AVERROR_OUTPUT_CHANGED  542 libavresample/utils.c             ret |= AVERROR_OUTPUT_CHANGED;
AVERROR_OUTPUT_CHANGED   33 libavutil/error.c #define AVERROR_INPUT_AND_OUTPUT_CHANGED (AVERROR_INPUT_CHANGED | AVERROR_OUTPUT_CHANGED)
AVERROR_OUTPUT_CHANGED   71 libswresample/swresample_frame.c             ret |= AVERROR_OUTPUT_CHANGED;