output stream #0.0 - maybe incorrect parameters such as bit_rate, rate, width or height
修改x264/common/common.c的x264_param_default()中：
//param->rc.i_rc_method = X264_RC_NONE;
param->rc.i_rc_method = X264_RC_ABR;
重新编译264，重新编译ffmpeg：
./ffmpeg -i beijing.mp4 -b 479k -s 320x240 -fs 1500 -y beijing.h264
/mnt $ ./ffmpeg -i beijing.mp4 -b 479k -s 320x240 -fs 1500 -y beijing.h264
ffmpeg version CVS, build 3342336, Copyright (c) 2000-2004 Fabrice Bellard
configuration: --prefix=/usr/local/ --enable-gpl --cpu=arm --enable-xvid --enable-x264 --enable-pthreads --disable-ffserver --disable-ffplay --cc=arm-hismall-linux-gcc --disable-strip
built on Nov 11 2008 09:47:01, gcc: 3.4.3 (release) (CodeSourcery ARM Q3cvs 2004)
Input #0, mov,mp4,m4a,3gp,3g2, from 'beijing.mp4':
Duration: 00:06:50.2, start: 0.000000, bitrate: 479 kb/s
Stream #0.0, 23.98 fps: Video: mpeg4, yuv420p, 320x240
Stream #0.1: Audio: mp4a / 0x6134706D, 16000 Hz, stereo
Output #0, h264, to 'beijing.h264':
Stream #0.0, nan fps: Video: h264, yuv420p, 320x240, q=2-31, 479 kb/s
Stream mapping:
Stream #0.0 -> #0.0
[h264 @ 0x3705fc]using SAR=1/1
[h264 @ 0x3705fc]using cpu capabilities: none!
Press [q] to stop encoding
frame= 519 q=25.0 Lsize= 1501kB time=21.6 bitrate= 568.2kbits/s
video:1501kB audio:0kB global headers:0kB muxing overhead 0.000000%
[h264 @ 0x3705fc]slice I:48 Avg QP:18.17 size: 10418 PSNR Mean Y:48.72 U:52.93 V:51.90 Avg:49.57 Global:45.65
[h264 @ 0x3705fc]slice P:471 Avg QP:22.15 size: 2198 PSNR Mean Y:45.54 U:51.02 V:49.82 Avg:46.54 Global:42.61
[h264 @ 0x3705fc]mb I I16..4: 24.5% 0.0% 75.5%
[h264 @ 0x3705fc]mb P I16..4: 8.2% 0.0% 4.8% P16..4: 42.0% 15.7% 5.8% 0.0% 0.0% skip:23.5%
[h264 @ 0x3705fc]final ratefactor: 20.83
[h264 @ 0x3705fc]SSIM Mean Y:0.9833328
[h264 @ 0x3705fc]PSNR Mean Y:45.838 U:51.198 V:50.012 Avg:46.823 Global:42.820 kb/s:567.41
/mnt $
共519帧，568.2kbits/s。共用时10分56秒88
