add initialize_avplay function

Signed-off-by: Jack <jack.wgm@gmail.com>
update ffmpeg to v1.1.3

Signed-off-by: Jack <jack.wgm@gmail.com>
fixed calc out_channels

Signed-off-by: Jack <jack.wgm@gmail.com>
update FFmpeg to v1.1.3

Signed-off-by: Jack <jack.wgm@gmail.com>
新版本FFmpeg解码出来的AVFrame.linesize[0]可能是错误的, 直接使用AVFrame.nb_samples.

Signed-off-by: Jack <jack.wgm@gmail.com>
Merge branch 'ffmpeg'

Conflicts:
	libav/avplay.c

Signed-off-by: Jack <jack.wgm@gmail.com>