Saturday, April 20, 2013

jni jnienv GetShortField example c c++ java


Get<type>Field Routines - GetShortField


NativeType Get<type>Field(JNIEnv *env, jobject obj,
jfieldID fieldID);

This family of accessor routines returns the value of an instance (nonstatic) field of an object. The field to access is specified by a field ID obtained by calling GetFieldID(). (GetShortField)

The following table describes the Get<type>Field routine name and result type. You should replace type in Get<type>Field with the Java type of the field, or use one of the actual routine names from the table, and replace NativeType with the corresponding native type for that routine.

Table 4-1a Get<type>Field Family of Accessor Routines

Get<type>Field Routine Name

Native Type

GetObjectField()

jobject

GetBooleanField()

jboolean

GetByteField()

jbyte

GetCharField()

jchar

GetShortField()

jshort

GetIntField()

jint

GetLongField()

jlong

GetFloatField()

jfloat

GetDoubleField()

jdouble
LINKAGE:
Indices in the JNIEnv interface function table:
Table 4-1b Get<type>Field Family of Accessor Routines

Get<type>Field Routine Name

Index

GetObjectField()
95

GetBooleanField()
96

GetByteField()
97

GetCharField()
98

GetShortField()
99

GetIntField()
100

GetLongField()
101

GetFloatField()
102

GetDoubleField()
103
PARAMETERS:

env: the JNI interface pointer.

obj: a Java object (must not be NULL).

fieldID: a valid field ID.

RETURNS:

Returns the content of the field.

Example - GetShortField


JNIEXPORT jint JNICALL Java_org_cablelabs_impl_manager_timeshift_TimeShiftBufferImpl_nTSBBufferingStart
    (JNIEnv *env, jobject obj, jint tunerID, jint tsbHandle, jobject listenerObj, jobject pidMapTable, jint bitrate)
{
    mpe_Error err;
    mpe_DvrBuffering tsbBufferingHandle;
    uint32_t pidCount = 0;
    mpe_DvrPidInfo *dvrPids = NULL;
    mpe_EdEventInfo *edHandle;
    jobjectArray  pidMapEntryArray;
    uint32_t p;
    jobject pidMapEntry;

    if(pidMapTable == 0 )
    {
        MPE_LOG(MPE_LOG_ERROR, MPE_MOD_JNI, "JNI(TSB): nTSBBufferingStart: ERROR - NULL PidMapTable\n");
        return MPE_DVR_ERR_INVALID_PARAM;
    }

    MPE_LOG( MPE_LOG_DEBUG, MPE_MOD_JNI, "JNI(TSB): nTSBBufferingStart(tuner %d, tsb %d, bitrate %d)\n",
             tunerID, tsbHandle, bitrate );

    // get the array of pid entries
    pidMapEntryArray = (*env)->GetObjectField(env, pidMapTable, jniutil_CachedIds.PidMapTable_pidMapEntryArray);
    pidCount = (*env)->GetIntField(env, pidMapTable, jniutil_CachedIds.PidMapTable_pidTableSize);

    MPE_LOG(MPE_LOG_DEBUG, MPE_MOD_JNI, "JNI(TSB): nTSBBufferingStart: number of pids is %d\n", pidCount);
    if(pidCount == 0 )
    {
        MPE_LOG(MPE_LOG_ERROR, MPE_MOD_JNI, "JNI(TSB): nTSBBufferingStart: ERROR - number of pids is %d\n", pidCount);
        return MPE_DVR_ERR_INVALID_PARAM;
    }

    // allocate dvr pidInfo table
    err = mpe_memAllocP(MPE_MEM_TEMP, sizeof(mpe_DvrPidInfo) * pidCount, (void**)&dvrPids);
    if (err != MPE_SUCCESS)
    {
        MPE_LOG(MPE_LOG_ERROR, MPE_MOD_JNI, "JNI(TSB): nTSBBufferingStart: ERROR - failed to allocate pid table\n");
        return err;
    }

    // Create the ed handle to pass into the DVR APIs
    mpe_edCreateHandle( listenerObj, MPE_ED_QUEUE_NORMAL, NULL, MPE_ED_TERMINATION_EVCODE,
                        MPE_DVR_EVT_SESSION_CLOSED, &edHandle );


    // walk through the pidEntryArray to create the DVR PidInfo table
    for(p=0; p < pidCount; p++)
    {
        // get pidMapEntryArray[p] (a PidMapEntry object)
        pidMapEntry = (*env)->GetObjectArrayElement(env,pidMapEntryArray, p);
        // get the PidmapEntry fields
        if (pidMapEntry != NULL)
        {
            dvrPids[p].srcPid = (uint16_t)(*env)->GetIntField(env, pidMapEntry, jniutil_CachedIds.PidMapEntry_srcPID);
            dvrPids[p].srcEltStreamType = (*env)->GetShortField(env, pidMapEntry, jniutil_CachedIds.PidMapEntry_srcElementaryStreamType);

            dvrPids[p].recPid = (uint16_t)(*env)->GetIntField(env, pidMapEntry, jniutil_CachedIds.PidMapEntry_recPID);
            dvrPids[p].recEltStreamType = (*env)->GetShortField(env, pidMapEntry, jniutil_CachedIds.PidMapEntry_recElementaryStreamType);;

            dvrPids[p].streamType = (*env)->GetShortField(env, pidMapEntry, jniutil_CachedIds.PidMapEntry_streamType);
            MPE_LOG( MPE_LOG_DEBUG, MPE_MOD_JNI, "JNI(TSB): nTSBBufferingStart: dvrPidInfo[%d]: type %d, src_pid %d(0x%x), src_elem %d(0x%x)\n",
                     p, dvrPids[p].streamType, dvrPids[p].srcPid,dvrPids[p].srcPid, dvrPids[p].srcEltStreamType,dvrPids[p].srcEltStreamType );
        }
   }

    err = mpe_dvrTsbBufferingStart( tunerID,
                                    (mpe_DvrTsb)tsbHandle,
                                    bitrate,
                                    edHandle->eventQ,
                                    (void *)edHandle,
                                    pidCount,
                                    dvrPids,
                                    &tsbBufferingHandle );


    if (err == MPE_SUCCESS)
    {

        // Store the resulting TSB buffering handle
        (*env)->SetIntField( env, obj,
                             jniutil_CachedIds.TimeShiftBufferImpl_bufferingHandle,
                             (int)tsbBufferingHandle );

        // update the PidMapTable with buffered pids
        jniutil_updatePidMapTable(env, pidCount, dvrPids, pidMapEntryArray);

    }
    // Free DVR PIDs
    if (dvrPids != NULL)
    {
        MPE_LOG(MPE_LOG_DEBUG, MPE_MOD_JNI, "JNI(TSB): nTSBBufferingStart:  calling mpe_memFreeP...\n", err);
        mpe_memFreeP(MPE_MEM_TEMP, dvrPids);
    }

    return err;
}