media-video/ffmpeg/files/4011d37cd6a61474ec45ea0d325518906aeb1204.patch

From 4011d37cd6a61474ec45ea0d325518906aeb1204 Mon Sep 17 00:00:00 2001
From: Linjie Fu <linjie.fu@intel.com>
Date: Sun, 7 Jul 2019 11:55:35 -0400
Subject: [PATCH] lavc/vaapi_decode: recreate hw_frames_ctx for vp9 without
 destroy va_context

VP9 allows resolution changes per frame. Currently in VAAPI, resolution
changes leads to va context destroy and reinit. This will cause
reference frame surface lost and produce garbage.

Though refs surface id could be passed to media driver and found in RTtbl,
vp9RefList[] in hal layer has already been destoryed. Thus the new
created VaContext could only got an empty RefList.

As libva allows re-create surface separately without changing the
context, this issue could be handled by only recreating hw_frames_ctx.

Set hwaccel_priv_data_keeping flag for vp9 to only recreating
hw_frame_ctx when dynamic resolution changing happens.

Could be verified by:
ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -i
./resolutions.ivf
-pix_fmt p010le -f rawvideo -vframes 20 -y vaapi.yuv

Signed-off-by: Linjie Fu <linjie.fu@intel.com>
---
 libavcodec/decode.c        |  9 +++++----
 libavcodec/internal.h      |  1 +
 libavcodec/pthread_frame.c |  2 ++
 libavcodec/vaapi_decode.c  | 38 ++++++++++++++++++++++----------------
 libavcodec/vaapi_vp9.c     |  4 ++++
 5 files changed, 34 insertions(+), 20 deletions(-)

diff --git a/libavcodec/decode.c b/libavcodec/decode.c
index be4fe41513c..fce714f2ab0 100644
--- a/libavcodec/decode.c
+++ b/libavcodec/decode.c
@@ -1062,7 +1062,7 @@ static int hwaccel_init(AVCodecContext *avctx,
         return AVERROR_PATCHWELCOME;
     }
 
-    if (hwaccel->priv_data_size) {
+    if (hwaccel->priv_data_size && !avctx->internal->hwaccel_priv_data) {
         avctx->internal->hwaccel_priv_data =
             av_mallocz(hwaccel->priv_data_size);
         if (!avctx->internal->hwaccel_priv_data)
@@ -1123,9 +1123,10 @@ int ff_get_format(AVCodecContext *avctx, const enum AVPixelFormat *fmt)
         return AV_PIX_FMT_NONE;
 
     for (;;) {
-        // Remove the previous hwaccel, if there was one.
-        hwaccel_uninit(avctx);
-
+        // Remove the previous hwaccel, if there was one,
+        // and no need for keeping.
+        if (!avctx->internal->hwaccel_priv_data_keeping)
+            hwaccel_uninit(avctx);
         user_choice = avctx->get_format(avctx, choices);
         if (user_choice == AV_PIX_FMT_NONE) {
             // Explicitly chose nothing, give up.
diff --git a/libavcodec/internal.h b/libavcodec/internal.h
index 17e1de8127a..cd3e6c7ae61 100644
--- a/libavcodec/internal.h
+++ b/libavcodec/internal.h
@@ -118,6 +118,7 @@ typedef struct AVCodecInternal {
      * hwaccel-specific private data
      */
     void *hwaccel_priv_data;
+    int hwaccel_priv_data_keeping;
 
     /**
      * checks API usage: after codec draining, flush is required to resume operation
diff --git a/libavcodec/pthread_frame.c b/libavcodec/pthread_frame.c
index 8faea75a498..eb2f32ed884 100644
--- a/libavcodec/pthread_frame.c
+++ b/libavcodec/pthread_frame.c
@@ -309,6 +309,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
             return err;
 
         dst->internal->hwaccel_priv_data = src->internal->hwaccel_priv_data;
+        dst->internal->hwaccel_priv_data_keeping = src->internal->hwaccel_priv_data_keeping;
 
         if (!!dst->hw_frames_ctx != !!src->hw_frames_ctx ||
             (dst->hw_frames_ctx && dst->hw_frames_ctx->data != src->hw_frames_ctx->data)) {
@@ -371,6 +372,7 @@ FF_DISABLE_DEPRECATION_WARNINGS
     dst->thread_safe_callbacks = src->thread_safe_callbacks;
 FF_ENABLE_DEPRECATION_WARNINGS
 #endif
+    dst->internal->hwaccel_priv_data_keeping = src->internal->hwaccel_priv_data_keeping;
 
     if (src->slice_count && src->slice_offset) {
         if (dst->slice_count < src->slice_count) {
diff --git a/libavcodec/vaapi_decode.c b/libavcodec/vaapi_decode.c
index a7abddb06be..0e2dfbf3b11 100644
--- a/libavcodec/vaapi_decode.c
+++ b/libavcodec/vaapi_decode.c
@@ -639,9 +639,13 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)
     VAStatus vas;
     int err;
 
-    ctx->va_config  = VA_INVALID_ID;
-    ctx->va_context = VA_INVALID_ID;
+    if (!ctx->va_config && !ctx->va_context){
+        ctx->va_config  = VA_INVALID_ID;
+        ctx->va_context = VA_INVALID_ID;
+    }
 
+    // Get a new hw_frames_ctx even if there is already one
+    // recreate surface without reconstuct va_context
     err = ff_decode_get_hw_frames_ctx(avctx, AV_HWDEVICE_TYPE_VAAPI);
     if (err < 0)
         goto fail;
@@ -656,21 +660,23 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)
     if (err)
         goto fail;
 
-    vas = vaCreateContext(ctx->hwctx->display, ctx->va_config,
-                          avctx->coded_width, avctx->coded_height,
-                          VA_PROGRESSIVE,
-                          ctx->hwfc->surface_ids,
-                          ctx->hwfc->nb_surfaces,
-                          &ctx->va_context);
-    if (vas != VA_STATUS_SUCCESS) {
-        av_log(avctx, AV_LOG_ERROR, "Failed to create decode "
-               "context: %d (%s).\n", vas, vaErrorStr(vas));
-        err = AVERROR(EIO);
-        goto fail;
-    }
+    if (ctx->va_context == VA_INVALID_ID) {
+        vas = vaCreateContext(ctx->hwctx->display, ctx->va_config,
+                              avctx->coded_width, avctx->coded_height,
+                              VA_PROGRESSIVE,
+                              ctx->hwfc->surface_ids,
+                              ctx->hwfc->nb_surfaces,
+                              &ctx->va_context);
+        if (vas != VA_STATUS_SUCCESS) {
+            av_log(avctx, AV_LOG_ERROR, "Failed to create decode "
+                   "context: %d (%s).\n", vas, vaErrorStr(vas));
+            err = AVERROR(EIO);
+            goto fail;
+        }
 
-    av_log(avctx, AV_LOG_DEBUG, "Decode context initialised: "
-           "%#x/%#x.\n", ctx->va_config, ctx->va_context);
+        av_log(avctx, AV_LOG_DEBUG, "Decode context initialised: "
+               "%#x/%#x.\n", ctx->va_config, ctx->va_context);
+    }
 
     return 0;
 
diff --git a/libavcodec/vaapi_vp9.c b/libavcodec/vaapi_vp9.c
index 776382f6837..d6444b70eaf 100644
--- a/libavcodec/vaapi_vp9.c
+++ b/libavcodec/vaapi_vp9.c
@@ -25,6 +25,7 @@
 #include "hwconfig.h"
 #include "vaapi_decode.h"
 #include "vp9shared.h"
+#include "internal.h"
 
 static VASurfaceID vaapi_vp9_surface_id(const VP9Frame *vf)
 {
@@ -44,6 +45,9 @@ static int vaapi_vp9_start_frame(AVCodecContext          *avctx,
     const AVPixFmtDescriptor *pixdesc = av_pix_fmt_desc_get(avctx->sw_pix_fmt);
     int err, i;
 
+    // keep hardware context because of DRC support for VP9
+    avctx->internal->hwaccel_priv_data_keeping = 1;
+
     pic->output_surface = vaapi_vp9_surface_id(&h->frames[CUR_FRAME]);
 
     pic_param = (VADecPictureParameterBufferVP9) {