[FFmpeg-devel] [PATCH v6 06/12] avdevice/dshow: implement get_device_list
Diederick Niehorster
dcnieho at gmail.com
Tue Dec 21 14:12:33 EET 2021
Needed to enable programmatic discovery of DirectShow devices
Signed-off-by: Diederick Niehorster <dcnieho at gmail.com>
---
libavdevice/dshow.c | 96 ++++++++++++++++++++++++++++++++++++++-------
1 file changed, 81 insertions(+), 15 deletions(-)
diff --git a/libavdevice/dshow.c b/libavdevice/dshow.c
index 0ef3b3d13e..e1702c8519 100644
--- a/libavdevice/dshow.c
+++ b/libavdevice/dshow.c
@@ -202,11 +202,14 @@ fail:
* retrieve the device with type specified by devtype and return the
* pointer to the object found in *pfilter.
* If pfilter is NULL, list all device names.
+ * If device_list is not NULL, populate it with found devices instead of
+ * outputting device names to log
*/
static int
dshow_cycle_devices(AVFormatContext *avctx, ICreateDevEnum *devenum,
enum dshowDeviceType devtype, enum dshowSourceFilterType sourcetype,
- IBaseFilter **pfilter, char **device_unique_name)
+ IBaseFilter **pfilter, char **device_unique_name,
+ AVDeviceInfoList **device_list)
{
struct dshow_ctx *ctx = avctx->priv_data;
IBaseFilter *device_filter = NULL;
@@ -238,18 +241,19 @@ dshow_cycle_devices(AVFormatContext *avctx, ICreateDevEnum *devenum,
IBindCtx *bind_ctx = NULL;
LPOLESTR olestr = NULL;
LPMALLOC co_malloc = NULL;
+ AVDeviceInfo *device = NULL;
int i;
r = CoGetMalloc(1, &co_malloc);
if (r != S_OK)
- goto fail1;
+ goto fail;
r = CreateBindCtx(0, &bind_ctx);
if (r != S_OK)
- goto fail1;
+ goto fail;
/* GetDisplayname works for both video and audio, DevicePath doesn't */
r = IMoniker_GetDisplayName(m, bind_ctx, NULL, &olestr);
if (r != S_OK)
- goto fail1;
+ goto fail;
unique_name = dup_wchar_to_utf8(olestr);
/* replace ':' with '_' since we use : to delineate between sources */
for (i = 0; i < strlen(unique_name); i++) {
@@ -259,34 +263,62 @@ dshow_cycle_devices(AVFormatContext *avctx, ICreateDevEnum *devenum,
r = IMoniker_BindToStorage(m, 0, 0, &IID_IPropertyBag, (void *) &bag);
if (r != S_OK)
- goto fail1;
+ goto fail;
var.vt = VT_BSTR;
r = IPropertyBag_Read(bag, L"FriendlyName", &var, NULL);
if (r != S_OK)
- goto fail1;
+ goto fail;
friendly_name = dup_wchar_to_utf8(var.bstrVal);
if (pfilter) {
if (strcmp(device_name, friendly_name) && strcmp(device_name, unique_name))
- goto fail1;
+ goto fail;
if (!skip--) {
r = IMoniker_BindToObject(m, 0, 0, &IID_IBaseFilter, (void *) &device_filter);
if (r != S_OK) {
av_log(avctx, AV_LOG_ERROR, "Unable to BindToObject for %s\n", device_name);
- goto fail1;
+ goto fail;
}
*device_unique_name = unique_name;
unique_name = NULL;
// success, loop will end now
}
} else {
- av_log(avctx, AV_LOG_INFO, " \"%s\"\n", friendly_name);
- av_log(avctx, AV_LOG_INFO, " Alternative name \"%s\"\n", unique_name);
+ if (device_list) {
+ device = av_mallocz(sizeof(AVDeviceInfo));
+ if (!device)
+ goto fail;
+
+ device->device_name = av_strdup(friendly_name);
+ device->device_description = av_strdup(unique_name);
+ if (!device->device_name || !device->device_description)
+ goto fail;
+
+ // make space in device_list for this new device
+ if (av_reallocp_array(&(*device_list)->devices,
+ (*device_list)->nb_devices + 1,
+ sizeof(*(*device_list)->devices)) < 0)
+ goto fail;
+
+ // store device in list
+ (*device_list)->devices[(*device_list)->nb_devices] = device;
+ (*device_list)->nb_devices++;
+ device = NULL; // copied into array, make sure not freed below
+ }
+ else {
+ av_log(avctx, AV_LOG_INFO, " \"%s\"\n", friendly_name);
+ av_log(avctx, AV_LOG_INFO, " Alternative name \"%s\"\n", unique_name);
+ }
}
-fail1:
+fail:
+ if (device) {
+ av_freep(&device->device_name);
+ av_freep(&device->device_description);
+ av_free(device);
+ }
if (olestr && co_malloc)
IMalloc_Free(co_malloc, olestr);
if (bind_ctx)
@@ -312,6 +344,39 @@ fail1:
return 0;
}
+static int dshow_get_device_list(AVFormatContext *avctx, AVDeviceInfoList *device_list)
+{
+ struct dshow_ctx *ctx = avctx->priv_data;
+ ICreateDevEnum *devenum = NULL;
+ int r;
+ int ret = AVERROR(EIO);
+
+ if (!device_list)
+ return AVERROR(EINVAL);
+
+ CoInitialize(0);
+
+ r = CoCreateInstance(&CLSID_SystemDeviceEnum, NULL, CLSCTX_INPROC_SERVER,
+ &IID_ICreateDevEnum, (void**)&devenum);
+ if (r != S_OK) {
+ av_log(avctx, AV_LOG_ERROR, "Could not enumerate system devices.\n");
+ goto error;
+ }
+
+ ret = dshow_cycle_devices(avctx, devenum, VideoDevice, VideoSourceDevice, NULL, NULL, &device_list);
+ if (ret < S_OK)
+ goto error;
+ ret = dshow_cycle_devices(avctx, devenum, AudioDevice, AudioSourceDevice, NULL, NULL, &device_list);
+
+error:
+ if (devenum)
+ ICreateDevEnum_Release(devenum);
+
+ CoUninitialize();
+
+ return ret;
+}
+
/**
* Cycle through available formats using the specified pin,
* try to set parameters specified through AVOptions and if successful
@@ -705,7 +770,7 @@ dshow_list_device_options(AVFormatContext *avctx, ICreateDevEnum *devenum,
char *device_unique_name = NULL;
int r;
- if ((r = dshow_cycle_devices(avctx, devenum, devtype, sourcetype, &device_filter, &device_unique_name)) < 0)
+ if ((r = dshow_cycle_devices(avctx, devenum, devtype, sourcetype, &device_filter, &device_unique_name, NULL)) < 0)
return r;
ctx->device_filter[devtype] = device_filter;
ctx->device_unique_name[devtype] = device_unique_name;
@@ -765,7 +830,7 @@ dshow_open_device(AVFormatContext *avctx, ICreateDevEnum *devenum,
av_log(avctx, AV_LOG_INFO, "Capture filter loaded successfully from file \"%s\".\n", filename);
} else {
- if ((r = dshow_cycle_devices(avctx, devenum, devtype, sourcetype, &device_filter, &device_filter_unique_name)) < 0) {
+ if ((r = dshow_cycle_devices(avctx, devenum, devtype, sourcetype, &device_filter, &device_filter_unique_name, NULL)) < 0) {
ret = r;
goto error;
}
@@ -1122,9 +1187,9 @@ static int dshow_read_header(AVFormatContext *avctx)
if (ctx->list_devices) {
av_log(avctx, AV_LOG_INFO, "DirectShow video devices (some may be both video and audio devices)\n");
- dshow_cycle_devices(avctx, devenum, VideoDevice, VideoSourceDevice, NULL, NULL);
+ dshow_cycle_devices(avctx, devenum, VideoDevice, VideoSourceDevice, NULL, NULL, NULL);
av_log(avctx, AV_LOG_INFO, "DirectShow audio devices\n");
- dshow_cycle_devices(avctx, devenum, AudioDevice, AudioSourceDevice, NULL, NULL);
+ dshow_cycle_devices(avctx, devenum, AudioDevice, AudioSourceDevice, NULL, NULL, NULL);
ret = AVERROR_EXIT;
goto error;
}
@@ -1329,6 +1394,7 @@ const AVInputFormat ff_dshow_demuxer = {
.read_header = dshow_read_header,
.read_packet = dshow_read_packet,
.read_close = dshow_read_close,
+ .get_device_list= dshow_get_device_list,
.flags = AVFMT_NOFILE | AVFMT_NOBINSEARCH | AVFMT_NOGENSEARCH | AVFMT_NO_BYTE_SEEK,
.priv_class = &dshow_class,
};
--
2.28.0.windows.1
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