IOS supoort soft h264 codec

[nikohpng]

Description

I want to support soft codec in ios. so I use rtc_use_h264=true, but I can't compile it.

Trace

ld64.lld: error: library not found for -lrt
ld64.lld: error: undefined symbol: _av_buffer_create
>>> referenced by obj/modules/video_coding/libwebrtc_h264.a(h264_decoder_impl.o)

ld64.lld: error: undefined symbol: _av_image_check_size
>>> referenced by obj/modules/video_coding/libwebrtc_h264.a(h264_decoder_impl.o)

ld64.lld: error: undefined symbol: _avcodec_align_dimensions
>>> referenced by obj/modules/video_coding/libwebrtc_h264.a(h264_decoder_impl.o)

ld64.lld: error: undefined symbol: _av_frame_alloc
>>> referenced by obj/modules/video_coding/libwebrtc_h264.a(h264_decoder_impl.o)

ld64.lld: error: undefined symbol: _avcodec_open2
>>> referenced by obj/modules/video_coding/libwebrtc_h264.a(h264_decoder_impl.o)

ld64.lld: error: undefined symbol: _avcodec_find_decoder
>>> referenced by obj/modules/video_coding/libwebrtc_h264.a(h264_decoder_impl.o)

ld64.lld: error: undefined symbol: _avcodec_alloc_context3
>>> referenced by obj/modules/video_coding/libwebrtc_h264.a(h264_decoder_impl.o)

ld64.lld: error: undefined symbol: _av_frame_unref
>>> referenced by obj/modules/video_coding/libwebrtc_h264.a(h264_decoder_impl.o)

ld64.lld: error: undefined symbol: _av_packet_free
>>> referenced by obj/modules/video_coding/libwebrtc_h264.a(h264_decoder_impl.o)

ld64.lld: error: undefined symbol: _av_buffer_get_opaque
>>> referenced by obj/modules/video_coding/libwebrtc_h264.a(h264_decoder_impl.o)

ld64.lld: error: undefined symbol: _avcodec_receive_frame
>>> referenced by obj/modules/video_coding/libwebrtc_h264.a(h264_decoder_impl.o)

ld64.lld: error: undefined symbol: _avcodec_send_packet
>>> referenced by obj/modules/video_coding/libwebrtc_h264.a(h264_decoder_impl.o)

ld64.lld: error: undefined symbol: _av_packet_alloc
>>> referenced by obj/modules/video_coding/libwebrtc_h264.a(h264_decoder_impl.o)

ld64.lld: error: undefined symbol: _avcodec_free_context
>>> referenced by obj/modules/video_coding/libwebrtc_h264.a(h264_decoder_impl.o)

Last

If there's any suggestion, thank you very much