build: add content uri support to FFmpeg

See https://ffmpeg.org//pipermail/ffmpeg-devel/2024-February/322247.html.

configure.py

@@ -121,6 +121,14 @@ def _gen_android_cross_file(cfg):
         url="https://ffmpeg.org/releases/ffmpeg-@[email protected]",
         dst_file="ffmpeg-@[email protected]",
         sha256="8684f4b00f94b85461884c3719382f1261f0d9eb3d59640a1f4ac0873616f968",
+        patches=[
+            "0001-avcodec-add-av_jni_-get-set-_android_app_ctx-helper.patch",
+            "0002-avformat-add-Android-content-resolver-protocol-suppo.patch",
+            "0003-avcodec-jni-use-size_t-to-store-structure-offsets.patch",
+            "0004-avcodec-jni-remove-unnecessary-NULL-checks-before-ca.patch",
+            "0005-avcodec-mediacodec_wrapper-use-an-OFFSET-macro-where.patch",
+            "0006-avcodec-mediacodec_wrapper-remove-unnecessary-NULL-c.patch",
+        ],
     ),
     ffmpeg_Windows=dict(
         version="6.1.1",
@@ -523,6 +531,7 @@ def _ffmpeg_setup(cfg):
             "http",
             "https",
             "pipe",
+            "android_content",
         ]
         filters = [
             "aformat",

patches/ffmpeg/0001-avcodec-add-av_jni_-get-set-_android_app_ctx-helper.patch

@@ -0,0 +1,97 @@
+From 15533f90bc98b4cebd84b4ead2d0dd322b4f8ea7 Mon Sep 17 00:00:00 2001
+From: Matthieu Bouron <[email protected]>
+Date: Mon, 12 Feb 2024 23:13:09 +0100
+Subject: [PATCH 1/6] avcodec: add av_jni_{get,set}_android_app_ctx helper
+
+This will allow users to pass the Android ApplicationContext which is mandatory
+to retrieve the ContentResolver responsible to resolve/open Android content-uri.
+---
+ libavcodec/jni.c | 40 ++++++++++++++++++++++++++++++++++++++++
+ libavcodec/jni.h | 17 +++++++++++++++++
+ 2 files changed, 57 insertions(+)
+
+diff --git a/libavcodec/jni.c b/libavcodec/jni.c
+index ae6490de9d..7d04d0a268 100644
+--- a/libavcodec/jni.c
++++ b/libavcodec/jni.c
+@@ -64,6 +64,36 @@ void *av_jni_get_java_vm(void *log_ctx)
+     return vm;
+ }
+
++int av_jni_set_android_app_ctx(void *app_ctx, void *log_ctx)
++{
++    JNIEnv *env = avpriv_jni_get_env(c);
++    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;
++}
++
++void *av_jni_get_android_app_ctx(void)
++{
++    void *ctx;
++
++    pthread_mutex_lock(&lock);
++    ctx = android_app_ctx;
++    pthread_mutex_unlock(&lock);
++
++    return ctx;
++}
++
+ #else
+
+ int av_jni_set_java_vm(void *vm, void *log_ctx)
+@@ -76,4 +106,14 @@ void *av_jni_get_java_vm(void *log_ctx)
+     return NULL;
+ }
+
++int av_jni_set_android_app_ctx(void *app_ctx, void *log_ctx)
++{
++    return AVERROR(ENOSYS);
++}
++
++void *av_jni_get_android_app_ctx(void)
++{
++    return NULL;
++}
++
+ #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);
++
+ #endif /* AVCODEC_JNI_H */
+-- 
+2.44.0
+

patches/ffmpeg/0002-avformat-add-Android-content-resolver-protocol-suppo.patch

@@ -0,0 +1,269 @@
+From 4cdded89ff4f00726d086021fe0de81ebc3eca73 Mon Sep 17 00:00:00 2001
+From: Matthieu Bouron <[email protected]>
+Date: Mon, 12 Feb 2024 23:14:35 +0100
+Subject: [PATCH 2/6] avformat: add Android content resolver protocol support
+
+Handles Android content-uri starting with content://.
+---
+ configure               |   2 +
+ doc/APIchanges          |   3 +
+ libavcodec/jni.c        |   3 +-
+ libavformat/Makefile    |   1 +
+ libavformat/file.c      | 157 ++++++++++++++++++++++++++++++++++++++++
+ libavformat/protocols.c |   1 +
+ 6 files changed, 166 insertions(+), 1 deletion(-)
+
+diff --git a/configure b/configure
+index bb5e630bad..790a1df7c8 100755
+--- a/configure
++++ b/configure
+@@ -3655,6 +3655,8 @@ xcbgrab_indev_suggest="libxcb_shm libxcb_shape libxcb_xfixes"
+ xv_outdev_deps="xlib_xv xlib_x11 xlib_xext"
+
+ # protocols
++android_content_protocol_deps="jni"
++android_content_protocol_select="file_protocol"
+ async_protocol_deps="threads"
+ bluray_protocol_deps="libbluray"
+ ffrtmpcrypt_protocol_conflict="librtmp_protocol"
+diff --git a/doc/APIchanges b/doc/APIchanges
+index 10f6667e9e..258e953ca6 100644
+--- a/doc/APIchanges
++++ b/doc/APIchanges
+@@ -2,6 +2,9 @@ The last version increases of all libraries were on 2023-02-09
+
+ API changes, most recent first:
+
++2024-02-xx - xxxxxxxxxx - lavc 60.41.100 - jni.h
++  Add av_jni_set_android_app_ctx() and av_jni_get_android_app_ctx().
++
+ 2024-02-26 - xxxxxxxxxx - lavf 60.22.101 - avformat.h
+   AV_DISPOSITION_DEPENDENT may now also be used for video streams
+   intended to be merged with other video streams for presentation.
+diff --git a/libavcodec/jni.c b/libavcodec/jni.c
+index 7d04d0a268..5a75d97f19 100644
+--- a/libavcodec/jni.c
++++ b/libavcodec/jni.c
+@@ -35,6 +35,7 @@
+ #include "ffjni.h"
+
+ static void *java_vm;
++static void *android_app_ctx;
+ static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
+
+ int av_jni_set_java_vm(void *vm, void *log_ctx)
+@@ -66,7 +67,7 @@ void *av_jni_get_java_vm(void *log_ctx)
+
+ int av_jni_set_android_app_ctx(void *app_ctx, void *log_ctx)
+ {
+-    JNIEnv *env = avpriv_jni_get_env(c);
++    JNIEnv *env = ff_jni_get_env(log_ctx);
+     if (!env)
+         return AVERROR(EINVAL);
+
+diff --git a/libavformat/Makefile b/libavformat/Makefile
+index 4a380668bd..08fe98a535 100644
+--- a/libavformat/Makefile
++++ b/libavformat/Makefile
+@@ -657,6 +657,7 @@ OBJS-$(CONFIG_LIBOPENMPT_DEMUXER)        += libopenmpt.o
+ OBJS-$(CONFIG_VAPOURSYNTH_DEMUXER)       += vapoursynth.o
+
+ # protocols I/O
++OBJS-$(CONFIG_ANDROID_CONTENT_PROTOCOL)  += file.o
+ OBJS-$(CONFIG_ASYNC_PROTOCOL)            += async.o
+ OBJS-$(CONFIG_APPLEHTTP_PROTOCOL)        += hlsproto.o
+ OBJS-$(CONFIG_BLURAY_PROTOCOL)           += bluray.o
+diff --git a/libavformat/file.c b/libavformat/file.c
+index 64df7ff6fb..1b2b69f090 100644
+--- a/libavformat/file.c
++++ b/libavformat/file.c
+@@ -40,6 +40,12 @@
+ #include <stdlib.h>
+ #include "os_support.h"
+ #include "url.h"
++#if CONFIG_ANDROID_CONTENT_PROTOCOL
++#include <jni.h>
++#include "libavcodec/jni.h"
++#include "libavcodec/ffjni.c"
++#endif
++
+
+ /* Some systems may not have S_ISFIFO */
+ #ifndef S_ISFIFO
+@@ -101,6 +107,21 @@ typedef struct FileContext {
+     int64_t initial_pos;
+ } FileContext;
+
++
++#if CONFIG_ANDROID_CONTENT_PROTOCOL
++static const AVOption android_content_options[] = {
++    { "blocksize", "set I/O operation maximum block size", offsetof(FileContext, blocksize), AV_OPT_TYPE_INT, { .i64 = INT_MAX }, 1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
++    { NULL }
++};
++
++static const AVClass android_content_class = {
++    .class_name = "android_content",
++    .item_name  = av_default_item_name,
++    .option     = android_content_options,
++    .version    = LIBAVUTIL_VERSION_INT,
++};
++#endif
++
+ static const AVOption file_options[] = {
+     { "truncate", "truncate existing files on write", offsetof(FileContext, trunc), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, AV_OPT_FLAG_ENCODING_PARAM },
+     { "blocksize", "set I/O operation maximum block size", offsetof(FileContext, blocksize), AV_OPT_TYPE_INT, { .i64 = INT_MAX }, 1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
+@@ -524,3 +545,139 @@ const URLProtocol ff_fd_protocol = {
+ };
+
+ #endif /* CONFIG_FD_PROTOCOL */
++
++#if CONFIG_ANDROID_CONTENT_PROTOCOL
++
++struct JFields {
++    jclass uri_class;
++    jmethodID parse_id;
++
++    jclass context_class;
++    jmethodID get_content_resolver_id;
++
++    jclass content_resolver_class;
++    jmethodID open_file_descriptor_id;
++
++    jclass parcel_file_descriptor_class;
++    jmethodID detach_fd_id;
++};
++
++#define OFFSET(x) offsetof(struct JFields, x)
++static const struct FFJniField jfields_mapping[] = {
++    { "android/net/Uri", NULL, NULL, FF_JNI_CLASS, OFFSET(uri_class), 1 },
++        { "android/net/Uri", "parse", "(Ljava/lang/String;)Landroid/net/Uri;", FF_JNI_STATIC_METHOD, OFFSET(parse_id), 1 },
++
++    { "android/content/Context", NULL, NULL, FF_JNI_CLASS, OFFSET(context_class), 1 },
++        { "android/content/Context", "getContentResolver", "()Landroid/content/ContentResolver;", FF_JNI_METHOD, OFFSET(get_content_resolver_id), 1 },
++
++    { "android/content/ContentResolver", NULL, NULL, FF_JNI_CLASS, OFFSET(content_resolver_class), 1 },
++        { "android/content/ContentResolver", "openFileDescriptor", "(Landroid/net/Uri;Ljava/lang/String;)Landroid/os/ParcelFileDescriptor;", FF_JNI_METHOD, OFFSET(open_file_descriptor_id), 1 },
++
++    { "android/os/ParcelFileDescriptor", NULL, NULL, FF_JNI_CLASS, OFFSET(parcel_file_descriptor_class), 1 },
++        { "android/os/ParcelFileDescriptor", "detachFd", "()I", FF_JNI_METHOD, OFFSET(detach_fd_id), 1 },
++
++    { NULL }
++};
++#undef OFFSET
++
++static int android_content_open(URLContext *h, const char *filename, int flags)
++{
++    FileContext *c = h->priv_data;
++    int fd, ret;
++    const char *mode_str = "r";
++
++    JNIEnv *env;
++    struct JFields jfields = { 0 };
++    jobject application_context = NULL;
++    jobject url = NULL;
++    jobject mode = NULL;
++    jobject uri = NULL;
++    jobject content_resolver = NULL;
++    jobject parcel_file_descriptor = NULL;
++
++    env = ff_jni_get_env(c);
++    if (!env) {
++        return AVERROR(EINVAL);
++    }
++
++    ret = ff_jni_init_jfields(env, &jfields, jfields_mapping, 0, c);
++    if (ret < 0) {
++        av_log(c, AV_LOG_ERROR, "failed to initialize jni fields\n");
++        return ret;
++    }
++
++    application_context = av_jni_get_android_app_ctx();
++    if (!application_context) {
++        av_log(c, AV_LOG_ERROR, "application context is not set\n");
++        ret = AVERROR_EXTERNAL;
++        goto done;
++    }
++
++    url = ff_jni_utf_chars_to_jstring(env, filename, c);
++    if (!url) {
++        ret = AVERROR_EXTERNAL;
++        goto done;
++    }
++
++    if (flags & AVIO_FLAG_WRITE && flags & AVIO_FLAG_READ)
++        mode_str = "rw";
++    else if (flags & AVIO_FLAG_WRITE)
++        mode_str = "w";
++
++    mode = ff_jni_utf_chars_to_jstring(env, mode_str, c);
++    if (!mode) {
++        ret = AVERROR_EXTERNAL;
++        goto done;
++    }
++
++    uri = (*env)->CallStaticObjectMethod(env, jfields.uri_class, jfields.parse_id, url);
++    ret = ff_jni_exception_check(env, 1, c);
++    if (ret < 0)
++        goto done;
++
++    content_resolver = (*env)->CallObjectMethod(env, application_context, jfields.get_content_resolver_id);
++    ret = ff_jni_exception_check(env, 1, c);
++    if (ret < 0)
++        goto done;
++
++    parcel_file_descriptor = (*env)->CallObjectMethod(env, content_resolver, jfields.open_file_descriptor_id, uri, mode);
++    ret = ff_jni_exception_check(env, 1, c);
++    if (ret < 0)
++        goto done;
++
++    fd = (*env)->CallIntMethod(env, parcel_file_descriptor, jfields.detach_fd_id);
++    ret = ff_jni_exception_check(env, 1, c);
++    if (ret < 0)
++        goto done;
++
++#if HAVE_SETMODE
++    setmode(fd, O_BINARY);
++#endif
++    c->fd = fd;
++    h->is_streamed = 0;
++
++done:
++    (*env)->DeleteLocalRef(env, url);
++    (*env)->DeleteLocalRef(env, mode);
++    (*env)->DeleteLocalRef(env, uri);
++    (*env)->DeleteLocalRef(env, content_resolver);
++    (*env)->DeleteLocalRef(env, parcel_file_descriptor);
++    ff_jni_reset_jfields(env, &jfields, jfields_mapping, 0, c);
++
++    return ret;
++}
++
++URLProtocol ff_android_content_protocol = {
++    .name                = "content",
++    .url_open            = android_content_open,
++    .url_read            = file_read,
++    .url_write           = file_write,
++    .url_seek            = file_seek,
++    .url_close           = file_close,
++    .url_get_file_handle = file_get_handle,
++    .url_check           = NULL,
++    .priv_data_size      = sizeof(FileContext),
++    .priv_data_class     = &android_content_class,
++};
++
++#endif /* CONFIG_ANDROID_CONTENT_PROTOCOL */
+diff --git a/libavformat/protocols.c b/libavformat/protocols.c
+index 360018b17c..93a6d67261 100644
+--- a/libavformat/protocols.c
++++ b/libavformat/protocols.c
+@@ -24,6 +24,7 @@
+
+ #include "url.h"
+
++extern const URLProtocol ff_android_content_protocol;
+ extern const URLProtocol ff_async_protocol;
+ extern const URLProtocol ff_bluray_protocol;
+ extern const URLProtocol ff_cache_protocol;
+-- 
+2.44.0
+