[FFmpeg-devel] [PATCH v4 1/6] avcodec: add av_jni_{get, set}_android_app_ctx helper

[Matthieu Bouron]

On Sun, Mar 17, 2024 at 11:38 PM Andreas Rheinhardt
<andreas.rheinhardt at outlook.com> wrote:
>
> Matthieu Bouron:
> > This will allow users to pass the Android ApplicationContext which is mandatory
> > to retrieve the ContentResolver responsible to resolve/open Android content-uri.
> > ---
> >  doc/APIchanges   |  3 +++
> >  libavcodec/jni.c | 42 ++++++++++++++++++++++++++++++++++++++++++
> >  libavcodec/jni.h | 17 +++++++++++++++++
> >  3 files changed, 62 insertions(+)
> >
> > diff --git a/doc/APIchanges b/doc/APIchanges
> > index a44c8e4f10..ae1868047e 100644
> > --- a/doc/APIchanges
> > +++ b/doc/APIchanges
> > @@ -2,6 +2,9 @@ The last version increases of all libraries were on 2024-03-07
> >
> >  API changes, most recent first:
> >
> > +2024-03-xx - xxxxxxxxxx - lavc 61.2.100 - jni.h
> > +  Add av_jni_set_android_app_ctx() and av_jni_get_android_app_ctx().
> > +
> >  2024-03-xx - xxxxxxxxxx - lavu 59.2.100 - channel_layout.h
> >    Add AV_CHANNEL_LAYOUT_RETYPE_FLAG_CANONICAL.
> >
> > diff --git a/libavcodec/jni.c b/libavcodec/jni.c
> > index ae6490de9d..cfe95bd1ec 100644
> > --- a/libavcodec/jni.c
> > +++ b/libavcodec/jni.c
> > @@ -77,3 +77,45 @@ void *av_jni_get_java_vm(void *log_ctx)
> >  }
> >
> >  #endif
> > +
> > +#if defined(__ANDROID__)
> > +
> > +int av_jni_set_android_app_ctx(void *app_ctx, void *log_ctx)
> > +{
> > +#if CONFIG_JNI
> > +    JNIEnv *env = ff_jni_get_env(log_ctx);
> > +    if (!env)
> > +        return AVERROR(EINVAL);
> > +
> > +    jobjectRefType type = (*env)->GetObjectRefType(env, app_ctx);
> > +    if (type != JNIGlobalRefType) {
> > +        av_log(log_ctx, AV_LOG_ERROR, "Application context must be passed as a global reference");
> > +        return AVERROR(EINVAL);
> > +    }
> > +
> > +    pthread_mutex_lock(&lock);
> > +    android_app_ctx = app_ctx;
> > +    pthread_mutex_unlock(&lock);
> > +
> > +    return 0;
> > +#else
> > +    return AVERROR(ENOSYS);
> > +#endif
> > +}
> > +
> > +void *av_jni_get_android_app_ctx(void)
> > +{
> > +#if CONFIG_JNI
> > +    void *ctx;
> > +
> > +    pthread_mutex_lock(&lock);
> > +    ctx = android_app_ctx;
> > +    pthread_mutex_unlock(&lock);
> > +
> > +    return ctx;
> > +#else
> > +    return NULL;
> > +#endif
> > +}
> > +
> > +#endif
> > diff --git a/libavcodec/jni.h b/libavcodec/jni.h
> > index dd99e92611..da8025f830 100644
> > --- a/libavcodec/jni.h
> > +++ b/libavcodec/jni.h
> > @@ -43,4 +43,21 @@ int av_jni_set_java_vm(void *vm, void *log_ctx);
> >   */
> >  void *av_jni_get_java_vm(void *log_ctx);
> >
> > +/*
> > + * Set the Android application context which will be used to retrieve the Android
> > + * content resolver to resolve content uris.
> > + *
> > + * @param app_ctx global JNI reference to the Android application context
> > + * @return 0 on success, < 0 otherwise
> > + */
> > +int av_jni_set_android_app_ctx(void *app_ctx, void *log_ctx);
> > +
> > +/*
> > + * Get the Android application context that has been set with
> > + * av_jni_set_android_app_ctx.
> > + *
> > + * @return a pointer the the Android application context
> > + */
> > +void *av_jni_get_android_app_ctx(void);
>
> This should mention that these functions are only available on android.

Added the following chunk locally to both functions:

  *
+ * This function is only available on Android.
+ *