版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/shizheng163/article/details/80476489
如有错误，请指正，谢谢。
部分返回值错误码
ffmpeg源码部分返回值形式为：
**AVERROR（EINVAL）**
**AVERROR（EPIPE）**
**AVERROR（ENOMEM）**
......
再看一下ffmpeg内部对于宏的实现，AVERROR
/* error handling */
#if EDOM > 0
#define AVERROR(e) (-(e)) ///< Returns a negative error code from a POSIX error code, to return from library functions.
#define AVUNERROR(e) (-(e)) ///< Returns a POSIX error code from a library function error return value.
#else
/* Some platforms have E* and errno already negated. */
#define AVERROR(e) (e)
#define AVUNERROR(e) (e)
#endif所以大胆猜测（新手，看过的源码太少），错误码计数比较小的值应该是操作系统内部定义好的错误码。
Linux error_base.h
#ifndef _ASM_GENERIC_ERRNO_BASE_H
#define _ASM_GENERIC_ERRNO_BASE_H
#define EPERM 1 /* Operation not permitted */
#define ENOENT 2 /* No such file or directory */
#define ESRCH 3 /* No such process */
#define EINTR 4 /* Interrupted system call */
#define EIO 5 /* I/O error */
#define ENXIO 6 /* No such device or address */
#define E2BIG 7 /* Argument list too long */
#define ENOEXEC 8 /* Exec format error */
#define EBADF 9 /* Bad file number */
#define ECHILD 10 /* No child processes */
#define EAGAIN 11 /* Try again */
#define ENOMEM 12 /* Out of memory */
#define EACCES 13 /* Permission denied */
#define EFAULT 14 /* Bad address */
#define ENOTBLK 15 /* Block device required */
#define EBUSY 16 /* Device or resource busy */
#define EEXIST 17 /* File exists */
#define EXDEV 18 /* Cross-device link */
#define ENODEV 19 /* No such device */
#define ENOTDIR 20 /* Not a directory */
#define EISDIR 21 /* Is a directory */
#define EINVAL 22 /* Invalid argument */
#define ENFILE 23 /* File table overflow */
#define EMFILE 24 /* Too many open files */
#define ENOTTY 25 /* Not a typewriter */
#define ETXTBSY 26 /* Text file busy */
#define EFBIG 27 /* File too large */
#define ENOSPC 28 /* No space left on device */
#define ESPIPE 29 /* Illegal seek */
#define EROFS 30 /* Read-only file system */
#define EMLINK 31 /* Too many links */
#define EPIPE 32 /* Broken pipe */
#define EDOM 33 /* Math argument out of domain of func */
#define ERANGE 34 /* Math result not representable */
#endif
av_interleaved_write_frame/av_write_frame 返回值
0代表发送/写入成功，负数表示错误码。
我遇到的几个错误码：
-22：参数错误，例如AVPacket的stream_index的值不正确，dts不过滤（没有递增）等等
-32：管道阻塞：这个一般是socket错误，我遇到的情况是，推流的服务器断开了socket链接，导致发送失败。（不知道为什么ffmpeg日志没有打印这个。）