lavc: add JNI support

This commit is contained in:
Matthieu Bouron 2015-09-28 15:18:56 +02:00
parent 6f5048f4a0
commit 3ab178516e
7 changed files with 771 additions and 0 deletions

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@ -196,6 +196,7 @@ Codecs:
interplayvideo.c Mike Melanson
ivi* Kostya Shishkov
jacosub* Clément Bœsch
jni*, ffjni* Matthieu Bouron
jpeg2000* Nicolas Bertrand
jpeg_ls.c Kostya Shishkov
jvdec.c Peter Ross

5
configure vendored
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@ -207,6 +207,7 @@ 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]
@ -1436,6 +1437,7 @@ EXTERNAL_LIBRARY_LIST="
gmp
gnutls
iconv
jni
ladspa
libass
libbluray
@ -5556,6 +5558,8 @@ 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 && { [ $target_os = "android" ] && check_header jni.h && enabled pthreads &&
check_lib2 "dlfcn.h" dlopen -ldl; }
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
@ -6324,6 +6328,7 @@ 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}"

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@ -9,6 +9,7 @@ HEADERS = avcodec.h \
d3d11va.h \
dirac.h \
dxva2.h \
jni.h \
qsv.h \
vaapi.h \
vda.h \
@ -30,6 +31,7 @@ OBJS = allcodecs.o \
dirac.o \
dv_profile.o \
imgconvert.o \
jni.o \
mathtables.o \
options.o \
parser.o \
@ -79,6 +81,7 @@ OBJS-$(CONFIG_IIRFILTER) += iirfilter.o
OBJS-$(CONFIG_IMDCT15) += imdct15.o
OBJS-$(CONFIG_INTRAX8) += intrax8.o intrax8dsp.o
OBJS-$(CONFIG_IVIDSP) += ivi_dsp.o
OBJS-$(CONFIG_JNI) += ffjni.o jni.o
OBJS-$(CONFIG_JPEGTABLES) += jpegtables.o
OBJS-$(CONFIG_LIBXVID) += libxvid_rc.o
OBJS-$(CONFIG_LLAUDDSP) += lossless_audiodsp.o
@ -936,6 +939,7 @@ SKIPHEADERS += %_tablegen.h \
SKIPHEADERS-$(CONFIG_D3D11VA) += d3d11va.h dxva2_internal.h
SKIPHEADERS-$(CONFIG_DXVA2) += dxva2.h dxva2_internal.h
SKIPHEADERS-$(CONFIG_JNI) += ffjni.h
SKIPHEADERS-$(CONFIG_LIBSCHROEDINGER) += libschroedinger.h
SKIPHEADERS-$(CONFIG_LIBUTVIDEO) += libutvideo.h
SKIPHEADERS-$(CONFIG_LIBVPX) += libvpx.h

485
libavcodec/ffjni.c Normal file
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@ -0,0 +1,485 @@
/*
* JNI utility functions
*
* 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 <dlfcn.h>
#include <jni.h>
#include <pthread.h>
#include <stdlib.h>
#include "libavutil/bprint.h"
#include "libavutil/log.h"
#include "config.h"
#include "jni.h"
#include "ffjni.h"
static JavaVM *java_vm = NULL;
static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
/**
* Check if JniInvocation has been initialized. Only available on
* Android >= 4.4.
*
* @param log_ctx context used for logging, can be NULL
* @return 0 on success, < 0 otherwise
*/
static int check_jni_invocation(void *log_ctx)
{
int ret = AVERROR_EXTERNAL;
void *handle = NULL;
void **jni_invocation = NULL;
handle = dlopen(NULL, RTLD_LOCAL);
if (!handle) {
goto done;
}
jni_invocation = (void **)dlsym(handle, "_ZN13JniInvocation15jni_invocation_E");
if (!jni_invocation) {
av_log(log_ctx, AV_LOG_ERROR, "Could not find JniInvocation::jni_invocation_ symbol\n");
goto done;
}
ret = !(jni_invocation != NULL && *jni_invocation != NULL);
done:
if (handle) {
dlclose(handle);
}
return ret;
}
/**
* Return created Java virtual machine using private JNI_GetCreatedJavaVMs
* function from the specified library name.
*
* @param name library name used for symbol lookups, can be NULL
* @param log_ctx context used for logging, can be NULL
* @return the current Java virtual machine in use
*/
static JavaVM *get_java_vm(const char *name, void *log_ctx)
{
JavaVM *vm = NULL;
jsize nb_vm = 0;
void *handle = NULL;
jint (*get_created_java_vms) (JavaVM ** vmBuf, jsize bufLen, jsize *nVMs) = NULL;
handle = dlopen(name, RTLD_LOCAL);
if (!handle) {
return NULL;
}
get_created_java_vms = (jint (*)(JavaVM **, jsize, jsize *)) dlsym(handle, "JNI_GetCreatedJavaVMs");
if (!get_created_java_vms) {
av_log(log_ctx, AV_LOG_ERROR, "Could not find JNI_GetCreatedJavaVMs symbol in library '%s'\n", name);
goto done;
}
if (get_created_java_vms(&vm, 1, &nb_vm) != JNI_OK) {
av_log(log_ctx, AV_LOG_ERROR, "Could not get created Java virtual machines\n");
goto done;
}
done:
if (handle) {
dlclose(handle);
}
return vm;
}
JNIEnv *ff_jni_attach_env(int *attached, void *log_ctx)
{
int ret = 0;
JNIEnv *env = NULL;
*attached = 0;
pthread_mutex_lock(&lock);
if (java_vm == NULL && (java_vm = av_jni_get_java_vm(log_ctx)) == NULL) {
av_log(log_ctx, AV_LOG_INFO, "Retrieving current Java virtual machine using Android JniInvocation wrapper\n");
if (check_jni_invocation(log_ctx) == 0) {
if ((java_vm = get_java_vm(NULL, log_ctx)) != NULL ||
(java_vm = get_java_vm("libdvm.so", log_ctx)) != NULL ||
(java_vm = get_java_vm("libart.so", log_ctx)) != NULL) {
av_log(log_ctx, AV_LOG_INFO, "Found Java virtual machine using Android JniInvocation wrapper\n");
}
}
}
pthread_mutex_unlock(&lock);
if (!java_vm) {
av_log(log_ctx, AV_LOG_ERROR, "Could not retrieve a Java virtual machine\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 ff_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 *ff_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, &copy);
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 ff_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 ff_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 = ff_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 = ff_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 ff_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 = ff_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 ff_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 = ff_jni_exception_check(env, mandatory, log_ctx)) < 0 && mandatory) {
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 = ff_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 = ff_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 = ff_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 = ff_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 */
ff_jni_reset_jfields(env, jfields, jfields_mapping, global, log_ctx);
}
return ret;
}
int ff_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;
}

150
libavcodec/ffjni.h Normal file
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@ -0,0 +1,150 @@
/*
* JNI utility functions
*
* 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 AVCODEC_FFJNI_H
#define AVCODEC_FFJNI_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 *ff_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 ff_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 characters on success, NULL
* otherwise
*/
char *ff_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 characters
* @param log_ctx context used for logging, can be NULL
* @return a Java string object on success, NULL otherwise
*/
jstring ff_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: errorMessage"
*
* @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 ff_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 occurred,
* 0 disables logging, != 0 enables logging
* @param log_ctx context used for logging, can be NULL
*/
int ff_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
};
/*
* Jni field describing a class, a field or a method to be retrieved using
* the ff_jni_init_jfields method.
*/
struct FFJniField {
const char *name;
const char *method;
const char *signature;
enum FFJniFieldType type;
int offset;
int mandatory;
};
/*
* Retrieve 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 retrieved
* @param global make the classes references global. It is the caller
* responsibility to properly release global references.
* @param log_ctx context used for logging, can be NULL
* @return 0 on success, < 0 otherwise
*/
int ff_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 threat the classes references as global and delete them
* accordingly
* @param log_ctx context used for logging, can be NULL
* @return 0 on success, < 0 otherwise
*/
int ff_jni_reset_jfields(JNIEnv *env, void *jfields, const struct FFJniField *jfields_mapping, int global, void *log_ctx);
#endif /* AVCODEC_FFJNI_H */

80
libavcodec/jni.c Normal file
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@ -0,0 +1,80 @@
/*
* JNI public API functions
*
* 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 <stdlib.h>
#include "config.h"
#include "jni.h"
#if CONFIG_JNI
#include <errno.h>
#include <jni.h>
#include <pthread.h>
#include "libavutil/log.h"
#include "libavutil/error.h"
#include "ffjni.h"
void *java_vm;
pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
int av_jni_set_java_vm(void *vm, void *log_ctx)
{
int ret = 0;
pthread_mutex_lock(&lock);
if (java_vm == NULL) {
java_vm = vm;
} else if (java_vm != vm) {
ret = AVERROR(EINVAL);
av_log(log_ctx, AV_LOG_ERROR, "A Java virtual machine has already been set");
}
pthread_mutex_unlock(&lock);
return ret;
}
void *av_jni_get_java_vm(void *log_ctx)
{
void *vm;
pthread_mutex_lock(&lock);
vm = java_vm;
pthread_mutex_unlock(&lock);
return vm;
}
#else
int av_jni_set_java_vm(void *vm, void *log_ctx)
{
return 0;
}
void *av_jni_get_java_vm(void *log_ctx)
{
return NULL;
}
#endif

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libavcodec/jni.h Normal file
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/*
* JNI public API functions
*
* 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 AVCODEC_JNI_H
#define AVCODEC_JNI_H
/*
* Manually set a Java virtual machine which will be used to retrieve the JNI
* environment. Once a Java VM is set it cannot be changed afterwards, meaning
* you can call multiple times av_jni_set_java_vm with the same Java VM pointer
* however it will error out if you try to set a different Java VM.
*
* @param vm Java virtual machine
* @param log_ctx context used for logging, can be NULL
* @return 0 on success, < 0 otherwise
*/
int av_jni_set_java_vm(void *vm, void *log_ctx);
/*
* Get the Java virtual machine which has been set with av_jni_set_java_vm.
*
* @param vm Java virtual machine
* @return a pointer to the Java virtual machine
*/
void *av_jni_get_java_vm(void *log_ctx);
#endif /* AVCODEC_JNI_H */