[FFmpeg-devel] [PATCH] libx264: fix -b_qfactor and -chromaoffset

Hii hiiragikei at gmail.com
Sat Aug 23 14:59:41 CEST 2014


Currently -b_qfactor and -chromaoffset have no effect in libx264, the 
attached patch is an attempt to fix the issue.

Move the corresponding lines after x264_param_default_preset() to 
prevent them being overwritten by it, make the two parameters functional.
Also make b_qfactor changeable by x264's tunings after the move.

(feel free to edit the commit message as I am not a native English speaker.)


-------------- next part --------------
From d8597d3f708c21deae40b21754173763c5a13658 Mon Sep 17 00:00:00 2001
From: Hii <hiiragikei at gmail.com>
Date: Sat, 23 Aug 2014 17:08:02 +0800
Subject: [PATCH] libx264: fix -b_qfactor and -chromaoffset

---
 libavcodec/libx264.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libavcodec/libx264.c b/libavcodec/libx264.c
index 7793581..8aff14d 100644
--- a/libavcodec/libx264.c
+++ b/libavcodec/libx264.c
@@ -371,8 +371,6 @@ static av_cold int X264_init(AVCodecContext *avctx)
 
     x4->params.b_deblocking_filter         = avctx->flags & CODEC_FLAG_LOOP_FILTER;
 
-    x4->params.rc.f_pb_factor             = avctx->b_quant_factor;
-    x4->params.analyse.i_chroma_qp_offset = avctx->chromaoffset;
     if (x4->preset || x4->tune)
         if (x264_param_default_preset(&x4->params, x4->preset, x4->tune) < 0) {
             int i;
@@ -430,6 +428,9 @@ static av_cold int X264_init(AVCodecContext *avctx)
 
     if (avctx->i_quant_factor > 0)
         x4->params.rc.f_ip_factor         = 1 / fabs(avctx->i_quant_factor);
+    if (avctx->b_quant_factor > 0)
+        x4->params.rc.f_pb_factor         = avctx->b_quant_factor;
+    x4->params.analyse.i_chroma_qp_offset = avctx->chromaoffset;
 
     if (avctx->me_method == ME_EPZS)
         x4->params.analyse.i_me_method = X264_ME_DIA;
@@ -827,6 +828,7 @@ static const AVCodecDefault x264_defaults[] = {
     { "flags2",           "0" },
     { "g",                "-1" },
     { "i_qfactor",        "-1" },
+    { "b_qfactor",        "-1" },
     { "qmin",             "-1" },
     { "qmax",             "-1" },
     { "qdiff",            "-1" },
-- 
1.9.0.msysgit.0


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