MediaRecorder start error codes

Question

I want to record raw h.264 video without sound and possibly HW accelerated (and stream it later). So I decided to use MediaRecorder (and the socket hack

Answer 1

Alright, I think I have an answer for you. The start function that is failing is defined in a file called mediarecorder.cpp. Found here:

frameworks/av/media/libmedia/mediarecorder.cpp

This start function returns a variable of type status_t, and corresponds to the error that you're seeing thrown.

Now, the type status_t is defined in a file called Errors.h which can be found here:

system/core/include/utils/Errors.h

This defines an enumeration that corresponds to status_t as seen here:

enum {
    OK                = 0,    // Everything's swell.
    NO_ERROR          = 0,    // No errors.

    UNKNOWN_ERROR       = 0x80000000,

    NO_MEMORY           = -ENOMEM,
    INVALID_OPERATION   = -ENOSYS,
    BAD_VALUE           = -EINVAL,
    BAD_TYPE            = 0x80000001,
    NAME_NOT_FOUND      = -ENOENT,
    PERMISSION_DENIED   = -EPERM,
    NO_INIT             = -ENODEV,
    ALREADY_EXISTS      = -EEXIST,
    DEAD_OBJECT         = -EPIPE,
    FAILED_TRANSACTION  = 0x80000002,
    JPARKS_BROKE_IT     = -EPIPE,
#if !defined(HAVE_MS_C_RUNTIME)
    BAD_INDEX           = -EOVERFLOW,
    NOT_ENOUGH_DATA     = -ENODATA,
    WOULD_BLOCK         = -EWOULDBLOCK, 
    TIMED_OUT           = -ETIMEDOUT,
    UNKNOWN_TRANSACTION = -EBADMSG,
#else    
    BAD_INDEX           = -E2BIG,
    NOT_ENOUGH_DATA     = 0x80000003,
    WOULD_BLOCK         = 0x80000004,
    TIMED_OUT           = 0x80000005,
    UNKNOWN_TRANSACTION = 0x80000006,
#endif    
    FDS_NOT_ALLOWED     = 0x80000007,
};

As you can see, some of the values here are taken from errno.h, so we just need to see which one equates to a value of 38.

According to this source, 38 corresponds to ENOSYS. So, if we look back at the status_t enumeration, we can see that in android, ENOSYS corresponds to an invalid operation. Not terribly helpful, but I hope this at least points you in the right direction.

Answer 2

I have meet this error code in my call recorder app. this error code will show in logcat when you start media recorder while the Microphone is in use in another app like a Voice Assistant (for example: Ok google, etc) or another call recorder application.