avdevice: add android_camera indev

This commit adds an indev for Android devices on API level 24+ which
uses the Android NDK Camera2 API to capture video from builtin cameras
Signed-off-by: Felix Matouschek <felix@matouschek.org>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

Changelog

@@ -39,6 +39,7 @@ version <next>:
 - Removed the ffmenc and ffmdec muxer and demuxer
 - VideoToolbox HEVC encoder and hwaccel
 - VAAPI-accelerated ProcAmp (color balance), denoise and sharpness filters
+- Add android_camera indev
 
 
 version 3.4:

MAINTAINERS

@@ -281,6 +281,7 @@ libavdevice
 
 
   avfoundation.m                        Thilo Borgmann
+  android_camera.c                      Felix Matouschek
   decklink*                             Marton Balint
   dshow.c                               Roger Pack (CC rogerdpack@gmail.com)
   fbdev_enc.c                           Lukasz Marek

configure

@@ -3081,6 +3081,8 @@ xmv_demuxer_select="riffdec"
 xwma_demuxer_select="riffdec"
 
 # indevs / outdevs
+android_camera_indev_deps="android camera2ndk mediandk pthreads"
+android_camera_indev_extralibs="-landroid -lcamera2ndk -lmediandk"
 alsa_indev_deps="alsa"
 alsa_outdev_deps="alsa"
 avfoundation_indev_deps="avfoundation corevideo coremedia pthreads"
@@ -5756,6 +5758,10 @@ check_lib shell32  "windows.h shellapi.h" CommandLineToArgvW   -lshell32
 check_lib wincrypt "windows.h wincrypt.h" CryptGenRandom       -ladvapi32
 check_lib psapi    "windows.h psapi.h"    GetProcessMemoryInfo -lpsapi
 
+check_lib android android/native_window.h ANativeWindow_acquire -landroid
+check_lib mediandk "stdint.h media/NdkImage.h" AImage_delete -lmediandk
+check_lib camera2ndk "stdbool.h stdint.h camera/NdkCameraManager.h" ACameraManager_create -lcamera2ndk
+
 enabled appkit       && check_apple_framework AppKit
 enabled audiotoolbox && check_apple_framework AudioToolbox
 enabled avfoundation && check_apple_framework AVFoundation

doc/indevs.texi

@@ -63,6 +63,46 @@ Set the number of channels. Default is 2.
 
 @end table
 
+@section android_camera
+
+Android camera input device.
+
+This input devices uses the Android Camera2 NDK API which is
+available on devices with API level 24+. The availability of
+android_camera is autodetected during configuration.
+
+This device allows capturing from all cameras on an Android device,
+which are integrated into the Camera2 NDK API.
+
+The available cameras are enumerated internally and can be selected
+with the @var{camera_index} parameter. The input file string is
+discarded.
+
+Generally the back facing camera has index 0 while the front facing
+camera has index 1.
+
+@subsection Options
+
+@table @option
+
+@item video_size
+Set the video size given as a string such as 640x480 or hd720.
+Falls back to the first available configuration reported by
+Android if requested video size is not available or by default.
+
+@item framerate
+Set the video framerate.
+Falls back to the first available configuration reported by
+Android if requested framerate is not available or by default (-1).
+
+@item camera_index
+Set the index of the camera to use. Default is 0.
+
+@item input_queue_size
+Set the maximum number of frames to buffer. Default is 5.
+
+@end table
+
 @section avfoundation
 
 AVFoundation input device.

libavdevice/Makefile

@@ -14,6 +14,7 @@ OBJS-$(CONFIG_SHARED)                    += reverse.o
 # input/output devices
 OBJS-$(CONFIG_ALSA_INDEV)                += alsa_dec.o alsa.o timefilter.o
 OBJS-$(CONFIG_ALSA_OUTDEV)               += alsa_enc.o alsa.o
+OBJS-$(CONFIG_ANDROID_CAMERA_INDEV)      += android_camera.o
 OBJS-$(CONFIG_AVFOUNDATION_INDEV)        += avfoundation.o
 OBJS-$(CONFIG_BKTR_INDEV)                += bktr.o
 OBJS-$(CONFIG_CACA_OUTDEV)               += caca.o

libavdevice/alldevices.c

@@ -29,6 +29,7 @@
 /* devices */
 extern AVInputFormat  ff_alsa_demuxer;
 extern AVOutputFormat ff_alsa_muxer;
+extern AVInputFormat  ff_android_camera_demuxer;
 extern AVInputFormat  ff_avfoundation_demuxer;
 extern AVInputFormat  ff_bktr_demuxer;
 extern AVOutputFormat ff_caca_muxer;

libavdevice/version.h

@@ -28,7 +28,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVDEVICE_VERSION_MAJOR  58
-#define LIBAVDEVICE_VERSION_MINOR   1
+#define LIBAVDEVICE_VERSION_MINOR   2
 #define LIBAVDEVICE_VERSION_MICRO 100
 
 #define LIBAVDEVICE_VERSION_INT AV_VERSION_INT(LIBAVDEVICE_VERSION_MAJOR, \