On the ffmpeg to mobile phone video to find the long-width of the video fell the problem

1. Overview

Recently with the code to mobile phone video, found a very strange phenomenon, obviously the source video object is vertical, turn the wrong, find a half-day to find is not cared for the video stream rotate value. Take a note.

2. Solutions

We can read the rotate value through Av_dict_get in the input stream and write this value to the output stream.

The code is as follows:

	if (InputStream)
		{
			Avdictionaryentry *tag = NULL;  
			Tag = Av_dict_get (Inputstream->metadata, "rotate", tag, 0);

			if (tag! = NULL)  
			{
				av_dict_set (&poutstream->metadata, "rotate", tag->value, 0);}
		}

Where: InputStream is the AVSTREAM structure pointer, is the input video stream. Poutstream is the input video stream.