bug: ffmpeg transcodes this wav, it incorrectly identifies this file as mp1, and coredump occurs during swr_convert.

[kellwang]

This wav audio is calling avformat_find_stream_info, and ffmpeg incorrectly identifies it as an mp1 file. When we use the api to transcode it, we continue to call the avcodec_send_packet and avcodec_receive_frame functions to obtain the audio content. Our program needs to transcode the audio to pcm, so we call swr_convert, it had a coredump error.

After investigation, we found that swr_convert called the invert_initial_buffer function, and when copying, the data pointer of src was NULL.