[FFmpeg-devel] [PATCH 1/5] lavu: add JNI support
Matthieu Bouron
matthieu.bouron at gmail.com
Mon Feb 15 18:52:26 CET 2016
From: Matthieu Bouron <matthieu.bouron at stupeflix.com>
---
configure | 4 +
libavutil/Makefile | 4 +
libavutil/jni.c | 55 +++++++
libavutil/jni.h | 42 +++++
libavutil/jni_internal.c | 391 +++++++++++++++++++++++++++++++++++++++++++++++
libavutil/jni_internal.h | 147 ++++++++++++++++++
6 files changed, 643 insertions(+)
create mode 100644 libavutil/jni.c
create mode 100644 libavutil/jni.h
create mode 100644 libavutil/jni_internal.c
create mode 100644 libavutil/jni_internal.h
diff --git a/configure b/configure
index 2148f11..d05ae4d 100755
--- a/configure
+++ b/configure
@@ -206,6 +206,7 @@ External library support:
--enable-gnutls enable gnutls, needed for https support
if openssl is not used [no]
--disable-iconv disable iconv [autodetect]
+ --enable-jni enable JNI support [no]
--enable-ladspa enable LADSPA audio filtering [no]
--enable-libass enable libass subtitles rendering,
needed for subtitles and ass filter [no]
@@ -1432,6 +1433,7 @@ EXTERNAL_LIBRARY_LIST="
gmp
gnutls
iconv
+ jni
ladspa
libass
libbluray
@@ -5455,6 +5457,7 @@ enabled decklink && { check_header DeckLinkAPI.h || die "ERROR: DeckLin
enabled frei0r && { check_header frei0r.h || die "ERROR: frei0r.h header not found"; }
enabled gmp && require2 gmp gmp.h mpz_export -lgmp
enabled gnutls && require_pkg_config gnutls gnutls/gnutls.h gnutls_global_init
+enabled jni && { check_header jni.h && enabled pthreads; }
enabled ladspa && { check_header ladspa.h || die "ERROR: ladspa.h header not found"; }
enabled libiec61883 && require libiec61883 libiec61883/iec61883.h iec61883_cmp_connect -lraw1394 -lavc1394 -lrom1394 -liec61883
enabled libass && require_pkg_config libass ass/ass.h ass_library_init
@@ -6222,6 +6225,7 @@ echo "threading support ${thread_type-no}"
echo "safe bitstream reader ${safe_bitstream_reader-no}"
echo "SDL support ${sdl-no}"
echo "opencl enabled ${opencl-no}"
+echo "JNI support ${jni-no}"
echo "texi2html enabled ${texi2html-no}"
echo "perl enabled ${perl-no}"
echo "pod2man enabled ${pod2man-no}"
diff --git a/libavutil/Makefile b/libavutil/Makefile
index 65b2d25..ab39d41 100644
--- a/libavutil/Makefile
+++ b/libavutil/Makefile
@@ -72,6 +72,8 @@ HEADERS-$(CONFIG_LZO) += lzo.h
HEADERS-$(CONFIG_OPENCL) += opencl.h
+HEADERS-$(CONFIG_JNI) += jni.h
+
ARCH_HEADERS = bswap.h \
intmath.h \
intreadwrite.h \
@@ -148,6 +150,7 @@ OBJS-$(!HAVE_ATOMICS_NATIVE) += atomic.o \
OBJS-$(CONFIG_LZO) += lzo.o
OBJS-$(CONFIG_OPENCL) += opencl.o opencl_internal.o
+OBJS-$(CONFIG_JNI) += jni.o jni_internal.o
OBJS += $(COMPAT_OBJS:%=../compat/%)
@@ -158,6 +161,7 @@ SKIPHEADERS-$(HAVE_ATOMICS_GCC) += atomic_gcc.h
SKIPHEADERS-$(HAVE_ATOMICS_SUNCC) += atomic_suncc.h
SKIPHEADERS-$(HAVE_ATOMICS_WIN32) += atomic_win32.h
SKIPHEADERS-$(CONFIG_OPENCL) += opencl.h
+SKIPHEADERS-$(CONFIG_JNI) += jni_internal.h
TESTPROGS = adler32 \
aes \
diff --git a/libavutil/jni.c b/libavutil/jni.c
new file mode 100644
index 0000000..fb89426
--- /dev/null
+++ b/libavutil/jni.c
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2015-2016 Matthieu Bouron <matthieu.bouron stupeflix.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "config.h"
+#include "jni.h"
+#include "log.h"
+
+#include <jni.h>
+#include <stdlib.h>
+#include <pthread.h>
+
+static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
+
+JavaVM *java_vm = NULL;
+
+void av_jni_register_java_vm(JavaVM *vm)
+{
+ pthread_mutex_lock(&lock);
+ if (java_vm) {
+ av_log(NULL, AV_LOG_INFO, "The Java VM has already been registered\n");
+ goto done;
+ }
+
+ java_vm = vm;
+done:
+ pthread_mutex_unlock(&lock);
+}
+
+JavaVM *av_jni_get_java_vm(void)
+{
+ JavaVM *vm;
+
+ pthread_mutex_lock(&lock);
+ vm = java_vm;
+ pthread_mutex_unlock(&lock);
+
+ return vm;
+}
diff --git a/libavutil/jni.h b/libavutil/jni.h
new file mode 100644
index 0000000..a6c5c16
--- /dev/null
+++ b/libavutil/jni.h
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2015-2016 Matthieu Bouron <matthieu.bouron stupeflix.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVUTIL_JNI_H
+#define AVUTIL_JNI_H
+
+#include <jni.h>
+
+/*
+ * Register a java virtual machine that will be used to manage the JNI
+ * environment.
+ *
+ * @param vm java virtual machine
+ */
+void av_jni_register_java_vm(JavaVM *vm);
+
+/*
+ * Get the registered java virtual machine.
+ *
+ * @return the java virtual machine, NULL if no java virtual machine has been
+ * registered
+ */
+JavaVM *av_jni_get_java_vm(void);
+
+#endif /* AVUTIL_JNI_H */
diff --git a/libavutil/jni_internal.c b/libavutil/jni_internal.c
new file mode 100644
index 0000000..f095469
--- /dev/null
+++ b/libavutil/jni_internal.c
@@ -0,0 +1,391 @@
+/*
+ * Copyright (c) 2015-2016 Matthieu Bouron <matthieu.bouron stupeflix.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "bprint.h"
+#include "config.h"
+#include "jni.h"
+#include "jni_internal.h"
+#include "log.h"
+
+#include <jni.h>
+#include <stdlib.h>
+
+extern JavaVM *java_vm;
+
+JNIEnv *avpriv_jni_attach_env(int *attached, void *log_ctx)
+{
+ int ret = 0;
+ JNIEnv *env = NULL;
+
+ *attached = 0;
+
+ if (java_vm == NULL) {
+ av_log(log_ctx, AV_LOG_ERROR, "No java virtual machine has been registered\n");
+ return NULL;
+ }
+
+ ret = (*java_vm)->GetEnv(java_vm, (void **)&env, JNI_VERSION_1_6);
+ switch(ret) {
+ case JNI_EDETACHED:
+ if ((*java_vm)->AttachCurrentThread(java_vm, &env, NULL) != 0) {
+ av_log(log_ctx, AV_LOG_ERROR, "Failed to attach the JNI environment to the current thread\n");
+ env = NULL;
+ } else {
+ *attached = 1;
+ }
+ break;
+ case JNI_OK:
+ break;
+ case JNI_EVERSION:
+ av_log(log_ctx, AV_LOG_ERROR, "The specified JNI version is not supported\n");
+ break;
+ default:
+ av_log(log_ctx, AV_LOG_ERROR, "Failed to get the JNI environment attached to this thread");
+ break;
+ }
+
+ return env;
+}
+
+int avpriv_jni_detach_env(void *log_ctx)
+{
+ if (java_vm == NULL) {
+ av_log(log_ctx, AV_LOG_ERROR, "No java virtual machine has been registered\n");
+ return AVERROR(EINVAL);
+ }
+
+ return (*java_vm)->DetachCurrentThread(java_vm);
+}
+
+char *avpriv_jni_jstring_to_utf_chars(JNIEnv *env, jstring string, void *log_ctx)
+{
+ char *ret = NULL;
+ const char *utf_chars = NULL;
+
+ jboolean copy = 0;
+
+ if (!string) {
+ return NULL;
+ }
+
+ utf_chars = (*env)->GetStringUTFChars(env, string, ©);
+ if ((*env)->ExceptionCheck(env)) {
+ (*env)->ExceptionClear(env);
+ av_log(log_ctx, AV_LOG_ERROR, "String.getStringUTFChars() threw an exception\n");
+ return NULL;
+ }
+
+ ret = av_strdup(utf_chars);
+
+ (*env)->ReleaseStringUTFChars(env, string, utf_chars);
+ if ((*env)->ExceptionCheck(env)) {
+ (*env)->ExceptionClear(env);
+ av_log(log_ctx, AV_LOG_ERROR, "String.releaseStringUTFChars() threw an exception\n");
+ return NULL;;
+ }
+
+ return ret;
+}
+
+jstring avpriv_jni_utf_chars_to_jstring(JNIEnv *env, const char *utf_chars, void *log_ctx)
+{
+ jstring ret;
+
+ ret = (*env)->NewStringUTF(env, utf_chars);
+ if ((*env)->ExceptionCheck(env)) {
+ (*env)->ExceptionClear(env);
+ av_log(log_ctx, AV_LOG_ERROR, "NewStringUTF() threw an exception\n");
+ return NULL;
+ }
+
+ return ret;
+}
+
+int avpriv_jni_exception_get_summary(JNIEnv *env, jthrowable exception, char **error, void *log_ctx)
+{
+ int ret = 0;
+
+ AVBPrint bp;
+
+ char *name = NULL;
+ char *message = NULL;
+
+ jclass class_class = NULL;
+ jmethodID get_name_id = NULL;
+
+ jclass exception_class = NULL;
+ jmethodID get_message_id = NULL;
+
+ jstring string;
+
+ av_bprint_init(&bp, 0, AV_BPRINT_SIZE_AUTOMATIC);
+
+ exception_class = (*env)->GetObjectClass(env, exception);
+ if ((*env)->ExceptionCheck(env)) {
+ (*env)->ExceptionClear(env);
+ av_log(log_ctx, AV_LOG_ERROR, "Could not find Throwable class\n");
+ ret = AVERROR_EXTERNAL;
+ goto done;
+ }
+
+ class_class = (*env)->GetObjectClass(env, exception_class);
+ if ((*env)->ExceptionCheck(env)) {
+ (*env)->ExceptionClear(env);
+ av_log(log_ctx, AV_LOG_ERROR, "Could not find Throwable class's class\n");
+ ret = AVERROR_EXTERNAL;
+ goto done;
+ }
+
+ get_name_id = (*env)->GetMethodID(env, class_class, "getName", "()Ljava/lang/String;");
+ if ((*env)->ExceptionCheck(env)) {
+ (*env)->ExceptionClear(env);
+ av_log(log_ctx, AV_LOG_ERROR, "Could not find method Class.getName()\n");
+ ret = AVERROR_EXTERNAL;
+ goto done;
+ }
+
+ string = (*env)->CallObjectMethod(env, exception_class, get_name_id);
+ if ((*env)->ExceptionCheck(env)) {
+ (*env)->ExceptionClear(env);
+ av_log(log_ctx, AV_LOG_ERROR, "Class.getName() threw an exception\n");
+ ret = AVERROR_EXTERNAL;
+ goto done;
+ }
+
+ if (string) {
+ name = avpriv_jni_jstring_to_utf_chars(env, string, log_ctx);
+ (*env)->DeleteLocalRef(env, string);
+ string = NULL;
+ }
+
+ get_message_id = (*env)->GetMethodID(env, exception_class, "getMessage", "()Ljava/lang/String;");
+ if ((*env)->ExceptionCheck(env)) {
+ (*env)->ExceptionClear(env);
+ av_log(log_ctx, AV_LOG_ERROR, "Could not find method java/lang/Throwable.getMessage()\n");
+ ret = AVERROR_EXTERNAL;
+ goto done;
+ }
+
+ string = (*env)->CallObjectMethod(env, exception, get_message_id);
+ if ((*env)->ExceptionCheck(env)) {
+ (*env)->ExceptionClear(env);
+ av_log(log_ctx, AV_LOG_ERROR, "Throwable.getMessage() threw an exception\n");
+ ret = AVERROR_EXTERNAL;
+ goto done;
+ }
+
+ if (string) {
+ message = avpriv_jni_jstring_to_utf_chars(env, string, log_ctx);
+ (*env)->DeleteLocalRef(env, string);
+ string = NULL;
+ }
+
+ if (name && message) {
+ av_bprintf(&bp, "%s: %s", name, message);
+ } else if (name && !message) {
+ av_bprintf(&bp, "%s occured", name);
+ } else if (!name && message) {
+ av_bprintf(&bp, "Exception: %s", message);
+ } else {
+ av_log(log_ctx, AV_LOG_WARNING, "Could not retreive exception name and message\n");
+ av_bprintf(&bp, "Exception occured");
+ }
+
+ ret = av_bprint_finalize(&bp, error);
+done:
+
+ av_free(name);
+ av_free(message);
+
+ if (class_class) {
+ (*env)->DeleteLocalRef(env, class_class);
+ }
+
+ if (exception_class) {
+ (*env)->DeleteLocalRef(env, exception_class);
+ }
+
+ if (string) {
+ (*env)->DeleteLocalRef(env, string);
+ }
+
+ return ret;
+}
+
+int avpriv_jni_exception_check(JNIEnv *env, int log, void *log_ctx)
+{
+ int ret;
+
+ jthrowable exception;
+
+ char *message = NULL;
+
+ if (!(*(env))->ExceptionCheck((env))) {
+ return 0;
+ }
+
+ if (!log) {
+ (*(env))->ExceptionClear((env));
+ return -1;
+ }
+
+ exception = (*env)->ExceptionOccurred(env);
+ (*(env))->ExceptionClear((env));
+
+ if ((ret = avpriv_jni_exception_get_summary(env, exception, &message, log_ctx)) < 0) {
+ (*env)->DeleteLocalRef(env, exception);
+ return ret;
+ }
+
+ (*env)->DeleteLocalRef(env, exception);
+
+ av_log(log_ctx, AV_LOG_ERROR, "%s\n", message);
+ av_free(message);
+
+ return -1;
+}
+
+int avpriv_jni_init_jfields(JNIEnv *env, void *jfields, const struct FFJniField *jfields_mapping, int global, void *log_ctx)
+{
+ int i, ret = 0;
+ jclass last_clazz = NULL;
+
+ for (i = 0; jfields_mapping[i].name; i++) {
+ int mandatory = jfields_mapping[i].mandatory;
+ enum FFJniFieldType type = jfields_mapping[i].type;
+
+ if (type == FF_JNI_CLASS) {
+ jclass clazz;
+
+ last_clazz = NULL;
+
+ clazz = (*env)->FindClass(env, jfields_mapping[i].name);
+ if ((ret = avpriv_jni_exception_check(env, mandatory, log_ctx) && mandatory) < 0) {
+ goto done;
+ }
+
+ last_clazz = *(jclass*)((uint8_t*)jfields + jfields_mapping[i].offset) =
+ global ? (*env)->NewGlobalRef(env, clazz) : clazz;
+ } else {
+
+ if (!last_clazz) {
+ ret = AVERROR_EXTERNAL;
+ break;
+ }
+
+ switch(type) {
+ case (FF_JNI_FIELD): {
+ jfieldID field_id = (*env)->GetFieldID(env, last_clazz, jfields_mapping[i].method, jfields_mapping[i].signature);
+ if ((ret = avpriv_jni_exception_check(env, mandatory, log_ctx)) < 0 && mandatory) {
+ goto done;
+ }
+
+ *(jfieldID*)((uint8_t*)jfields + jfields_mapping[i].offset) = field_id;
+ break;
+ }
+ case (FF_JNI_STATIC_FIELD): {
+ jfieldID field_id = (*env)->GetStaticFieldID(env, last_clazz, jfields_mapping[i].method, jfields_mapping[i].signature);
+ if ((ret = avpriv_jni_exception_check(env, mandatory, log_ctx)) < 0 && mandatory) {
+ goto done;
+ }
+
+ *(jfieldID*)((uint8_t*)jfields + jfields_mapping[i].offset) = field_id;
+ break;
+ }
+ case (FF_JNI_METHOD): {
+ jmethodID method_id = (*env)->GetMethodID(env, last_clazz, jfields_mapping[i].method, jfields_mapping[i].signature);
+ if ((ret = avpriv_jni_exception_check(env, mandatory, log_ctx)) < 0 && mandatory) {
+ goto done;
+ }
+
+ *(jmethodID*)((uint8_t*)jfields + jfields_mapping[i].offset) = method_id;
+ break;
+ }
+ case (FF_JNI_STATIC_METHOD): {
+ jmethodID method_id = (*env)->GetStaticMethodID(env, last_clazz, jfields_mapping[i].method, jfields_mapping[i].signature);
+ if ((ret = avpriv_jni_exception_check(env, mandatory, log_ctx)) < 0 && mandatory) {
+ goto done;
+ }
+
+ *(jmethodID*)((uint8_t*)jfields + jfields_mapping[i].offset) = method_id;
+ break;
+ }
+ default:
+ av_log(log_ctx, AV_LOG_ERROR, "Unknown JNI field type\n");
+ ret = AVERROR(EINVAL);
+ goto done;
+ }
+ }
+ }
+
+done:
+ if (ret < 0) {
+ /* reset jfields in case of failure so it does not leak references */
+ avpriv_jni_reset_jfields(env, jfields, jfields_mapping, global, log_ctx);
+ }
+
+ return ret;
+}
+
+int avpriv_jni_reset_jfields(JNIEnv *env, void *jfields, const struct FFJniField *jfields_mapping, int global, void *log_ctx)
+{
+ int i;
+
+ for (i = 0; jfields_mapping[i].name; i++) {
+ enum FFJniFieldType type = jfields_mapping[i].type;
+
+ switch(type) {
+ case (FF_JNI_CLASS): {
+ jclass clazz = *(jclass*)((uint8_t*)jfields + jfields_mapping[i].offset);
+ if (!clazz)
+ continue;
+
+ if (global) {
+ (*env)->DeleteGlobalRef(env, clazz);
+ } else {
+ (*env)->DeleteLocalRef(env, clazz);
+ }
+
+ *(jclass*)((uint8_t*)jfields + jfields_mapping[i].offset) = NULL;
+ break;
+ }
+ case (FF_JNI_FIELD): {
+ *(jfieldID*)((uint8_t*)jfields + jfields_mapping[i].offset) = NULL;
+ break;
+ }
+ case (FF_JNI_STATIC_FIELD): {
+ *(jfieldID*)((uint8_t*)jfields + jfields_mapping[i].offset) = NULL;
+ break;
+ }
+ case (FF_JNI_METHOD): {
+ *(jmethodID*)((uint8_t*)jfields + jfields_mapping[i].offset) = NULL;
+ break;
+ }
+ case (FF_JNI_STATIC_METHOD): {
+ *(jmethodID*)((uint8_t*)jfields + jfields_mapping[i].offset) = NULL;
+ break;
+ }
+ default:
+ av_log(log_ctx, AV_LOG_ERROR, "Unknown JNI field type\n");
+ }
+ }
+
+ return 0;
+}
diff --git a/libavutil/jni_internal.h b/libavutil/jni_internal.h
new file mode 100644
index 0000000..6e66cc2
--- /dev/null
+++ b/libavutil/jni_internal.h
@@ -0,0 +1,147 @@
+/*
+ * Copyright (c) 2015-2016 Matthieu Bouron <matthieu.bouron stupeflix.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVUTIL_JNI_INTERNAL_H
+#define AVUTIL_JNI_INTERNAL_H
+
+#include <jni.h>
+
+/*
+ * Attach a JNI environment to the current thread.
+ *
+ * @param attached pointer to an integer that will be set to 1 if the
+ * environment has been attached to the current thread or 0 if it is
+ * already attached.
+ * @param log_ctx context used for logging, can be NULL
+ * @return the JNI environment on success, NULL otherwise
+ */
+JNIEnv *avpriv_jni_attach_env(int *attached, void *log_ctx);
+
+/*
+ * Detach the JNI environment from the current thread.
+ *
+ * @param log_ctx context used for logging, can be NULL
+ * @return 0 on success, < 0 otherwise
+ */
+int avpriv_jni_detach_env(void *log_ctx);
+
+/*
+ * Convert a jstring to its utf characters equivalent.
+ *
+ * @param env JNI environment
+ * @param string java string to convert
+ * @param log_ctx context used for logging, can be NULL
+ * @return a pointer to an array of unicode caracters on success, NULL
+ * otherwise
+ */
+char *avpriv_jni_jstring_to_utf_chars(JNIEnv *env, jstring string, void *log_ctx);
+
+/*
+ * Convert utf chars to its jstring equivalent.
+ *
+ * @param env JNI environment
+ * @param utf_chars a pointer to an array of unicode caracters
+ * @param log_ctx context used for logging, can be NULL
+ * @return a java string object on success, NULL otherwise
+ */
+jstring avpriv_jni_utf_chars_to_jstring(JNIEnv *env, const char *utf_chars, void *log_ctx);
+
+/*
+ * Extract the error summary from a jthrowable in the form of "className: errorMesage"
+ *
+ * @param env JNI environment
+ * @param exception exception to get the summary from
+ * @param error address pointing to the error, the value is updated if a
+ * summary can be extracted
+ * @param log_ctx context used for logging, can be NULL
+ * @return 0 on success, < 0 otherwise
+ */
+int avpriv_jni_exception_get_summary(JNIEnv *env, jthrowable exception, char **error, void *log_ctx);
+
+/*
+ * Check if an exception has occurred,log it using av_log and clear it.
+ *
+ * @param env JNI environment
+ * @param log value used to enable logging if an exception has occured,
+ * 0 disables logging, != 0 enables logging
+ * @param log_ctx context used for logging, can be NULL
+ */
+int avpriv_jni_exception_check(JNIEnv *env, int log, void *log_ctx);
+
+/*
+ * Jni field type.
+ */
+enum FFJniFieldType {
+
+ FF_JNI_CLASS,
+ FF_JNI_FIELD,
+ FF_JNI_STATIC_FIELD,
+ FF_JNI_METHOD,
+ FF_JNI_STATIC_METHOD
+
+} MemberType;
+
+/*
+ * Jni field describing a class, a field or a method to be retrived using
+ * the avpriv_jni_init_jfields method.
+ */
+struct FFJniField {
+
+ const char *name;
+ const char *method;
+ const char *signature;
+ enum FFJniFieldType type;
+ int offset;
+ int mandatory;
+
+};
+
+/*
+ * Retreive class references, field ids and method ids to an arbitrary structure.
+ *
+ * @param env JNI environment
+ * @param jfields a pointer to an arbitrary structure where the different
+ * fields are declared and where the FFJNIField mapping table offsets are
+ * pointing to
+ * @param jfields_mapping null terminated array of FFJNIFields describing
+ * the class/field/method to be retrived
+ * @param global, wheter or not to make the classes reference global, it is
+ * the caller responsability to properly release global references.
+ * @param log_ctx context used for logging, can be NULL
+ * @return 0 on success, < 0 otherwise
+ */
+int avpriv_jni_init_jfields(JNIEnv *env, void *jfields, const struct FFJniField *jfields_mapping, int global, void *log_ctx);
+
+/*
+ * Delete class references, field ids and method ids of an arbitrary structure.
+ *
+ * @param env JNI environment
+ * @param jfields a pointer to an arbitrary structure where the different
+ * fields are declared and where the FFJNIField mapping table offsets are
+ * pointing to
+ * @param jfields_mapping null terminated array of FFJNIFields describing
+ * the class/field/method to be deleted
+ * @param global, wheter or not the classes reference are global
+ * @param log_ctx context used for logging, can be NULL
+ * @return 0 on success, < 0 otherwise
+ */
+int avpriv_jni_reset_jfields(JNIEnv *env, void *jfields, const struct FFJniField *jfields_mapping, int global, void *log_ctx);
+
+#endif /* AVUTIL_JNI_INTERNAL_H */
--
2.7.1
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