From 3a9662af6c741f8354b1ca97642f78f5c02e2e8f Mon Sep 17 00:00:00 2001
From: Mark Thompson <sw@jkqxz.net>
Date: Tue, 13 Sep 2016 00:25:07 +0100
Subject: [PATCH] vaapi_h264: Fix HRD bit_rate/cpb_size scaling
There should be an extra offset of 6 on bit_rate_scale and of 4 on
cpb_size_scale which were not accounted for here.
---
libavcodec/vaapi_encode_h264.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/libavcodec/vaapi_encode_h264.c b/libavcodec/vaapi_encode_h264.c
index 5bd56057cdb..9d6ff27a961 100644
--- a/libavcodec/vaapi_encode_h264.c
+++ b/libavcodec/vaapi_encode_h264.c
@@ -861,14 +861,14 @@ static int vaapi_encode_h264_init_sequence_params(AVCodecContext *avctx)
// Try to scale these to a sensible range so that the
// golomb encode of the value is not overlong.
mseq->bit_rate_scale =
- av_clip(av_log2(avctx->bit_rate) - 15, 0, 15);
+ av_clip_uintp2(av_log2(avctx->bit_rate) - 15 - 6, 4);
mseq->bit_rate_value_minus1[0] =
- (avctx->bit_rate >> mseq->bit_rate_scale) - 1;
+ (avctx->bit_rate >> mseq->bit_rate_scale + 6) - 1;
mseq->cpb_size_scale =
- av_clip(av_log2(priv->hrd_params.hrd.buffer_size) - 15, 0, 15);
+ av_clip_uintp2(av_log2(priv->hrd_params.hrd.buffer_size) - 15 - 4, 4);
mseq->cpb_size_value_minus1[0] =
- (priv->hrd_params.hrd.buffer_size >> mseq->cpb_size_scale) - 1;
+ (priv->hrd_params.hrd.buffer_size >> mseq->cpb_size_scale + 4) - 1;
// CBR mode isn't actually available here, despite naming.
mseq->cbr_flag[0] = 0;
--
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