I have the error C4576 in Visual studio 2015 when I tried to compile the file: transcoding.c.
The source code of this file is here: transcoding.c>
Old question, but... The solution is pretty simple:
AVRational tb; tb.num = 1; tb.den = enc_ctx->sample_rate; enc_ctx->time_base = tb;
or
enc_ctx->time_base.num = 1; enc_ctx->time_base.den = enc_ctx->sample_rate;