static const AVOption options[]={
{"b", "set bitrate (in bits/s)", OFFSET(bit_rate), AV_OPT_TYPE_INT, {.dbl = AV_CODEC_DEFAULT_BITRATE }, INT_MIN, INT_MAX, V|A|E},
-{"ab", "this option is deprecated, use b", OFFSET(bit_rate), AV_OPT_TYPE_INT, {.dbl = AV_CODEC_DEFAULT_BITRATE }, INT_MIN, INT_MAX, A|E},
{"bt", "set video bitrate tolerance (in bits/s)", OFFSET(bit_rate_tolerance), AV_OPT_TYPE_INT, {.dbl = AV_CODEC_DEFAULT_BITRATE*20 }, 1, INT_MAX, V|E},
{"flags", NULL, OFFSET(flags), AV_OPT_TYPE_FLAGS, {.dbl = DEFAULT }, 0, UINT_MAX, V|A|E|D, "flags"},
{"mv4", "use four motion vector by macroblock (mpeg4)", 0, AV_OPT_TYPE_CONST, {.dbl = CODEC_FLAG_4MV }, INT_MIN, INT_MAX, V|E, "flags"},