[FFmpeg-devel] [PATCH] Add get_device_list() to AVFoundation input device.

[Daniel Ly]

This makes avdevice_list_input_sources() available for
device_name = "avfoundation".

I didn't yet retrofit avf_read_header() to use the new function to
keep this patch small. I will post the follow-up patch in the same
thread.

Signed-off-by: Daniel Ly <nalply at gmail.com>
---
 libavdevice/avfoundation.m | 98 ++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 90 insertions(+), 8 deletions(-)

diff --git a/libavdevice/avfoundation.m b/libavdevice/avfoundation.m
index 763e675..19ce2a0 100644
--- a/libavdevice/avfoundation.m
+++ b/libavdevice/avfoundation.m
@@ -34,6 +34,7 @@
 #include "libavformat/internal.h"
 #include "libavutil/internal.h"
 #include "libavutil/parseutils.h"
+#include "libavutil/avstring.h"
 #include "libavutil/time.h"
 #include "avdevice.h"
 
@@ -1007,6 +1008,86 @@ static int avf_read_packet(AVFormatContext *s, AVPacket *pkt)
     return 0;
 }
 
+static int avf_add_device_info(AVDeviceInfoList *list, AVFormatContext *s,
+    int index, const char *description, const char *model)
+{
+    AVDeviceInfo *info = av_mallocz(sizeof(AVDeviceInfo));
+    if (!info) return AVERROR(ENOMEM);
+
+    info->device_name = av_asprintf("[%d] %s: %s", index, description, model);
+    info->device_description = strdup(description);
+    if (!info->device_name || !info->device_description) {
+        av_free(info);
+        return AVERROR(ENOMEM);
+    }
+
+    av_log(s->priv_data, AV_LOG_INFO, "%s\n", info->device_name);
+    av_dynarray_add(&list->devices, &list->nb_devices, info);
+
+    return list ? list->nb_devices : AVERROR(ENOMEM);
+}
+
+
+static int avf_get_device_list(struct AVFormatContext *s, struct AVDeviceInfoList *list) 
+{
+    int result = 0, index;
+    const char *localizedName, *modelID;
+
+    av_log(s->priv_data, AV_LOG_INFO, "AVFoundation video devices:\n");
+    NSArray *video_devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
+    for (AVCaptureDevice *device in video_devices) {
+        @autoreleasepool {
+            index         = [video_devices indexOfObject:device];
+            localizedName = [[device localizedName] UTF8String];
+            modelID       = [[device modelID] UTF8String];
+
+            result = avf_add_device_info(list, s, index, localizedName, modelID);
+            if (result < 0) break;
+        }
+    }
+    [video_devices release];
+
+
+#if !TARGET_OS_IPHONE && __MAC_OS_X_VERSION_MIN_REQUIRED >= 1070
+    uint32_t num_screens = 0;
+    CGGetActiveDisplayList(0, NULL, &num_screens);
+
+    if (num_screens > 0) {
+        CGDirectDisplayID screens[num_screens];
+        CGGetActiveDisplayList(num_screens, screens, &num_screens);
+        int i;
+        for (i = 0; i < num_screens; i++) {
+            char buf[30];
+            snprintf(buf, 30, "Capture screen %d", i);
+        
+            // No screen name available (as model). Implementation is arcane
+            // and uses deprecated API. See stackoverflow.com/q/24348142/220060
+            result = avf_add_device_info(list, s, index + i + 1, buf, "-"); 
+            if (result < 0) break;
+        }
+    }
+#endif
+
+    av_log(s->priv_data, AV_LOG_INFO, "AVFoundation audio devices:\n");
+    NSArray *audio_devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
+    for (AVCaptureDevice *device in audio_devices) {
+        @autoreleasepool {
+            index         = [audio_devices indexOfObject:device];
+            localizedName = [[device localizedName] UTF8String];
+            modelID       = [[device modelID] UTF8String];
+
+            result = avf_add_device_info(list, s, index, localizedName, modelID);
+            if (result < 0) break;
+        }
+    }
+    [audio_devices release];
+
+    // Make the first device default if it exists.
+    list->default_device = list->nb_devices > 0 ? 0 : -1;
+
+    return result;
+}
+
 static int avf_close(AVFormatContext *s)
 {
     AVFContext* ctx = (AVFContext*)s->priv_data;
@@ -1038,12 +1119,13 @@ static const AVClass avf_class = {
 };
 
 AVInputFormat ff_avfoundation_demuxer = {
-    .name           = "avfoundation",
-    .long_name      = NULL_IF_CONFIG_SMALL("AVFoundation input device"),
-    .priv_data_size = sizeof(AVFContext),
-    .read_header    = avf_read_header,
-    .read_packet    = avf_read_packet,
-    .read_close     = avf_close,
-    .flags          = AVFMT_NOFILE,
-    .priv_class     = &avf_class,
+    .name            = "avfoundation",
+    .long_name       = NULL_IF_CONFIG_SMALL("AVFoundation input device"),
+    .priv_data_size  = sizeof(AVFContext),
+    .read_header     = avf_read_header,
+    .read_packet     = avf_read_packet,
+    .read_close      = avf_close,
+    .get_device_list = avf_get_device_list,
+    .flags           = AVFMT_NOFILE,
+    .priv_class      = &avf_class,
 };
-- 
1.8.1.4