ffmpeg 返回错误数字含义
我们是用ffmpeg库函数是，例如在调用av_read_frame、avcodec_decode_video2，会给我们返回一个数值。
例如错误值-1094995529， 将其转换成十六进制为-0x41444E49，在ACSII中， 0x41 = 'A', 0x44 = 'D', 0x4E = 'N, and 0x49 = 'I'。
因为返回的错误值是经过FFERRTAG（可以理解为大小端及正负）转换过的，所以 ADNI 就是 INDA。
#define AVERROR_BSF_NOT_FOUND FFERRTAG(0xF8,'B','S','F') ///< Bitstream filter not found
#define AVERROR_BUG FFERRTAG( 'B','U','G','!') ///< Internal bug, also see AVERROR_BUG2
#define AVERROR_BUFFER_TOO_SMALL FFERRTAG( 'B','U','F','S') ///< Buffer too small
#define AVERROR_DECODER_NOT_FOUND FFERRTAG(0xF8,'D','E','C') ///< Decoder not found
#define AVERROR_DEMUXER_NOT_FOUND FFERRTAG(0xF8,'D','E','M') ///< Demuxer not found
#define AVERROR_ENCODER_NOT_FOUND FFERRTAG(0xF8,'E','N','C') ///< Encoder not found
#define AVERROR_EOF FFERRTAG( 'E','O','F',' ') ///< End of file
#define AVERROR_EXIT FFERRTAG( 'E','X','I','T') ///< Immediate exit was requested; the called function should not be r
estarted
#define AVERROR_EXTERNAL FFERRTAG( 'E','X','T',' ') ///< Generic error in an external library
#define AVERROR_FILTER_NOT_FOUND FFERRTAG(0xF8,'F','I','L') ///< Filter not found
#define AVERROR_INVALIDDATA FFERRTAG( 'I','N','D','A') ///< Invalid data found when processing input
#define AVERROR_MUXER_NOT_FOUND FFERRTAG(0xF8,'M','U','X') ///< Muxer not found
#define AVERROR_OPTION_NOT_FOUND FFERRTAG(0xF8,'O','P','T') ///< Option not found
#define AVERROR_PATCHWELCOME FFERRTAG( 'P','A','W','E') ///< Not yet implemented in FFmpeg, patches welcome
#define AVERROR_PROTOCOL_NOT_FOUND FFERRTAG(0xF8,'P','R','O') ///< Protocol not found
#define AVERROR_STREAM_NOT_FOUND FFERRTAG(0xF8,'S','T','R') ///< Stream not found参考：http://www.codeweblog.com/%E4%B8%80%E4%BA%9B%E9%94%99%E8%AF%AF%E7%A0%81%E7%9A%84%E5%80%BC/
https://stackoverflow.com/questions/23832366/avcodec-decode-video2-returns-the-value-1094995529-in-the-threaded-function