[FFmpeg-devel] [PATCH v3] libavcodec/vp9: fix ref-frame size judging method

[Yan Cen]

From: yancen <cenx.yan at intel.com>

There is no need all reference frame demension is valid in libvpx.

So this change contains three part:
1. Change each judgement's loglevel from "ERROR" to "WARNING"
2. Make sure at least one of frames that this frame references has valid dimension.
3. All judgements fail would report "ERROR".

Signed-off-by: Xiang Haihao <haihao.xiang at intel.com>
Signed-off-by: Li Zhong <zhong.li at intel.com>
Signed-off-by: Yan Cen <cenx.yan at intel.com>
---
 libavcodec/vp9.c | 51 +++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 43 insertions(+), 8 deletions(-)

diff --git a/libavcodec/vp9.c b/libavcodec/vp9.c
index acf3ffc..58e7312 100644
--- a/libavcodec/vp9.c
+++ b/libavcodec/vp9.c
@@ -555,11 +555,37 @@ static int decode_frame_header(AVCodecContext *avctx,
             s->s.h.signbias[1]    = get_bits1(&s->gb) && !s->s.h.errorres;
             s->s.h.refidx[2]      = get_bits(&s->gb, 3);
             s->s.h.signbias[2]    = get_bits1(&s->gb) && !s->s.h.errorres;
-            if (!s->s.refs[s->s.h.refidx[0]].f->buf[0] ||
-                !s->s.refs[s->s.h.refidx[1]].f->buf[0] ||
-                !s->s.refs[s->s.h.refidx[2]].f->buf[0]) {
-                av_log(avctx, AV_LOG_ERROR, "Not all references are available\n");
-                return AVERROR_INVALIDDATA;
+            if (0 == sizeof(s->s.refs[s->s.h.refidx[0]])) {
+                if (0 == sizeof(s->s.refs[s->s.h.refidx[1]].f->buf[0])) {
+                    if (0 == s->s.refs[s->s.h.refidx[2]].f->buf[0]) {
+                        av_log(avctx, AV_LOG_ERROR, "All references are unavailable\n");
+                        return AVERROR_INVALIDDATA;
+                    } else {
+                        av_frame_copy(s->s.refs[s->s.h.refidx[1]].f,s->s.refs[s->s.h.refidx[2]].f);
+                        av_frame_copy(s->s.refs[s->s.h.refidx[0]].f,s->s.refs[s->s.h.refidx[2]].f);
+                    }
+                } else {
+                    if (0 == sizeof(s->s.refs[s->s.h.refidx[2]].f->buf[0])) {
+                        av_frame_copy(s->s.refs[s->s.h.refidx[0]].f,s->s.refs[s->s.h.refidx[1]].f);
+                        av_frame_copy(s->s.refs[s->s.h.refidx[2]].f,s->s.refs[s->s.h.refidx[1]].f);
+                    } else {
+                        av_frame_copy(s->s.refs[s->s.h.refidx[0]].f,s->s.refs[s->s.h.refidx[1]].f);
+                    }
+                }
+            } else {
+                if (0 == sizeof(s->s.refs[s->s.h.refidx[1]].f->buf[0])) {
+                    if (0 == sizeof(s->s.refs[s->s.h.refidx[2]].f->buf[0])) {
+                        s->s.refs[s->s.h.refidx[1]].f = s->s.refs[s->s.h.refidx[2]].f = s->s.refs[s->s.h.refidx[0]].f;
+                        av_frame_copy(s->s.refs[s->s.h.refidx[1]].f,s->s.refs[s->s.h.refidx[0]].f);
+                        av_frame_copy(s->s.refs[s->s.h.refidx[2]].f,s->s.refs[s->s.h.refidx[0]].f);
+                    } else {
+                        av_frame_copy(s->s.refs[s->s.h.refidx[1]].f,s->s.refs[s->s.h.refidx[0]].f);
+                    }
+                } else {
+                    if (0 == sizeof(s->s.refs[s->s.h.refidx[2]].f->buf[0])) {
+                        av_frame_copy(s->s.refs[s->s.h.refidx[2]].f,s->s.refs[s->s.h.refidx[1]].f);
+                    }
+                }
             }
             if (get_bits1(&s->gb)) {
                 w = s->s.refs[s->s.h.refidx[0]].f->width;
@@ -790,6 +816,7 @@ static int decode_frame_header(AVCodecContext *avctx,
 
     /* check reference frames */
     if (!s->s.h.keyframe && !s->s.h.intraonly) {
+        int has_valid_ref_frame = 0;
         for (i = 0; i < 3; i++) {
             AVFrame *ref = s->s.refs[s->s.h.refidx[i]].f;
             int refw = ref->width, refh = ref->height;
@@ -802,12 +829,15 @@ static int decode_frame_header(AVCodecContext *avctx,
                 return AVERROR_INVALIDDATA;
             } else if (refw == w && refh == h) {
                 s->mvscale[i][0] = s->mvscale[i][1] = 0;
+                has_valid_ref_frame = 1;
             } else {
-                if (w * 2 < refw || h * 2 < refh || w > 16 * refw || h > 16 * refh) {
-                    av_log(avctx, AV_LOG_ERROR,
+                int is_ref_frame_invalid = (w * 2 < refw || h * 2 < refh || w > 16 * refw || h > 16 * refh);
+                if (is_ref_frame_invalid) {
+                    av_log(avctx, AV_LOG_WARNING,
                            "Invalid ref frame dimensions %dx%d for frame size %dx%d\n",
                            refw, refh, w, h);
-                    return AVERROR_INVALIDDATA;
+                } else {
+                    has_valid_ref_frame = 1;
                 }
                 s->mvscale[i][0] = (refw << 14) / w;
                 s->mvscale[i][1] = (refh << 14) / h;
@@ -815,6 +845,11 @@ static int decode_frame_header(AVCodecContext *avctx,
                 s->mvstep[i][1] = 16 * s->mvscale[i][1] >> 14;
             }
         }
+        if (!has_valid_ref_frame) {
+            av_log(avctx, AV_LOG_ERROR,
+                   "Referenced frame has invalid size\n");
+            return AVERROR_INVALIDDATA;
+        }
     }
 
     if (s->s.h.keyframe || s->s.h.errorres || (s->s.h.intraonly && s->s.h.resetctx == 3)) {
-- 
2.7.4