[FFmpeg-devel,RFC,v2,3/3] libavutil: Add thumbnail output to vaapi_h264 decoder

diff --git a/libavutil/frame.c b/libavutil/frame.c
index dcf1fc3d17..14bcb456c9 100644
--- a/libavutil/frame.c
+++ b/libavutil/frame.c
@@ -842,6 +842,7 @@  const char *av_frame_side_data_name(enum AVFrameSideDataType type)
 #endif
     case AV_FRAME_DATA_DYNAMIC_HDR_PLUS: return "HDR Dynamic Metadata SMPTE2094-40 (HDR10+)";
     case AV_FRAME_DATA_REGIONS_OF_INTEREST: return "Regions Of Interest";
+    case AV_FRAME_DATA_THUMBNAIL_INFO: return "Thumbnail Information";
     }
     return NULL;
 }
diff --git a/libavutil/frame.h b/libavutil/frame.h
index 8aa3e88367..2f3ac0cb23 100644
--- a/libavutil/frame.h
+++ b/libavutil/frame.h
@@ -179,6 +179,11 @@  enum AVFrameSideDataType {
      * array element is implied by AVFrameSideData.size / AVRegionOfInterest.self_size.
      */
     AV_FRAME_DATA_REGIONS_OF_INTEREST,
+
+    /**
+     * VDENC Thumbnail information.
+     */
+    AV_FRAME_DATA_THUMBNAIL_INFO,
 };
 
 enum AVActiveFormatDescription {
@@ -235,6 +240,14 @@  typedef struct AVRegionOfInterest {
     AVRational qoffset;
 } AVRegionOfInterest;
 
+/**
+ * Structure to hold Information of Thumbnail.
+ *
+ */
+typedef struct AVThumbnailInfo {
+    uint8_t *data;
+} AVThumbnailInfo;
+
 /**
  * This structure describes decoded (raw) audio or video data.
  *
diff --git a/libavutil/hwcontext_vaapi.c b/libavutil/hwcontext_vaapi.c
index 8624369bb9..cacd352ebb 100644
--- a/libavutil/hwcontext_vaapi.c
+++ b/libavutil/hwcontext_vaapi.c
@@ -642,8 +642,74 @@  static void vaapi_frames_uninit(AVHWFramesContext *hwfc)
     av_freep(&ctx->attributes);
 }
 
+static int vaapi_get_thumbnail_buffer(AVHWFramesContext *hwfc, AVFrame *frame)
+{
+    AVVAAPIFramesContext *avfc = hwfc->hwctx;
+    AVFrameSideData *frame_thumbnail_sd = av_frame_get_side_data(frame,
+                                                           AV_FRAME_DATA_THUMBNAIL_INFO);
+    if (frame_thumbnail_sd) {
+        AVVAAPIDeviceContext *hwctx = hwfc->device_ctx->hwctx;
+        VASurfaceID thumbnail_surface_id;
+        VASurfaceAttrib attrib;
+        unsigned int rt_format;
+        AVBufferRef *ref;
+        VAStatus vas;
+
+        memset(&attrib, 0, sizeof(attrib));
+        attrib.type = VASurfaceAttribPixelFormat;
+        attrib.flags = VA_SURFACE_ATTRIB_SETTABLE;
+        attrib.value.type = VAGenericValueTypeInteger;
+
+        switch (avfc->thumbnail_format) {
+        case AV_PIX_FMT_NV12:
+            attrib.value.value.i = VA_FOURCC_NV12;
+            rt_format = VA_RT_FORMAT_YUV420;
+            break;
+        case AV_PIX_FMT_ARGB:
+            attrib.value.value.i = VA_FOURCC_ARGB;
+            rt_format = VA_RT_FORMAT_RGB32;
+            break;
+        default:
+            av_log(hwfc, AV_LOG_ERROR, "Unknown sfc format: %d\n", avfc->thumbnail_format);
+            return AVERROR(EINVAL);
+        }
+
+        vas = vaCreateSurfaces(hwctx->display, rt_format,
+                               avfc->thumbnail_width, avfc->thumbnail_height,
+                               &thumbnail_surface_id, 1,
+                               &attrib, 1);
+        if (vas != VA_STATUS_SUCCESS) {
+            av_log(hwfc, AV_LOG_ERROR, "Failed to create sfc surface: "
+                   "%d (%s).\n", vas, vaErrorStr(vas));
+            return AVERROR(EIO);
+        }
+
+        av_log(hwfc, AV_LOG_DEBUG, "Created sfc surface %#x. thumbnail_format(%d), w(%d), h(%d)\n",
+               thumbnail_surface_id, avfc->thumbnail_format, avfc->thumbnail_width, avfc->thumbnail_height);
+
+        ref = av_buffer_create((uint8_t*)(uintptr_t)thumbnail_surface_id,
+                               sizeof(thumbnail_surface_id), &vaapi_buffer_free,
+                               hwfc, AV_BUFFER_FLAG_READONLY);
+        if (!ref) {
+            vaDestroySurfaces(hwctx->display, &thumbnail_surface_id, 1);
+            return AVERROR(EIO);
+        }
+
+        frame_thumbnail_sd->buf = ref;
+
+        av_log(hwfc, AV_LOG_DEBUG, "Created sfc av buffer ref: %p\n", ref);
+
+    } else {
+        av_log(hwfc, AV_LOG_DEBUG, "VDSFC frame_thumbnail_sd is null\n");
+    }
+
+    return 0;
+}
+
 static int vaapi_get_buffer(AVHWFramesContext *hwfc, AVFrame *frame)
 {
+    int err;
+
     frame->buf[0] = av_buffer_pool_get(hwfc->pool);
     if (!frame->buf[0])
         return AVERROR(ENOMEM);
@@ -653,6 +719,11 @@  static int vaapi_get_buffer(AVHWFramesContext *hwfc, AVFrame *frame)
     frame->width   = hwfc->width;
     frame->height  = hwfc->height;
 
+    //create sfc surface, put it in side data
+    err = vaapi_get_thumbnail_buffer(hwfc, frame);
+    if (err)
+        return err;
+
     return 0;
 }
 
@@ -784,7 +855,7 @@  static int vaapi_map_frame(AVHWFramesContext *hwfc,
     // assume for now that the user is not aware of that and would therefore
     // prefer not to be given direct-mapped memory if they request read access.
     if (ctx->derive_works && dst->format == hwfc->sw_format &&
-        ((flags & AV_HWFRAME_MAP_DIRECT) || !(flags & AV_HWFRAME_MAP_READ))) {
+        ((flags & AV_HWFRAME_MAP_DIRECT) || (flags & AV_HWFRAME_MAP_READ))) {
         vas = vaDeriveImage(hwctx->display, surface_id, &map->image);
         if (vas != VA_STATUS_SUCCESS) {
             av_log(hwfc, AV_LOG_ERROR, "Failed to derive image from "
diff --git a/libavutil/hwcontext_vaapi.h b/libavutil/hwcontext_vaapi.h
index 0b2e071cb3..5031211f2c 100644
--- a/libavutil/hwcontext_vaapi.h
+++ b/libavutil/hwcontext_vaapi.h
@@ -100,6 +100,12 @@  typedef struct AVVAAPIFramesContext {
      */
     VASurfaceID     *surface_ids;
     int           nb_surfaces;
+
+    // Thumbnail info
+    int thumbnail_flags;
+    int thumbnail_format;
+    int thumbnail_width;
+    int thumbnail_height;
 } AVVAAPIFramesContext;
 
 /**