[FFmpeg-devel] [PATCH v2 2/3] avfilter/vf_hwmap: get the AVHWDeviceType from outlink format

[Tong Wu]

When a derive_device_type is not specified, the hwmap filter should be
able to retrieve AVHWDeviceType from outlink->format and create
corresponding hwdevice context.

Signed-off-by: Tong Wu <tong1.wu at intel.com>
---
 libavfilter/vf_hwmap.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/libavfilter/vf_hwmap.c b/libavfilter/vf_hwmap.c
index 2e03dfc1fe..136980c982 100644
--- a/libavfilter/vf_hwmap.c
+++ b/libavfilter/vf_hwmap.c
@@ -70,23 +70,32 @@ static int hwmap_config_output(AVFilterLink *outlink)
     device_is_derived = 0;
 
     if (inlink->hw_frames_ctx) {
+        enum AVHWDeviceType type;
         hwfc = (AVHWFramesContext*)inlink->hw_frames_ctx->data;
 
         if (ctx->derive_device_type) {
-            enum AVHWDeviceType type;
-
             type = av_hwdevice_find_type_by_name(ctx->derive_device_type);
             if (type == AV_HWDEVICE_TYPE_NONE) {
                 av_log(avctx, AV_LOG_ERROR, "Invalid device type.\n");
                 err = AVERROR(EINVAL);
                 goto fail;
             }
+        } else {
+            type = av_hwdevice_get_type_by_pix_fmt(outlink->format);
+            if (type == AV_HWDEVICE_TYPE_NONE) {
+                av_log(avctx, AV_LOG_ERROR, "Could not get device type from "
+                       "format %s.\n", av_get_pix_fmt_name(outlink->format));
+                err = AVERROR(EINVAL);
+                goto fail;
+            }
+        }
 
+        if (!device || ctx->derive_device_type) {
             err = av_hwdevice_ctx_create_derived(&device, type,
-                                                 hwfc->device_ref, 0);
+                                                hwfc->device_ref, 0);
             if (err < 0) {
                 av_log(avctx, AV_LOG_ERROR, "Failed to created derived "
-                       "device context: %d.\n", err);
+                    "device context: %d.\n", err);
                 goto fail;
             }
             device_is_derived = 1;
-- 
2.35.1.windows.2