From 4823b3b5091bc2ee04bddcb72a94e3d84f1ae699 Mon Sep 17 00:00:00 2001
From: unknown <2010263188@qq.com>
Date: Sun, 19 Jan 2020 16:52:13 +0800
Subject: [PATCH] add color table for 8-bit gray scale raw image data

---
 libavformat/riffenc.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/libavformat/riffenc.c b/libavformat/riffenc.c
index c04d55c423..e33bcdb339 100644
--- a/libavformat/riffenc.c
+++ b/libavformat/riffenc.c
@@ -242,6 +242,15 @@ void ff_put_bmp_header(AVIOContext *pb, AVCodecParameters *par,
     avio_wl32(pb, pal_avi ? 1 << par->bits_per_coded_sample : 0);
     avio_wl32(pb, 0);
 
+	if (par->bits_per_coded_sample == 8) {
+		for(int i=0; i<256; i++) {
+			avio_w8(pb,i);
+			avio_w8(pb,i);
+			avio_w8(pb,i);
+			avio_w8(pb,0);
+		}
+	}
+
     if (!ignore_extradata) {
         if (par->extradata_size) {
             avio_write(pb, par->extradata, extradata_size);
-- 
2.25.0.windows.1